Transient neural activity in human parietal cortex during spatial attention shifts

Area of Science:

• Neuroscience
• Cognitive Psychology
• Visual Attention Research

Background:

• Selective attention enhances neural processing of attended stimuli.
• Top-down control signals, originating from the posterior parietal cortex, are crucial for spatial attention.
• Understanding the neural dynamics of attention shifts is key to cognitive neuroscience.

Purpose of the Study:

• To investigate the distinct roles of extrastriate cortex and posterior parietal cortex in spatial attention shifts.
• To differentiate the neural mechanisms underlying the initiation versus maintenance of attention.

Main Methods:

• Utilized rapid, event-related functional magnetic resonance imaging (fMRI) in human observers.
• Monitored brain activity during covert shifts of spatial attention between peripheral locations.
• Analyzed activation patterns in extrastriate and posterior parietal cortices.

Main Results:

• Extrastriate cortex showed sustained activation following attention shifts to the contralateral visual field.
• Posterior parietal cortex exhibited transient activation specifically during the act of shifting attention.
• The temporal dynamics of activation differed significantly between these two brain regions.

Conclusions:

• Posterior parietal cortex activation is linked to the discrete event of shifting spatial attention.
• Extrastriate cortex activity supports the sustained maintenance of attended locations.
• These findings differentiate the neural correlates of attention shifting versus attention maintenance.