On the independence of physical and nominal codes: a correlational analysis

In studies of college students, normal children at three grades, and learning-disabled children, physical and nominal matching procedures were highly correlated, (range .72-.96). In each instance, expected time differences favoring physical matches were replicated. Comparable results were found with both tachistoscopic and paper-and-pencil methods. In two studies where relevant data were available, correlations were not significantly attenuated when the effects of motor speed were partialled out. The results challenge the premise that nominal and physical matching measures are empirically independent, invalidate their application as measures of independent types of information processing, and help explain inconsistent findings in hemispheric specialization research.     

The use of an intermittent schedule of reinforcement to evaluate detection dogs’ generalization from smokeless-powder

Animal Cognition - Odor generalization is essential for detection dogs. Regardless of its importance, limited research is available on detection dog odor generalization. The objectives of this...     

Neuropsychological evidence for case-specific reading: Multi-letter units in visual word recognition

We describe a patient (GK) who shows symptoms associated with Balint's syndrome and attentional dyslexia. GK was able to read words, but not nonwords. He also made many misidentification and mislocation errors when reporting letters in words, suggesting that his word-naming ability did not depend upon preserved position-coded, letter identification. We show that GK was able to read lower-case words better than upper-case words, but upper-case abbreviations better than lower-case abbreviations. Spacing the letters in abbreviations disrupted identification, as did mixing the case of letters within words. These data cannot be explained in terms of letter-based reading or preserved holistic word recognition. We propose that GK was sensitive to the visual familiarity of adjacent letter forms.     

A search for context-stimulus associations in latent inhibition

Six experiments investigated the effects of pre-exposure to a tone on the subsequent acquisition of conditioned suppression by rats. In Experiments 1-3 the response suppressed was drinking; in Experiments 4-6 it was food-rewarded lever pressing. Repeated exposure to the tone resulted in latent inhibition, i.e., a retardation in the acquisition of suppression. The size of the latent inhibition effect was reduced when a different context was used for conditioning from that used for pre-exposure (Experiment 2). When the context remained the same throughout, a phase of exposure to the context alone, interposed between pre-exposure and conditioning, had no influence on the size of the latent inhibition effect ultimately observed. This last result casts doubt upon Wagner's (1976, 1979) theory of the role of contextual factors in latent inhibition, and alternative accounts are considered.