scholarly journals Perisaccadic flash mislocalization suggesting compression of visual space may come from a simple monotonic extraretinal signal whose onset time varies across the retina

2010 ◽  
Vol 7 (9) ◽  
pp. 732-732 ◽  
Author(s):  
J. Pola
Keyword(s):  
Onset Time ◽  
Visual Space ◽  
Extraretinal Signal

Response and Reinforcement in Operant Audiometry

1987 ◽  
Vol 52 (3) ◽  
pp. 294-299 ◽  
Author(s):  
Michael A. Primus
Keyword(s):  
Operant Conditioning ◽  
Space Versus ◽  
Visual Space ◽  
Central Processing ◽  
Operant Discrimination ◽  
Conditioning Rate ◽  
Significant Difference ◽  
Simple Detection ◽  
Variable Success ◽  
Response Task

Variable success in audiometric assessment of young children with operant conditioning indicates the need for systematic examination of commonly employed techniques. The current study investigated response and reinforcement features of two operant discrimination paradigms with normal I7-month-old children. Findings indicated more responses prior to the onset of habituation when the response task was based on complex central processing skills (localization and coordination of auditory/visual space) versus simple detection. Use of animation in toy reinforcers resulted in more than a twofold increase in the number of subject responses. Results showed no significant difference in response conditioning rate or consistency for the response tasks and forms of reinforcement examined.

Editorial: Human motion perception, eye movements, and orientation in visual space

2000 ◽  
Vol 59 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Rudolf Groner ◽  
Marina T. Groner ◽  
Kazuo Koga
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Visual Space ◽  
Human Motion

Focusing of Visuospatial Attention

2001 ◽  
Vol 15 (4) ◽  
pp. 256-274 ◽  
Author(s):  
Caterina Pesce ◽  
Rainer Bösel
Keyword(s):  
Reaction Times ◽  
Visual Space ◽  
Spatial Relation ◽  
Stimulus Onset ◽  
Visuospatial Attention ◽  
Task Demands ◽  
Time Interval ◽  
Behavioral Studies ◽  
Task Conditions ◽  
Simple Rt

Abstract In the present study we explored the focusing of visuospatial attention in subjects practicing and not practicing activities with high attentional demands. Similar to the studies of Castiello and Umiltà (e. g., 1990) , our experimental procedure was a variation of Posner's (1980) basic paradigm for exploring covert orienting of visuospatial attention. In a simple RT-task, a peripheral cue of varying size was presented unilaterally or bilaterally from a central fixation point and followed by a target at different stimulus-onset-asynchronies (SOAs). The target could occur validly inside the cue or invalidly outside the cue with varying spatial relation to its boundary. Event-related brain potentials (ERPs) and reaction times (RTs) were recorded to target stimuli under the different task conditions. RT and ERP findings showed converging aspects as well as dissociations. Electrophysiological results revealed an amplitude modulation of the ERPs in the early and late Nd time interval at both anterior and posterior scalp sites, which seems to be related to the effects of peripheral informative cues as well as to the attentional expertise. Results were: (1) shorter latency effects confirm the positive-going amplitude enhancement elicited by unilateral peripheral cues and strengthen the criticism against the neutrality of spatially nonpredictive peripheral cueing of all possible target locations which is often presumed in behavioral studies. (2) Longer latency effects show that subjects with attentional expertise modulate the distribution of the attentional resources in the visual space differently than nonexperienced subjects. Skilled practice may lead to minimizing attentional costs by automatizing the use of a span of attention that is adapted to the most frequent task demands and endogenously increases the allocation of resources to cope with less usual attending conditions.

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

Spatial suppression due to statistical regularities is driven by distractor suppression not by target activation

2018 ◽  
Author(s):  
Michel Failing ◽  
Benchi Wang ◽  
Jan Theeuwes
Keyword(s):  
High Probability ◽  
Target Location ◽  
Target Selection ◽  
Visual Space ◽  
Alternative Interpretation ◽  
Distractor Location ◽  
Target Presentation ◽  
Statistical Regularities ◽  
Low Probability ◽  
Presentation Experiment

Where and what we attend to is not only determined by what we are currently looking for but also by what we have encountered in the past. Recent studies suggest that biasing the probability by which distractors appear at locations in visual space may lead to attentional suppression of high probability distractor locations which effectively reduces capture by a distractor but also impairs target selection at this location. However, in many of these studies introducing a high probability distractor location was tantamount to increasing the probability of the target appearing in any of the other locations (i.e. the low probability distractor locations). Here, we investigate an alternative interpretation of previous findings according to which attentional selection at high probability distractor locations is not suppressed. Instead, selection at low probability distractor locations is facilitated. In two visual search tasks, we found no evidence for this hypothesis: neither when there was only a bias in target presentation but no bias in distractor presentation (Experiment 1), nor when there was only a bias in distractor presentation but no bias in target presentation (Experiment 2). We conclude that recurrent presentation of a distractor in a specific location leads to attentional suppression of that location through a mechanism that is unaffected by any regularities regarding the target location.

INTERSCALENE BRACHIAL PLEXUS BLOCK WITH A NERVE STIMULATOR FOR CLAVICULAR FRACTURE SURGERY

2014 ◽  
pp. 20-24
Author(s):  
Van Minh Nguyen
Keyword(s):  
Side Effects ◽  
Brachial Plexus ◽  
Brachial Plexus Block ◽  
Clavicle Fracture ◽  
Onset Time ◽  
Clavicular Fracture ◽  
Nerve Stimulator ◽  
Interscalene Brachial Plexus Block ◽  
Plexus Block ◽  
Fracture Surgery

Objective:To evaluate the effectiveness and side effects, complications of interscalene brachial plexus block with a nerve stimulator for clavicular fracture surgery. Materials and Methods:In a prospective descriptive study, fifty patients received interscalene brachial plexus block for fixation of clavicle fracture. The dose was 7 mg/kg of 1% lidocaine mixed with 1 : 200000 adrenaline. Results:The success rate was 94%, including 4% of patients needed sedation and small amount of narcotic, failure rate was 6%. The minimal stimulating current of the nerve location was 0.46 ±0.08 mA, the onset time of sensory block was 8.86 ±2.65min. There were 3 complications with one Horner’s syndrome and two hoarsenesses. Conclusion:We found that in patients undergoing fixation of clavicle fracture the interscalene block with a nerve stimulator was an effective anesthetic with a low rate of side effects and complications. Key words:Interscalene block, nerve stimulator, clavicular fracture surgery.

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