scholarly journals An Investigation in the Role of the Visual Target in Stabilometry.

2000 ◽  
Vol 59 (6) ◽  
pp. 568-573 ◽  
Author(s):  
Keiko Soma ◽  
Takanobu Kunihiro ◽  
Akio Yoshida
Keyword(s):  
Visual Target

Role of the posterior parietal cortex in updating reaching movements to a visual target

10.1038/9219 ◽  
1999 ◽  
Vol 2 (6) ◽  
pp. 563-567 ◽  
Author(s):  
M. Desmurget ◽  
C. M. Epstein ◽  
R. S. Turner ◽  
C. Prablanc ◽  
G. E. Alexander ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Visual Target ◽  
Reaching Movements ◽  
Posterior Parietal

The role of brachial muscle spindle signals in assignment of visual direction

1993 ◽  
Vol 70 (4) ◽  
pp. 1578-1584 ◽  
Author(s):  
P. DiZio ◽  
C. E. Lathan ◽  
J. R. Lackner
Keyword(s):  
Apparent Motion ◽  
Muscle Spindle ◽  
Target Location ◽  
Biceps Brachii ◽  
Visual Target ◽  
Visual Direction ◽  
Muscle Vibration ◽  
Illusory Motion ◽  
The Stability

1. In the oculobrachial illusion, a target light attached to the unseen stationary hand is perceived as moving and changing spatial position when illusory motion of the forearm is elicited by brachial muscle vibration. Our goal was to see whether we could induce apparent motion and displacement of two retinally fixed targets in opposite directions by the use of oculobrachial illusions. 2. We vibrated both biceps brachii, generating illusory movements of the two forearms in opposite directions, and measured any associated changes in perceived distance between target lights on the unseen stationary hands. The stability of visual fixation of one of the targets was also measured. 3. The seen distance between the stationary targets increased significantly when vibration induced an illusory increase in felt distance between the hands, both with binocular and monocular viewing. 4. Subjects maintained fixation accuracy equally well during vibration-induced illusory increases in visual target separation and in a no-vibration control condition. Fixation errors were not correlated with the extent or direction of illusory visual separation. 5. These findings indicate that brachial muscle spindle signals can contribute to an independent representation of felt target location in head-centric coordinates that can be interrelated with a visual representation of target location generated by retinal and oculomotor signals. 6. A model of how these representations are interrelated is proposed, and its relation to other intersensory interactions is discussed.

Electrophysiological correlates of detecting a visual target and detecting its absence: The role of feature dimensions

2010 ◽  
Vol 48 (11) ◽  
pp. 3365-3370 ◽  
Author(s):  
Elkan G. Akyürek ◽  
Angela Dinkelbach ◽  
Anna Schubö ◽  
Hermann J. Müller
Keyword(s):  
Visual Target

scholarly journals Learning to search. The importance of eye movements in the decrease of response times during a visual choice reaction time task

2016 ◽  
Vol 9 (5) ◽  
Author(s):  
Aleksandra Kroll ◽  
Monika Mak ◽  
Jerzy Samochowiec
Keyword(s):  
Eye Movements ◽  
Reaction Time ◽  
Choice Reaction Time ◽  
Visual Target ◽  
Response Times ◽  
Reaction Times ◽  
Reaction Time Task ◽  
Visual Tasks ◽  
Target Searching

Reaction times are often used as an indicator of the efficiency of the processes in thecentral nervous system. While extensive research has been conducted on the possibleresponse time correlates, the role of eye movements in visual tasks is yet unclear. Here wereport data to support the role of eye movements during visual choice reaction time training.Participant performance, reaction times, and total session duration improved. Eyemovementsshowed expected changes in saccade amplitude and resulted in improvementin visual target searching.

The Role of Subcortical Visual Structures in Target Foveation Control

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 291-291
Author(s):  
G I Novikov
Keyword(s):  
Eye Movements ◽  
Visual Target ◽  
Receptive Fields ◽  
Movement Control ◽  
Lateral Geniculate Body ◽  
Electrophysiological Data ◽  
Electrical Microstimulation ◽  
Neuronal Populations

The role of subcortical levels—the lateral geniculate body (LGB) and superior colliculus (SC) of cat—in the control of foveation eye movements is described by a model based on our own electrophysiological data. These data include the characteristics of eye movements elicited by local electrical microstimulation of neuronal structures in the LGB and the SC. The model represents a multilevel system forming the program of foveation eye movements by performing the following actions in temporal sequence: determination of the position of the visual target in retinotopic coordinates, determination of its craniotopic coordinates and determination of the direction and calculation of the velocity of the moving visual target. I discuss algorithms and neuronal mechanisms (including electrophysiological data on single neurons and neuronal populations) of subcortical levels of the cat visual system taking part in foveation eye-movement control for stationary and moving visual objects, as well as the role of directional and orientation properties of receptive fields of subcortical neurons in this control.

scholarly journals Identification of Visual Stimuli is Improved by Accompanying Auditory Stimuli: The Role of Eye Movements and Sound Location

Perception ◽  
10.1068/p3126 ◽  
2001 ◽  
Vol 30 (7) ◽  
pp. 795-810 ◽  
Author(s):  
Melanie C Doyle ◽  
Robert J Snowden
Keyword(s):  
Visual Information ◽  
Target Location ◽  
Visual Target ◽  
Response Times ◽  
Target Identification ◽  
Spatial Location ◽  
Auditory Signal ◽  
Attentional Disengagement ◽  
Auditory Signals

Can auditory signals influence the processing of visual information? The present study examined the effects of simple auditory signals (clicks and noise bursts) whose onset was simultaneous with that of the visual target, but which provided no information about the target. It was found that such a signal enhances performance in the visual task: the accessory sound reduced response times for target identification with no cost to accuracy. The spatial location of the sound (whether central to the display or at the target location) did not modify this facilitation. Furthermore, the same pattern of facilitation was evident whether the observer fixated centrally or moved their eyes to the target. The results were not altered by changes in the contrast (and therefore visibility) of the visual stimulus or by the perceived utility of the spatial location of the sound. We speculate that the auditory signal may promote attentional ‘disengagement’ and that, as a result, observers are able to process the visual target sooner when sound accompanies the display relative to when visual information is presented alone.

scholarly journals Role of motor execution in the ocular tracking of self-generated movements

2016 ◽  
Vol 116 (6) ◽  
pp. 2586-2593 ◽  
Author(s):  
Jing Chen ◽  
Matteo Valsecchi ◽  
Karl R. Gegenfurtner
Keyword(s):  
Opposite Direction ◽  
Visual Target ◽  
Decision Processes ◽  
Motor Execution ◽  
Mechanical Device ◽  
Motor Commands ◽  
Motor Intention ◽  
Ocular Tracking ◽  
Pursuit Gain

When human observers track the movements of their own hand with their gaze, the eyes can start moving before the finger (i.e., anticipatory smooth pursuit). The signals driving anticipation could come from motor commands during finger motor execution or from motor intention and decision processes associated with self-initiated movements. For the present study, we built a mechanical device that could move a visual target either in the same direction as the participant's hand or in the opposite direction. Gaze pursuit of the target showed stronger anticipation if it moved in the same direction as the hand compared with the opposite direction, as evidenced by decreased pursuit latency, increased positional lead of the eye relative to target, increased pursuit gain, decreased saccade rate, and decreased delay at the movement reversal. Some degree of anticipation occurred for incongruent pursuit, indicating that there is a role for higher-level movement prediction in pursuit anticipation. The fact that anticipation was larger when target and finger moved in the same direction provides evidence for a direct coupling between finger and eye motor commands.

scholarly journals Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Vision ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 49
Author(s):  
Sabine Born
Keyword(s):  
Visual Target ◽  
Target Position ◽  
Decisive Role ◽  
Saccadic Suppression ◽  
General Stability ◽  
Steady Fixation ◽  
Continuous Scale ◽  
Improved Performance

Across saccades, small displacements of a visual target are harder to detect and their directions more difficult to discriminate than during steady fixation. Prominent theories of this effect, known as saccadic suppression of displacement, propose that it is due to a bias to assume object stability across saccades. Recent studies comparing the saccadic effect to masking effects suggest that suppression of displacement is not saccade-specific. Further evidence for this account is presented from two experiments where participants judged the size of displacements on a continuous scale in saccade and mask conditions, with and without blanking. Saccades and masks both reduced the proportion of correctly perceived displacements and increased the proportion of missed displacements. Blanking improved performance in both conditions by reducing the proportion of missed displacements. Thus, if suppression of displacement reflects a bias for stability, it is not a saccade-specific bias, but a more general stability assumption revealed under conditions of impoverished vision. Specifically, I discuss the potentially decisive role of motion or other transient signals for displacement perception. Without transients or motion, the quality of relative position signals is poor, and saccadic and mask-induced suppression of displacement reflects performance when the decision has to be made on these signals alone. Blanking may improve those position signals by providing a transient onset or a longer time to encode the pre-saccadic target position.

Influence of Prosodic Boundaries on Comprehension of Spoken English Sentences

1998 ◽  
Vol 87 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Dawn G. Blasko ◽  
Michael D. Hall
Keyword(s):  
Visual Target ◽  
Syntactic Structure ◽  
Spoken Language ◽  
Syntactic Ambiguity ◽  
Spoken English ◽  
Production Parameters ◽  
Sentence Meaning ◽  
Prosodic Boundaries

Three experiments investigated the role of prosody in the comprehension of auditory sentences. In Exp. 1 an analysis of three novice talkers and one expert talker verified the production parameters of one type of syntactic ambiguity and showed that pitch cues were more prominent than duration cues. In Exp. 2, 16 listeners used prosodic information to make consistent decisions reliably about phrase boundaries. In Exp. 3, 40 participants listened to sentences in which prosody was inconsistent with later morphosyntactic information, indicated their understanding, and then judged whether a visual target was related to the meaning of the sentence. Inconsistent prosody slowed comprehension and contributed to slower, less accurate judgments of sentence meaning. This suggests that prosodic information contributes to the perception of spoken language and can affect comprehension even when the syntactic structure indicated by prosody is contradicted by subsequent morphosyntactic information.

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