Signal processing during and across saccades

Area of Science:

• Cognitive psychology
• Neuroscience
• Visual perception

Background:

• Traditionally, visual perceptual processing was believed to occur exclusively during eye fixations.
• The extent to which postperceptual processes, such as target classification and response selection, occur during saccades remains an open question.

Purpose of the Study:

• To investigate whether target classification and response selection can continue during saccadic eye movements.
• To determine if these cognitive processes are limited to fixation periods.

Main Methods:

• Experiments involved presenting two visual signals (S1 and S2) at a large angular distance.
• Subjects fixated S1, identified it as a target or non-target, and then saccaded to S2.
• Response selection was assessed by manipulating stimulus-response compatibility and saccade size.

Main Results:

• Target classification of S1 could occur during the saccade to S2, as evidenced by set size effects on S2 fixation duration.
• Further experiments confirmed that target classification can indeed proceed during saccades.
• Response selection was also found to continue during saccades, with compatibility effects diminishing for larger saccades.

Conclusions:

• Cognitive processes, including target classification and response selection, are not strictly confined to eye fixations.
• These processes can effectively occur and be completed during saccadic eye movements.
• The findings challenge traditional models of visual processing and attention during naturalistic eye movements.