Physical exertion impairs individual representation while preserving mean representation in visual short-term memory.

Area of Science:

• Cognitive psychology
• Neuroscience
• Human perception

Background:

• Perceptual averaging extracts ensemble means from visual stimuli, a key visual short-term memory (VSTM) function.
• Physical exertion is known to impair VSTM, but its effect on perceptual averaging is unknown.

Purpose of the Study:

• To investigate the impact of concurrent physical exertion on VSTM's perceptual averaging ability.
• To determine if physical load affects the representation of ensemble means in VSTM.

Main Methods:

• A dual-task paradigm combined facial expression recognition with isometric handgrip contractions at low (5%) and high (40%) physical loads.
• Participants memorized facial expressions and identified probes while performing physical tasks.

Main Results:

• High physical load impaired overall memory performance, reducing hit rates and discriminability while increasing false alarms.
• Recognition accuracy for the mean face and the precision of mean representation (σ) were unaffected by physical load.
• Item-specific memory representation in VSTM was disrupted, but mean representation remained resilient.

Conclusions:

• Concurrent physical exertion disrupts individual item representation in VSTM due to attentional resource competition.
• Perceptual averaging, or mean representation in VSTM, is stable and robust against dual-task interference from physical exertion.