This wiki page summarizes the primary executive function (EF) tasks administered in CATSLife. Data provided here include ONLY those data collected during CATSLife wave 1.

For earlier waves of EF assessment (LTS sample only), please see the corresponding page on the LTS wiki: Executive Function Tests. (Note: this may require additional permissions).

EFs were first assessed in the LTS sample only at ages 17 and 23. Researchers at IBG have focused on 9 EF tests originally examined by Friedman et al. (2006, 2008) and subsequent publications, though some other related measures (working memory span, flanker, card sort) are available at age 17. This battery of 9 tasks was shortened to 6 tasks during the CATSLife assessment.

The third wave of EF assessment is also a little complicated. EFs were assessed in the LTS subsample (mean age 28) as part of both the LTS MRI grant (PI Naomi Friedman) and the CATSLife wave 1 grant (PIs Wadsworth & Reynolds). 175 individuals completed both EF assessments, mostly because their CATSLife assessment occurred greater than 1 year after the MRI assessment. All individuals from CAP completed EF tasks as a part of CATSLife only (mean age 38).

The first publication using CATSLife EF data was Gustavson et al (2022; PDF), which provides some additional information about the EF assessment and effort to harmonize data across LTS-MRI and CATSLife assessments.

(Note: these descriptions are copied from Gustavson et al. 2022, but they ONLY focus on the CATSLife version of the tasks. See the paper for differences between CATSLife and LTS MRI versions of the tasks!)

Antisaccade: In the antisaccade task (Roberts et al., 1994), participants had to avoid a reflexive tendency to saccade to a cue stimulus and instead immediately look to the opposite side of the screen in time to identify a digit (1–9) that appeared briefly before being masked. The CATSLife version was a shortened version of the one used at the age 23 LTS assessment (Friedman et al., 2016). Participants completed 12 practice and 18 actual prosaccade trials to familiarize themselves with the task and reinforce the prepotent response, followed by 12 practice antisaccade trials then two blocks (36 antisaccade trials each) that increased in difficulty. Each trial began with a centered fixation cross that remained on the screen for one of nine durations from 1,500 to 3,500 ms (in 250-ms increments). The subsequent cue was a black 1/8 in. square (inner edge 3.375 in. from the center), which appeared on the left or right of the screen with equal probability. The cue remained on the screen for 233 ms in the first antisaccade block and 200 ms in the second antisaccade block and the initial prosaccade blocks. Once it disappeared, a numeric target (a digit 1–9, 26 pt Helvetica font, presented in a 7/16 in. square with its inner edge 3.25 in. from the fixation) appeared for 150 ms before being masked, on the same side as the cue (prosaccade block) or on the opposite side (antisaccade blocks). The mask remained on the screen until the participant verbalized the target number (or guessed), and the experimenter entered the response, initiating the next trial. Each block contained two warm up trials that were not included in the analyses.

Stroop: The color-word Stroop task (Stroop, 1935) required participants to avoid the dominant tendency to read words, and instead name the colors in which the words were printed (on a black background). This task, which was completed in the laboratory for all participants, was the same one used at the age 23 LTS assessment (Friedman et al., 2016). On each trial, a 750 ms blank period was followed by a 250 ms white fixation cross, then a colored target, which remained on the screen until the participant reported the color. RTs were collected by using voice key, and stimuli disappeared as soon as the voice key detected the response. The task began with 10 practice and 42 actual neutral trials (colored strings of 3–5 asterisks), followed by a block of 10 practice and 42 actual congruent trials (RED, BLUE, and GREEN printed in the congruent color), and ended with two blocks of 42 incongruent trials (color words printed in incongruent colors). Each block included two warm-up trials that were not included in the analyses. The dependent measure was reaction time (RT) interference, obtained by subtracting mean RT for correct asterisks trials from mean RT correct incongruent trials.

Letter Memory Task (Morris & Jones, 1990): This was same one used at the age 23 LTS assessment (Friedman et al., 2016). Participants saw a list of letters presented one at a time for 3 seconds. With each letter, participants said aloud the four most recent letters that appeared. The dependent measure was the proportion of sets correctly rehearsed across 12 trials (four trials each of length 9, 11, or 13 letters; 132 total sets). Points were given for rehearsing only the correct letters in the correct serial order.

Keep Track Yntema, 1963), participants saw a list of 15 words presented one at a time on the screen at a rate of 2 seconds per word. The words were drawn from a list of 36 words, 6 words in each of 6 categories (animals, colors, countries, distances, metals, and relatives). They were instructed to remember only the most recent word presented from the target specified categories (displayed on the bottom of the screen during the entire trial) and respond at the end of the trial when a prompt appeared (“???”). In the scanner version, the response period lasted for 10 s during which the participant vocalized answers. In the laboratory version, participants also vocalized their answers, but there was no time limit. Recall trials were intermixed with fixation blocks and comparison READ trials in which participants were instructed to read words without trying to remember them. The dependent measure was the proportion of total words recalled across all 9 trials (36 words in the laboratory version: three trials each of three, four, and five categories; 33 words in the scanner version: three trials of three categories and six trials of four categories).

The two shifting tasks required participants to switch between categorization dimensions according to a cue that appeared 350 ms before the stimulus and remained on the screen along with the target stimulus until the participant entered the response. The dependent measures for both tasks were local switch costs based on blocks in which the two tasks were intermixed: The mean RT during trials that required a switch between categorization rules minus the mean RT during trials where the same rule was repeated (64 trials per condition in the behavioral tasks, 96 per condition in the scanner version of the number–letter task). The task consisted of 12 practice then 32 actual task 1 trials (e.g., living/nonliving), 12 practice then 32 actual task 2 trials (e.g., small/big), then 24 practice and 2 blocks of 64 actual mixed task trials (50% required a task switch). There was a 350 ms response to cue interval, and a 200-ms buzz sounded for errors (buzzes were removed for the scanner version). Each block included two (single-task blocks) or four (mixed blocks) warm-up trials that were not included in the analyses. In the scanner version of the number-letter task, the trials were arranged in shorter blocks of 13 trials (12 trials þ 1 warm-up trial) each, which were intermixed with 20-s rest blocks. Each block was preceded by an instruction indicating the trial type (TOP, BOTTOM, MIXED, or FIXATION). In mixed blocks, half the trials were switch trials. The task contained 16 mixed blocks, 8 single-task blocks, and 8 fixation blocks.

Category Switching (Mayr & Kliegl, 2000): Subjects judged whether words described something living or nonliving or something bigger or smaller than a soccer ball, based on a cue symbol (a heart or a cross) that appeared above the word. This task was the same one used at the age 23 LTS assessment (Friedman et al., 2016).

Number-Letter Switching (Rogers & Monsell, 1995), participants used two buttons on a ms-accurate button box to indicate whether number–letter or letter–number pairs contained a vowel or consonant or contained an odd or even number, based on where the stimulus appeared in a quadrant of a square on the screen (top or bottom). The cue was the darkening of the border around the quadrant in which the target would appear.

Gustavson, D. E., Reynolds, C. A., Corley, R. A., Wadsworth, S. J., Hewitt, J. K., & Friedman, N. P. (2022). Genetic associations between executive functions and intelligence: A combined twin and adoption study. Journal of Experimental Psychology: General, 151, 1745-1761. http://doi.org/10.1037/xge0001168. PDF

See also earlier publication on EF data in LTS only: Executive Function Tests

(UNDER CONSTRUCTION)

Ages: Wave 1

Category: Cognitive

Reminder: see this page for Executive Function tests in LTS: LTS Executive Function Tests.

CATSLife1 EF data - Harmonized Note: This is the harmonized datafile from Gustavson et al. 2022 including LTS-MRI & CATSLife1 (N=1,238)

CATSLife1 EF data - CATSLife Only Note: This includes CATSLife 1 data only (no LTS-MRI). It also includes columns for reliability (N=773)

Variable Names: Only post-processed subject-level data are provided here. Individual trial level files are archived by Daniel Gustavson & Naomi Friedman.

CATSLife 1 EF Variables - CATSLife ONLY

CATSLife 1 EF Variables - Gustavson2022 Harmonized CATSLife & LTSMRI

The following links are pdfs of the data dictionaries. To return to this page, please push the back button on your browser.

CATSLife 1 EF Data Dictionary - CATSLife only

CATSLife 1 EF Data Dictionary - Gustavson2022 Harmonized CATSLife & LTS-MRI

It is highly recommended you speak with Daniel Gustavson and/or Naomi Friedman if you are analyzing data from CATSLife 1 to make sure you include the correct EF task variables (and do not miss cases).