library(tidyverse)
library(here)
library(lmerTest)
library(MuMIn)
library(lme4)
library(dotenv)
library(broom)
library(broom.mixed)
library(effects)
library(emmeans)

env_file = here(".env")
default_project = "main"
if (file.exists(env_file)) {
  load_dot_env(file = env_file)
  PROJECT_VERSION <- Sys.getenv("PROJECT_VERSION")
  if (PROJECT_VERSION == "") {
    PROJECT_VERSION <- default_project
  }
} else {
  PROJECT_VERSION <- default_project
}
source("lmer_helpers.R")

Load data

trial_metadata <- read.csv(here("data","metadata","level-trialtype_data.csv"))
trial_summary_data <- read.csv(here("data",PROJECT_VERSION, "processed_data","level-trials_data.csv"))

usable_trials <- trial_summary_data |>
  # excluding possible scam participant
  filter(exclude_participant_insufficient_data == 0 & trial_exclusion == 0 & exclude_participant == 0 & SubjectInfo.subjID != "PH2RNZ") 

# Merging with similarity information and mean-centering main effects
trials_with_effect_vars <- usable_trials |>
  left_join(trial_metadata) |>
  mutate(age_in_months = SubjectInfo.testAge/30)
Joining with `by = join_by(Trials.trialID, Trials.targetImage,
Trials.distractorImage, Trials.imagePair)`

Sanity check - making sure all participants have at least 16 trials and that we have 83 participants

low_trial_count <- trials_with_effect_vars |> distinct(SubjectInfo.subjID,Trials.trialID) |> summarize(n=n(),.by=SubjectInfo.subjID) |> filter(n < 25)
nrow(trials_with_effect_vars |> distinct(SubjectInfo.subjID))
[1] 91
tidy_model <- function(main_effect){
  table_data <- tidy(main_effect, effects = "fixed") %>%
  mutate(
    #p.value = 2 * (1 - pt(abs(statistic),df)),  # Calculate p-values for lmer - just using default calculated ones
    p.value.condensed = case_when(
      p.value < .001 ~ "<.001", 
      p.value < .01 ~ "<.01",
      p.value < .05 ~ "<.05",
      TRUE ~ sprintf("%.3f", p.value)),
    term = case_when(
      term == "(Intercept)" ~ "Intercept",
      term == "scale(age_in_months)" ~ "Age (scaled)",
      #term == "scale(image_similarity)" ~ "Target-distractor image embedding similarity (scaled)",
      TRUE ~ term
    )
  ) %>%
  rename(
    Predictor = term,
    "b" = estimate,
    "SE" = std.error,
    "t" = statistic,  # Note: changed from z to t for lmer
    "p" = p.value.condensed,
    "p.full" = p.value
  ) %>%
  mutate(across(c("b", "SE", "t"), ~round(., 2)))
  return(table_data)
}

Run mixed-effects model

Model 1: This is the model we said we’d run in our pre-reg

prereg_main_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity)*scale(age_in_months)
                    + (scale(text_similarity) | SubjectInfo.subjID)
                    + (1|Trials.targetImage) 
                    + (1|Trials.imagePair),
                    data = trials_with_effect_vars)

summary(prereg_main_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) * scale(age_in_months) +  
    (scale(text_similarity) | SubjectInfo.subjID) + (1 | Trials.targetImage) +  
    (1 | Trials.imagePair)
   Data: trials_with_effect_vars

REML criterion at convergence: 7006.3

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-2.8148 -0.6245 -0.0230  0.6602  2.7597 

Random effects:
 Groups             Name                   Variance  Std.Dev. Corr 
 SubjectInfo.subjID (Intercept)            0.0174669 0.13216       
                    scale(text_similarity) 0.0002581 0.01606  -0.25
 Trials.targetImage (Intercept)            0.0147133 0.12130       
 Trials.imagePair   (Intercept)            0.0017978 0.04240       
 Residual                                  0.9606505 0.98013       
Number of obs: 2476, groups:  
SubjectInfo.subjID, 91; Trials.targetImage, 24; Trials.imagePair, 16

Fixed effects:
                                            Estimate Std. Error       df
(Intercept)                                 -0.00840    0.03659 23.37423
scale(text_similarity)                      -0.05291    0.02752 11.28920
scale(age_in_months)                         0.05829    0.02411 90.79815
scale(text_similarity):scale(age_in_months) -0.03078    0.01978 91.78174
                                            t value Pr(>|t|)  
(Intercept)                                  -0.230   0.8204  
scale(text_similarity)                       -1.923   0.0801 .
scale(age_in_months)                          2.418   0.0176 *
scale(text_similarity):scale(age_in_months)  -1.556   0.1231  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__)
scl(txt_sm) -0.007              
scl(g_n_mn)  0.002 -0.007       
scl(_):(__) -0.007 -0.004 -0.003

Currently, it looks like text_similarity is singular. I tried removing the correlation between similarity and subject but that did not work so removign the random intercept

text_similarity_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity)*scale(age_in_months)
                    + (1 | SubjectInfo.subjID)
                    + (1|Trials.targetImage) 
                    + (1|Trials.imagePair),
                    data = trials_with_effect_vars)
summary(text_similarity_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) * scale(age_in_months) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage) + (1 |  
    Trials.imagePair)
   Data: trials_with_effect_vars

REML criterion at convergence: 7006.3

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-2.8124 -0.6239 -0.0226  0.6615  2.7627 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01748  0.13222 
 Trials.targetImage (Intercept) 0.01470  0.12124 
 Trials.imagePair   (Intercept) 0.00180  0.04243 
 Residual                       0.96090  0.98026 
Number of obs: 2476, groups:  
SubjectInfo.subjID, 91; Trials.targetImage, 24; Trials.imagePair, 16

Fixed effects:
                                              Estimate Std. Error         df
(Intercept)                                 -8.481e-03  3.659e-02  2.339e+01
scale(text_similarity)                      -5.291e-02  2.747e-02  1.164e+01
scale(age_in_months)                         5.830e-02  2.412e-02  9.090e+01
scale(text_similarity):scale(age_in_months) -3.081e-02  1.971e-02  2.378e+03
                                            t value Pr(>|t|)  
(Intercept)                                  -0.232   0.8187  
scale(text_similarity)                       -1.926   0.0788 .
scale(age_in_months)                          2.418   0.0176 *
scale(text_similarity):scale(age_in_months)  -1.563   0.1181  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__)
scl(txt_sm) -0.001              
scl(g_n_mn)  0.002 -0.007       
scl(_):(__) -0.007 -0.005  0.010

Singular fit debugs for image similarity

Swapping text similarity with image similarity:

image_similarity_effect <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)
                    + (scale(image_similarity) | SubjectInfo.subjID)
                    + (1|Trials.targetImage) 
                    + (1|Trials.imagePair), 
                    data = trials_with_effect_vars)
boundary (singular) fit: see help('isSingular')
summary(image_similarity_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    (scale(image_similarity) | SubjectInfo.subjID) + (1 | Trials.targetImage) +  
    (1 | Trials.imagePair)
   Data: trials_with_effect_vars

REML criterion at convergence: 7004.4

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.77998 -0.62742 -0.02154  0.66497  2.79679 

Random effects:
 Groups             Name                    Variance  Std.Dev. Corr
 SubjectInfo.subjID (Intercept)             0.0180635 0.13440      
                    scale(image_similarity) 0.0007765 0.02787  1.00
 Trials.targetImage (Intercept)             0.0151305 0.12301      
 Trials.imagePair   (Intercept)             0.0006291 0.02508      
 Residual                                   0.9595821 0.97958      
Number of obs: 2476, groups:  
SubjectInfo.subjID, 91; Trials.targetImage, 24; Trials.imagePair, 16

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                   -0.009043   0.035908  24.484218
scale(image_similarity)                       -0.063791   0.025625  12.185108
scale(age_in_months)                           0.058504   0.024235  91.933938
scale(image_similarity):scale(age_in_months)  -0.025213   0.019894 746.746833
                                             t value Pr(>|t|)  
(Intercept)                                   -0.252   0.8033  
scale(image_similarity)                       -2.489   0.0282 *
scale(age_in_months)                           2.414   0.0178 *
scale(image_similarity):scale(age_in_months)  -1.267   0.2054  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__)
scl(mg_sml)  0.043              
scl(g_n_mn)  0.002 -0.002       
scl(_):(__)  0.001 -0.005  0.092
optimizer (nloptwrap) convergence code: 0 (OK)
boundary (singular) fit: see help('isSingular')

running into a singular fit, I tried removing each of the random effects but only removing the random slope of image_similarity and the random intercept for image pair fixed this. This is okay for now since we see a similar effect with the singular model and this model. (although the effect below is stronger)

image_similarity_effect <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)
                     + (1 | SubjectInfo.subjID)
                     + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)
summary(image_similarity_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7005.3

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-2.7952 -0.6299 -0.0274  0.6671  2.7858 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01753  0.1324  
 Trials.targetImage (Intercept) 0.01554  0.1247  
 Residual                       0.96098  0.9803  
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -8.886e-03  3.553e-02  2.967e+01
scale(image_similarity)                      -6.297e-02  2.472e-02  1.565e+02
scale(age_in_months)                          5.851e-02  2.412e-02  9.086e+01
scale(image_similarity):scale(age_in_months) -2.540e-02  1.969e-02  2.386e+03
                                             t value Pr(>|t|)  
(Intercept)                                   -0.250   0.8042  
scale(image_similarity)                       -2.547   0.0118 *
scale(age_in_months)                           2.425   0.0173 *
scale(image_similarity):scale(age_in_months)  -1.290   0.1972  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__)
scl(mg_sml) -0.002              
scl(g_n_mn)  0.002 -0.003       
scl(_):(__)  0.000 -0.006  0.006

Adding in covariates

Now for the fun stuff: adding in our covariates using our original model – only doing this for text similarity for now because of the singular effects

main_image_effect <- lmer(scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) + scale(AoA_Est_target)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)

main_text_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity) + scale(age_in_months) + scale(AoA_Est_target)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)
summary(main_image_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    scale(AoA_Est_target) + (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7003.9

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.82166 -0.62489 -0.01889  0.67371  2.81361 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01720  0.13113 
 Trials.targetImage (Intercept) 0.00909  0.09534 
 Residual                       0.96153  0.98058 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -8.364e-03  3.136e-02  2.742e+01
scale(image_similarity)                      -4.562e-02  2.409e-02  1.170e+02
scale(age_in_months)                          5.785e-02  2.405e-02  9.097e+01
scale(AoA_Est_target)                        -7.943e-02  2.836e-02  2.308e+01
scale(image_similarity):scale(age_in_months) -2.563e-02  1.970e-02  2.386e+03
                                             t value Pr(>|t|)  
(Intercept)                                   -0.267   0.7917  
scale(image_similarity)                       -1.893   0.0608 .
scale(age_in_months)                           2.405   0.0182 *
scale(AoA_Est_target)                         -2.801   0.0101 *
scale(image_similarity):scale(age_in_months)  -1.301   0.1933  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E
scl(mg_sml) -0.004                     
scl(g_n_mn)  0.003 -0.005              
scl(AA_Es_)  0.010 -0.256  0.010       
scl(_):(__)  0.000 -0.008  0.006  0.004
summary(main_text_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) + scale(age_in_months) +  
    scale(AoA_Est_target) + (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 6999.7

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.81200 -0.61927 -0.02444  0.66947  2.78715 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.017067 0.13064 
 Trials.targetImage (Intercept) 0.008141 0.09023 
 Residual                       0.962357 0.98100 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                        Estimate Std. Error        df t value Pr(>|t|)   
(Intercept)            -0.008134   0.030688 29.346063  -0.265  0.79281   
scale(text_similarity) -0.044777   0.023607 90.933150  -1.897  0.06103 . 
scale(age_in_months)    0.058185   0.024029 91.040497   2.421  0.01744 * 
scale(AoA_Est_target)  -0.087013   0.026941 23.867742  -3.230  0.00359 **
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__)
scl(txt_sm) -0.002              
scl(g_n_mn)  0.003 -0.009       
scl(AA_Es_)  0.009 -0.123  0.010
r.squaredGLMM(main_image_effect)
            R2m       R2c
[1,] 0.01431936 0.0405489
r.squaredGLMM(main_text_effect)
            R2m        R2c
[1,] 0.01365485 0.03883147

Text similarity is still on the verge of significance

Checking if text similarity and image similarity are differently correlated with AoA

cor.test(trial_metadata$AoA_Est_target, trial_metadata$text_similarity)

    Pearson's product-moment correlation

data:  trial_metadata$AoA_Est_target and trial_metadata$text_similarity
t = 0.42649, df = 30, p-value = 0.6728
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
 -0.2786047  0.4150887
sample estimates:
       cor 
0.07763097 
cor.test(trial_metadata$AoA_Est_target, trial_metadata$image_similarity)

    Pearson's product-moment correlation

data:  trial_metadata$AoA_Est_target and trial_metadata$image_similarity
t = 1.4523, df = 30, p-value = 0.1568
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
 -0.1014633  0.5553600
sample estimates:
      cor 
0.2562984 

Well image similarity has a higher r but both are still insignificant.

image_model <- summary(main_image_effect)
image_model
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    scale(AoA_Est_target) + (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7003.9

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.82166 -0.62489 -0.01889  0.67371  2.81361 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01720  0.13113 
 Trials.targetImage (Intercept) 0.00909  0.09534 
 Residual                       0.96153  0.98058 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -8.364e-03  3.136e-02  2.742e+01
scale(image_similarity)                      -4.562e-02  2.409e-02  1.170e+02
scale(age_in_months)                          5.785e-02  2.405e-02  9.097e+01
scale(AoA_Est_target)                        -7.943e-02  2.836e-02  2.308e+01
scale(image_similarity):scale(age_in_months) -2.563e-02  1.970e-02  2.386e+03
                                             t value Pr(>|t|)  
(Intercept)                                   -0.267   0.7917  
scale(image_similarity)                       -1.893   0.0608 .
scale(age_in_months)                           2.405   0.0182 *
scale(AoA_Est_target)                         -2.801   0.0101 *
scale(image_similarity):scale(age_in_months)  -1.301   0.1933  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E
scl(mg_sml) -0.004                     
scl(g_n_mn)  0.003 -0.005              
scl(AA_Es_)  0.010 -0.256  0.010       
scl(_):(__)  0.000 -0.008  0.006  0.004
vs_image_effect <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)
                    + scale(MeanSaliencyDiff)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)

vs_text_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity)*scale(age_in_months)
                    + scale(MeanSaliencyDiff)
                    + (scale(text_similarity) | SubjectInfo.subjID) 
                    + (1|Trials.targetImage)
                    + (1|Trials.imagePair), 
                    data = trials_with_effect_vars)
summary(vs_image_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    scale(MeanSaliencyDiff) + (1 | SubjectInfo.subjID) + (1 |  
    Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7010.5

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.79601 -0.62995 -0.02772  0.66689  2.78608 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01753  0.1324  
 Trials.targetImage (Intercept) 0.01633  0.1278  
 Residual                       0.96111  0.9804  
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -8.977e-03  3.600e-02  2.878e+01
scale(image_similarity)                      -6.292e-02  2.492e-02  1.436e+02
scale(age_in_months)                          5.850e-02  2.413e-02  9.087e+01
scale(MeanSaliencyDiff)                       9.248e-04  2.938e-02  4.543e+01
scale(image_similarity):scale(age_in_months) -2.541e-02  1.970e-02  2.386e+03
                                             t value Pr(>|t|)  
(Intercept)                                   -0.249   0.8049  
scale(image_similarity)                       -2.524   0.0127 *
scale(age_in_months)                           2.425   0.0173 *
scale(MeanSaliencyDiff)                        0.031   0.9750  
scale(image_similarity):scale(age_in_months)  -1.290   0.1972  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(MSD)
scl(mg_sml) -0.001                     
scl(g_n_mn)  0.002 -0.004              
scl(MnSlnD)  0.024  0.068 -0.009       
scl(_):(__)  0.000 -0.006  0.006 -0.010
summary(vs_text_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) * scale(age_in_months) +  
    scale(MeanSaliencyDiff) + (scale(text_similarity) | SubjectInfo.subjID) +  
    (1 | Trials.targetImage) + (1 | Trials.imagePair)
   Data: trials_with_effect_vars

REML criterion at convergence: 7011.5

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.81386 -0.62430 -0.02362  0.66043  2.76315 

Random effects:
 Groups             Name                   Variance  Std.Dev. Corr 
 SubjectInfo.subjID (Intercept)            0.0174633 0.13215       
                    scale(text_similarity) 0.0002475 0.01573  -0.26
 Trials.targetImage (Intercept)            0.0155468 0.12469       
 Trials.imagePair   (Intercept)            0.0017476 0.04180       
 Residual                                  0.9607953 0.98020       
Number of obs: 2476, groups:  
SubjectInfo.subjID, 91; Trials.targetImage, 24; Trials.imagePair, 16

Fixed effects:
                                             Estimate Std. Error        df
(Intercept)                                 -0.008415   0.037035 22.750359
scale(text_similarity)                      -0.052770   0.027633 11.298025
scale(age_in_months)                         0.058258   0.024111 90.804895
scale(MeanSaliencyDiff)                      0.004043   0.029206 41.144733
scale(text_similarity):scale(age_in_months) -0.030773   0.019779 91.303360
                                            t value Pr(>|t|)  
(Intercept)                                  -0.227   0.8223  
scale(text_similarity)                       -1.910   0.0819 .
scale(age_in_months)                          2.416   0.0177 *
scale(MeanSaliencyDiff)                       0.138   0.8906  
scale(text_similarity):scale(age_in_months)  -1.556   0.1232  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(MSD)
scl(txt_sm) -0.007                     
scl(g_n_mn)  0.002 -0.007              
scl(MnSlnD)  0.023  0.022 -0.009       
scl(_):(__) -0.007 -0.004 -0.003 -0.006

Just a sanity check that adding our saliency metric as a covariate does not affect our similarity effects.

Alternate window analyses

Only using first instance of an item

first_instance_target <- trials_with_effect_vars |>
  group_by(SubjectInfo.subjID, Trials.targetImage) |>
  arrange(Trials.ordinal, .by_group = TRUE) |>
  slice(1) |>
  ungroup()
  
first_instance_primary_target <- first_instance_target |>
  filter(Trials.trialType %in% c("easy", "hard"))
  
first_instance_image_pair <- trials_with_effect_vars |>
  group_by(SubjectInfo.subjID, Trials.imagePair) |>
  arrange(Trials.ordinal, .by_group = TRUE) |>
  slice(1) |>
  ungroup()

first_instance_effect <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)*scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | Trials.ordinal)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = first_instance_target)

first_instance_pt_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity)*scale(age_in_months)*scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | Trials.ordinal)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = first_instance_primary_target)

first_instance_image_pair_effect <- lmer(scale(corrected_target_looking) ~ scale(text_similarity)*scale(age_in_months)*scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | Trials.ordinal)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = first_instance_image_pair)

summary(first_instance_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) *  
    scale(AoA_Est_target) + scale(MeanSaliencyDiff) + (1 | Trials.ordinal) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: first_instance_target

REML criterion at convergence: 5497.6

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.86068 -0.62838 -0.00198  0.66777  2.74935 

Random effects:
 Groups             Name        Variance  Std.Dev.
 SubjectInfo.subjID (Intercept) 2.257e-02 0.150232
 Trials.ordinal     (Intercept) 3.153e-05 0.005615
 Trials.targetImage (Intercept) 1.029e-02 0.101429
 Residual                       9.558e-01 0.977657
Number of obs: 1936, groups:  
SubjectInfo.subjID, 91; Trials.ordinal, 47; Trials.targetImage, 24

Fixed effects:
                                                                     Estimate
(Intercept)                                                        -3.433e-03
scale(image_similarity)                                            -4.836e-02
scale(age_in_months)                                                5.764e-02
scale(AoA_Est_target)                                              -8.140e-02
scale(MeanSaliencyDiff)                                            -2.871e-03
scale(image_similarity):scale(age_in_months)                       -2.427e-03
scale(image_similarity):scale(AoA_Est_target)                       1.301e-03
scale(age_in_months):scale(AoA_Est_target)                         -4.547e-02
scale(image_similarity):scale(age_in_months):scale(AoA_Est_target)  1.359e-02
                                                                   Std. Error
(Intercept)                                                         3.586e-02
scale(image_similarity)                                             2.909e-02
scale(age_in_months)                                                2.842e-02
scale(AoA_Est_target)                                               3.202e-02
scale(MeanSaliencyDiff)                                             2.938e-02
scale(image_similarity):scale(age_in_months)                        2.402e-02
scale(image_similarity):scale(AoA_Est_target)                       3.045e-02
scale(age_in_months):scale(AoA_Est_target)                          2.370e-02
scale(image_similarity):scale(age_in_months):scale(AoA_Est_target)  2.363e-02
                                                                           df
(Intercept)                                                         2.418e+01
scale(image_similarity)                                             6.720e+01
scale(age_in_months)                                                1.082e+02
scale(AoA_Est_target)                                               2.130e+01
scale(MeanSaliencyDiff)                                             3.085e+01
scale(image_similarity):scale(age_in_months)                        1.872e+03
scale(image_similarity):scale(AoA_Est_target)                       3.464e+01
scale(age_in_months):scale(AoA_Est_target)                          1.840e+03
scale(image_similarity):scale(age_in_months):scale(AoA_Est_target)  1.846e+03
                                                                   t value
(Intercept)                                                         -0.096
scale(image_similarity)                                             -1.662
scale(age_in_months)                                                 2.028
scale(AoA_Est_target)                                               -2.542
scale(MeanSaliencyDiff)                                             -0.098
scale(image_similarity):scale(age_in_months)                        -0.101
scale(image_similarity):scale(AoA_Est_target)                        0.043
scale(age_in_months):scale(AoA_Est_target)                          -1.919
scale(image_similarity):scale(age_in_months):scale(AoA_Est_target)   0.575
                                                                   Pr(>|t|)  
(Intercept)                                                          0.9245  
scale(image_similarity)                                              0.1011  
scale(age_in_months)                                                 0.0450 *
scale(AoA_Est_target)                                                0.0188 *
scale(MeanSaliencyDiff)                                              0.9228  
scale(image_similarity):scale(age_in_months)                         0.9195  
scale(image_similarity):scale(AoA_Est_target)                        0.9662  
scale(age_in_months):scale(AoA_Est_target)                           0.0552 .
scale(image_similarity):scale(age_in_months):scale(AoA_Est_target)   0.5653  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD) sc(_):(__) s(_):(A s(__):
scl(mg_sml) -0.047                                                      
scl(g_n_mn)  0.001 -0.014                                               
scl(AA_Es_)  0.025 -0.319  0.015                                        
scl(MnSlnD) -0.023 -0.068 -0.015  0.062                                 
scl(_):(__) -0.010 -0.022 -0.035  0.007 -0.006                          
s(_):(AA_E_ -0.292  0.158  0.003 -0.084  0.087  0.004                   
s(__):(AA_E  0.018  0.010  0.022  0.007 -0.015 -0.348     -0.013        
s(_):(__):(  0.005  0.005 -0.283 -0.005 -0.007  0.171     -0.007  -0.071
summary(first_instance_pt_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) * scale(age_in_months) *  
    scale(AoA_Est_target) + scale(MeanSaliencyDiff) + (1 | Trials.ordinal) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: first_instance_primary_target

REML criterion at convergence: 2041.8

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.85231 -0.62731 -0.02125  0.65454  2.79976 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.019242 0.13872 
 Trials.ordinal     (Intercept) 0.003945 0.06281 
 Trials.targetImage (Intercept) 0.007197 0.08484 
 Residual                       0.959696 0.97964 
Number of obs: 712, groups:  
SubjectInfo.subjID, 91; Trials.ordinal, 35; Trials.targetImage, 8

Fixed effects:
                                                                   Estimate
(Intercept)                                                         0.02123
scale(text_similarity)                                             -0.08484
scale(age_in_months)                                                0.04577
scale(AoA_Est_target)                                              -0.13727
scale(MeanSaliencyDiff)                                             0.01551
scale(text_similarity):scale(age_in_months)                         0.03462
scale(text_similarity):scale(AoA_Est_target)                        0.04684
scale(age_in_months):scale(AoA_Est_target)                         -0.01635
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  -0.03583
                                                                  Std. Error
(Intercept)                                                          0.05490
scale(text_similarity)                                               0.05485
scale(age_in_months)                                                 0.04323
scale(AoA_Est_target)                                                0.05126
scale(MeanSaliencyDiff)                                              0.05130
scale(text_similarity):scale(age_in_months)                          0.04519
scale(text_similarity):scale(AoA_Est_target)                         0.04804
scale(age_in_months):scale(AoA_Est_target)                           0.04058
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)    0.04419
                                                                         df
(Intercept)                                                         6.69518
scale(text_similarity)                                            700.93727
scale(age_in_months)                                              124.40097
scale(AoA_Est_target)                                               5.64017
scale(MeanSaliencyDiff)                                            19.87701
scale(text_similarity):scale(age_in_months)                       699.96298
scale(text_similarity):scale(AoA_Est_target)                      143.06829
scale(age_in_months):scale(AoA_Est_target)                        630.44692
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target) 678.14119
                                                                  t value
(Intercept)                                                         0.387
scale(text_similarity)                                             -1.547
scale(age_in_months)                                                1.059
scale(AoA_Est_target)                                              -2.678
scale(MeanSaliencyDiff)                                             0.302
scale(text_similarity):scale(age_in_months)                         0.766
scale(text_similarity):scale(AoA_Est_target)                        0.975
scale(age_in_months):scale(AoA_Est_target)                         -0.403
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  -0.811
                                                                  Pr(>|t|)  
(Intercept)                                                         0.7109  
scale(text_similarity)                                              0.1224  
scale(age_in_months)                                                0.2918  
scale(AoA_Est_target)                                               0.0389 *
scale(MeanSaliencyDiff)                                             0.7655  
scale(text_similarity):scale(age_in_months)                         0.4438  
scale(text_similarity):scale(AoA_Est_target)                        0.3312  
scale(age_in_months):scale(AoA_Est_target)                          0.6872  
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)   0.4178  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD) sc(_):(__) s(_):(A s(__):
scl(txt_sm) -0.165                                                      
scl(g_n_mn)  0.029 -0.022                                               
scl(AA_Es_) -0.050  0.358 -0.008                                        
scl(MnSlnD) -0.082  0.513 -0.048  0.101                                 
scl(_):(__)  0.004 -0.006 -0.162  0.029  0.003                          
s(_):(AA_E_  0.356 -0.465  0.048 -0.137 -0.224  0.040                   
s(__):(AA_E -0.002  0.027 -0.051  0.027 -0.010  0.416     -0.002        
s(_):(__):(  0.030  0.035  0.399 -0.001 -0.002 -0.415      0.014  -0.137
summary(first_instance_image_pair_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(text_similarity) * scale(age_in_months) *  
    scale(AoA_Est_target) + scale(MeanSaliencyDiff) + (1 | Trials.ordinal) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: first_instance_image_pair

REML criterion at convergence: 4002.3

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.83685 -0.64175 -0.02266  0.64978  2.79951 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.019286 0.1389  
 Trials.ordinal     (Intercept) 0.003092 0.0556  
 Trials.targetImage (Intercept) 0.007483 0.0865  
 Residual                       0.954090 0.9768  
Number of obs: 1407, groups:  
SubjectInfo.subjID, 91; Trials.ordinal, 33; Trials.targetImage, 24

Fixed effects:
                                                                    Estimate
(Intercept)                                                       -4.019e-03
scale(text_similarity)                                            -5.152e-02
scale(age_in_months)                                               4.710e-02
scale(AoA_Est_target)                                             -1.145e-01
scale(MeanSaliencyDiff)                                           -1.035e-02
scale(text_similarity):scale(age_in_months)                       -2.666e-02
scale(text_similarity):scale(AoA_Est_target)                       1.694e-02
scale(age_in_months):scale(AoA_Est_target)                        -5.052e-02
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  1.458e-02
                                                                  Std. Error
(Intercept)                                                        3.746e-02
scale(text_similarity)                                             2.957e-02
scale(age_in_months)                                               2.999e-02
scale(AoA_Est_target)                                              3.235e-02
scale(MeanSaliencyDiff)                                            3.176e-02
scale(text_similarity):scale(age_in_months)                        2.660e-02
scale(text_similarity):scale(AoA_Est_target)                       2.888e-02
scale(age_in_months):scale(AoA_Est_target)                         2.694e-02
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  2.512e-02
                                                                          df
(Intercept)                                                        1.982e+01
scale(text_similarity)                                             8.329e+01
scale(age_in_months)                                               9.181e+01
scale(AoA_Est_target)                                              2.422e+01
scale(MeanSaliencyDiff)                                            3.590e+01
scale(text_similarity):scale(age_in_months)                        1.316e+03
scale(text_similarity):scale(AoA_Est_target)                       6.172e+01
scale(age_in_months):scale(AoA_Est_target)                         1.378e+03
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  1.386e+03
                                                                  t value
(Intercept)                                                        -0.107
scale(text_similarity)                                             -1.742
scale(age_in_months)                                                1.571
scale(AoA_Est_target)                                              -3.539
scale(MeanSaliencyDiff)                                            -0.326
scale(text_similarity):scale(age_in_months)                        -1.002
scale(text_similarity):scale(AoA_Est_target)                        0.587
scale(age_in_months):scale(AoA_Est_target)                         -1.875
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)   0.580
                                                                  Pr(>|t|)   
(Intercept)                                                        0.91564   
scale(text_similarity)                                             0.08517 . 
scale(age_in_months)                                               0.11966   
scale(AoA_Est_target)                                              0.00166 **
scale(MeanSaliencyDiff)                                            0.74640   
scale(text_similarity):scale(age_in_months)                        0.31632   
scale(text_similarity):scale(AoA_Est_target)                       0.55957   
scale(age_in_months):scale(AoA_Est_target)                         0.06100 . 
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  0.56180   
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD) sc(_):(__) s(_):(A s(__):
scl(txt_sm) -0.017                                                      
scl(g_n_mn) -0.001  0.002                                               
scl(AA_Es_) -0.006 -0.083  0.018                                        
scl(MnSlnD) -0.004  0.025 -0.001  0.075                                 
scl(_):(__)  0.006 -0.021 -0.003  0.041  0.035                          
s(_):(AA_E_ -0.085  0.121  0.040  0.176  0.219 -0.030                   
s(__):(AA_E  0.019  0.037 -0.024  0.023 -0.040 -0.046     -0.024        
s(_):(__):(  0.039 -0.039 -0.059 -0.018 -0.014  0.132      0.040   0.170

Random order effects

main_image_effect_ordinal <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | Trials.ordinal)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)
summary(main_image_effect_ordinal)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    scale(AoA_Est_target) + scale(MeanSaliencyDiff) + (1 | Trials.ordinal) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7009

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.82655 -0.63385 -0.01613  0.67450  2.80043 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.017305 0.13155 
 Trials.ordinal     (Intercept) 0.001863 0.04316 
 Trials.targetImage (Intercept) 0.009719 0.09859 
 Residual                       0.959754 0.97967 
Number of obs: 2476, groups:  
SubjectInfo.subjID, 91; Trials.ordinal, 52; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -7.986e-03  3.269e-02  2.586e+01
scale(image_similarity)                      -4.590e-02  2.427e-02  1.143e+02
scale(age_in_months)                          5.796e-02  2.407e-02  9.098e+01
scale(AoA_Est_target)                        -7.971e-02  2.881e-02  2.249e+01
scale(MeanSaliencyDiff)                       2.927e-04  2.643e-02  3.585e+01
scale(image_similarity):scale(age_in_months) -2.523e-02  1.970e-02  2.384e+03
                                             t value Pr(>|t|)  
(Intercept)                                   -0.244   0.8089  
scale(image_similarity)                       -1.892   0.0611 .
scale(age_in_months)                           2.408   0.0180 *
scale(AoA_Est_target)                         -2.766   0.0111 *
scale(MeanSaliencyDiff)                        0.011   0.9912  
scale(image_similarity):scale(age_in_months)  -1.281   0.2005  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD)
scl(mg_sml) -0.004                            
scl(g_n_mn)  0.002 -0.005                     
scl(AA_Es_)  0.010 -0.255  0.010              
scl(MnSlnD)  0.020  0.029 -0.009  0.019       
scl(_):(__)  0.000 -0.008  0.006  0.003 -0.010

Order does not explain much variance.

Target image order effects

ranked_trials <- trials_with_effect_vars |>
  group_by(SubjectInfo.subjID, Trials.targetImage) |>
  arrange(Trials.ordinal, .by_group = TRUE) |>
  mutate(
    slice_num = row_number(),
    order = case_when(
      slice_num == 1 ~ -0.5,
      slice_num == 2 ~ 0.5,
      TRUE ~ NA
    )
  )
main_image_effect_ranked <- lmer(scale(corrected_target_looking) ~ scale(image_similarity)*scale(age_in_months)
                    + scale(AoA_Est_target)
                    + (scale(order))
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = ranked_trials)
# |> filter(Trials.trialType %in% c("easy", "hard")
summary(main_image_effect_ranked)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_similarity) * scale(age_in_months) +  
    scale(AoA_Est_target) + (scale(order)) + (1 | SubjectInfo.subjID) +  
    (1 | Trials.targetImage)
   Data: ranked_trials

REML criterion at convergence: 7006.8

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.79650 -0.62416 -0.02258  0.66026  2.75160 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.016739 0.12938 
 Trials.targetImage (Intercept) 0.008273 0.09096 
 Residual                       0.961445 0.98053 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -4.653e-03  3.078e-02  2.678e+01
scale(image_similarity)                      -4.488e-02  2.387e-02  1.114e+02
scale(age_in_months)                          5.777e-02  2.395e-02  9.098e+01
scale(AoA_Est_target)                        -8.096e-02  2.777e-02  2.294e+01
scale(order)                                  3.662e-02  2.126e-02  5.941e+02
scale(image_similarity):scale(age_in_months) -2.504e-02  1.970e-02  2.385e+03
                                             t value Pr(>|t|)   
(Intercept)                                   -0.151   0.8810   
scale(image_similarity)                       -1.880   0.0627 . 
scale(age_in_months)                           2.413   0.0178 * 
scale(AoA_Est_target)                         -2.916   0.0078 **
scale(order)                                   1.722   0.0855 . 
scale(image_similarity):scale(age_in_months)  -1.271   0.2038   
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E scl(r)
scl(mg_sml) -0.004                            
scl(g_n_mn)  0.003 -0.005                     
scl(AA_Es_)  0.008 -0.258  0.010              
scale(ordr)  0.064  0.009 -0.002 -0.024       
scl(_):(__)  0.001 -0.008  0.005  0.003  0.018

Z-scoring embeddings

main_image_effect_zscored <- lmer(scale(corrected_target_looking) ~ scale(image_sim)*scale(age_in_months)*scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)
summary(main_image_effect_zscored)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: 
scale(corrected_target_looking) ~ scale(image_sim) * scale(age_in_months) *  
    scale(AoA_Est_target) + scale(MeanSaliencyDiff) + (1 | SubjectInfo.subjID) +  
    (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7020.8

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.76788 -0.62397 -0.02101  0.66876  2.77752 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.01740  0.1319  
 Trials.targetImage (Intercept) 0.01002  0.1001  
 Residual                       0.96018  0.9799  
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                                              Estimate
(Intercept)                                                 -1.716e-02
scale(image_sim)                                            -5.102e-02
scale(age_in_months)                                         5.473e-02
scale(AoA_Est_target)                                       -7.764e-02
scale(MeanSaliencyDiff)                                     -7.578e-04
scale(image_sim):scale(age_in_months)                       -1.457e-02
scale(image_sim):scale(AoA_Est_target)                       2.402e-02
scale(age_in_months):scale(AoA_Est_target)                  -4.268e-02
scale(image_sim):scale(age_in_months):scale(AoA_Est_target)  1.290e-02
                                                            Std. Error
(Intercept)                                                  3.306e-02
scale(image_sim)                                             2.421e-02
scale(age_in_months)                                         2.464e-02
scale(AoA_Est_target)                                        2.904e-02
scale(MeanSaliencyDiff)                                      2.658e-02
scale(image_sim):scale(age_in_months)                        2.051e-02
scale(image_sim):scale(AoA_Est_target)                       2.501e-02
scale(age_in_months):scale(AoA_Est_target)                   2.035e-02
scale(image_sim):scale(age_in_months):scale(AoA_Est_target)  2.013e-02
                                                                    df t value
(Intercept)                                                  2.646e+01  -0.519
scale(image_sim)                                             1.417e+02  -2.108
scale(age_in_months)                                         9.931e+01   2.221
scale(AoA_Est_target)                                        2.259e+01  -2.673
scale(MeanSaliencyDiff)                                      3.546e+01  -0.029
scale(image_sim):scale(age_in_months)                        2.379e+03  -0.711
scale(image_sim):scale(AoA_Est_target)                       6.964e+01   0.960
scale(age_in_months):scale(AoA_Est_target)                   2.381e+03  -2.098
scale(image_sim):scale(age_in_months):scale(AoA_Est_target)  2.380e+03   0.641
                                                            Pr(>|t|)  
(Intercept)                                                   0.6080  
scale(image_sim)                                              0.0368 *
scale(age_in_months)                                          0.0286 *
scale(AoA_Est_target)                                         0.0137 *
scale(MeanSaliencyDiff)                                       0.9774  
scale(image_sim):scale(age_in_months)                         0.4773  
scale(image_sim):scale(AoA_Est_target)                        0.3402  
scale(age_in_months):scale(AoA_Est_target)                    0.0361 *
scale(image_sim):scale(age_in_months):scale(AoA_Est_target)   0.5218  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD) sc(_):(__) s(_):(A s(__):
scal(mg_sm)  0.031                                                      
scl(g_n_mn)  0.001 -0.008                                               
scl(AA_Es_)  0.000 -0.258  0.010                                        
scl(MnSlnD)  0.025  0.046 -0.008  0.014                                 
scl(_):(__) -0.006 -0.004  0.036  0.001 -0.006                          
s(_):(AA_E_ -0.248 -0.136  0.002  0.041 -0.022 -0.002                   
s(__):(AA_E  0.012  0.000 -0.014  0.008 -0.003 -0.260     -0.005        
s(_):(__):(  0.003 -0.002 -0.210 -0.001 -0.008 -0.136      0.002   0.066

Baseline window as a covariate

baseline_covariate_looking_text <- lmer(scale(mean_target_looking_critical_window) ~ scale(age_in_months)*scale(text_similarity)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + scale(mean_target_looking_baseline_window)
                    + (scale(text_similarity) || SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)

baseline_covariate_looking_image <- lmer(scale(mean_target_looking_critical_window) ~ scale(age_in_months)*scale(image_similarity)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + scale(mean_target_looking_baseline_window)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)

summary(baseline_covariate_looking_text)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(mean_target_looking_critical_window) ~ scale(age_in_months) *  
    scale(text_similarity) + scale(AoA_Est_target) + scale(MeanSaliencyDiff) +  
    scale(mean_target_looking_baseline_window) + (scale(text_similarity) ||  
    SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 6694.9

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.73407 -0.72246  0.07168  0.76240  2.40301 

Random effects:
 Groups               Name                   Variance Std.Dev.
 SubjectInfo.subjID   (Intercept)            0.031728 0.17812 
 SubjectInfo.subjID.1 scale(text_similarity) 0.002694 0.05191 
 Trials.targetImage   (Intercept)            0.021091 0.14523 
 Residual                                    0.828964 0.91047 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                              Estimate Std. Error         df
(Intercept)                                    0.00178    0.03998   32.47778
scale(age_in_months)                           0.06043    0.02616   88.75213
scale(text_similarity)                        -0.04923    0.02577  108.22062
scale(AoA_Est_target)                         -0.13464    0.03426   22.77036
scale(MeanSaliencyDiff)                        0.02856    0.02983   51.98623
scale(mean_target_looking_baseline_window)     0.28182    0.01871 2433.15399
scale(age_in_months):scale(text_similarity)   -0.03113    0.01912   86.90694
                                            t value Pr(>|t|)    
(Intercept)                                   0.045 0.964756    
scale(age_in_months)                          2.310 0.023190 *  
scale(text_similarity)                       -1.910 0.058774 .  
scale(AoA_Est_target)                        -3.930 0.000679 ***
scale(MeanSaliencyDiff)                       0.957 0.342807    
scale(mean_target_looking_baseline_window)   15.065  < 2e-16 ***
scale(age_in_months):scale(text_similarity)  -1.628 0.107047    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) sc(__) scl(_) s(AA_E s(MSD) s(____
scl(g_n_mn)  0.004                                   
scl(txt_sm) -0.001 -0.007                            
scl(AA_Es_)  0.013  0.007 -0.118                     
scl(MnSlnD)  0.026 -0.008  0.056  0.025              
scl(mn____) -0.011  0.007 -0.005  0.027 -0.023       
scl(__):(_) -0.006  0.008 -0.003  0.002 -0.005 -0.007
summary(baseline_covariate_looking_image)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(mean_target_looking_critical_window) ~ scale(age_in_months) *  
    scale(image_similarity) + scale(AoA_Est_target) + scale(MeanSaliencyDiff) +  
    scale(mean_target_looking_baseline_window) + (1 | SubjectInfo.subjID) +  
    (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 6698.5

Scaled residuals: 
    Min      1Q  Median      3Q     Max 
-2.7150 -0.7282  0.0709  0.7634  2.4479 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.03168  0.1780  
 Trials.targetImage (Intercept) 0.02198  0.1483  
 Residual                       0.83259  0.9125  
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                   1.294e-03  4.046e-02  3.178e+01
scale(age_in_months)                          6.047e-02  2.617e-02  8.873e+01
scale(image_similarity)                      -2.816e-02  2.519e-02  1.955e+02
scale(AoA_Est_target)                        -1.335e-01  3.545e-02  2.359e+01
scale(MeanSaliencyDiff)                       2.846e-02  3.026e-02  4.938e+01
scale(mean_target_looking_baseline_window)    2.822e-01  1.874e-02  2.437e+03
scale(age_in_months):scale(image_similarity) -2.678e-02  1.834e-02  2.377e+03
                                             t value Pr(>|t|)    
(Intercept)                                    0.032 0.974690    
scale(age_in_months)                           2.311 0.023178 *  
scale(image_similarity)                       -1.118 0.264932    
scale(AoA_Est_target)                         -3.766 0.000971 ***
scale(MeanSaliencyDiff)                        0.941 0.351522    
scale(mean_target_looking_baseline_window)    15.061  < 2e-16 ***
scale(age_in_months):scale(image_similarity)  -1.460 0.144504    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) sc(__) scl(_) s(AA_E s(MSD) s(____
scl(g_n_mn)  0.004                                   
scl(mg_sml) -0.002 -0.006                            
scl(AA_Es_)  0.013  0.007 -0.227                     
scl(MnSlnD)  0.026 -0.008  0.105  0.007              
scl(mn____) -0.010  0.007 -0.034  0.033 -0.025       
scl(__):(_)  0.000  0.005 -0.005  0.002 -0.009 -0.005

Similar predictions to our original model.

Adding window type as a covariate

trials_window_type_separated <- trials_with_effect_vars |>
  pivot_longer(cols=c(mean_target_looking_critical_window, mean_target_looking_baseline_window), names_to="window_type", values_to="target_looking") |>
  mutate(window_type = str_replace(window_type, "mean_target_looking_", "")) |>
  mutate(trial_window_c = case_when(
    window_type=="critical_window" ~ 0.5,
    window_type=="baseline_window" ~ -0.5))

window_type_looking_text <- lmer(scale(target_looking) ~ scale(age_in_months)*trial_window_c*scale(text_similarity)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_window_type_separated)

window_type_looking_image <- lmer(scale(target_looking) ~ scale(age_in_months)*trial_window_c*scale(image_similarity)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (scale(image_similarity) | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_window_type_separated)

summary(window_type_looking_image)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(target_looking) ~ scale(age_in_months) * trial_window_c *  
    scale(image_similarity) + scale(AoA_Est_target) + scale(MeanSaliencyDiff) +  
    (scale(image_similarity) | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_window_type_separated

REML criterion at convergence: 13896.5

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.22883 -0.72198  0.02836  0.76614  2.04846 

Random effects:
 Groups             Name                    Variance  Std.Dev. Corr 
 SubjectInfo.subjID (Intercept)             0.0118259 0.10875       
                    scale(image_similarity) 0.0008384 0.02895  -0.21
 Trials.targetImage (Intercept)             0.0254849 0.15964       
 Residual                                   0.9417824 0.97045       
Number of obs: 4952, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                                              Estimate
(Intercept)                                                  1.795e-02
scale(age_in_months)                                         2.402e-02
trial_window_c                                               1.763e-01
scale(image_similarity)                                      1.671e-02
scale(AoA_Est_target)                                       -1.088e-01
scale(MeanSaliencyDiff)                                      3.169e-02
scale(age_in_months):trial_window_c                          6.997e-02
scale(age_in_months):scale(image_similarity)                -9.385e-03
trial_window_c:scale(image_similarity)                      -7.275e-02
scale(age_in_months):trial_window_c:scale(image_similarity) -2.974e-02
                                                            Std. Error
(Intercept)                                                  3.749e-02
scale(age_in_months)                                         1.791e-02
trial_window_c                                               2.758e-02
scale(image_similarity)                                      2.075e-02
scale(AoA_Est_target)                                        3.481e-02
scale(MeanSaliencyDiff)                                      2.694e-02
scale(age_in_months):trial_window_c                          2.758e-02
scale(age_in_months):scale(image_similarity)                 1.413e-02
trial_window_c:scale(image_similarity)                       2.759e-02
scale(age_in_months):trial_window_c:scale(image_similarity)  2.752e-02
                                                                    df t value
(Intercept)                                                  2.559e+01   0.479
scale(age_in_months)                                         8.639e+01   1.341
trial_window_c                                               4.740e+03   6.393
scale(image_similarity)                                      1.817e+02   0.806
scale(AoA_Est_target)                                        2.320e+01  -3.126
scale(MeanSaliencyDiff)                                      7.023e+01   1.176
scale(age_in_months):trial_window_c                          4.740e+03   2.537
scale(age_in_months):scale(image_similarity)                 8.480e+01  -0.664
trial_window_c:scale(image_similarity)                       4.740e+03  -2.637
scale(age_in_months):trial_window_c:scale(image_similarity)  4.740e+03  -1.080
                                                            Pr(>|t|)    
(Intercept)                                                  0.63606    
scale(age_in_months)                                         0.18342    
trial_window_c                                              1.78e-10 ***
scale(image_similarity)                                      0.42157    
scale(AoA_Est_target)                                        0.00472 ** 
scale(MeanSaliencyDiff)                                      0.24356    
scale(age_in_months):trial_window_c                          0.01123 *  
scale(age_in_months):scale(image_similarity)                 0.50833    
trial_window_c:scale(image_similarity)                       0.00838 ** 
scale(age_in_months):trial_window_c:scale(image_similarity)  0.27998    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) sc(__) trl_w_ scl(_) s(AA_E s(MSD) sc(__):__ s(__):( t__:(_
scl(g_n_mn)  0.002                                                            
tril_wndw_c  0.000  0.000                                                     
scl(mg_sml) -0.009 -0.007  0.000                                              
scl(AA_Es_)  0.015  0.006  0.000 -0.188                                       
scl(MnSlnD)  0.028 -0.010  0.000  0.189 -0.005                                
scl(g__):__  0.000  0.000  0.000  0.000  0.000  0.000                         
scl(__):(_)  0.000 -0.023  0.000 -0.003  0.002 -0.008  0.000                  
trl_wn_:(_)  0.000  0.000  0.000  0.000  0.000  0.000 -0.001     0.000        
s(__):__:(_  0.000  0.000  0.000  0.000  0.000  0.000  0.006     0.000  -0.012
tidy_model(window_type_looking_text)
# A tibble: 10 × 8
   effect Predictor                          b    SE     t     df   p.full p    
   <chr>  <chr>                          <dbl> <dbl> <dbl>  <dbl>    <dbl> <chr>
 1 fixed  Intercept                       0.02  0.04  0.48   23.8 6.38e- 1 0.638
 2 fixed  Age (scaled)                    0.02  0.02  1.35   86.4 1.80e- 1 0.180
 3 fixed  trial_window_c                  0.18  0.03  6.4  4828.  1.66e-10 <.001
 4 fixed  scale(text_similarity)         -0.02  0.02 -1.17  272.  2.44e- 1 0.244
 5 fixed  scale(AoA_Est_target)          -0.1   0.03 -2.85   20.8 9.71e- 3 <.01 
 6 fixed  scale(MeanSaliencyDiff)         0.02  0.03  0.85   74.5 3.99e- 1 0.399
 7 fixed  scale(age_in_months):trial_wi…  0.07  0.03  2.55 4828.  1.09e- 2 <.05 
 8 fixed  scale(age_in_months):scale(te… -0.01  0.01 -0.81 4860.  4.20e- 1 0.420
 9 fixed  trial_window_c:scale(text_sim… -0.06  0.03 -2.09 4828.  3.70e- 2 <.05 
10 fixed  scale(age_in_months):trial_wi… -0.04  0.03 -1.39 4828.  1.65e- 1 0.165

The interaction makes sense, plotting the predictions here to try to understand what’s going on

trials_window_type_separated$predicted <- predict(window_type_looking_image)

# Plot interaction effect
ggplot(trials_window_type_separated, aes(x = image_similarity, y = predicted, color = factor(window_type))) +
  geom_point(alpha = 0.5) +   # Add points for raw data
  geom_smooth(method = "lm", se = TRUE) +  # Add regression lines
  labs(title = "Interaction Between Trial Window & Image Similarity",
       x = "Scaled Image Similarity",
       y = "Predicted Target Looking",
       color = "Trial Window") +
  theme_minimal()
`geom_smooth()` using formula = 'y ~ x'

This is also making me wonder whether we see any signal in how infants look at images in the baseline window. ## Baseline window looking

baseline_looking_image <- lmer(scale(mean_target_looking_baseline_window) ~ scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | SubjectInfo.subjID), 
                    data = trials_with_effect_vars)
boundary (singular) fit: see help('isSingular')
summary(baseline_looking_image)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(mean_target_looking_baseline_window) ~ scale(AoA_Est_target) +  
    scale(MeanSaliencyDiff) + (1 | SubjectInfo.subjID)
   Data: trials_with_effect_vars

REML criterion at convergence: 7031.3

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-1.75217 -0.73601 -0.01836  0.76794  1.76245 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.0000   0.0000  
 Residual                       0.9959   0.9979  
Number of obs: 2476, groups:  SubjectInfo.subjID, 91

Fixed effects:
                          Estimate Std. Error         df t value Pr(>|t|)   
(Intercept)             -1.231e-15  2.006e-02  2.473e+03   0.000  1.00000   
scale(AoA_Est_target)   -4.386e-02  2.006e-02  2.473e+03  -2.187  0.02887 * 
scale(MeanSaliencyDiff)  5.471e-02  2.006e-02  2.473e+03   2.727  0.00643 **
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) s(AA_E
scl(AA_Es_) 0.000        
scl(MnSlnD) 0.000  0.005 
optimizer (nloptwrap) convergence code: 0 (OK)
boundary (singular) fit: see help('isSingular')

Can’t get this to not be not singular but still fun to see that saliency is predictive.

Using a shorter critical window

short_image_effect <- lmer(scale(corrected_target_looking_short) ~ scale(image_similarity)*scale(age_in_months)
                    + scale(AoA_Est_target)
                    + scale(MeanSaliencyDiff)
                    + (1 | SubjectInfo.subjID) 
                    + (1|Trials.targetImage), 
                    data = trials_with_effect_vars)

short_text_effect <- lmer(scale(corrected_target_looking_short) ~ scale(text_similarity)*scale(age_in_months)*scale(AoA_Est_target)
                    + (1 | SubjectInfo.subjID)
                    + (1 | Trials.targetImage), 
                    data = trials_with_effect_vars)
summary(short_text_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(corrected_target_looking_short) ~ scale(text_similarity) *  
    scale(age_in_months) * scale(AoA_Est_target) + (1 | SubjectInfo.subjID) +  
    (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7014.4

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.64342 -0.64400 -0.00667  0.67117  2.67872 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.012906 0.11360 
 Trials.targetImage (Intercept) 0.008015 0.08952 
 Residual                       0.963283 0.98147 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                                                    Estimate
(Intercept)                                                         -0.01308
scale(text_similarity)                                              -0.03885
scale(age_in_months)                                                 0.07433
scale(AoA_Est_target)                                               -0.07705
scale(text_similarity):scale(age_in_months)                         -0.02155
scale(text_similarity):scale(AoA_Est_target)                         0.03069
scale(age_in_months):scale(AoA_Est_target)                          -0.04273
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)    0.01107
                                                                  Std. Error
(Intercept)                                                          0.03002
scale(text_similarity)                                               0.02367
scale(age_in_months)                                                 0.02313
scale(AoA_Est_target)                                                0.02731
scale(text_similarity):scale(age_in_months)                          0.02019
scale(text_similarity):scale(AoA_Est_target)                         0.02261
scale(age_in_months):scale(AoA_Est_target)                           0.02018
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)    0.01851
                                                                          df
(Intercept)                                                         26.89591
scale(text_similarity)                                             104.62642
scale(age_in_months)                                                91.05618
scale(AoA_Est_target)                                               24.18882
scale(text_similarity):scale(age_in_months)                       2380.05572
scale(text_similarity):scale(AoA_Est_target)                        61.81199
scale(age_in_months):scale(AoA_Est_target)                        2387.00281
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target) 2379.59345
                                                                  t value
(Intercept)                                                        -0.436
scale(text_similarity)                                             -1.641
scale(age_in_months)                                                3.213
scale(AoA_Est_target)                                              -2.822
scale(text_similarity):scale(age_in_months)                        -1.067
scale(text_similarity):scale(AoA_Est_target)                        1.357
scale(age_in_months):scale(AoA_Est_target)                         -2.118
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)   0.598
                                                                  Pr(>|t|)   
(Intercept)                                                        0.66661   
scale(text_similarity)                                             0.10376   
scale(age_in_months)                                               0.00181 **
scale(AoA_Est_target)                                              0.00940 **
scale(text_similarity):scale(age_in_months)                        0.28600   
scale(text_similarity):scale(AoA_Est_target)                       0.17959   
scale(age_in_months):scale(AoA_Est_target)                         0.03432 * 
scale(text_similarity):scale(age_in_months):scale(AoA_Est_target)  0.54989   
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E sc(_):(__) s(_):(A s(__):
scl(txt_sm) -0.012                                               
scl(g_n_mn)  0.002 -0.010                                        
scl(AA_Es_) -0.011 -0.104  0.012                                 
scl(_):(__) -0.009 -0.004 -0.004  0.002                          
s(_):(AA_E_ -0.110  0.091  0.003  0.181  0.010                   
s(__):(AA_E  0.013  0.002 -0.015  0.004 -0.051     -0.013        
s(_):(__):(  0.003  0.009 -0.074 -0.011  0.192      0.000   0.204
summary(short_image_effect)
Linear mixed model fit by REML. t-tests use Satterthwaite's method [
lmerModLmerTest]
Formula: scale(corrected_target_looking_short) ~ scale(image_similarity) *  
    scale(age_in_months) + scale(AoA_Est_target) + scale(MeanSaliencyDiff) +  
    (1 | SubjectInfo.subjID) + (1 | Trials.targetImage)
   Data: trials_with_effect_vars

REML criterion at convergence: 7009.8

Scaled residuals: 
     Min       1Q   Median       3Q      Max 
-2.70462 -0.65711 -0.01135  0.66973  2.73256 

Random effects:
 Groups             Name        Variance Std.Dev.
 SubjectInfo.subjID (Intercept) 0.012707 0.11273 
 Trials.targetImage (Intercept) 0.008632 0.09291 
 Residual                       0.965452 0.98257 
Number of obs: 2476, groups:  SubjectInfo.subjID, 91; Trials.targetImage, 24

Fixed effects:
                                               Estimate Std. Error         df
(Intercept)                                  -8.088e-03  3.027e-02  2.554e+01
scale(image_similarity)                      -4.193e-02  2.401e-02  1.137e+02
scale(age_in_months)                          7.523e-02  2.304e-02  9.017e+01
scale(AoA_Est_target)                        -7.588e-02  2.806e-02  2.347e+01
scale(MeanSaliencyDiff)                       1.022e-02  2.588e-02  3.653e+01
scale(image_similarity):scale(age_in_months) -2.373e-02  1.973e-02  2.387e+03
                                             t value Pr(>|t|)   
(Intercept)                                   -0.267  0.79145   
scale(image_similarity)                       -1.746  0.08343 . 
scale(age_in_months)                           3.265  0.00155 **
scale(AoA_Est_target)                         -2.704  0.01252 * 
scale(MeanSaliencyDiff)                        0.395  0.69507   
scale(image_similarity):scale(age_in_months)  -1.203  0.22928   
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Correlation of Fixed Effects:
            (Intr) scl(_) sc(__) s(AA_E s(MSD)
scl(mg_sml) -0.004                            
scl(g_n_mn)  0.002 -0.005                     
scl(AA_Es_)  0.010 -0.257  0.010              
scl(MnSlnD)  0.020  0.024 -0.009  0.019       
scl(_):(__)  0.000 -0.009  0.006  0.004 -0.010