M. Anderson et al., REACTION-TIME MEASURES OF SPEED OF PROCESSING - SPEED OF RESPONSE SELECTION INCREASES WITH AGE BUT SPEED OF STIMULUS CATEGORIZATION DOES NOT, British journal of developmental psychology, 15, 1997, pp. 145-157
We report an experiment that investigates the relationship between spe
ed of information processing and development. The goal of the experime
nt was to compare developmental changes at two stages of processing--r
esponse selection and stimulus categorization. The experiment compared
developmental change on three kinds of reaction time task. The first
was a standard Jensen (1982) procedure which separates the decision an
d motor components of reaction time, the second was a modification of
this procedure suggested by Smith & Carew (1987) to control for possib
le anticipatory strategies, and the third was a more traditional react
ion time task where each stimulus is paired with a unique response (li
ghts-to-keys). Age changes in speed of information processing were fou
nd for the lights-to-keys task but not for either of the Jensen tasks.
We argue that this is because the lights-to-keys task taps response s
election factors that change with age and that are orthogonal to diffe
rences in speed of stimulus categorization indexed by the standard Jen
sen task. If the latter is taken as the purer index of speed of proces
sing then we conclude that speed of processing does not change with ag
e.