Sequential dynamics of memory load: contralateral delay activity and behavioral evidence

Working memory is a fundamental component of human cognition, essential for performing complex tasks that require holding and manipulating information. Visuospatial working memory (VSWM) enables the temporary retention of visual and spatial information, with its neural correlates, such as contralateral delay activity (CDA, a component of event-related potentials), providing insights into memory load dynamics. This study aimed to investigate how sequentially presented items are maintained and integrated into VSWM.

Twenty-three participants performed a task where three visual items were presented sequentially, followed by a retro-cue and a test array, while accuracy and CDA were measured.

Behavioral results showed significant differences in accuracy across item positions, with the third item yielding the lowest accuracy. Electrophysiological findings revealed that CDA amplitude was more negative for the second item, suggesting greater cognitive resources were allocated to it compared to the first and third items. Correlations between working memory capacity, task performance, and CDA amplitudes suggest that individuals with higher working memory capacity can better adapt resource distribution to handle sequential information processing, particularly under conditions of increased cognitive load.

These results suggest that VSWM management involves dynamic, nonuniform allocation of cognitive resources influenced by the serial position of items. These insights expand our understanding of how VSWM processes sequential inputs and may inform future studies on optimizing cognitive strategies for tasks involving complex visual and spatial information.