Neural signatures of intransitive preferences

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Science

Background:

• Decision-making is often assumed to involve rank-ordering options by subjective value.
• This rank-ordering implies choices should be transitive (A>B, B>C implies A>C).
• However, empirical evidence shows frequent violations of transitivity in human choices.

Purpose of the Study:

• To investigate the neural mechanisms underlying intransitive choices in financial gamble decisions.
• To determine if subjective value representations are consistently ordinal and transitive.
• To explore how context and attribute weighting influence decision-making and lead to intransitivities.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to observe brain activity during decision tasks.
• Participants made choices between gambles with varying magnitude and probability of financial gains.
• Behavioral data on choice preferences were analyzed alongside neural activation patterns.

Main Results:

• Behavioral intransitivities were prevalent, occurring because gambles were evaluated comparatively, not independently.
• Neural value signals in prefrontal and parietal cortices were not consistently ordinal but reflected context-dependent preference ranks.
• Activation in the insula (magnitude) and posterior cingulate (probability) correlated with variable attribute weighting, explaining shifts in preference.

Conclusions:

• Intransitive choices arise from context-dependent value computations rather than stable, ordinal preferences.
• Neural systems involved in risky decision-making dynamically represent preferences based on local comparisons.
• Brain activity patterns in specific regions (insula, posterior cingulate) underlie the variable weighting of gamble attributes, leading to intransitive decision-making.