Neural Dynamics of Multiattribute Decision Making Under Choice Overload

The present study examines the neural mechanisms of value-based multiattribute decision making through the lens of choice overload during consumer choice. Two behavioral experiments established that choice sets of a moderate size with nine options were perceived as most optimal compared to choice sets with three and 24 options, and options chosen from the largest set size were judged to be the least satisfying. A functional MRI study then examined how the brain responds to choice sets varying in size and complexity by manipulating the number of options presented as well as the presence of asymmetrically dominated decoy alternatives during a simulated online shopping task. Results showed that the dorsolateral prefrontal cortex (DLPFC) activity followed an inverse U-shape as a function of choice set size, peaking for moderately sized choice sets. The anterior cingulate cortex (ACC) exhibited a linear trend with choice set size. Trials containing decoy options elicited greater activation of the anterior insula (AIns) and DLPFC. Computational modeling of choice behavior revealed a greater tendency to utilize a simplifying lexicographic decision strategy as decision difficulty increased, and individual differences in decision strategies were reflected in activity of the ACC and AIns. These findings advance understanding of how the brain integrates effort, control, and strategy during complex value-based decisions.