Impulsivity and perception: individual differences in the processing of the local and global dimensions of stimuli

There appears to be an association between a "global" mode of perceptual processing and a cluster of personality traits, one of which is impulsivity. The goal of the present study was to clarify this relationship. Subjects differing in impulsivity (as measured by a self-report inventory) performed speeded cardsorting tasks. They sorted stimuli consisting of large letters made up of smaller letters. Highly impulsive subjects had no more difficulty than other subjects in ignoring the large, "global," letters when they tried to attend to the smaller, "local," letters of which they were composed, nor were they more vulnerable than other subjects to Stroop-like response interference produced by the global letters. High impulsives did have particular difficulty when the task required that they integrate the information provided by the local and global letters. This finding can be explained in terms of individual differences in the value placed on speed relative to accuracy in information processing.