Latent Inhibition Deficits in Hyperactive Children

Latent inhibition (LI), the retardation of associative learning as a function of prior stimulus exposure, is believed to reflect normal attentional processes. Previous research has demonstrated an attenuated LI effect in acute schizophrenics as well as normal subjects who rate high on schizotypal scales. The present study examined LI in two age groups (66.1 and 77.4 months) of hyperactive and normal children. The younger normal children exhibited LI while the older ones did not. Neither of the hyperactive groups displayed LI. The loss of LI in the hyperactive subjects was explained by proposing that these children are deficient in processing non-salient, irrelevant stimuli.