Showing papers by "Marc Jeannerod published in 1995"

Representation of hand position prior to movement and motor variability

Abstract: Pointing accurary of six humn subjects was measured in two blocked conditions where the hand was either never visible (T: target only) or only visible in static position prior to movement onset (H+T: hand + target). It was shown in condition H +T that, viewing the hand prior to movement greatly decreased end-point variability compared with condition T. This effect was associated with a significant modification of the movement kinematics: the H+T condition induced a shortened acceleration phase with a corresponding lengthened deceleration phase, compared with the T condition. These results led us to the hypothesis that viewing the hand prior to movement onset allowed a decrease of pointing variability through a feedback process. This hypothesis was further tested by turning the target off during the deceleration phase of the movement at half peak velocity- Ht was shown that turning the target off had no effect upon the T condition but induced a significant increase of pointing variability in the H+T condition. This result suggests that vision of the static hand enhances the proprioceptive localization of the limb and allows for a better visual to kinesthesic feedback.

Analogical Transfer in Sequence Learning.

Abstract: Analogical transfer in problem solving is a fundamental aspect of human intelligence that involves exploiting knowledge about the solution for one problem to solve an0ther.l In order to provide a quantifiable measure of analogical transfer in sequence learning (ATSL), we developed a novel extension of the serial reaction time (SRT) paradigm. To quantify the underlying representational and computational requirements for ATSL we extended a neurobiologically based model of primate prefrontal cortex (PFC) and basal ganglia function in visuomotor sequence learning* to address analogical transfer. We compared the behavior of this model with preliminary data from normal subjects and patients with frontostriatal dysfunction [idiopathic dopa-sensitive Parkinson’s disease (PD)] in the ATSL paradigm.

The neuropsychology of mental imagery

Abstract: Introduction - perspectives on the cognitive neuroscience of mental imagery, SM Kosslyn et al Part 1 Learning and memory: the efficacy of imagery mnemonics in memory remediation, JTE Richardson memory for different kinds of mental images - role of contextual and autobiographic variables, R De Beni and F Pazzaglia Part 2 Perception and action: imagery without perception - a case study of anosognosia for cortical blindness, G Goldenberg et al preserved visual imagery in visual form agnosia, P Servos and M Goodale motor imagery - perception or action?, J Annett mental imagery in the motor context, M Jeannerod the role of subvocalization in auditory imagery, D Smith et al Part 3 Information processing: current issues in the neuropsychology of image generation, MJ Farah generating visual mental images - deficits after brain damage, C Stangalino et al two types of image generation - evidence for left- and right-hemisphere processes, SM Kosslyn et al mental scanning of visual images generated from verbal descriptions - towards a model of image accuracy, M Denis et al the mental and the neural - psychological and neural studies of mental rotation and memory scanning, AP Georgopolous and G Pellizer Part 4 Reasoning: visuospatial working memory - structures and variables affecting a capacity measure, T Vecchi et al analogical representation and language structure, G Geminiani et al Afterword - varieties of visual representation - how are we to analyze the concept of mental image?, L Cooper