Almost 40 years ago I began what turned out to be a programme of research on the way in which experience can change the effectiveness of the events used as stimuli in standard associative learning procedures. In this personal history I will describe my early (failed) attempts to find evidence for the acquired distinctiveness of cues, and my conclusion that experience tends to reduce, not enhance the associability of stimuli. I then go on to describe my attempts to square this conclusion with the stubborn empirical fact that, in some circumstances, pretraining with (or preexposure to) stimuli, can facilitate subsequent discrimination between them. I describe experiments (conducted mostly with rats as the subjects) showing how some of these effects can be explained in associative terms. Others, however, seemed to demand an explanation in terms of a new learning process that modulates the effective salience of stimuli. I go on to describe attempts to specify the nature of this process, and (bringing the story up to date) to describe recent experiments investigating the effects of salience modulation in human perceptual learning.

To evaluate the clinical and ecological validity of affect recognition (AR) measures in a sample of community-dwelling schizophrenic outpatients (N = 40), we analyzed the relation of facial and vocal AR to intellectual, symptomatic, and quality-of-life criteria. Facial and vocal AR showed virtually identical patterns of association with these criteria, suggesting that both modalities of AR draw on the same underlying heteromodal capacity. Specifically, AR was correlated with a subset of intellectual abilities (verbal–semantic, executive–attentional), but was unrelated to age, education, or neuroleptic dose. In terms of clinical and ecological criteria, AR errors correlated with more severe psychotic symptoms (positive and disorganized) and with lower quality of life (relationships, community participation, and richness of intrapsychic experience). Even after controlling for subjects' intellectual abilities and illness severity, inaccurate AR was associated with bizarre behaviors (involving sociosexual interactions, clothing, appearance) and with impoverished interpersonal relations. Thus, while difficulty identifying basic affective cues is related to general cognitive and illness-severity factors, it appears to have specific functional implications that do not depend on generalized impairment. Assessment of AR may identify a subgroup of schizophrenic patients who have a central defect in the heteromodal monitoring of emotional-social displays, associated with dysregulation of social behaviors and disruption of interpersonal relations. (JINS, 2000, 6, 649–658.)