PE preanalysis
2025-11-25
Description
Goal here is to take advantage of the burst study design to create new metrics: practice effects (PE) and intraindividual variation (IIV). First issue is how to define PEs. We run into very abnormal distributions (strong positive skew). I’ve looked at the PE in 3 ways, and provide descriptions belwo.
a-Basic PE: These are calcualted as max score minus first score within that visit. I had also looked at last score minus first score within a chapeter.
b-Adjusted PE: Here I removed any participants with basic PE of 0. This is a little odd, but the goal here was to take the sub sample that demonstrated PEs. It also removes the high positive skew. I then log transformed this variable.
c-LME-derived PEs. These are participant-specific slopes derived from LMEs. These are a bit iffy if you ask me, but last time we did this Walter Kremens asked that we take a look. I like the idea, but I’m not sure we have the data to do it, and there also isn’t all that much person-specific variation.
Tables
Demographics by FTLD CDR GLOBAL
| Overall | 0 | 0.5 | 1 | 2 | 3 | p | test | |
|---|---|---|---|---|---|---|---|---|
| n | 453 | 256 | 98 | 65 | 33 | 1 | ||
| age (mean (SD)) | 53.11 (14.34) | 46.20 (12.86) | 59.54 (11.86) | 65.14 (8.49) | 63.36 (9.58) | 74.00 (NA) | NA | |
| educ (mean (SD)) | 16.69 (6.07) | 16.77 (5.76) | 16.18 (2.60) | 16.20 (2.85) | 18.55 (14.61) | 18.00 (NA) | NA | |
| baseline_ftldcdr_sb (mean (SD)) | 1.80 (2.97) | 0.00 (0.00) | 1.66 (0.93) | 5.04 (1.39) | 9.33 (2.54) | 15.00 (NA) | NA | |
| chng_ftldcdrbox (mean (SD)) | 0.25 (1.30) | 0.01 (0.13) | 0.47 (0.91) | 0.48 (2.37) | 1.42 (3.75) | NaN (NA) | 0.001 | |
| gender = M (%) | 193 (42.6) | 78 (30.5) | 52 (53.1) | 40 (61.5) | 23 (69.7) | 0 ( 0.0) | <0.001 | |
| genetic_carrier (%) | <0.001 | |||||||
| CARRY | 169 (37.3) | 123 (48.0) | 34 (34.7) | 6 ( 9.2) | 6 (18.2) | 0 ( 0.0) | ||
| CONTROL | 132 (29.1) | 105 (41.0) | 18 (18.4) | 6 ( 9.2) | 3 ( 9.1) | 0 ( 0.0) | ||
| NA | 152 (33.6) | 28 (10.9) | 46 (46.9) | 53 (81.5) | 24 (72.7) | 1 (100.0) |
Cognitive scores by FTLD CDR GLOBAl
| Overall | 0 | 0.5 | 1 | 2 | 3 | p | test | |
|---|---|---|---|---|---|---|---|---|
| n | 453 | 256 | 98 | 65 | 33 | 1 | ||
| dprime.nback (mean (SD)) | 2.95 (0.78) | 3.05 (0.64) | 2.65 (1.08) | 2.45 (1.03) | 2.62 (0.98) | NaN (NA) | 0.001 | |
| pe.nback.basic (mean (SD)) | 0.47 (0.52) | 0.46 (0.47) | 0.47 (0.65) | 0.61 (0.68) | 0.36 (0.51) | NaN (NA) | 0.801 | |
| pe.nback.basic.adj (mean (SD)) | -0.82 (1.08) | -0.80 (1.02) | -1.01 (1.34) | -0.31 (0.75) | -0.30 (NA) | NaN (NA) | NA | |
| pe.nback.lme (mean (SD)) | 0.13 (0.08) | 0.14 (0.07) | 0.11 (0.11) | 0.16 (0.09) | 0.12 (0.08) | NaN (NA) | 0.130 | |
| iiv_nback (mean (SD)) | 0.40 (0.29) | 0.37 (0.24) | 0.47 (0.43) | 0.52 (0.38) | 0.53 (0.21) | NaN (NA) | 0.063 | |
| speed_accuracy_incg.stroop (mean (SD)) | 5.11 (1.86) | 5.53 (1.64) | 4.02 (1.85) | 2.99 (2.15) | 2.09 (1.17) | NaN (NA) | <0.001 | |
| pe.stroop.basic (mean (SD)) | 1.15 (1.04) | 1.18 (1.02) | 1.03 (1.13) | 1.29 (0.76) | 0.77 (1.20) | NaN (NA) | 0.686 | |
| pe.stroop.basic.adj (mean (SD)) | 0.01 (0.87) | -0.02 (0.90) | 0.12 (0.80) | 0.28 (0.42) | -0.50 (1.80) | NaN (NA) | 0.513 | |
| pe.stroop.lme (mean (SD)) | 0.55 (0.08) | 0.55 (0.07) | 0.54 (0.11) | 0.55 (0.08) | 0.55 (0.05) | NaN (NA) | 0.992 | |
| iiv_stroop (mean (SD)) | 0.77 (0.54) | 0.75 (0.54) | 0.79 (0.57) | 0.95 (0.41) | 1.02 (0.18) | NaN (NA) | 0.548 | |
| mean_correct_by_chapter.humi (mean (SD)) | 2.79 (0.85) | 3.22 (0.65) | 2.50 (0.67) | 2.08 (0.62) | 1.68 (0.73) | 1.67 (NA) | NA | |
| pe.humi.basic (mean (SD)) | 0.42 (0.42) | 0.43 (0.43) | 0.41 (0.42) | 0.41 (0.43) | 0.38 (0.44) | 0.00 (NA) | NA | |
| pe.humi.basic.adj (mean (SD)) | -0.80 (0.86) | -0.75 (0.84) | -0.83 (0.83) | -0.88 (0.99) | -0.88 (0.89) | NaN (NA) | 0.821 | |
| pe.humi.lme (mean (SD)) | 0.14 (0.03) | 0.15 (0.02) | 0.13 (0.02) | 0.12 (0.03) | 0.11 (0.03) | 0.09 (NA) | NA | |
| iiv_humi (mean (SD)) | 0.32 (0.21) | 0.33 (0.21) | 0.31 (0.21) | 0.35 (0.23) | 0.30 (0.24) | 0.24 (NA) | NA | |
| satt_incg_speed_accuracy.flanker (mean (SD)) | 6.30 (1.14) | 6.79 (0.33) | 6.12 (1.09) | 5.54 (1.37) | 4.60 (1.96) | 4.73 (NA) | NA | |
| pe.flanker.basic (mean (SD)) | 0.27 (0.44) | 0.19 (0.18) | 0.30 (0.46) | 0.44 (0.53) | 0.62 (1.06) | 0.00 (NA) | NA | |
| pe.flanker.basic.adj (mean (SD)) | -1.54 (0.99) | -1.75 (0.85) | -1.47 (1.03) | -1.06 (0.97) | -0.86 (1.51) | NaN (NA) | <0.001 | |
| pe.flanker.lme (mean (SD)) | 0.07 (0.08) | 0.05 (0.03) | 0.07 (0.07) | 0.11 (0.08) | 0.19 (0.22) | 0.04 (NA) | NA | |
| iiv_flanker (mean (SD)) | 0.21 (0.26) | 0.13 (0.10) | 0.24 (0.27) | 0.30 (0.31) | 0.51 (0.58) | 0.46 (NA) | NA |
Histograms
Dprime
## $dprime.nback
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## $pe.nback.basic
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## $pe.nback.basic.adj
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## $pe.nback.lme
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## $iiv_nback
Stroop
## $speed_accuracy_incg.stroop
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## $pe.stroop.basic
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## $pe.stroop.basic.adj
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## $pe.stroop.lme
##
## $iiv_stroop
Humi
## $mean_correct_by_chapter.humi
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## $pe.humi.basic
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## $pe.humi.basic.adj
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## $pe.humi.lme
##
## $iiv_humi
Flanker
## $satt_incg_speed_accuracy.flanker
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## $pe.flanker.basic
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## $pe.flanker.basic.adj
##
## $pe.flanker.lme
##
## $iiv_flanker