Elsevier

Acta Psychologica

Volume 84, Issue 2, November 1993, Pages 135-159
Acta Psychologica

On the time course and accuracy of spatial localization: Basic data and a two-process model

https://doi.org/10.1016/0001-6918(93)90024-LGet rights and content

Abstract

This article addresses the question how fast and accurate the location of a single stimulus can be perceived. In Experiment 1, we measured localization performance in a task which required subjects to perceive and report the location of a single target stimulus (‘*’ sign) presented in one square of an imaginary 25×19 grid. Two factors were varied: stimulus duration and stimulus eccentricity. Stimulus duration was manipulated by employing a backward masking stimulus. Ten intervals (stimulus onset asynchronies) separated target and masking stimulus: 25, 50, 75, 100, 125, 150, 200, 250, 300, and 350 ms. Stimulus eccentricity was manipulated by presenting the target stimulus at five different distances from the fixation point. The observer localized the target stimulus by moving the cursor from the middle of the grid (the initial fixation point) to the perceived target location by pressing the ‘arrow’ keys on the keyboard. Localization performance showed to be typically related to stimulus duration. That is, two components could be distinguished: The first component represented an initial steep rise in localization performance during the first 50 ms of stimulus duration; the second component represented a gradual rise in localization performance after 50 ms, reaching maximal performance at about 300 ms. We interpreted these two localization performance functions as reflecting the operation of two systems, namely the attentional system for the initial strong increase and the eye movement system for the subsequent gradual increase. In Experiment 2, we measured saccadic eye response latencies to clarify the role of eye movements in localization performance. It was found that in 98.4% of all trials saccades were executed, and, moreover, that saccadic eye response latency decreased with increasing stimulus duration. In Experiment 3, we compared localization performance in the absence and presence of eye movements and demonstrated that localization performance for stimulus durations up to 50 ms was independent of eye movements. Overall, the present findings were interpreted as evidence in support of a two-process model of localization performance in which a shift of attention is followed by a rapid eye movement toward the target location. In line with a continuous flow conception of visual information processing, our model assumes that location information takes time to develop in the visual system; hence, an observer's localization response may be based on qualitatively different processes operating on qualitatively different kinds of information. In case of short duration stimuli, information conveyed by transient cells is used by the attentional system to shift attention toward the target location; this results in course location information being available. In case of longer duration stimuli, information conveyed by sustained cells is used by the eye movement system to prepare and generate a saccade toward the target location. Fine location information therefore depends on the accuracy of the generated saccade which in turn depends on the duration of the stimulus. A final gaze hypothesis is advanced to capture the importance of eye position information in manual aiming performance. Finally, it is emphasized that the present findings require confirmation and extensions; possible directions for future research are discussed.

References (73)

  • R.A. Abrams et al.

    Eye-hand coordination: Oculomotor control in rapid aimed limb movements

    Journal of Experimental Psychology: Human Perception and Performance

    (1990)
  • M. Alpern

    Metacontrast

    Journal of Optical Society America

    (1953)
  • J. Atkinson et al.

    ‘Where’ and ‘what’ in visual search

    Perception

    (1989)
  • J.R. Bergen et al.

    Parallel versus serial processing in rapid pattern discrimination

    Nature

    (1983)
  • B.G. Breitmeyer

    Visual masking: An integrative approach

    (1984)
  • B.G. Breitmeyer et al.

    Implications of sustained and transient channels for theories of visual pattern masking, saccadic suppression, and information processing

    Psychological Review

    (1976)
  • B. Bridgeman et al.

    Relation between cognitive and motor-oriented systems of visual position perception

    Journal of Experimental Psychology: Human Perception and Performance

    (1979)
  • D.E. Broadbent

    The hidden preattentive process

    American Psychologist

    (1977)
  • B. Butler

    Selective attention and stimulus localization in visual perception

    Canadian Journal of Psychology

    (1980)
  • B. Butler

    Identification and localization in tachistoscopic recognition: The effects of data- and resource-limitations

    Canadian Journal of Psychology

    (1981)
  • C.M. Butter et al.

    Contrasting behavioral methods in the analysis of vision in monkeys with lesions of the striate cortex or the superior colliculus

  • A.O. Dick et al.

    An analysis of hierarchical processing in visual perception

    Canadian Journal of Psychology

    (1969)
  • V. Di Lollo

    Temporal integration in visual memory

    Journal of Experimental Psychology: General

    (1980)
  • V. Di Lollo et al.

    Two forms of persistence in visual information processing

    Journal of Experimental Psychology: Human Perception and Performance

    (1988)
  • B.M. Dow

    Functional classes of cells and their laminar distribution in monkey visual cortex

    Journal of Neurophysiology

    (1974)
  • C.W. Eriksen

    Attentional search of the visual field

  • C.W. Eriksen et al.

    Temporal factors in visual information processing: A tutorial review

  • C.W. Eriksen et al.

    Information processing in visual search: A continuous flow conception and experimental results

    Perception and Psychophysics

    (1979)
  • J.M. Findlay

    Visual information processing for saccadic eye movements

  • J.M. Findlay

    Visual computation and saccadic eye movements: A theoretical perspective

    Spatial Vision

    (1987)
  • J.D. Fisk et al.

    The effects of instructions to subjects on the programming of visually directed reaching movements

    Journal of Motor Behavior

    (1989)
  • Y. Fukuda et al.

    Retinal distribution and central projections of Y-, X- and W-cells of the cat's retina

    Journal of Neurophysiology

    (1974)
  • M.E. Goldberg et al.

    Activity of superior colliculus in behaving monkeys: II. Effects of attention on neuronal response

    Journal of Neurophysiology

    (1972)
  • R. Held

    Dissociation of visual functions by deprivation and rearrangement

    Psychologische Forschung

    (1968)
  • J.M. Henderson

    Stimulus discrimination following covert attentional orienting to an exogenous cue

    Journal of Experimental Psychology: Human Perception and Performance

    (1991)
  • W.E. Hick

    On the rate of gain of information

    Quarterly Journal of Experimental Psychology

    (1952)
  • Cited by (0)

    Acknowledgement: We acknowledge the helpful comments of Harold Bekkering, Bruno Breitmeyer, Walter Gerbino, Foppe ten Hoor, Toon Huson, Jacques Paillard, Bruce Pollatsek, and an anonymous reviewer on an earlier version of this manuscript.

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