Is "Blank" a suitable neutral prime for event-related potential experiments?
ABSTRACT We report an experiment that evaluates whether BLANK or an unrelated prime is a more suitable baseline for assessing priming for an ERP study. Sixteen subjects performed a lexical decision task with a 1 s prime-target stimulus onset asynchrony. Increased amplitude for the N400 was observed for targets in the unrelated prime condition whereas targets in the BLANK prime condition evoked activity that was more like that in the related prime condition. Theoretically, we conclude that the N400 reflects semantic integration. Pragmatically, we conclude that the BLANK prime is a better neutral prime but that unrelated primes yield stronger N400 effects.
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ABSTRACT: Individuals with generalized anxiety disorder (GAD) display poor emotional conflict adaptation, a cognitive control process requiring the adjustment of performance based on previous-trial conflict. It is unclear whether GAD-related conflict adaptation difficulties are present during tasks without emotionally-salient stimuli. We examined conflict adaptation using the N2 component of the event-related potential (ERP) and behavioral responses on a Flanker task from 35 individuals with GAD and 35 controls. Groups did not differ on conflict adaptation accuracy; individuals with GAD also displayed intact RT conflict adaptation. In contrast, individuals with GAD showed decreased amplitude N2 principal component for conflict adaptation. Correlations showed increased anxiety and depressive symptoms were associated with longer RT conflict adaptation effects and lower ERP amplitudes, but not when separated by group. We conclude that individuals with GAD show reduced conflict-related component processes that may be influenced by compensatory processes, even in the absence of emotionally-salient stimuli.Biological psychology 09/2013; · 4.36 Impact Factor
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ABSTRACT: Individuals with major depressive disorder (MDD) show alterations in the cognitive control function of conflict processing. We examined the influence of these deficits on behavioral and event-related potential (ERP) indices of conflict adaptation, a cognitive control process wherein previous-trial congruency modulates current-trial performance, in 55 individuals with MDD and 55 matched controls. ERPs were calculated while participants completed a modified flanker task. There were nonsignificant between-groups differences in response time, error rate, and N2 indices of conflict adaptation. Higher depressive symptom scores were associated with smaller mean N2 conflict adaptation scores for individuals with MDD and when collapsed across groups. Results were consistent when comorbidity and medications were analyzed. These findings suggest N2 conflict adaptation is associated with depressive symptoms rather than clinical diagnosis alone.Psychophysiology 06/2013; · 3.29 Impact Factor
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ABSTRACT: Little is known about the functional impact of putative deficits in white-matter connectivity across the corpus callosum (CC) in individuals with autism spectrum disorders (ASDs). We utilized the temporal sensitivity of event-related potentials to examine the interhemispheric transfer time (IHTT) of basic visual information across the CC in youth with high-functioning ASD relative to healthy controls. We conducted two experiments: a visual letter matching experiment (n = 46) and a visual picture matching experiment, (n = 48) and utilized both electrophysiological (N1 and P1 amplitudes and latencies) and behavioral [response times (RTs), error rates] indices of IHTT. There were no significant group differences on either experiment for RTs, error rates, or N1 and P1 latencies, suggesting that on basic tasks the timing of information flow across the CC may not be altered in high functioning ASD.Journal of Autism and Developmental Disorders 07/2013; · 3.06 Impact Factor