Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The contribution of vision and proprioception to judgements of finger proximity (1998)
    Springer
    Experimental brain research 118 (1998), S. 415-420 
    Details
    ISSN: 1432-1106
    Keywords: Key words Vergence ; Depth perception ; Proprioception ; Limb position ; Pointing ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We sought to determine whether an increase in judged egocentric distance created by increasing vergence-specified distance would be negated when participants pointed at their own finger. It was found that ocular position dominates limb proprioception in the judgement of finger distance in the sagittal plane when vision is available. In contrast, an increase in perceived egocentric distance was largely attenuated by the presence of limb proprioception in reduced visual cue conditions. We conclude that the relative contribution of vergence to perceived distance depends upon the strength of the vergence effort signal when there are other cues present. Furthermore, if the distance percept includes a major contribution from retinal cues, then the visual component will dominate the limb proprioception component. If the visual component is largely determined by vergence information, limb proprioception will make a significant contribution and actually dominate when the vergence effort signal is weak. The results extend previous studies that have found a similar relationship between ocular position and limb proprioception in the perception of a finger′s location in the coronal plane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050295
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The size-distance paradox is a cognitive phenomenon (1999)
    Springer
    Experimental brain research 126 (1999), S. 578-582 
    Details
    ISSN: 1432-1106
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The perceived size of a fixated object is known to be a function of the perceived fixation distance. The size-distance paradox has been posited as evidence that the perceived distance of a fixated object is, in turn, influenced by the object’s perceived size. If this is correct then it challenges a widely accepted account (modified weak fusion) of how the nervous system combines multiple sources of information. We hypothesised that the influence of perceived size on the perception of distance is likely to be restricted to conscious perceptual judgements. If our hypothesis is correct then the size-distance paradox should not be observed when observers make action-based distance judgements. In line with this expectation we observed the size-distance paradox when participants made verbal reports on target distance but found no paradoxical judgements in a group who were asked to point at the target. We therefore suggest that the size-distance paradox should not be taken as evidence that perceived size feeds back into distance perception.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050766
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Looking at the task in hand: vergence eye movements and perceived size (1997)
    Springer
    Experimental brain research 117 (1997), S. 501-506 
    Details
    ISSN: 1432-1106
    Keywords: Key words Vergence ; Depth perception ; Illusion ; Accommodation ; Emmert’s law
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  A retinal afterimage of the hand changes size when the same unseen hand is moved backwards and forwards in darkness. We demonstrate that arm movements per se are not sufficient to cause a size change and that vergence eye movements are a necessary and sufficient condition for the presence of the illusory size change. We review previous literature to illustrate that changing limb position in the dark alters vergence angle and we explain the illusion via this mechanism. A discussion is provided on why altering limb position causes a change in vergence and we speculate on the underlying mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050246
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Attention in action or obstruction of movement? A kinematic analysis of avoidance behavior in prehension (1998)
    Springer
    Experimental brain research 120 (1998), S. 352-368 
    Details
    ISSN: 1432-1106
    Keywords: Key words Prehension ; Attention ; Obstacle ; Arm movement ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Obstacle avoidance strategies are of two basic but interrelated types: moving around an obstacle to that body parts do not come too close, and slowing down. In reaching-to-grasp, avoidance may involve the transport component, the grasp formation component, or both. There has been little research that has directly examined obstacle avoidance strategies during reaches-to-grasp. Several recent reports describe experiments in which reaches-to-grasp were made when nontarget objects were present in the workspace. The effects of these nontargets were interpreted as being due to their distracting effects rather than their obstructing effects. The results of these studies are reinterpreted as being due to the non-target’s obstructing effects. The obstacle interpretation is more parsimonious and better predicts the pattern of results than the distractor interpretation. Predictions of the obstacle interpretation were examined in an experiment in which participants were required to reach to grasp a target in the presence of another object in various locations. The results were exactly in line with the interpretation of the object as an obstacle and the data show how grasp and transport movements are subtly adjusted so as to avoid potential obstacles. It is proposed that people move so as not to bring body parts within a minimum preferred distance from nontarget objects within the workspace. What constitutes the preferred distance in a particular context appears to depend upon the speed of movement and a variety of psychological factors related to the cost that a person attaches to a collision.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050409
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A framework for considering the role of afference and efference in the control and perception of ocular position (1998)
    Springer
    Biological cybernetics 79 (1998), S. 175-189 
    Details
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract. It has been well established that extra-retinal information is used in the perception of visual direction and distance. Furthermore, a number of studies have established that both efference copy and afferent discharge contribute to the extra-retinal signal. Despite this, no model currently exists to explain how the signals which arise through oculomotor control contribute to perception. This paper attempts to provide such a framework. The first part of the paper outlines the framework [the cyclopean equilibrium point (EP) model] and considers the binoculus or cyclopean eye from the perspective of a current account of motor control (the EP hypothesis). An existing model is used to describe how the nervous system could utilise available efference copy and afferent extra retinal signals when determining the direction and distance of cyclopean fixation. Although the cyclopean EP model is speculative, it allows for a parsimonious framework when considering the oculomotor contribution to perception. The model has the additional advantage of being consistent with current theories regarding the control and perception of limb movement. The second part of the paper shows that the model is biologically plausible, demonstrates the use of the proposed model in describing the central control of eye movements with regard to non-conjugate peripheral adaptation and reconciles seemingly disparate empirical findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004220050469
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...