Neurons of Macaque Frontal Eye Field Signal Reward-Related Surprise.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Visual Attention

Background:

• The frontal eye field (FEF) is integral to controlling visual attention.
• Stimulus salience, which captures attention, can be influenced by cognitive factors like surprise.
• FEF neuronal responses strengthen when stimuli capture spatial attention.

Purpose of the Study:

• To investigate if surprise-induced salience enhances visual response strength in the FEF.
• To determine the neural mechanisms underlying surprise processing in the FEF.

Main Methods:

• Neuronal activity was recorded in two male monkeys.
• Monkeys received cues predicting reward size (good/bad), followed by a cue announcing reward size.
• Expectation violation (surprise) was induced by mismatching the cues.

Main Results:

• FEF neurons showed stronger responses to cues that violated expectations compared to those that confirmed them.
• Enhanced neuronal firing during surprise was associated with decreased spike-count correlation, suggesting attention capture.
• Both positive and negative surprises increased firing rates, but with different latencies and independent strength variations across neurons.

Conclusions:

• Surprise-induced salience modulates FEF activity, enhancing neuronal responses.
• Distinct neural mechanisms may underlie responses to positive versus negative surprises.
• FEF plays a key role in processing unexpected events and guiding attention accordingly.