Head and eye movements are each facilitated by the offset of a central fixation point in a virtual gap paradigm

2020 ◽  
Author(s):  
Jason Flindall ◽  
Aman Sara ◽  
Alan Kingstone
Keyword(s):  
Eye Movements ◽  
Central Fixation Point ◽  
Gap Paradigm ◽  
Central Fixation

Altered Control of Visual Fixation and Saccadic Eye Movements in Attention-Deficit Hyperactivity Disorder

2003 ◽  
Vol 90 (1) ◽  
pp. 503-514 ◽  
Author(s):  
Douglas P. Munoz ◽  
Irene T. Armstrong ◽  
Karen A. Hampton ◽  
Kimberly D. Moore
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Eye Movements ◽  
Attention Deficit ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Stimulus Presentation ◽  
Central Fixation Point ◽  
Hyperactivity Disorder ◽  
Saccade Task ◽  
Central Fixation

Attention-deficit hyperactivity disorder (ADHD) is characterized by the overt symptoms of impulsiveness, hyperactivity, and inattention. A frontostriatal pathophysiology has been hypothesized to produce these symptoms and lead to reduced ability to inhibit unnecessary or inappropriate behavioral responses. Oculomotor tasks can be designed to probe the ability of subjects to generate or inhibit reflexive and voluntary responses. Because regions of the frontal cortex and basal ganglia have been identified in the control of voluntary responses and saccadic suppression, we hypothesized that children and adults diagnosed with ADHD may have specific difficulties in oculomotor tasks requiring the suppression of reflexive or unwanted saccadic eye movements. To test this hypothesis, we measured eye movement performance in pro- and anti-saccade tasks of 114 ADHD and 180 control participants ranging in age from 6 to 59 yr. In the pro-saccade task, participants were instructed to look from a central fixation point toward an eccentric visual target. In the anti-saccade task, stimulus presentation was identical, but participants were instructed to suppress the saccade to the stimulus and instead look from the central fixation point to the side opposite the target. The state of fixation was manipulated by presenting the target either when the central fixation point was illuminated (overlap condition) or at some time after it disappeared (gap condition). In the pro-saccade task, ADHD participants had longer reaction times, greater intra-subject variance, and their saccades had reduced peak velocities and increased durations. In the anti-saccade task, ADHD participants had greater difficulty suppressing reflexive pro-saccades toward the eccentric target, increased reaction times for correct anti-saccades, and greater intra-subject variance. In a third task requiring prolonged fixation, ADHD participants generated more intrusive saccades during periods when they were required to maintain steady fixation. The results suggest that ADHD participants have reduced ability to suppress unwanted saccades and control their fixation behavior voluntarily, a finding that is consistent with a fronto-striatal pathophysiology. The findings are discussed in the context of recent neurophysiological data from nonhuman primates that have identified important control signals for saccade suppression that emanate from frontostriatal circuits.

Effects of superior temporal polysensory area lesions on eye movements in the macaque monkey

1995 ◽  
Vol 73 (1) ◽  
pp. 1-19 ◽  
Author(s):  
S. P. Scalaidhe ◽  
T. D. Albright ◽  
H. R. Rodman ◽  
C. G. Gross
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Temporal Cortex ◽  
Saccadic Eye Movements ◽  
Saccade Latency ◽  
Vertical Meridian ◽  
Central Fixation Point ◽  
Visuomotor Behavior ◽  
Visual Targets ◽  
Central Fixation

1. On the basis of its anatomic connections and single-unit properties, the superior temporal polysensory area (STP) would seem to be primarily involved in visuospatial functions. We have examined the effects of lesions of STP on saccadic eye movements, visual fixation, and smooth pursuit eye movements to directly test the hypothesis that STP is involved in visuospatial and visuomotor behavior. 2. Seven monkeys were trained to make saccades to targets 8, 15, and 22 degrees from a central fixation point along the horizontal meridian and 8 degrees from the central fixation point along the vertical meridian. One monkey was also trained to make saccades to auditory targets. The same monkeys were trained to foveate a stationary central fixation point and to follow it with a smooth pursuit eye movement when it began moving 5, 13, or 20 degrees/s. Four monkeys received unilateral STP lesions, one received a bilateral STP lesion, and as a control, two received unilateral inferior temporal cortex (IT) lesions. After testing, three of the animals with unilateral STP lesions received an additional STP lesion in the hemisphere contralateral to the first lesion. Similarly, one animal with a unilateral IT lesion received an additional IT lesion in the hemisphere contralateral to the first lesion. 3. All monkeys with complete removal of STP showed a significant increase in saccade latency to the most peripheral contralateral target, and most also had increased saccade latencies to the other contralateral targets. Saccades directed to targets along the vertical meridian or toward targets in the hemifield ipsilateral to the lesion were not impaired by removal of STP. By contrast, IT lesions did not impair the monkeys' ability to make saccadic eye movements to visual stimuli at any location, showing that saccades to visually guided targets are not impaired nonspecifically by damage to visual cortex. 4. The deficit in making eye movements after STP lesions was specific to saccade latency, with little effect on the accuracy of saccades to visual targets. 5. In the one monkey trained to make saccades to auditory targets, removal of STP did not impair saccades to auditory targets contralateral to its lesion, despite this monkey showing the largest increase in saccades latencies to visual targets. 6. There was complete recovery of saccade latency to the baseline level of performance on the saccade task after all STP lesions.(ABSTRACT TRUNCATED AT 400 WORDS)

Movements of the Retinae of Jumping Spiders (Salticidae: Dendryphantinae) in Response to Visual Stimuli

1969 ◽  
Vol 51 (2) ◽  
pp. 471-493 ◽  
Author(s):  
M. F. LAND
Keyword(s):  
Eye Movements ◽  
Spontaneous Activity ◽  
Visual Axis ◽  
Retinal Surface ◽  
Jumping Spiders ◽  
Spatial Alignment ◽  
Edge Detectors ◽  
Central Regions ◽  
Stimulation Of ◽  
Central Fixation

1. Movements made by the principal eyes of jumping spiders (Phidippus and Metaphidippus spp.) have been investigated using an ophthalmoscopic technique which permits simultaneous observation and stimulation of the retinal surface. 2. The eye-movements are produced by six muscles. Four are attached to the carapace, and displace each retina latero-medially and dorso-ventrally. The remaining pair are thin bands of muscle which encircle the eye-tube. These twist the eye-tube, rotating the retina about the visual axis (torsion). 3. The nerve supplying these muscles contains only six axons. Each axon terminates in one of the six muscles. 4. Four types of eye-movements are observed. These are spontaneous activity, saccades, tracking and scanning. All movements are usually conjugate. 5. Spontaneous activity consists of a very variable, periodic side-to-side motion of the retinae. It is associated with states of high excitability, and occurs whether or not there is any structure in the field of view. 6. Saccades occur when a small stimulus (e.g. a dark dot) is presented to, or moved upon, the retinae of either the principal eyes or the antero-lateral eyes. In a saccade the retinae move towards the image of the target so that they come to rest with their central regions fixated on the target. 7. If the target moves the retinae track it, maintaining central fixation. 8. Scanning normally follows a saccade. It consists of an oscillatory, side-to-side movement of the retinae across the stimulus, with a period of 1-2 sec., and a simultaneous torsional movement in which the retinae partially rotate about the visual axes, through an angle of approximately 50° and with a period of 5-15 sec. 9. Jumping spiders distinguish other jumping spiders from potential prey by the geometry of their legs. It is suggested that scanning is a pattern-recognition procedure in which the torsional movements are concerned with the spatial alignment of line or edge detectors, and the horizontal component with providing relative motion between these detectors and the stationary stimulus.

scholarly journals Voluntary Spatial Attention has Different Effects on Voluntary and Reflexive Saccades

2003 ◽  
Vol 3 ◽  
pp. 881-902 ◽  
Author(s):  
Stephanie K. Seidlits ◽  
Tammie Reza ◽  
Kevin A. Briand ◽  
Anne B. Sereno
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Fundamental Issue ◽  
Fixation Condition ◽  
The Subject ◽  
Symbolic Cues ◽  
The Relationship ◽  
Reflexive Saccades ◽  
Gap Paradigm

Although numerous studies have investigated the relationship between saccadic eye movements and spatial attention, one fundamental issue remains controversial. Some studies have suggested that spatial attention facilitates saccades, whereas others have claimed that eye movements are actually inhibited when spatial attention is engaged. However, these discrepancies may be because previous research has neglected to separate and specify the effects of attention for two distinct types of saccades, namely reflexive (stimulus-directed) and voluntary (antisaccades). The present study explored the effects of voluntary spatial attention on both voluntary and reflexive saccades. Results indicate that voluntary spatial attention has different effects on the two types of saccades. Antisaccades were always greatly facilitated following the engagement of spatial attention by symbolic cues (arrows) informing the subject where the upcoming saccade should be directed. Reflexive saccades showed little or no cueing effects and exhibited significant facilitation only when these cues were randomly intermixed with uncued trials. In addition, the present study tested the effects of fixation condition (gap, step, and overlap) on attentional modulation. Cueing effects did not vary due to fixation condition. Thus, voluntary spatial attention consistently showed different effects on voluntary and reflexive saccades, and there was no evidence in these studies that voluntary cues inhibit reflexive saccades, even in a gap paradigm.

scholarly journals Attention Combines Similarly in Covert and Overt Conditions

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 16
Author(s):  
Blair ◽  
Ristic
Keyword(s):  
Eye Movements ◽  
Human Behavior ◽  
Combined Effect ◽  
Combined Effects ◽  
Unexpected Events ◽  
Do So ◽  
Central Fixation

Attention is classically classified according to mode of engagement into voluntary and reflexive, and type of operation into covert and overt. The first distinguishes whether attention is elicited intentionally or by unexpected events; the second, whether attention is directed with or without eye movements. Recently, this taxonomy has been expanded to include automated orienting engaged by overlearned symbols and combined attention engaged by a combination of several modes of function. However, so far, combined effects were demonstrated in covert conditions only, and, thus, here we examined if attentional modes combined in overt responses as well. To do so, we elicited automated, voluntary, and combined orienting in covert, i.e., when participants responded manually and maintained central fixation, and overt cases, i.e., when they responded by looking. The data indicated typical effects for automated and voluntary conditions in both covert and overt data, with the magnitudes of the combined effect larger than the magnitude of each mode alone as well as their additive sum. No differences in the combined effects emerged across covert and overt conditions. As such, these results show that attentional systems combine similarly in covert and overt responses and highlight attention’s dynamic flexibility in facilitating human behavior.

scholarly journals Cortical Dynamics during the Preparation of Antisaccadic and Prosaccadic Eye Movements in Humans in a Gap Paradigm

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e63751 ◽  
Author(s):  
Isabel Cordones ◽  
Carlos M. Gómez ◽  
Miguel Escudero
Keyword(s):  
Eye Movements ◽  
Cortical Dynamics ◽  
Gap Paradigm

The Effects of the Fixation Cue in Inhibition of Return

2013 ◽  
pp. 109-118
Author(s):  
Yujie Li ◽  
Chunlin Li ◽  
Jinglong Wu
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Inhibition Of Return ◽  
Stimulus Onset ◽  
Central Fixation Point ◽  
Object A ◽  
Potential Target ◽  
Attentional Effect ◽  
Onset Asynchrony ◽  
Target Locations ◽  
Central Fixation

In experiments examining inhibition of return (IOR), an attentional effect that inhibits the returning of attention to a previously attended location or object, a second cue during the stimulus onset asynchrony (SOA) period is typically used. This is done to control the reorienting of attention from a peripherally cued location back to the central fixation point before the target appears. Recently, there have been numerous studies which demonstrate that fixation cues are effective in revealing IOR. Plenty of factors have been shown to influence the effects of the fixation cue in IOR, including the time onset of the fixation cue, the number of potential target locations, the attentional demands of performing the task, the modality of the fixation cue, and the condition of participants. Here, the authors review previous work that has examined the effects of the fixation cue in IOR.

Some Factors in the Recognition of Tachistoscopically Presented Alphabetical Arrays

1972 ◽  
Vol 35 (3) ◽  
pp. 951-959 ◽  
Author(s):  
Robert Fudin ◽  
John T. Kenny
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Retinal Location ◽  
Right Visual Field ◽  
Central Fixation Point ◽  
Information Delay ◽  
The Difference ◽  
The Right ◽  
The Relationship ◽  
Central Fixation

Six-letter nonsense arrays, constructed from a 12-letter population which was not made known to 20 Ss, were tachistoscopically shown successively in the right visual field (RVF) and left visual field (LVF) at three displacements from a central fixation point. Recognition scores were higher for stimuli in the RVF at each displacement. In each case RVF superiority was limited to letters in the first array-half (letters 1, 2, 3). These results agree with prior findings obtained with targets made up of six letters known to S (Fudin, 1969). Reportability of a tachistoscopically exposed letter, in part, is a function of the relationship between its retinal location and the delay before it is scanned. Location determines the amount of information a letter contains before it starts to fade-out (the more acute the area, the greater the information), delay determines the period of information dissipation prior to scanning. These ideas were used to explain the contrast between high error scores for middle-array letters in the bow-shaped error curves found in this experiment and the low values often reported for these letters when targets are shown across fixation, and the finding that the difference between error scores for letters in the first and second array-halves was greater for targets at each displacement in the right than the left visual field.

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