Temperament Affected Visuospatial Orienting on Discrimination Tasks.

In the Posner cueing paradigm, the early attentional capture and subsequent inhibition of return (IOR) of attention to the same location, although they are microscale phenomena measured in milliseconds, seem to encapsulate the interaction between two fundamental dimensions of behavior - engaging in and sustaining activity versus withdrawing from and inhibiting activity. In the field of differential psychology, the dynamics of reciprocal relations between these behavioral dimensions have been thought to be determined by central nervous system properties that constitute an individual's temperament. Yet the research on any differential effects of temperament on visuospatial orienting is rather sparse and has produced ambiguous results. Here, we used saccadic responses to measure whether individual differences in reactivity as a temperamental trait might affect orienting of visuospatial attention on discrimination cueing tasks. Our results suggested that, in individuals with lower reactivity, attentional capture took place at a short stimulus onset asynchrony (SOA), producing a facilitatory cueing effect, which was not the case in those who were higher in reactivity. We explain and discuss these results with the Regulative Theory of Temperament.