DATA_PATH <- here("data/processed/syntactic_bootstrapping_tidy_data.csv") # make all variables (i.e. things that might change) as capital letters at the top of the scripts

ma_data <- read_csv(DATA_PATH)   %>%
  filter(language == "English",
         population_type == "typically_developing",
         stimuli_modality == "video")

Data Overview

#N_effect_sizes <- length((!is.na(ma_data$d_calc))&!(ma_data$d_calc ==0))
#N_papers <- length(unique(ma_data$unique_id))

# let's do this in the tidyverse way (which is much more readable)
n_effect_sizes <- ma_data %>%
  filter(!is.na(d_calc)) %>%
  nrow()

n_papers <- ma_data %>%
  distinct(unique_id) %>%
  nrow()

There are 63 effect sizes collected from 17 different papers.

Here are the papers in this analysis:

ma_data %>%
  count(short_cite) %>%
  arrange(-n) %>%
  DT::datatable()

mean age is misssing for one

Variable Summary

Continuous variables

CONTINUOUS_VARS <- c("n_1", "x_1", "sd_1", "d_calc", "d_var_calc", "mean_age")

long_continuous <- ma_data %>%
  pivot_longer(cols = CONTINUOUS_VARS)

long_continuous %>%
  ggplot(aes(x = value)) +
  geom_histogram() + 
  facet_wrap(~ name, scale = "free_x") +
  labs(title = "Distribution of continuous measures")

long_continuous %>%
  group_by(name) %>%
  summarize(mean = mean(value),
            sd = sd(value)) %>%
  kable()
name mean sd
d_calc 0.4488370 2.2721814
d_var_calc 0.3400485 0.6908566
mean_age NA NA
n_1 13.6825397 5.7720835
sd_1 0.1075735 0.0737094
x_1 0.5384772 0.1222712

Categorical variables

CATEGORICAL_VARS <- c("sentence_structure", "language", "population_type", 
                     "agent_argument_type", "patient_argument_type", "stimuli_type",
                     "stimuli_modality", "presentation_type", "character_identification",
                     "test_mass_or_distributed", "practice_phase")

long_categorical <- ma_data %>%
  pivot_longer(cols = CATEGORICAL_VARS) %>%
  count(name, value) # this is a short cut for group_by() %>% summarize(count = n()) 

long_categorical %>%
  ggplot(aes(x = value, y = n)) +  
  facet_wrap(~ name, scale = "free_x") +
  geom_col(position = 'dodge',width=0.4) + 
  theme(text = element_text(size=8),
        axis.text.x = element_text(angle = 90, hjust = 1))  # rotate x-axis text

Explore Moderators

no moderators

all

m1 <- rma.mv(d_calc, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m1)
## 
## Multivariate Meta-Analysis Model (k = 63; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -200.5332   401.0665   405.0665   409.3207   405.2699   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.5904  0.7684     17     no  short_cite 
## 
## Test for Heterogeneity:
## Q(df = 62) = 559.8747, p-val < .0001
## 
## Model Results:
## 
## estimate      se    zval    pval   ci.lb   ci.ub 
##   0.5485  0.1927  2.8470  0.0044  0.1709  0.9262  ** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

<36

ma_data_young_only <- ma_data %>%
    mutate(age_months = mean_age/30.44) %>% 
    filter(age_months < 36) 

m_young <- rma.mv(d_calc, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data_young_only)
summary(m_young)
## 
## Multivariate Meta-Analysis Model (k = 54; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -157.3340   314.6681   318.6681   322.6087   318.9081   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6028  0.7764     15     no  short_cite 
## 
## Test for Heterogeneity:
## Q(df = 53) = 448.4174, p-val < .0001
## 
## Model Results:
## 
## estimate      se    zval    pval   ci.lb   ci.ub 
##   0.5159  0.2075  2.4865  0.0129  0.1092  0.9225  * 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Age only

all

ma_data %>% 
  ggplot(aes(x = mean_age/30.44, y = d_calc, size = n_1)) +
  geom_point() +
  geom_smooth(method = "lm") +
  geom_smooth(color = "red") +
  ylab("Effect Size") +
  xlab("Age (days)") +
  ggtitle("Syntactical Bootstrapping effect size vs. Age (months)") +
  theme(legend.position = "none") 

m_age <- rma.mv(d_calc ~ mean_age, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age)
## 
## Multivariate Meta-Analysis Model (k = 62; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -186.7742   373.5485   379.5485   385.8315   379.9770   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6391  0.7994     17     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 60) = 533.1630, p-val < .0001
## 
## Test of Moderators (coefficient 2):
## QM(df = 1) = 8.1015, p-val = 0.0044
## 
## Model Results:
## 
##           estimate      se     zval    pval    ci.lb   ci.ub 
## intrcpt    -0.3883  0.3899  -0.9958  0.3193  -1.1525  0.3759     
## mean_age    0.0011  0.0004   2.8463  0.0044   0.0003  0.0019  ** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

< 36

Let’s only look at ES for kids < 36

ma_data_young_only %>%
  ggplot(aes(x = age_months, y = d_calc, size = n_1)) +
  geom_point() +
  geom_smooth(method = "lm") +
  geom_smooth(color = "red") +
  ylab("Effect Size") +
  xlab("Age (days)") +
  ggtitle("Syntactical Bootstrapping effect size vs. Age (days)") +
  theme(legend.position = "none") 

m_age_young <- rma.mv(d_calc ~ mean_age, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data_young_only)
summary(m_age_young)
## 
## Multivariate Meta-Analysis Model (k = 54; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -156.3612   312.7224   318.7224   324.5762   319.2224   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6248  0.7904     15     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 52) = 443.1411, p-val < .0001
## 
## Test of Moderators (coefficient 2):
## QM(df = 1) = 0.0434, p-val = 0.8349
## 
## Model Results:
## 
##           estimate      se    zval    pval    ci.lb   ci.ub 
## intrcpt     0.3152  0.9877  0.3191  0.7497  -1.6206  2.2509    
## mean_age    0.0003  0.0013  0.2084  0.8349  -0.0022  0.0027    
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

age and sentence structure

all

ma_data %>% 
  filter(sentence_structure != "bare_verb") %>%
  mutate(age_months = mean_age/30.44) %>% 
  ggplot(aes(x = age_months, y = d_calc, size = n_1, , color = sentence_structure)) +
  geom_point() +
  geom_smooth(method = "lm") +
  ylab("Effect Size") +
  xlab("Age (days)") +
  ggtitle("Syntactical Bootstrapping effect size vs. Age (days)") 

m_age_sentence <- rma.mv(d_calc ~ mean_age + sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_sentence)
## 
## Multivariate Meta-Analysis Model (k = 62; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -172.8666   345.7332   353.7332   362.0434   354.4739   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.7409  0.8607     17     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 59) = 524.8546, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 36.0580, p-val < .0001
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                        -0.6222  0.4042  -1.5393  0.1237  -1.4144 
## mean_age                        0.0009  0.0004   2.3228  0.0202   0.0001 
## sentence_structuretransitive    0.6163  0.1169   5.2714  <.0001   0.3872 
##                                ci.ub 
## intrcpt                       0.1700      
## mean_age                      0.0017    * 
## sentence_structuretransitive  0.8455  *** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Interaction:

m_age_sentence <- rma.mv(d_calc ~ mean_age * sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_sentence)
## 
## Multivariate Meta-Analysis Model (k = 62; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -171.9204   343.8407   353.8407   364.1430   354.9946   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.7469  0.8642     17     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 58) = 524.8480, p-val < .0001
## 
## Test of Moderators (coefficients 2:4):
## QM(df = 3) = 36.9478, p-val < .0001
## 
## Model Results:
## 
##                                        estimate      se     zval    pval 
## intrcpt                                 -1.3139  0.8450  -1.5550  0.1199 
## mean_age                                 0.0018  0.0011   1.7339  0.0829 
## sentence_structuretransitive             1.3364  0.7824   1.7081  0.0876 
## mean_age:sentence_structuretransitive   -0.0009  0.0010  -0.9305  0.3521 
##                                          ci.lb   ci.ub 
## intrcpt                                -2.9700  0.3422    
## mean_age                               -0.0002  0.0039  . 
## sentence_structuretransitive           -0.1970  2.8698  . 
## mean_age:sentence_structuretransitive  -0.0029  0.0010    
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

< 36 months

ma_data_young_only <- ma_data %>%
    mutate(age_months = mean_age/30.44) %>% 
    filter(age_months < 36) 

ma_data_young_only %>% 
  filter(sentence_structure != "bare_verb") %>%
  ggplot(aes(x = age_months, y = d_calc, size = n_1, , color = sentence_structure)) +
  geom_point() +
  geom_smooth(method = "lm") +
  ylab("Effect Size") +
  xlab("Age (days)") +
  ggtitle("Syntactical Bootstrapping effect size vs. Age (days)") 

m_age_sentence_young <- rma.mv(d_calc ~ mean_age + sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data_young_only)
summary(m_age_sentence_young)
## 
## Multivariate Meta-Analysis Model (k = 54; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -143.1808   286.3617   294.3617   302.0890   295.2312   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6921  0.8319     15     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 51) = 431.5026, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 26.3325, p-val < .0001
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                         0.8651  1.0097   0.8568  0.3916  -1.1139 
## mean_age                       -0.0009  0.0013  -0.7085  0.4787  -0.0034 
## sentence_structuretransitive    0.6097  0.1189   5.1258  <.0001   0.3765 
##                                ci.ub 
## intrcpt                       2.8441      
## mean_age                      0.0016      
## sentence_structuretransitive  0.8428  *** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Age and character identification

ma_data %>% 
  ggplot(aes(x = mean_age, y = d_calc, color = character_identification)) +
  geom_point() +
  geom_smooth(method = "lm") +
  ylab("Effect Size") +
  xlab("Age (days)") +
  theme_classic() 

m_age_char <- rma.mv(d_calc ~ mean_age + character_identification, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_char)
## 
## Multivariate Meta-Analysis Model (k = 33; method: REML)
## 
##   logLik  Deviance       AIC       BIC      AICc 
## -75.0093  150.0185  158.0185  163.6233  159.6185   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.9654  0.9826     11     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 30) = 293.4893, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 6.3893, p-val = 0.0410
## 
## Model Results:
## 
##                              estimate      se     zval    pval    ci.lb   ci.ub 
## intrcpt                       -0.6467  0.6567  -0.9847  0.3248  -1.9339  0.6405 
## mean_age                       0.0010  0.0004   2.4136  0.0158   0.0002  0.0019 
## character_identificationyes    0.5846  0.6292   0.9292  0.3528  -0.6486  1.8178 
##  
## intrcpt 
## mean_age                     * 
## character_identificationyes 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Age and practice_phase

ma_data %>% 
ggplot(aes(x = mean_age, y = d_calc, color = practice_phase)) +
  geom_point() +
  ylab("Effect Size") +
  geom_smooth(method = "lm") +
  xlab("Age (days)") +
  theme_classic()

m_age_practice <- rma.mv(d_calc ~ mean_age + practice_phase, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_practice)
## 
## Multivariate Meta-Analysis Model (k = 40; method: REML)
## 
##   logLik  Deviance       AIC       BIC      AICc 
## -95.0446  190.0892  198.0892  204.5329  199.3392   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    1.0053  1.0026     11     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 37) = 343.8912, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 6.9090, p-val = 0.0316
## 
## Model Results:
## 
##                    estimate      se     zval    pval    ci.lb   ci.ub 
## intrcpt             -0.8482  0.8814  -0.9624  0.3359  -2.5758  0.8793     
## mean_age             0.0011  0.0004   2.5977  0.0094   0.0003  0.0020  ** 
## practice_phaseyes    0.6834  0.8101   0.8436  0.3989  -0.9043  2.2712     
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Age and test_mass_or_distributed

ma_data %>% 
  ggplot(aes(x = mean_age, y = d_calc, color = test_mass_or_distributed)) +
  geom_point() +
  ylab("Effect Size") +
  geom_smooth(method = "lm") +
  xlab("Age (days)") +
  theme_classic()

m_age_test <- rma.mv(d_calc ~ mean_age + test_mass_or_distributed, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_test)
## 
## Multivariate Meta-Analysis Model (k = 62; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -184.9207   369.8413   377.8413   386.1515   378.5821   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6459  0.8037     17     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 59) = 520.6656, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 9.0675, p-val = 0.0107
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                        -0.5649  0.4298  -1.3142  0.1888  -1.4073 
## mean_age                        0.0012  0.0004   2.9598  0.0031   0.0004 
## test_mass_or_distributedmass    0.4369  0.4475   0.9764  0.3289  -0.4401 
##                                ci.ub 
## intrcpt                       0.2776     
## mean_age                      0.0019  ** 
## test_mass_or_distributedmass  1.3140     
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
m_age_test_int <- rma.mv(d_calc ~ mean_age * test_mass_or_distributed, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_test_int)
## 
## Multivariate Meta-Analysis Model (k = 62; method: REML)
## 
##    logLik   Deviance        AIC        BIC       AICc 
## -182.9227   365.8454   375.8454   386.1476   376.9992   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.6380  0.7987     17     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 58) = 515.5189, p-val < .0001
## 
## Test of Moderators (coefficients 2:4):
## QM(df = 3) = 11.1403, p-val = 0.0110
## 
## Model Results:
## 
##                                        estimate      se     zval    pval 
## intrcpt                                 -0.6627  0.4342  -1.5263  0.1269 
## mean_age                                 0.0013  0.0004   3.1785  0.0015 
## test_mass_or_distributedmass             2.7121  1.6401   1.6536  0.0982 
## mean_age:test_mass_or_distributedmass   -0.0030  0.0021  -1.4415  0.1495 
##                                          ci.lb   ci.ub 
## intrcpt                                -1.5137  0.1883     
## mean_age                                0.0005  0.0021  ** 
## test_mass_or_distributedmass           -0.5024  5.9266   . 
## mean_age:test_mass_or_distributedmass  -0.0071  0.0011     
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Age and vocabulary

ma_data_with_vocab <- ma_data %>% 
  mutate(vocab = case_when(!is.na(productive_vocab_median) ~ productive_vocab_median,
                           !is.na(productive_vocab_mean) ~ productive_vocab_mean,
                            TRUE ~ NA_real_),
         vocab_source = case_when(!is.na(productive_vocab_median) ~ "median",
                           !is.na(productive_vocab_mean) ~ "mean",
                            TRUE ~ NA_character_)) 
ma_data_with_vocab %>%
  ggplot(aes(x = mean_age, y = vocab, color = vocab_source)) +
  geom_point() +
  geom_smooth(method = "lm") +
  theme_classic()

ma_data_with_vocab %>%
  ggplot(aes(x = productive_vocab_median, y = d_calc)) +
  geom_point() +
  geom_smooth(method = "lm") +
  theme_classic()

cor.test(ma_data_with_vocab$mean_age,
         ma_data_with_vocab$productive_vocab_median)
## 
##  Pearson's product-moment correlation
## 
## data:  ma_data_with_vocab$mean_age and ma_data_with_vocab$productive_vocab_median
## t = 16.671, df = 28, p-value = 4.524e-16
## alternative hypothesis: true correlation is not equal to 0
## 95 percent confidence interval:
##  0.9029205 0.9776844
## sample estimates:
##       cor 
## 0.9531389
m_age_vocab <- rma.mv(d_calc ~ productive_vocab_median + sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_vocab)
## 
## Multivariate Meta-Analysis Model (k = 30; method: REML)
## 
##   logLik  Deviance       AIC       BIC      AICc 
## -73.8888  147.7776  155.7776  160.9610  157.5958   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.9426  0.9709      6     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 27) = 204.9175, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 22.5110, p-val < .0001
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                         0.4692  0.5463   0.8588  0.3904  -0.6015 
## productive_vocab_median        -0.0045  0.0073  -0.6197  0.5355  -0.0189 
## sentence_structuretransitive    0.9011  0.1904   4.7335  <.0001   0.5280 
##                                ci.ub 
## intrcpt                       1.5398      
## productive_vocab_median       0.0098      
## sentence_structuretransitive  1.2741  *** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
m_age_vocab_age <- rma.mv(d_calc ~ mean_age + sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data %>% filter(!is.na(productive_vocab_median)))
summary(m_age_vocab_age)
## 
## Multivariate Meta-Analysis Model (k = 30; method: REML)
## 
##   logLik  Deviance       AIC       BIC      AICc 
## -72.9358  145.8716  153.8716  159.0550  155.6898   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    0.8799  0.9380      6     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 27) = 198.1789, p-val < .0001
## 
## Test of Moderators (coefficients 2:3):
## QM(df = 2) = 23.7496, p-val < .0001
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                         2.1872  1.5713   1.3920  0.1639  -0.8924 
## mean_age                       -0.0027  0.0021  -1.2738  0.2027  -0.0068 
## sentence_structuretransitive    0.9154  0.1907   4.8010  <.0001   0.5417 
##                                ci.ub 
## intrcpt                       5.2669      
## mean_age                      0.0014      
## sentence_structuretransitive  1.2892  *** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Mega-model

m_age_mega <- rma.mv(d_calc ~ mean_age + test_mass_or_distributed + practice_phase + character_identification + sentence_structure, V = d_var_calc,
                            random = ~ 1 | short_cite, data = ma_data)
summary(m_age_mega)
## 
## Multivariate Meta-Analysis Model (k = 26; method: REML)
## 
##   logLik  Deviance       AIC       BIC      AICc 
## -53.1003  106.2006  120.2006  127.1707  129.5339   
## 
## Variance Components:
## 
##             estim    sqrt  nlvls  fixed      factor 
## sigma^2    2.1458  1.4649      8     no  short_cite 
## 
## Test for Residual Heterogeneity:
## QE(df = 20) = 221.8624, p-val < .0001
## 
## Test of Moderators (coefficients 2:6):
## QM(df = 5) = 14.8364, p-val = 0.0111
## 
## Model Results:
## 
##                               estimate      se     zval    pval    ci.lb 
## intrcpt                        -2.1083  1.3594  -1.5509  0.1209  -4.7726 
## mean_age                        0.0011  0.0005   2.5186  0.0118   0.0003 
## test_mass_or_distributedmass   -0.8569  1.6326  -0.5249  0.5997  -4.0567 
## practice_phaseyes               1.2165  1.3295   0.9150  0.3602  -1.3892 
## character_identificationyes     1.1810  1.3250   0.8913  0.3728  -1.4160 
## sentence_structuretransitive    0.6522  0.2465   2.6452  0.0082   0.1690 
##                                ci.ub 
## intrcpt                       0.5561     
## mean_age                      0.0020   * 
## test_mass_or_distributedmass  2.3428     
## practice_phaseyes             3.8222     
## character_identificationyes   3.7780     
## sentence_structuretransitive  1.1354  ** 
## 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

```