DOI: 10.5061/dryad.qnk98sfs5
title: Relating genetic variations in dopamine brain transmission to task performance with and without rewards

description: To evaluate potential genetic influences on learning in young people with
 and without cerebral palsy (CP), we calculated individual dopamine-related
 gene scores and compared these to the ability to learn two different
 tasks, an implicit sequence learning task, the Serial Reaction Time Task
 (SRTT) and a probabilistic classification task, the Weather Prediction
 Task (WPT).  For the SRTT, 85% of trials had the same sequence
 (i.e., probable) which should lead to implicit learning; 15% were a
 different sequence (i.e., improbable), The SRTT was also administered in
 an unrewarded condition and a rewarded one known to increase circulating
 levels of dopamine, each consisting of 20 trials each.  Data are
 presented for each block for 4 different outcomes (unrewarded probable
 which is considered the baseline learning score; unrewarded improbable;
 rewarded probable which indicates the effect of rewards on learning, and
 rewarded improbable). There were two outcome measures for each set of
 blocks: Reaction Time and Error Rate. For the WPT, the Feedback condition
 (rewarded) had 150 training trials during which they received rewards for
 accurate performance  Training for the Paired association
 condition consisted of showing them the cards and the outcome for each of
 the 150 trials. Then both the Feedback (FB) and the Paired Association
 (PA) conditions had a test which was used for data analysis. Both the
 proportion correct and reaction time were the outcome
 measures.    Gene scores are presented
 individually and in a summed gene score for each participant. All analyses
 reported in the paper were performed using these data or values computed
 from these data. The main analyses were to determine if learning occurred,
 whether it differed by participant groups, or whether it was improved with
 rewards.  Finally, the central hypothesis was tested which was on
 the influences of gene scores on learning with and without
 rewards. 
description: All task-related data were collected on computer programs which
 required participants to press certain keys to indicate responses and to
 do so as accurately and quickly as possible.  Summary scores were
 calculated for each set of trials for each condition. Outcomes for tasks
 included Reaction Time and Error Rate, (for SRTT) or proportion correct
 (for WPT).  Genetic data were collected through blood samples, sent to a
 company to perform the genetic analyses, from which we extracted the
 specific variants for each individual to calculate a combined dopamine
 gene score.   Statistical analyses included repeated
 measures GLM to assess learning over the training period for the group as
 a whole and for subgroups in both the rewarded and unrewarded conditions. 
 The primary analysis also added gene score group (high or low) to the
 GLM.  Independent t-tests were also used to compare scores across groups,
 and correlations were performed to relate performance on the two tasks,
 relationship of gene scores to task performance, and speed vs. accuracy
 measures. 
description: # Relating genetic variations in dopamine brain transmission to task
 performance with and without rewards
 [https://doi.org/10.5061/dryad.qnk98sfs5](https://doi.org/10.5061/dryad.qnk98sfs5) ## Description of the data and file structure Title: Relating genetic variations in dopamine brain transmission to task performance with and without rewards Contact: Diane Damiano, National Institutes of Health, [damianod@cc.nih.gov](mailto:damianod@cc.nih.gov) Date created: 2024/09/17 Licenses or restrictions: none Methods for data collection: a specialized computer program that provided instruction to participants, administered all items and recorded reaction time, error rate for SRTT and proportion correct and reaction time for WPT. ### Files and variables #### File: DOPAMINEALLDATAWORKSHEET.xlsx **Description:** Excel file includes participant group, age group at enrollment  (1 = 6-10, 2 = 11-15, 3 = 16-20, 4 = 21-25), sex, gene group, individual gene variant scores (COMT = catechol-O - methyltransferase; DRD1 = dopamine receptor subtype D1; DRD2 = dopamine receptor subtype D2; DRD3 = dopamine receptor subtype D3; DAT = dopamine transporter gene; BDNF = brain-derived neurotrophic factor), Serial reaction time task (SRTT) data for four conditions each with 20 blocks of 10 trials, first for the outcome of reaction time (ms) and then for Error Rate (% incorrect button presses over 10 trials). Next are the Mean Data across blocks for Reaction Time and Error Rate for four conditions (U/P = unrewarded probable which presented the same sequence of button presses in 85% of trials to stimulate implicit learning and was the baseline learning score; U/I = unrewarded improbable which presented a different infrequent sequence of presses; R/P = rewarded probable which was the rewarded learning score; R/I = rewarded improbable which was the control reward condition. The remaining data are from the Weather Prediction Test (WPT), first for the Feedback (FB) or rewarded condition during the 150 training trials, with each group of 50 trials presented in each of three columns for Proportion Correct (% of trials), followed by the FB training mean across all trials. The data used to assess learning were the testing trials which are presented next for the FB and then for the Paired Association (PD) conditions. Data for the WPT Reaction Time (ms) are presented in the same column format (three groups of FB training trials, the Training Mean, then testing data for FB and PA). The next two columns present data for the first 25 testing trials, then the last 25 testing trials, then the subtraction of the two for Percent Correct, then the same sets of columns for Reaction Time. The last two columns are the difference scores between the FB and the PA conditions to evaluate the effect of rewards (FB) on baseline learning (PA) for Proportion Correct and Reaction Time. ##### Variables * SRTT Reaction time (ms) for each of 20 blocks of 10 trials X 4 conditions (U/P. U/I. R/P, R/I) * SRTT Error rate (% incorrect button presses) for each of 20 blocks of trials X 4 conditions * Mean SRTT Reaction Time X 4 conditions * Mean SRTT Error Rate X 4 conditions * WPT Feedback (FB) training x 3 50 trial blocks for Proportion Correct * WPT FB training mean for Proportion Correct * WPT FB and PA (Paired Association) testing scores for Proportion correct * Same sequence of columns for WPT Reaction Time (ms) results * WPT FB-PA results for Proportion Correct * WPT FB-PA results for Reaction Time