A study of the attentional changes accompanying orienting to different types of change stimuli

The effects of the orienting response on subsequent motor response efficiency were studied. Subjects underwent a standard habituation series of fifteen trials. On the sixteenth trial, they received one of four stimuli each of which was followed by a reaction time (RT) task: (a) same stimulus as the habituation stimulus, (b) slide of the word 'COMING' which subjects had been forewarned would precede the reaction time task, (c) subject's own name, (d) innocuous change stimulus. The results showed that RT was generally slowed in the stimulus-related change conditions compared with the no change condition, indicating that orienting to a novel or significant stimulus does not result in a generalized alerting or arousal. While skin conductance and heart rate data show no difference between the various change trial conditions, digital pulse amplitude changes, particularly later in the processing of the stimulus complex, differentiated these conditions. The data elucidate the information processing changes that accompany orienting. The significance and theoretical implications of the data are discussed.