Previewing distractors reduces efficiency of visual processing at previewed locations.

Area of Science:

• Cognitive psychology
• Visual perception
• Neuroscience

Background:

• Visual marking excludes previously seen items from visual search when new items appear.
• This phenomenon may involve inhibiting irrelevant information at old item locations.
• Previous research indicates reduced sensitivity to contrast changes at old locations.

Purpose of the Study:

• To investigate the underlying mechanisms of reduced sensitivity in visual marking.
• To differentiate between increased internal noise and decreased calculation efficiency as causes for reduced sensitivity.
• To understand how visual marking impacts attentional resource allocation during visual search.

Main Methods:

• Utilized equivalent noise analysis to assess sensitivity changes.
• Measured reaction times during a visual search task.
• Analyzed threshold-versus-noise contrast functions to estimate internal noise and calculation efficiency.

Main Results:

• Calculation efficiency was significantly lower at old locations compared to new locations.
• Internal noise showed a slight decrease, rather than an increase, at old locations.
• Reduced sensitivity at old locations is primarily attributed to decreased calculation efficiency.

Conclusions:

• The reduction in sensitivity during visual marking stems from decreased calculation efficiency.
• Visual marking may optimize visual search by reallocating limited attentional resources away from previewed locations.
• An inhibitory template likely aids in reserving attentional resources for effective target detection.