Electrodermal lability, errors, and reaction times: an examination of the motor impulsivity hypothesis.

Two studies were designed to investigate the effects of electrodermal lability on errors and reaction times (RTs). In Study 1 (n = 56) subjects performed an RT task that in different phases either required only fast responding or additionally discrimination and selection of one of two response alternatives according to specified rules that had to be stored in memory. Results showed that labiles (above the median of resting non-specific electrodermal responses) displayed significantly faster RTs when only speed was required. There were no differences between labiles and stabiles (below the median) in RTs and error rate when discriminations and response selections had to be made. In Study 2 (n = 52) task demands were reduced. Subjects were only required to discriminate between two events and to respond by releasing or retaining one key. Labiles displayed significantly faster RTs. There was furthermore a tendency among labiles to produce fewer False-Responses, i.e. releasing the key when it should be retained. Additional joint analyses of RT and error data revealed a tendency among labiles to perform the task more efficiently. Results are discussed in terms of motor impulsivity and information-processing accounts of electrodermal lability.