Increasing Working Memory Load Reduces Processing of Cross-Modal Task-Irrelevant Stimuli Even after Controlling for...

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• The load theory (LT) of attention posits that high cognitive load increases distractibility.
• Empirical evidence for LT is inconsistent, potentially due to variations in executive capacity (EC) and task difficulty.

Purpose of the Study:

• To investigate if increased working memory (WM) load enhances early processing of task-irrelevant stimuli.
• To control for individual differences in EC and task difficulty in a cross-modal attention paradigm.

Main Methods:

• Utilized a cross-modal paradigm with a visual WM task under high and low load conditions.
• Employed event-related potentials (ERPs) to measure neural activity in response to visual and auditory stimuli.
• Individually titrated task difficulty to ensure comparability across participants with varying EC.

Main Results:

• Behavioral results confirmed successful load manipulation and titration.
• ERPs showed a load-related increase in posterior slow wave, indicating sustained attention.
• Under high WM load, the auditory N1 component (early auditory processing) decreased in response to distractors.

Conclusions:

• Increased WM load enhances attentional engagement and protects against cross-modal distractors.
• Findings challenge the classic load theory and support alternative models of attention.
• Controlled cognitive load and EC are crucial for understanding attention and distraction.