Decision-related activity in the macaque dorsal visual pathway

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Visual Processing

Background:

• Higher cortical areas are implicated more in decision-making than sensory areas.
• Neuronal activity related to decisions is expected to vary with cortical hierarchy.

Purpose of the Study:

• To investigate if changes in neuronal activity during error trials systematically depend on cortical hierarchical position.
• To examine neuronal activity in extrastriate visual areas during a visual direction discrimination task.

Main Methods:

• Recorded neuronal activity of direction-selective neurons in four macaque extrastriate visual areas (V3A, MT, MST, FST).
• Monkeys discriminated the direction of moving visual stimuli under varying luminance contrast conditions.
• Analyzed neuronal activity changes during error trials compared to correct trials.

Main Results:

• Neuronal activity significantly reduced in all recorded areas during error trials, particularly at low and intermediate luminance contrast.
• Activity reduction was approximately 50% across all visual areas, independent of hierarchical position in the dorsal visual pathway.
• Activity reduction was profound at low stimulus contrast but nonsignificant at high stimulus contrast, depending on decision direction relative to stimulus motion.

Conclusions:

• Activity reduction on error trials in the dorsal visual pathway is independent of cortical hierarchy.
• Findings suggest that reduced attention, potentially linked to stimulus expectation, contributes to errors in visual decision-making.
• The observed pattern indicates a consistent neural mechanism for error processing across early visual areas.