A neuropsychological investigation of decisional certainty

Abstract

The certainty that one feels following a decision increases decision-making efficiency, but can also result in decreased decision accuracy. In the current study, a neuropsychological approach was used to examine the impact of damage to the ventromedial prefrontal cortex (vmPFC) on core psychological processes promoting decision certainty: selective exposure, overconfidence, and decisiveness. Given previous research demonstrating that vmPFC damage disrupts the generation of negative emotional (somatic) states that have been associated with selective exposure and overconfidence, it was hypothesized that damage to the vmPFC would disrupt engagement in selective exposure, decrease overconfidence, and increase indecision. Individuals with vmPFC damage exhibited increased indecision, but contrary to our hypothesis, engaged in similar levels of selective exposure and overconfidence as the comparison groups. These results indicate that indecision may be an important psychological mechanism involved in decision-making impairments associated with vmPFC injury. The results also suggest that the vmPFC may not be critical for selective exposure or overconfidence, which provides support for a recent "desirability" account of selective exposure.

Keywords: Brain damage; Decisiveness; Information seeking; Overconfidence; Selective exposure; Ventromedial prefrontal cortex.

Figure 1

Basic procedure for each round. After completing this procedure for all four artwork pairs, participants read the full comments for the titles they selected and then made a second confidence estimate.

Figure 2

Lesion overlap map for the nine vmPFC patients, showing mesial, ventral, and frontal views of the lesion overlaps. The color bar indicates the number of overlapping lesions at each voxel. The area of maximal overlap lies in the vmPFC.

Figure 3

Pre-decisional and post-decisional response times (in seconds) averaged across the four rounds and for each round by group. Error bars represent standard error.