Ignoring distractors takes its (memory) toll.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Attention Studies

Background:

• Effective attentional selection necessitates filtering out task-irrelevant stimuli.
• Understanding the cognitive mechanisms and costs associated with attentional filtering is crucial for explaining cognitive performance.

Purpose of the Study:

• To quantify the cognitive cost of filtering irrelevant stimuli using an object-based attention paradigm.
• To investigate how factors like distractor probability, number of distractors, and working memory capacity influence filtering costs.

Main Methods:

• Employed an object-based attention paradigm across four experiments with 320 participants.
• Participants performed orientation discrimination on Gabor patches, presented alone or with irrelevant distractors.
• Measured filtering cost as increased response times in mixed blocks versus pure blocks.

Main Results:

• A robust filtering cost was observed, scaling with distractor probability and the number of distractors (1-4).
• The cost diminished with random interleaving of eight distractors but reappeared with orderly presentation, suggesting a working memory capacity limit.
• Filtering cost correlated negatively with interference on distractor-present trials and was independent of distractor semantic content.

Conclusions:

• Attentional filtering incurs a significant cognitive cost, modulated by distractor characteristics and cognitive load.
• Working memory plays a key role in managing attentional filtering, with capacity limits leading to strategy shifts.
• Findings support the active maintenance of distractor templates in working memory during attentional selection.