Abstract
This study examined correlates between a behavioral measure of interhemispheric transfer (IHT), performance on tasks targeting right and left hemispheric functions, and resting electroencephalography (EEG). IHT was measured using the Poffenberger Paradigm, a reaction time (RT) task based on the inference that participants will have speeded RTs to a visual target ipsilateral to the responding hand compared to a contralateral target. The neural processes indexed by this crossed-uncrossed difference (CUD) is debated in the literature due to its high variability. This study utilizes the individual variability of the CUD to examine individual differences in behavioral and neural measures of hemispheric function. The resting EEG data of 28 participants were recorded. Participants completed the Poffenberger Paradigm, a temporal discrimination task, line bisection task, and the Remote Associates Task (RAT). Right minus left average spectral power (ASP) for theta, alpha, beta, and gamma EEG frequencies across 8 equivalent scalp locations were regressed onto task performance. Location F3/4 emerged for the beta band: larger beta ASP in the right versus left hemisphere predicted faster right-to-left IHT, while larger beta at F3/4 in the left hemisphere correlated with left-to-right IHT. For the RAT, smaller alpha and larger beta in the right hemisphere at location F7/8 predicted better performance. For temporal sensitivity, location P3/4 for beta and location T7/8 for the theta loaded significantly, with higher ASP in the left electrodes predictive of better performance. Participants with slower right-to-left IHT demonstrated, via Pearson’s correlations, significantly larger pseudoneglect. Participants with faster right-to-left IHT demonstrated marginally significant increases in performance on the RAT and temporal sensitivity. Findings demonstrate individual differences in lateralized neural function in conjunction with IHT and behavior and will be discussed in terms of characterizing the relationship between individual neural activity and behavioral performance, with an emphasis on implications for clinical populations.
Meeting abstract presented at VSS 2015