University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Response modality and spatial location: The effect of temporal delay on response accuracy in adults and children.

Garner, Joanna Kate. (1999) Response modality and spatial location: The effect of temporal delay on response accuracy in adults and children. Doctoral thesis, University of Surrey (United Kingdom)..

Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (22MB) | Preview


Neurological and clinical evidence suggests that specialised processing pathways differ functionally in the way visual information is processed, whether the goal is perceptual representation or action, (Milner & Goodale, 1995). These pathways may differ in emphasis on the same information. While the visuo-motor pathway may need to represent aspects of the environment in relation to the self, the visuo-perceptual pathway may need to form enduring representations in such a way as to overcome changes in item appearance due to self-motion. A second point of difference concerns temporal durability within each pathway. The visuo-motor pathway may rapidly update information in order to "keep up" with changes in the relationship between self and environment but the visuo-perceptual pathway may not operate under such constraints. In normal subjects a two-second critical parameter on visuo-motor accuracy has been noted, (Elliott & Madalena, 1987) as have spatial dissociations between visuo-motor and visuo-perceptual errors, (Gentilucci & Negrotti, 1994). Three experiments further investigate temporal and spatial parameters surrounding response accuracy in normal adults and 6- to 10-year old children. Experiment one suggests that a two second pre-response delay induces a systematic distortion in the extent of visuo-motor responses while perceptual judgments retain accuracy. A loss of sensitivity accompanied all responses with delay, suggesting processing common to both pathways also occurs. The provision of reference lights in an otherwise dark workspace significantly reduced the effect of exceeding visuo- motor capacity, suggesting that pointing responses can utilise allocentric information where necessary. Experiment two focuses on response-modality differences in relation to continuous information of the target location, and finds that reliance on this information varies with eccentricity for visuo-motor but not visuo-perceptual responses. These results are consistent with requirements of force-control specific to visuo-motor behaviour and suggest that continuous visual information regarding target position crucially supplements proprioception in a manner distinguishable from the effect of pre-movement delay. The finding augments understanding of differences in the use of visual information between visuo-motor and visuo-perceptual modalities. Experiment three investigates visuo-motor accuracy in children and finds that a one-second delay systematically distorts accuracy but in a manner akin to that noted in adults. For children, distortion precedes loss in sensitivity and extent of response is more fragile than directional components. Seven to eight year olds' particular difficulties suggest deficits in movement force compensation which operate independently of visuo-motor processing.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors :
Garner, Joanna Kate.
Date : 1999
Contributors :
Depositing User : EPrints Services
Date Deposited : 09 Nov 2017 12:12
Last Modified : 16 Mar 2018 16:22

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800