Learning to categorize perceptually similar stimuli can result in people becoming more sensitive to differences along perceptual dimensions that are relevant to category membership and/or less sensitive to equivalent differences along irrelevant perceptual dimensions. These effects of acquired distinctiveness and acquired equivalence may be caused…

Two experiments assessed the effects of extinguishing a conditioned cue on subsequent context conditioning. Each experiment used a different video-game method where sensors predicted attacking spaceships and participants responded to the sensor in a way that prepared them for the upcoming attack. In Experiment 1 extinction of a cue which signaled…

In both healthy participants and various patient populations, performance on attentional set-shifting tasks has been found to be affected by learned irrelevance and/or perseveration. The present study examined whether or not these processes also play a role during the initial discrimination learning phase of those tasks. To this end, participants…

The effect of stimulus novelty, an attentional variable, on learning set acquisition was investigated. Learning set (LS) acquisition refers to an improvement in performance across a series of problems which have a common basis of solution. The design of this study involved two groups, one in which the positive stimulus on Trial 2 involved the…

Research based upon a Ph.D. dissertation submitted to the Graduate School, University of Pittsburgh, and supported in part by U.S. Public Health Service grant MH-1290 and by the New York State Research Foundation.

Second graders were administered a two-choice discrimination task in which irrelevant dimensions were correlated .50, .75, or 1.00 with the 100 percent rewarded cue. Results indicate that learning was most impeded in the .75 condition and was most efficient in the 1.00 condition. These results support the Hypothesis Testing Theory of…

The present experiment examined the choice behavior of humans during the learning of a reversal (R) shift as an empirical test of attentional explanations of the overtraining reversal effect. (Author/RK)

Research supported by a U.S. Public Health Service fellowship grant and by grant No. 01368-04 from the National Institute of Child Health and Human Development.

Three experiments examined 4- to 10-month-olds' perception of audio-visual (A-V) temporal synchrony cues in the presence or absence of rhythmic pattern cues. Results established that infants of all ages could discriminate between two different audio-visual rhythmic events. Only 10-month-olds detected a desynchronization of the auditory and visual…

Research supported in part by a Public Health Service Fellowship (MH-6668) and by Grant M-3519 from the National Institute of Mental Health, U.S. Public Health Service.

The present study operationally defines selective attention in terms of tactile observing responses measured by percentage contact time per trial to the relevant stimulus dimension, and investigates the changes of these responses in a discrimination shift paradigm under the effect of overlearning. (Author)

Three experiments investigated 4-, 6-, and 8-month-olds' perception of the audible, visible, and combined attributes of bimodally specified syllables. Results suggested that at 4 months, infants attended primarily to the featural information, at 6 months primarily to the asynchrony, and at 8 months to both features independently. (Author/KB)

This study investigated the effects of two stimulus manipulations (spatial distinctness and number of dimensions) on the performance of 24 kindergartners and 24 fifth graders in (1) tasks requiring distributed attention and (2) tasks requiring selective attention. Results suggest that kindergartners attempt to use one processing mode (distributed…

Three experiments assessed the intersensory redundancy hypothesis in early infancy. Findings indicated that habituation to a bimodal rhythm resulted in discrimination of a novel rhythm, whereas habituation to the same rhythm presented unimodally resulted in no evidence of discrimination. Temporal synchrony between the bimodal auditory and visual…