Spatial attention in perceptual decision making as revealed by response-locked classification image analysis

Area of Science:

• Cognitive psychology
• Neuroscience
• Visual perception

Background:

• Humans often make decisions by serially processing visual information from multiple locations.
• Spatial attention and eye movements are critical for this serial visual processing.

Purpose of the Study:

• To investigate the impact of spatial attention on dynamic decision-making during visual target detection.
• To analyze how attention modulates information processing relative to reaction time.

Main Methods:

• Classification image (CI) analysis was employed, time-locked to the observer's reaction time (RT).
• Participants performed a rapid visual target detection task with a gradually increasing contrast in dynamic noise, guided by spatial cues.

Main Results:

• A spatiotemporally biphasic CI profile was observed, peaking approximately 350 ms before response.
• Valid spatial cues at the target location reduced RT and amplified the CI, particularly when presented 500–1250 ms prior to response.

Conclusions:

• Sustained attention to a cued location enhances the gain of spatiotemporal contrast detectors.
• A simple perceptual decision model, incorporating attentional gain modulation, quantitatively explains the observed results in dynamic visual tasks.