Presaccadic Processes in the Generation of Pro and anti Saccades in Human Subjects—A Reaction-Time Study

Perception ◽  
1995 ◽  
Vol 24 (11) ◽  
pp. 1265-1280 ◽  
Author(s):  
Heike Weber
Keyword(s):  
Lead Time ◽  
Human Subjects ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Brain Structures ◽  
Stimulus Onset ◽  
Error Rates ◽  
Previous Trial ◽  
Anti Saccades ◽  
Actual Trial

It has been widely acknowledged that the generation of an anti saccade, ie a saccade towards the direction opposite to that of a visual stimulus, requires the correct function of special brain structures. In the present study attempts were made to measure the time consumption of brain processes preceding the execution of pro and anti saccades. The saccadic eye movements of five adult human subjects were investigated in a series of combined pro/anti saccade tasks with the aid of the gap and the overlap paradigms. The type of trial—pro saccade and anti saccade—was defined by the structure of the stimulus. In some sessions the subjects were, in addition, preinformed about the actual command by a cue at different lead times before stimulus onset. Pro-saccade and anti-saccade trials were randomly intermixed in equal proportions. High error rates (>30% of all trials in some subjects) occurred in the test sessions without preinformative cues. These errors had long reaction times (∼200 ms), whereas the latencies of correct pro or correct anti saccades were even longer (∼350 ms). Analysis of the errors revealed that they were related to the situation in the previous trial: a correct response in the previous trial enhanced the chance of making a saccade of the same type in the actual trial by up to 30%. This pretrial effect occurred whether the actual trial was a pro-saccade or an anti-saccade command. With a cue lead time of 100 ms the numbers of errors decreased, but the latencies of the correct pro or anti saccades were about 70 ms longer than those obtained in the nonrandom control. With a 200 ms cue lead time the reaction times corresponded to those in the control condition. The results suggest that the situation in a given trial creates a kind of default program for the saccade preparation in the next trial. When a cue about the actual command is given early enough, the default program is overridden correspondingly. The perception of the cue and the programming of the corresponding saccade takes an additional 150 to 200 ms.

Theory of Visual Attention (TVA)

2014 ◽  
Author(s):  
Claus Bundesen ◽  
Thomas Habekost
Keyword(s):  
Visual Attention ◽  
Single Cell ◽  
Human Subjects ◽  
Genetic Research ◽  
Reaction Times ◽  
Error Rates ◽  
Healthy Human ◽  
Computational Theory ◽  
Healthy Human Subjects ◽  
Psychological Studies

The theory of visual attention introduced by Bundesen (1990) is reviewed. The authors first describe TVA as a formal computational theory of visual attention and summarize applications of TVA to psychological studies of performance (reaction times and error rates) in healthy human subjects. They then explain their neurophysiological interpretation of TVA, NTVA, and exemplify how NTVA accounts for findings from single-cell studies in primates. Finally the authors review how TVA has been applied to study attentional functions in neuropsychological, pharmacological, and genetic research.

scholarly journals Express saccades and superior colliculus responses are sensitive to short-wavelength cone contrast

2016 ◽  
Vol 113 (24) ◽  
pp. 6743-6748 ◽  
Author(s):  
Nathan J. Hall ◽  
Carol L. Colby
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Short Wavelength ◽  
Human Subjects ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Express Saccades ◽  
Color Information ◽  
Express Saccade ◽  
Psychophysical Studies

A key structure for directing saccadic eye movements is the superior colliculus (SC). The visual pathways that project to the SC have been reported to carry only luminance information and not color information. Short-wavelength–sensitive cones (S-cones) in the retina make little or no contribution to luminance signals, leading to the conclusion that S-cone stimuli should be invisible to SC neurons. The premise that S-cone stimuli are invisible to the SC has been used in numerous clinical and human psychophysical studies. The assumption that the SC cannot use S-cone stimuli to guide behavior has never been tested. We show here that express saccades, which depend on the SC, can be driven by S-cone input. Further, express saccade reaction times and changes in SC activity depend on the amount of S-cone contrast. These results demonstrate that the SC can use S-cone stimuli to guide behavior. We conclude that the use of S-cone stimuli is insufficient to isolate SC function in psychophysical and clinical studies of human subjects.

The Perception of Involuntary Prosaccades in an Antisaccade Task

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 275-275
Author(s):  
A Mokler ◽  
B Fischer
Keyword(s):  
Error Rate ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Error Rates ◽  
Data Sets ◽  
Antisaccade Task ◽  
Key Press ◽  
Extra Peak ◽  
The Mean ◽  
Strong Mode

In an antisaccade task subjects are required to generate a voluntary saccade to the side opposite to a small visual stimulus. With fixation-point offset preceding stimulus onset (gap) subjects produce some involuntary saccades to the stimulus and correct them by a second saccade. We wanted to know whether the subjects recognised their errors and whether a recognised sequence (error followed by correction) is different from an unrecognised sequence. To test the access to the correction mechanism, subjects were asked in subsequent experiments to produce the error-correction sequence voluntarily (voluntary sequence). We used the gap = 200 ms condition. A valid cue was presented 100 ms before stimulus onset. This manipulation increased the error rate (Fischer and Weber, 1996 Experimental Brain Research109 507 – 512). Subjects indicated errors by key-press. The rate of recognised and unrecognised errors, saccadic size, reaction times (SRT), and correction times (CRT) were determined. Altogether 93 data sets (400 trials each) from 38 subjects were analysed. The mean error rate was 20%, of which 62% went unrecognised. In sessions with high error rates the fraction of unrecognised errors was high. The SRT of the errors ranged from 80 to 170 ms with a strong mode of express saccades at 100 ms. Both types of errors had the same mean SRT of 117 – 119 ms. The unrecognised errors were 0.4 deg smaller. They were corrected after a mean CRT of 95 ms. The recognised errors were corrected after 127 ms; in the voluntary sequence the correction occurred after 217 ms. The CRT distributions differ from each other with the unrecognised errors having an extra peak around 45 ms, suggesting different modes of correction, to which perception has different access. These results raise the question why the large and long-lasting changes of the retinal image escape the conscious perception so often.

Phonological and semantic activation in reading two-kanji compound words

2000 ◽  
Vol 21 (4) ◽  
pp. 487-503 ◽  
Author(s):  
AIKO MORITA ◽  
FUMIKO MATSUDA
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Error Rates ◽  
Semantic Activation ◽  
Phonological Information ◽  
Semantic Interference ◽  
Compound Words ◽  
Phonological Interference ◽  
Onset Asynchrony

The purpose of this study was to examine whether phonological information was activated automatically in processing two-kanji compound words. In Experiment 1, 27 participants judged whether pairs of the words were homophones, while another 27 participants judged whether pairs were synonyms. Stimulus onset asynchrony (SOA) was 140 ms, 230 ms, or 320 ms. In Experiment 2, 36 participants were asked to make one of the two judgments, as in Experiment 1. SOA was determined individually. The following results were found. Reaction times showed semantic interference. Phonological interference was observed only under the shortest SOA in Experiment 2. Error rates showed phonological and semantic interferences even when SOA was the longest. These findings support the universal phonological principle.

Long-Term Musical Training Alters Tactile Temporal-Order Judgment

2018 ◽  
Vol 31 (5) ◽  
pp. 373-389 ◽  
Author(s):  
Simon P. Landry ◽  
François Champoux
Keyword(s):  
Temporal Order ◽  
Temporal Order Judgment ◽  
Musical Training ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Error Rates ◽  
Training Environment ◽  
Temporal Order Judgement ◽  
The Impact

Long-term musical training is an enriched multisensory training environment that can alter uni- and multisensory substrates and abilities. Amongst these altered abilities are faster reaction times for simple and complex sensory tasks. The crossed arm temporal-order judgement (TOJ) task is a complex tactile task in which TOJ error rate increases when arms are crossed. Reaction times (RTs) for this task are typically proportionate to the difficulty of the stimulus onset asynchrony (SOA) and increase more when the arms are crossed than when uncrossed. The objective of this study was to study the impact of musical training on RTs and accuracy for the crossed arm TOJ task. Seventeen musicians and 20 controls were tested. Musicians had significantly faster RTs for all crossed arm conditions and half of the uncrossed conditions. However, musicians had significantly more TOJ errors for the crossed posture. We speculate that faster musician TOJ RTs leave little time to consolidate conflicting internal and external task-related information when crossing the arms, leading to increased incorrect responses. These results provide novel insights on the potential mechanisms underlying the increased TOJ error rates when arms are crossed. Moreover, they add to the growing literature of altered sensory ability in musicians and propose an unexpected consequence of faster reaction times.

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.

Time after time: support for memory accounts of temporal preparation.

2019 ◽  
Author(s):  
Joe Butler ◽  
Samuel Ngabo ◽  
Marcus Missal
Keyword(s):  
Response Times ◽  
Reaction Times ◽  
Evidence Base ◽  
Higher Order ◽  
Order Effects ◽  
Previous Trial ◽  
Adaptive Responses ◽  
Temporal Preparation ◽  
Subsequent Trial ◽  
Higher Order Effects

Complex biological systems build up temporal expectations to facilitate adaptive responses to environmental events, in order to minimise costs associated with incorrect responses, and maximise the benefits of correct responses. In the lab, this is clearly demonstrated in tasks which show faster response times when the period between warning (S1) and target stimulus (S2) on the previous trial was short and slower when the previous trial foreperiod was long. The mechanisms driving such higher order effects in temporal preparation paradigms are still under debate, with key theories proposing that either i) the foreperiod leads to automatic modulation of the arousal system which influences responses on the subsequent trial, or ii) that exposure to a foreperiod results in the creation of a memory trace which is used to guide responses on the subsequent trial. Here we provide data which extends the evidence base for the memory accounts, by showing that previous foreperiod exposures are cumulative with reaction times shortening after repeated exposures; whilst also demonstrate that the higher order effects associated with a foreperiod remain active for several trials.

scholarly journals Giving Subjects the Eye and Showing Them the Finger: Socio-Biological Cues and Saccade Generation in the Anti-Saccade Task

Perception ◽  
10.1068/p7085 ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 131-147 ◽  
Author(s):  
Nicola J Gregory ◽  
Timothy L Hodgson
Keyword(s):  
Opposite Direction ◽  
Reaction Times ◽  
Oculomotor System ◽  
Short Soas ◽  
Stimulus Onset ◽  
Saccade Direction ◽  
Saccade Task ◽  
Saccadic Reaction Times ◽  
Saccadic Responses ◽  
Gaze Cues

Pointing with the eyes or the finger occurs frequently in social interaction to indicate direction of attention and one's intentions. Research with a voluntary saccade task (where saccade direction is instructed by the colour of a fixation point) suggested that gaze cues automatically activate the oculomotor system, but non-biological cues, like arrows, do not. However, other work has failed to support the claim that gaze cues are special. In the current research we introduced biological and non-biological cues into the anti-saccade task, using a range of stimulus onset asynchronies (SOAs). The anti-saccade task recruits both top–down and bottom–up attentional mechanisms, as occurs in naturalistic saccadic behaviour. In experiment 1 gaze, but not arrows, facilitated saccadic reaction times (SRTs) in the opposite direction to the cues over all SOAs, whereas in experiment 2 directional word cues had no effect on saccades. In experiment 3 finger pointing cues caused reduced SRTs in the opposite direction to the cues at short SOAs. These findings suggest that biological cues automatically recruit the oculomotor system whereas non-biological cues do not. Furthermore, the anti-saccade task set appears to facilitate saccadic responses in the opposite direction to the cues.

Traffic Signal Color Recognition Is a Problem for Both Protan and Deutan Color-Vision Deficients

2003 ◽  
Vol 45 (3) ◽  
pp. 495-503 ◽  
Author(s):  
David A. Atchison ◽  
Carol A. Pedersen ◽  
Stephen J. Dain ◽  
Joanne M. Wood
Keyword(s):  
Color Vision ◽  
Response Times ◽  
Reaction Times ◽  
Error Rates ◽  
Traffic Signal ◽  
White Background ◽  
Signal Design ◽  
Traffic Light ◽  
Light Signals ◽  
Signal Color

We investigated the effect of color-vision deficiency on reaction times and accuracy of identification of traffic light signals. Participants were 20 color-normal and 49 color-deficient males, the latter divided into subgroups of different severity and type. Participants performed a tracking task. At random intervals, stimuli simulating standard traffic light signals were presented against a white background at 5° to right or left. Participants identified stimulus color (red/yellow/green) by pressing an appropriate response button. Mean response times for color normals were 525, 410, and 450 ms for red, yellow, and green lights, respectively. For color deficients, response times to red lights increased with increase in severity of color deficiency, with deutans performing worse than protans of similar severity: response times of deuteranopes and protanopes were 53% and 35% longer than those of color normals. A similar pattern occurred for yellow lights, with deuteranopes and protanopes having increased response times of 85% and 53%, respectively. For green lights, response times of all groups were similar. Error rates showed patterns similar to those of response times. Contrary to previous studies, deutans performed much worse than protans of similar severity. Actual or potential applications of this research include traffic signal design and driver licensing.

Foveal Attention Modulates Responses to Peripheral Stimuli

2000 ◽  
Vol 83 (4) ◽  
pp. 2443-2452 ◽  
Author(s):  
Simo Vanni ◽  
Kimmo Uutela
Keyword(s):  
Visual Field ◽  
Target Location ◽  
Peripheral Vision ◽  
Human Subjects ◽  
Stimulus Onset ◽  
Visual Object ◽  
Frontal Eye Field ◽  
L1 Norm ◽  
Luminance Stimulus ◽  
The Right

When attending to a visual object, peripheral stimuli must be monitored for appropriate redirection of attention and gaze. Earlier work has revealed precentral and posterior parietal activation when attention has been directed to peripheral vision. We wanted to find out whether similar cortical areas are active when stimuli are presented in nonattended regions of the visual field. The timing and distribution of neuromagnetic responses to a peripheral luminance stimulus were studied in human subjects with and without attention to fixation. Cortical current distribution was analyzed with a minimum L1-norm estimate. Attention enhanced responses 100–160 ms after the stimulus onset in the right precentral cortex, close to the known location of the right frontal eye field. In subjects whose right precentral region was not distinctly active before 160 ms, focused attention commonly enhanced right inferior parietal responses between 180 and 240 ms, whereas in the subjects with clear earlier precentral response no parietal enhancement was detected. In control studies both attended and nonattended stimuli in the peripheral visual field evoked the right precentral response, whereas during auditory attention the visual stimuli failed to evoke such response. These results show that during focused visual attention the right precentral cortex is sensitive to stimuli in all parts of the visual field. A rapid response suggests bypassing of elaborate analysis of stimulus features, possibly to encode target location for a saccade or redirection of attention. In addition, load for frontal and parietal nodi of the attentional network seem to vary between individuals.

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