scholarly journals Detection of Visual Stimulus Onset Time

2008 ◽  
Vol 2 ◽  
Author(s):  
Çelik Umut
Keyword(s):  
Visual Stimulus ◽  
Onset Time ◽  
Stimulus Onset

Stimulus onset-to-onset time determines the dichotic temporal order threshold

2001 ◽  
Author(s):  
Harvey Babkoff ◽  
Elisheva Ben-Artzi ◽  
Leah Fostick
Keyword(s):  
Temporal Order ◽  
Onset Time ◽  
Stimulus Onset

Audiovisual Simultaneity Judgements in Synaesthesia

2021 ◽  
pp. 1-12
Author(s):  
Anna Borgolte ◽  
Ahmad Bransi ◽  
Johanna Seifert ◽  
Sermin Toto ◽  
Gregor R. Szycik ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Temporal Order ◽  
Multisensory Processing ◽  
Sensory Modality ◽  
Stimulus Onset ◽  
Control Subjects ◽  
Visual Events

Abstract Synaesthesia is a multimodal phenomenon in which the activation of one sensory modality leads to an involuntary additional experience in another sensory modality. To date, normal multisensory processing has hardly been investigated in synaesthetes. In the present study we examine processes of audiovisual separation in synaesthesia by using a simultaneity judgement task. Subjects were asked to indicate whether an acoustic and a visual stimulus occurred simultaneously or not. Stimulus onset asynchronies (SOA) as well as the temporal order of the stimuli were systematically varied. Our results demonstrate that synaesthetes are better in separating auditory and visual events than control subjects, but only when vision leads.

scholarly journals The influence of temporal predictability on express visuomotor responses

2020 ◽  
Author(s):  
Samuele Contemori ◽  
Gerald E. Loeb ◽  
Brian D. Corneil ◽  
Guy Wallis ◽  
Timothy J. Carroll
Keyword(s):  
Superior Colliculus ◽  
Onset Time ◽  
Surface Emg ◽  
Stimulus Onset ◽  
Target Motion ◽  
Target Velocity ◽  
Moving Target ◽  
Visuomotor Transformations ◽  
Shoulder Muscles ◽  
Temporal Predictability

ABSTRACTVolitional visuomotor responses in humans are generally thought to manifest 100ms or more after stimulus onset. Under appropriate conditions, however, much faster target-directed responses can be produced at upper limb and neck muscles. These “express” responses have been termed stimulus-locked responses (SLRs) and are proposed to be modulated by visuomotor transformations performed subcortically via the superior colliculus. Unfortunately, for those interested in studying SLRs, these responses have proven difficult to detect consistently across individuals. The recent report of an effective paradigm for generating SLRs in 100% of participants appears to change this. The task required the interception of a moving target that emerged from behind a barrier at a time consistent with the target velocity. Here we aimed to reproduce the efficacy of this paradigm for eliciting SLRs and to test the hypothesis that its effectiveness derives from the predictability of target onset time as opposed to target motion per se. In one experiment, we recorded surface EMG from shoulder muscles as participants made reaches to intercept temporally predictable or unpredictable targets. Consistent with our hypothesis, predictably timed targets produced more frequent and stronger SLRs than unpredictably timed targets. In a second experiment, we compared different temporally predictable stimuli and observed that transiently presented targets produced larger and earlier SLRs than sustained moving targets. Our results suggest that target motion is not critical for facilitating the expression of an SLR and that timing predictability does not rely on extrapolation of a physically plausible motion trajectory. These findings provide support for a mechanism whereby an internal timer, probably located in cerebral cortex, primes the processing of both visual input and motor output within the superior colliculus to produce SLRs.

Orienting Responses as a Function of Age and Task Complexity

1976 ◽  
Vol 42 (2) ◽  
pp. 543-553 ◽  
Author(s):  
Roger L. Greene
Keyword(s):  
Age Differences ◽  
Visual Stimulus ◽  
Task Complexity ◽  
Age Groups ◽  
Stimulus Onset ◽  
Age Related ◽  
Stimulus Content ◽  
Stimulus Offset ◽  
Age Related Changes ◽  
And Task

Age-related differences in the elicitation and habituation of orienting responses to the onset and offset of stimuli have been suggested by several authors. Electrodermal and cardiac orienting responses to the onset and offset of a visual stimulus were measured in three age groups (4 yr., 7 yr., and undergraduate). Each S made one of three judgments: non-signal (observe stimulus), content (color of stimulus), and duration (length of time stimulus presented). Few age differences were found in elicitation or habituation of orienting responses to stimulus onset or offset. There was a trend for elicitation of orienting responses to stimulus offset to be age-related, but the failure to find any other age-related changes made this difference somewhat questionable. Instructions as to the judgment to be made by S were the primary determinants of orienting responses to stimulus onset and offset across all age groups.

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.

scholarly journals Done in 100 ms: path-dependent visuomotor transformation in the human upper limb

2018 ◽  
Vol 119 (4) ◽  
pp. 1319-1328 ◽  
Author(s):  
Chao Gu ◽  
J. Andrew Pruszynski ◽  
Paul L. Gribble ◽  
Brian D. Corneil
Keyword(s):  
Reference Frame ◽  
Upper Limb ◽  
Visual Stimulus ◽  
Visual Information ◽  
Task Complexity ◽  
Stimulus Onset ◽  
Movement Trajectory ◽  
Limb Muscle ◽  
Muscle Recruitment ◽  
Human Upper Limb

A core assumption underlying mental chronometry is that more complex tasks increase cortical processing, prolonging reaction times. In this study we show that increases in task complexity alter the magnitude, rather than the latency, of the output for a circuit that rapidly transforms visual information into motor actions. We quantified visual stimulus-locked responses (SLRs), which are changes in upper limb muscle recruitment that evolve at a fixed latency ~100 ms after novel visual stimulus onset. First, we studied the underlying reference frame of the SLR by dissociating the initial eye and hand position. Despite its quick latency, we found that the SLR was expressed in a hand-centric reference frame, suggesting that the circuit mediating the SLR integrated retinotopic visual information with body configuration. Next, we studied the influence of planned movement trajectory, requiring participants to prepare and generate either curved or straight reaches in the presence of obstacles to attain the same visual stimulus location. We found that SLR magnitude was influenced by the planned movement trajectory to the same visual stimulus. On the basis of these results, we suggest that the circuit mediating the SLR lies in parallel to other well-studied corticospinal pathways. Although the fixed latency of the SLR precludes extensive cortical processing, inputs conveying information relating to task complexity, such as body configuration and planned movement trajectory, can preset nodes within the circuit underlying the SLR to modulate its magnitude. NEW & NOTEWORTHY We studied stimulus-locked responses (SLRs), which are changes in human upper limb muscle recruitment that evolve at a fixed latency ~100 ms after novel visual stimulus onset. We showed that despite its quick latency, the circuitry mediating the SLR transformed a retinotopic visual signal into a hand-centric motor command that is modulated by the planned movement trajectory. We suggest that the circuit generating the SLR is mediated through a tectoreticulospinal, rather than a corticospinal, pathway.

scholarly journals Done in 100 ms: Path-dependent visuomotor transformation in the human upper limb

2017 ◽  
Author(s):  
Chao Gu ◽  
J. Andrew Pruszynski ◽  
Paul L. Gribble ◽  
Brian D. Corneil
Keyword(s):  
Upper Limb ◽  
Visual Stimulus ◽  
Visual Information ◽  
Task Complexity ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Movement Trajectory ◽  
Cortical Processing ◽  
Mental Chronometry ◽  
Motor Actions

ABSTRACTA core assumption underlying mental chronometry is that more complex tasks increase cortical processing, prolonging reaction times. Here we show that increases in task complexity alter the magnitude, rather than the latency, of the output for a circuit that rapidly transforms visual information into motor actions. We quantified visual stimulus-locked responses (SLRs), which are changes in upper limb muscle recruitment that evolve at a fixed latency ∼100 ms after novel visual stimulus onset. First, we studied the underlying reference frame of the SLR, by dissociating initial eye and hand position. Despite its quick latency, we found that the SLR was expressed in a hand-centric reference frame, suggesting that the circuit mediating the SLR integrated retinotopic visual information with body configuration. Next, we studied the influence of planned movement trajectory, requiring participants to prepare and generate curved or straight reaches in the presence of obstacles to attain the same visual stimulus. We found that SLR magnitude reflected the initial planned movement trajectory, regardless of the ensuing movement curvature. Based on these results, we suggest that the circuit mediating the SLR lies in parallel to other well-studied corticospinal pathways. Although the fixed latency of the SLR precludes extensive cortical processing, inputs conveying information relating to task complexity, such as body configuration and planned movement trajectory, can pre-set nodes within the circuit underlying to the SLR to modulate its magnitude.SIGNIFICANCE STATEMENTA core assumption underlying mental chronometry is that more complex tasks increase cortical processing, prolonging reaction times. Here, we showed that increases in task complexity altered the magnitude, rather than the latency, of a circuit that rapidly transforms visual information into motor actions. We focus on stimulus-locked responses (SLRs), which are changes in upper limb muscle recruitment that evolve at a fixed latency ∼100 ms after novel visual stimulus onset. We showed that despite is quick latency, the circuitry mediating the SLR transformed a retinotopic visual signal into a hand-centric motor command suitable to contribute to the initial movement trajectory. We suggest that this circuit lies in parallel to other well-studied corticospinal pathways.

Effects of Stimulus-Onset Asynchrony on the Dichotic Performance of Children with Auditory-Processing Disorders

1979 ◽  
Vol 22 (2) ◽  
pp. 197-211 ◽  
Author(s):  
Emily A. Tobey ◽  
John K. Cullen ◽  
Donald L. Rampp ◽  
Ann M. Fleischer-Gallagher
Keyword(s):  
Auditory Processing ◽  
Clinical Manifestations ◽  
Onset Time ◽  
Stop Consonant ◽  
Learning Disabled ◽  
Stimulus Onset ◽  
Auditory Processing Disorders ◽  
Disabled Children ◽  
Accurate Identification ◽  
Control Subjects

Dichotic stop-consonant-vowel identification was investigated in two experiments using two groups of learning-disabled children demonstrating clinical manifestations of auditory-processing disorders, and two groups of matched, control subjects. Two-item, forced-choice paradigms were used in both experiments. Overall (total) dichotic performance for the two learning-disabled groups was significantly lower than that of the control subjects in all dichotic conditions. This lower performance was attributable to the number of trials in which both stimulus items were correctly identified. Analysis of trials in which only one response was correct showed no differences between the groups in terms of magnitude or direction of ear-advantage (right). In conditions where stimulus onsets were separated by 30, 90, and 150 msec, analysis of one-correct trials demonstrated more accurate identification of the temporally lagging stimulus for all subjects. However, as the onset-time separation increased, the control group’s identification of leading and lagging items approached equality. The learning-disabled group, on the other hand, showed little increase in identification of temporally leading items even when stimuli were separated by 150 msec. These data suggest learning-disabled children with auditory-processing disorders may have a reduced temporal efficiency in processing rapidly varying acoustic patterns associated with stop-consonants that is observable when speech perceptual mechanisms are stressed through dichotic competition.

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