Response bias and physiological reactivity

Sixteen Ss were selected from a group of 30 adult males for low and high levels of physiological reactivity, as defined by several measures of electrodermal activity (EDA). They were subsequently tested on two occasions on a tone discrimination task in which confidence ratings were required. High EDA Ss discriminated a significantly greater number of tones, but this apparent superiority was not due to their superior sensitivity, but to a greater bias towards responding positively to signals. The results were discussed in relation to possible mechanisms mediating individual differences in response bias and physiological reactivity.