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

• Published in: The European journal of neuroscience Vol. 48; no. 7; pp. 2527 - 2536
• Main Authors: Zammit, Nowell, Falzon, Owen, Camilleri, Kenneth, Muscat, Richard
• Format: Journal Article
• Language: English
• Published: France Wiley Subscription Services, Inc 01.10.2018
• Subjects: Adolescent; Adolescents; Adult; Alpha Rhythm - physiology; alpha–beta band oscillatory signatures; Attention deficit hyperactivity disorder; Beta Rhythm - physiology; Brain - physiology; Cognitive ability; EEG; electroencephalography; Electroencephalography - methods; Female; Humans; Male; Memory; Memory, Short-Term - physiology; Mental disorders; Reaction Time - physiology; Rhythms; Scalp; Semantics; Short term memory; Synchronization; Teenagers; Visual stimuli; working memory; Young Adult; young adults; electroencephalography; adolescents; working memory; alpha-beta band oscillatory signatures; young adults
• ISSN: 0953-816X; 1460-9568; 1460-9568
• DOI: 10.1111/ejn.13897

The timing of neural activity is an intriguing way of exposing behaviorally 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 electroencephalography activity during the encoding interval of a delayed matching‐to‐sample task with that recorded during a control task. The additional use of non‐verbal/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 non‐verbal/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 attention deficit hyperactivity disorder. Here, we addressed alpha–beta desynchronization during encoding by contrasting human EEG activity during the encoding interval of a delayed matching‐to‐sample task with that recorded during a control task. We show that encoding‐relevant alpha–beta decrements reported in subsequent memory effect paradigms can be replicated via a nonverbal/semantic delayed matching‐to‐sample task and that these are also evident in healthy adolescents, in addition to adults, as has been previously demonstrated.