Voluntary orienting is dissociated from target detection in human posterior parietal cortex

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• The parietal cortex is essential for visual attention, guiding our focus to specific spatial locations.
• Two main hypotheses exist: one suggests voluntary attentional orienting, while the other emphasizes reorienting to unexpected targets.

Purpose of the Study:

• To investigate the distinct roles of parietal cortex regions in voluntary attention orienting versus reorienting to salient targets.
• To differentiate the neural mechanisms underlying different types of visual attention using functional neuroimaging.

Main Methods:

• Event-related functional magnetic resonance imaging (ER-fMRI) was employed to measure brain activity.
• Participants' brain responses were recorded during tasks involving attending to and detecting visual stimuli at attended and unattended locations.

Main Results:

• Specific parietal regions showed differential activation patterns based on attentional demands.
• The intraparietal sulcus was primarily activated when a location was voluntarily attended prior to target presentation.
• The right temporoparietal junction showed greater activation when detecting targets, especially at unattended locations.

Conclusions:

• Distinct subregions within the parietal cortex mediate different aspects of visual attention.
• The findings support a functional segregation within the parietal cortex for voluntary orienting and stimulus-driven reorienting of attention.