Neural representation of the decisional reference point in monkeys

Area of Science:

• Neuroscience
• Decision Science
• Cognitive Neuroscience

Background:

• The decisional reference point is crucial for evaluating options but its neural basis is poorly understood.
• Behavioral studies confirm its existence, yet direct neural evidence is lacking.

Purpose of the Study:

• To investigate the neural encoding of the reference point at single-neuron and population levels.
• To identify brain regions involved in reference-dependent decision-making.

Main Methods:

• Analysis of neural activity in macaques during a wealth accumulation task.
• Task design dissociated objective reward values from the reference point.
• Examined neural signals across six frontal regions.

Main Results:

• Reference-related signals were broadly distributed at the single-neuron level across frontal regions.
• The ventral bank of the anterior cingulate cortex (vbACC) showed significant population-level encoding of the reference point.
• Dorsal ACC and dorsolateral prefrontal cortex encoded reference-dependent subjective value signals at the population level.

Conclusions:

• A dedicated neural circuit for reference dependence is suggested by signal timing and connectivity.
• The vbACC may act as a central source for reference point signals.
• vbACC signals potentially modulate downstream value-encoding regions.