Working memory alpha-beta band oscillatory signatures in adolescents and young adults

Abstract

The timing of neural activity is an intriguing way of exposing behaviourally-relevant neural activity, as neural populations exploit transient windows of synchronized activations to exchange dynamic communications in the service of various cognitive operations. The link between neural synchrony and working memory (WM) has been supported at the theoretical and empirical level. However, findings have also shown that WM encoding is also related to significant alpha-beta desynchronization. These findings have been primarily recorded during subsequent memory effect paradigms that compare correct with incorrect encoding trials. The dissociable contribution imparted by various processes to WM performance suggests that incorrect performance may not be directly translatable to unsuccessful encoding. Here, we address the relationship between alpha-beta desynchronization and encoding through the use of an alternative paradigm design by contrasting frontal and parietal human scalp EEG activity during the encoding interval of a delayed-matching to sample task with that recorded during a control task. The additional use of nonverbal/semantic visual stimulation and recruitment of typically developing adolescent subjects, has led us to the conclusion that encoding-relevant alpha-beta decrements can be replicated via a nonverbal/semantic delayed matching to sample task and these are also evident in typically developing adolescents, in addition to adults, as has been previously demonstrated. The identification of encoding-related alpha-beta decrements in adolescent subjects performing such WM tasks may open new avenues to explore whether such a rhythmic signature may explain WM and electrophysiological deficits that emerge in various adolescent neuropsychiatric disorders such as ADHD.

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