Serge Larochelle

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A diminished top-down influence has been proposed in autism, to account for enhanced performance in low-level perceptual tasks. Applied to perceptual categorization, this hypothesis predicts a diminished influence of category on discrimination. In order to test this hypothesis, we compared categorical perception in 16 individuals with and 16 individuals(More)
This study demonstrates residual mental deficits in patients who have apparently recovered after closed head injury. Twenty closed head injury patients were compared to 20 normal control subjects matched for age, sex, handedness, education, language, and IQ. All received a series of neuropsychological tests. Discriminant function analysis significantly(More)
A longitudinal study of three patients with CT-scan documented paramedian thalamic infarctions (bilateral, primarily right, unilateral left) is reported and the neuropsychology of human paramedian thalamic infarction is reviewed. The neuropsychological deficits following these selected lesions, the nature of the clinical memory disorder, and the(More)
S. W. Allen and L. R. Brooks (1991) have shown that exemplar memory can affect categorization even when participants are provided with a classification rule. G. Regehr and L. R. Brooks (1993) argued that stimuli must be individuated for such effects to occur. In this study, the authors further analyze the conditions that yield exemplar effects in this rule(More)
Armstrong, Gleitman, and Gleitman (1983) reported shorter categorization times for members of well-defined categories judged more typical. They concluded that these effects could not originate in a graded, similarity-based category representation and consequently that the typicality effects obtained with natural categories might not be indicative of such a(More)
Available studies on categorization in autism indicate possibly intact category formation, performed through atypical processes. Category learning was investigated in 16 high-functioning autistic and 16 IQ-matched nonautistic participants, using a category structure that could generate a conflict between the application of a rule and exemplar memory.(More)
Users of powerful but complex software packagesdo not take full advantageof the functionality of their tools. Advisory systems, or consultants, offer a solution to this problem by providing continuous and on-the-job help and training advice. However, consultants have not yet had any practical implementation outside an experimental setting. We propose an(More)
A large, single-frame, visual-memory search experiment is reported in which memory and display loads of 1, 2, and 4 alphanumeric characters were factorially combined. In addition to the usual Consistent Mapping and Varied Mapping conditions, the experiment also involved a Categorical Varied Mapping condition in which different sets of stimuli switched roles(More)
Schneider and Shiffrin (1977) proposed that training under consistent stimulus-response mapping (CM) leads to automatic target detection in search tasks. Other theories, such as Treisman and Gelade's (1980) feature integration theory, consider target-distractor discriminability as the main determinant of search performance. The first two experiments pit(More)