BOLD subjective value signals exhibit robust range adaptation.

Area of Science:

• Neuroscience
• Decision Science
• Cognitive Psychology

Background:

• Decision-making theories often assume a common subjective value (SV) scale for choice options.
• Neural correlates of SV are widespread but their range adaptation in humans is unknown.
• Adaptive coding theories predict that value signals should adjust to the range of values presented.

Purpose of the Study:

• To investigate whether blood-oxygen-level-dependent (BOLD) signals for SV exhibit range adaptation in humans.
• To test if the slope of SV responses varies inversely with the range of decision values.
• To identify brain regions involved in SV range adaptation.

Main Methods:

• Human participants made choices between immediate and delayed monetary rewards.
• Two conditions were used: delayed options spanned a narrow or wide range of SVs.
• BOLD signals were analyzed in regions tracking SV, including posterior cingulate, ventral striatum, anterior cingulate, and ventromedial prefrontal cortex.

Main Results:

• SV-tracking activity was found in the posterior cingulate, ventral striatum, anterior cingulate, and ventromedial prefrontal cortex.
• Evidence for range adaptation was observed: SV response slope was steeper in the narrow range condition compared to the wide range condition.
• Statistically significant slope changes consistent with range adaptation were confirmed in the posterior cingulate and ventral striatum.

Conclusions:

• Human BOLD signals for subjective value demonstrate range adaptation, consistent with adaptive coding theories.
• The findings imply that the interpretation of BOLD SV responses needs to consider the context-dependent range of values.
• This study provides the first evidence of SV range adaptation in human BOLD signals.