Neural representation of the decisional reference point in monkeys

Area of Science:

• Neuroscience
• Decision Science
• Cognitive Neuroscience

Background:

• Decision-making theories posit an internal reference point for evaluating options.
• The neural mechanisms underlying reference point encoding remain largely uncharacterized.

Purpose of the Study:

• To identify the neural basis of reference point encoding at single-neuron and population levels.
• To investigate the role of frontal cortical regions in reference-dependent valuation.

Main Methods:

• Dense single-neuron recordings were obtained from macaques performing a wealth accumulation task.
• The task dissociated objective reward values from the decisional reference point.
• Neural activity was analyzed across six frontal regions, including the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC).

Main Results:

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

Conclusions:

• The ventral anterior cingulate cortex (vbACC) plays a crucial role in encoding the reference point at the population level.
• A dedicated neural circuit, potentially involving the vbACC as a source signal, underlies reference-dependent valuation.
• These findings advance our understanding of the neural basis of decision-making and subjective value computation.