Temporal expectation modulates the neural dynamics of delayed responses to working memory representations

Temporal expectation can induce anticipatory attention to enhance perceptual processing and optimise behaviours. However, it remains unexplored whether temporal expectation benefits delayed responses to information maintained in working memory (WM) and the underlying neural dynamics that support the benefits. Here we addressed these issues in behavioural and electroencephalography (EEG) experiments. Participants performed a rotation discrimination WM task. Temporal expectation was manipulated by varying the predictability for when a test probe would occur after a delay interval. We first demonstrated that temporal predictability benefited WM performance. Our EEG results showed decreased alpha power over the left posterior brain regions during the delay interval for high than low predictability trials. Importantly, we found earlier enhancement of the lateralised alpha power and the lateralised readiness potential for high than low predictability trials when WM contents were accessed for responses during the probe period. Finally, we found concurrent selection and preparation for responses when the probe onset was predictable but motor preparation lagged behind response selection when the probe onset was more variable. Together, this study provides new insights into the proactive, dynamic nature of the anticipatory deployment of attention in guiding WM maintenance and delayed responses.