The Role of Retinal Orientation in the Egocentric Organization of a Visual Stimulus

1968 ◽  
Vol 79 (2) ◽  
pp. 283-289
Author(s):  
D. A. Begelman
Keyword(s):  
Visual Stimulus

BLIND MEXICAN CAVE FISH (ASTYANAX HUBBSI) RESPOND TO MOVING VISUAL STIMULI

1994 ◽  
Vol 188 (1) ◽  
pp. 89-101 ◽  
Author(s):  
T Teyke ◽  
S Schaerer
Keyword(s):  
Visual Stimulus ◽  
Swimming Velocity ◽  
Environmental Cues ◽  
Cave Fish ◽  
Optomotor Response ◽  
Aquarium Fish ◽  
Modified Theory ◽  
Test Aquarium ◽  
Optomotor Behaviour

In apparatus for measuring optomotor behaviour, blind Mexican cave fish, Astyanax hubbsi, increase their swimming velocity upon rotation of a striped cylinder, i.e. in response to a solely visual stimulus. The fish follow the movements of the stripes at (i) rotation velocities between 60 degrees s-1 and 80 degrees s-1, (ii) light intensities of less than 20 lx and, (iii) stimulus widths subtending an angle of less than 1 °. Extirpation of the vestigial eye structures does not affect the response to the moving visual stimulus, which indicates that the response is mediated by extra-ocular photoreceptors. An optomotor response can be reliably evoked in a round test aquarium. Fish do not respond when the test aquarium contains environmental cues, such as bars on the wall or when a section of the round aquarium is divided off. This indicates that the fish obtain information about their environment from different sensory sources and that the visual stimulus is effective only when no other means of orientation are available. We suggest a modified theory of the optomotor response, which emphasizes the crucial role of the environment in eliciting the response and which permits behaviours more complex than just following the stimulus.

The role of vision on postural strategy evaluated in patients affected by congenital nystagmus as an experimental model

1999 ◽  
Vol 9 (6) ◽  
pp. 445-451
Author(s):  
S. Di Girolamo ◽  
W. Di Nardo ◽  
A. Cosenza ◽  
F. Ottaviani ◽  
A. Dickmann ◽  
...  
Keyword(s):  
Visual System ◽  
Postural Control ◽  
Visual Stimulus ◽  
Postural Balance ◽  
Visual Cues ◽  
Normal Subjects ◽  
Congenital Nystagmus ◽  
Dynamic Posturography ◽  
Normal Controls

The role of vision in postural control is crucial and is strictly related to the characteristics of the visual stimulus and to the performance of the visual system. The purpose of this investigation was to evaluate the effects of chronically reduced visual cues upon postural control in patients affected by Congenital Nystagmus (CN). These patients have developed since birth a postural strategy mainly based on vestibular and somatosensorial cues. Fifteen patients affected by CN and 15 normal controls (NC) were enrolled in the study and evaluated by means of dynamic posturography. The overall postural control in CN patients was impaired as demonstrated by the equilibrium score and by the changes of the postural strategy. This impairment was even more enhanced in CN than in NC group when somatosensorial cues were experimentally reduced. An aspecific pattern of visual impairment and a pathological composite score were also present. Our data outline that in patients affected by CN an impairment of the postural balance is present especially when the postural control relies mainly on visual cues. Moreover, a decrease in accuracy of the somatosensory cues has a proportionally greater effect on balance than it has on normal subjects.

The Effects of Cue Reliability on Crossmodal Recalibration in Adults and Children

2021 ◽  
pp. 1-19
Author(s):  
Sophie Rohlf ◽  
Patrick Bruns ◽  
Brigitte Röder
Keyword(s):  
Multisensory Integration ◽  
Sound Localization ◽  
Visual Stimulus ◽  
Cue Combination ◽  
Single Exposure ◽  
Visual Cue ◽  
Cue Reliability ◽  
Adults And Children ◽  
Ventriloquist Effect

Abstract Reliability-based cue combination is a hallmark of multisensory integration, while the role of cue reliability for crossmodal recalibration is less understood. The present study investigated whether visual cue reliability affects audiovisual recalibration in adults and children. Participants had to localize sounds, which were presented either alone or in combination with a spatially discrepant high- or low-reliability visual stimulus. In a previous study we had shown that the ventriloquist effect (indicating multisensory integration) was overall larger in the children groups and that the shift in sound localization toward the spatially discrepant visual stimulus decreased with visual cue reliability in all groups. The present study replicated the onset of the immediate ventriloquist aftereffect (a shift in unimodal sound localization following a single exposure of a spatially discrepant audiovisual stimulus) at the age of 6–7 years. In adults the immediate ventriloquist aftereffect depended on visual cue reliability, whereas the cumulative ventriloquist aftereffect (reflecting the audiovisual spatial discrepancies over the complete experiment) did not. In 6–7-year-olds the immediate ventriloquist aftereffect was independent of visual cue reliability. The present results are compatible with the idea of immediate and cumulative crossmodal recalibrations being dissociable processes and that the immediate ventriloquist aftereffect is more closely related to genuine multisensory integration.

Latency of Vocalization Onset for Stutterers and Nonstutterers under Conditions of Auditory and Visual, Cueing

1981 ◽  
Vol 46 (3) ◽  
pp. 307-312 ◽  
Author(s):  
Stephen C. McFarlane ◽  
Kenneth G. Shipley
Keyword(s):  
Motor Control ◽  
Auditory System ◽  
Visual Stimulus ◽  
Onset Time ◽  
Onset Latency ◽  
Visual Cueing ◽  
System Functioning ◽  
Auditory Cueing

The purpose of this study was to determine whether stutterers and nonstutterers differed in latency of vocalization onset as a function of auditory and visual stimulus presentations. Twelve adult stutterers and 12 adult nonstutterers were compared for phonation onset latency under conditions of visual, right ear auditory, and left ear auditory cueing. Analyses of the data indicated that (a) overall phonation onset time did not differ significantly between the groups, (b) no significant differences were found for phonation onset time under conditions of combined auditory cueing, (c) stutterers were significantly slower for /pℵ/ when auditory cueing was presented to either the left ear, (d) stutterers were significantly slower for /pℵ/ and /bℵ/ when the values were combined for the left ear, and (e) there were no significant differences between stutterers' and nonstutterers' phonation onset times under visual cueing. The results are interpreted to implicate a possible role of auditory system functioning in stutterers' motor control for speech tasks such as phonation onset.

Role of monkey precentral cortex in control of voluntary jaw movements

1975 ◽  
Vol 38 (1) ◽  
pp. 146-157 ◽  
Author(s):  
E. S. Luschei ◽  
G. M. Goodwin
Keyword(s):  
Electrical Stimulation ◽  
Visual Stimulus ◽  
Neural Pathways ◽  
Unilateral Lesion ◽  
Jaw Movements ◽  
Face Area ◽  
The Face ◽  
Bilateral Lesions

Monkeys were trained to produce a low, steady biting force for 0.5-2.5 s, and then a rapid forceful bite in response to a visual stimulus. After large bilateral lesions of the precentral face area, monkeys emitted repetitive forceful bites on the apparatus, but could not perform the force-holding task. They eventually relearned the task, but the force exerted was never as steady as it was prelesion, and often oscillated at about 2 and/or 5-6 Hz. After retraining, two animals with large bilateral lesions of the face area produced median RT responses equal to or only slightly longer than their prelesion performance, indicating that neural pathways not involving the precentral cortex can mediate quick visual RT responses. The variability of RTs was permanently increased, probably as a result of the persistent unsteadiness of the force-holding response. Incomplete bilateral lesions of the precentral face area, a complete unilateral lesion of that area, and bilateral lesions adjacent regions of cortex produced either mild, transient difficulties with the biting taks, or no problems at all. The results indicate that the precentral cortex has a role in the control of voluntary jaw movements. Lesions caused difficulty in controlling, but not producing, closing jaw movements, thereby suggesting that this role is predominantly to inhibit jaw-closing motoneurons or the systems that excite them. Electrical stimulation studies of the face area of the precentral cortex of the unanesthetized monkey point to the same conclusion.

The Perception of Brief Temporal Intervals: Power Functions for Auditory and Visual Stimulus Intervals

Perception ◽  
1977 ◽  
Vol 6 (6) ◽  
pp. 703-709 ◽  
Author(s):  
Douglas J Bobko ◽  
Jack G Thompson ◽  
Harvey R Schiffman
Keyword(s):  
Visual Stimulus ◽  
Standard Stimulus ◽  
Visual Stimuli ◽  
Power Functions ◽  
Stimulus Modality ◽  
Temporal Intervals ◽  
The Relationship

Two experiments were performed to examine the role of method of estimation and the employment of a standard stimulus on the judged duration of auditory and visual stimuli presented for brief temporal intervals (0.25 to 5.0 s). The results indicate that the relationship between judged and physical duration is nearly direct and linear. Psychophysical methodology and stimulus modality exerted little influence on the obtained power functions.

On music’s potential to convey meaning in film: A systematic review of empirical evidence

2019 ◽  
pp. 030573561983501 ◽  
Author(s):  
Ann-Kristin Herget
Keyword(s):  
Systematic Review ◽  
Empirical Evidence ◽  
Visual Stimulus ◽  
Empirical Studies ◽  
Film Music ◽  
Future Research ◽  
Abstraction Level ◽  
Research Questions ◽  
Stimulus Materials

With its schema-activating potential to influence an audience’s perception and interpretation of film plot and protagonists, film music goes far beyond the role of an emotionalizing accessory in film contexts. For this review, 24 German and English empirical studies that tested music’s potential to convey meaning were identified to be compared in their research questions, the characteristics of their methods, designs, samples, and stimulus materials, as well as main results. Depending on the degree of realism and the abstraction level of the audio-visual stimulus material, differently connoted music or music of different genres trigger supra-individual associations, which make the recipients’ perceptual patterns and evaluations of film plot and protagonists predictable. The review provides a systematization of music’s effects as well as methodological and content-related indications for future research.

scholarly journals Exploring the Determinants of Color Perception Using #Thedress and Its Variants: The Role of Spatio-Chromatic Context, Chromatic Illumination, and Material–Light Interaction

Perception ◽  
2020 ◽  
Vol 49 (11) ◽  
pp. 1235-1251
Author(s):  
Stacey Aston ◽  
Kristina Denisova ◽  
Anya Hurlbert ◽  
Maria Olkkonen ◽  
Bradley Pearce ◽  
...  
Keyword(s):  
Visual System ◽  
Visual Stimulus ◽  
Color Perception ◽  
Spectral Composition ◽  
Light Sources ◽  
Light Spectra ◽  
Visual Systems ◽  
Spatial Configurations ◽  
People’S Perceptions

The colors that people see depend not only on the surface properties of objects but also on how these properties interact with light as well as on how light reflected from objects interacts with an individual’s visual system. Because individual visual systems vary, the same visual stimulus may elicit different perceptions from different individuals. #thedress phenomenon drove home this point: different individuals viewed the same image and reported it to be widely different colors: blue and black versus white and gold. This phenomenon inspired a collection of demonstrations presented at the Vision Sciences Society 2015 Meeting which showed how spatial and temporal manipulations of light spectra affect people’s perceptions of material colors and illustrated the variability in individual color perception. The demonstrations also explored the effects of temporal alterations in metameric lights, including Maxwell’s Spot, an entoptic phenomenon. Crucially, the demonstrations established that #thedress phenomenon occurs not only for images of the dress but also for the real dress under real light sources of different spectral composition and spatial configurations.

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