DOI: 10.5061/dryad.j91v7
title: Data from: No enhancement of 24-hour visuomotor skill retention by post-practice caffeine administration

description: Caffeine is widely consumed throughout the world and appears to indirectly
 facilitate learning and memory through effects on attention and
 motivation. Animal work indicates that post-training caffeine
 administration augments inhibitory avoidance memory, spatial memory, and
 object memory. In humans, post-training caffeine administration enhances
 the ability to discern between familiar images and new, similar images.
 However, the effect of post-training caffeine administration on motor
 memory has not been examined. Therefore, we tested two groups of low
 caffeine consumers (average weekly consumption ≤500 mg) in a double-blind,
 placebo-controlled study involving acquisition of a continuous isometric
 visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150
 repetitions) of training on the continuous isometric visuomotor skill and
 subsequently ingested either 200 mg of caffeine or placebo. On day 2,
 subjects completed an additional 5 blocks of training. Day 1 mean
 performance and performance variability were both similar between groups,
 suggesting that both groups acquired the motor skill similarly. For mean
 performance on Day 2, patterns of re-learning, mean performance learning
 magnitudes, mean performance learning rates, and mean performance
 retention magnitudes were all similar between groups. For performance
 variability on Day 2, there was a small trend towards increased
 variability in the caffeine group during re-learning, but performance
 variability learning magnitudes and performance variability retention
 magnitudes did not differ between groups. Because motor skill acquisition
 can also be conceptualized as a reduction in performance variability,
 these results suggest that there may be a small negative effect of
 post-practice caffeine administration on memory of a newly-learned
 visuomotor skill. Overall, we found no evidence to suggest that
 post-training caffeine administration enhances 24-hour retention of a
 newly-learned continuous visuomotor skill, and these results support the
 notion that memory-enhancing effects of post-training caffeine ingestion
 may be task-specific.
description: Hussain&Cole2015_CaffeineIntakeSurveyThis file includes the caffeine intake survey subjects completed.Hussain&Cole2015_CaffeineIntakeSurvey_KEYThis file includes the corresponding amounts of caffeine (estimated) in each item listed on the caffeine intake survey.Hussain&Cole2015_listoftrialstoremoveThis file contains a list of trials that should be removed during analyses (i.e., data collection errors occurred during these trials).Hussain&Cole2015 Processed DataThis file includes all processed data (means, SDs, rate values, subject characteristics).Hussain&Cole2015_processeddata.xlsxHussain&Cole2015_exponentialfitsThis file includes all parameters from exponential fitting with the least-squares method.Hussain&Cole2015_complexwaveformThis data file includes the force values for the complex waveform. This waveform was used to calculate RMSE between the depicted waveform and subject's tracking performance. The force values used for this calculation are in column three of this file.Hussain&Cole2015_AnalyzeTracking_newThis file includes a MATLAB analysis code that calculates root mean square error (RMSE) for each subject's tracking trajectory compared to the complex waveform. This code also calculates means and standard deviations for each subject for each block of practice.AnalyzeTracking_new.mHussain&Cole2015 All Raw DataThis .zip folder includes all raw data (i.e., force values) for each subject tested. The force values are in column 3 of each file.