Microsaccades inhibition triggered by a repetitive visual distractor is not subject to habituation: Implications for the programming of reflexive saccades

Cortex ◽  
2020 ◽  
Vol 131 ◽  
pp. 251-264
Author(s):  
Francesca Bonetti ◽  
Matteo Valsecchi ◽  
Massimo Turatto

1994 ◽  
Vol 6 (4) ◽  
pp. 400-411 ◽  
Author(s):  
Avishai Henik ◽  
Robert Rafal ◽  
Dell Rhodes

Nine patients with chronic, unilateral lesions of the dorso-lateral prefrontal cortex including the frontal eye fields (FEF) made saccades toward contralesional and ipsilesional fields. The saccades were either voluntarily directed in response to arrows in the center of a visual display, or were reflexively summoned by a peripheral visual signal. Saccade latencies were compared to those made by seven neurologic control patients with chronic, unilateral lesions of dorsolateral prefrontal cortex sparing the FEF, and by 13 normal control subjects. In both the normal and neurologic control subjects, reflexive saccades had shorter Latencies than voluntary saccades. In the FEF lesion patients, voluntary saccades had longer latencies toward the contralesional field than toward the ipsilesional field. The opposite pattern was found for reflexive saccades: latencies of saccades to targets in the contralesional field were shorter than saccades summoned to ipsilesional targets. Reflexive saccades toward the ipsilesional field had abnormally prolonged latencies; they were comparable to the latencies observed for voluntary Saccades. The effect of FEF lesions on saccacles contrasted with those observed in a second experiment requiring a key press response: FEF lesion patients were slower in making key press responses to signals detected in the contralesional field. To assess covert attention and preparatory set the effects of precues providing advance information were measured in both saccade and key press experiments. Neither patient group showed any deficiency in using precues to shift attention or to prepare saccades. The FEF facilitates the generation of voluntary saccatles and also inhibits reflexive saccades to exogenous signals. FEF lesions may disinhibit the ipsilesional midbrain which in turn may inhibit the opposite colliculus to slow reflexive saccades toward the ipsilesional field.



1991 ◽  
Vol 1 (2) ◽  
pp. 171-180
Author(s):  
Junko Fukushima ◽  
Kikuro Fukushima ◽  
Nobuyuki Morita ◽  
Itaru Yamashita

Some schizophrenic patients have been known to have frontal cortical dysfunction. In view of the evidence that voluntary purposive eye movements and rapid head movements involve areas of the frontal cortex, investigations of saccade performance have been carried out on schizophrenics in various laboratories. We have compared performance of schizophrenic patients in tasks involving inhibition of reflexive saccades (no-saccade) and initiation of saccades without target (memory-saccade) with performance in. the antisaccade task. These measures were also compared with results of eye-head coordination tasks. Schizophrenics showed more errors and significantly longer latencies, with lower peak velocities at large amplitudes, in both the anti saccade task and the memory-saccade task. Performance with coordinated eye-head movement was basically similar, except for significantly longer latencies of head movement. These results suggest that schizophrenics may have a disturbance in initiating and executing purposive saccades without targets, and that dysfunction of the frontal cortex may contribute to this disturbance.



2002 ◽  
Vol 14 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Jason P. Mitchell ◽  
C. Neil Macrae ◽  
Iain D. Gilchrist

Conscious behavioral intentions can frequently fail under conditions of attentional depletion. In attempting to trace the cognitive origin of this effect, we hypothesized that failures of action control—specifically, oculomotor movement—can result from the imposition of fronto-executive load. To evaluate this prediction, participants performed an antisaccade task while simultaneously completing a working-memory task that is known to make variable demands on prefrontal processes (n-back task, see Jonides et al., 1997). The results of two experiments are reported. As expected, antisaccade error rates were increased in accordance with the fronto-executive demands of the n-back task (Experiment 1). In addition, the debilitating effects of working-memory load were restricted to the inhibitory component of the antisaccade task (Experiment 2). These findings corroborate the view that working memory operations play a critical role in the suppression of prepotent behavioral responses.



1999 ◽  
Vol 22 (4) ◽  
pp. 688-689
Author(s):  
Wolfgang Heide ◽  
Andreas Sprenger ◽  
Detlef Kömpf

In this commentary we describe findings in normal human subjects and in patients with visual hemineglect that support the importance of higher-level influences on saccade generation during visual exploration. As the duration of fixations increases with increases in the cognitive demand of the task, the timing of exploratory saccades is controlled more by centers of cognitive and perceptual processing at levels 4 and 5 than by reflex-like automatic processes at level 3. In line with this, unilateral frontal eye field lesions impair systematic, intentional saccadic exploration of visual scenes, causing prolonged fixations and contralesional hemineglect, but leave visually triggered reflexive saccades largely intact.



2003 ◽  
Vol 3 ◽  
pp. 881-902 ◽  
Author(s):  
Stephanie K. Seidlits ◽  
Tammie Reza ◽  
Kevin A. Briand ◽  
Anne B. Sereno

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.



Perception ◽  
1998 ◽  
Vol 27 (9) ◽  
pp. 1041-1054 ◽  
Author(s):  
Katsumi Watanabe ◽  
Shinsuke Shimojo

Identical visual targets moving across each other with equal and constant speed can be perceived either to bounce off or to stream through each other. This bistable motion perception has been studied mostly in the context of motion integration. Since the perception of most ambiguous motion is affected by attention, there is the possibility of attentional modulation occurring in this case as well. We investigated whether distraction of attention from the moving targets would alter the relative frequency of each percept. During the observation of the streaming/bouncing motion event in the peripheral visual field, visual attention was disrupted by an abrupt presentation of a visual distractor at various timings and locations (experiment 1; exogenous distraction of attention) or by the demand of an additional discrimination task (experiments 2 and 3; endogenous distraction of attention). Both types of distractions of attention increased the frequency of the bouncing percept and decreased that of the streaming percept. These results suggest that attention may facilitate the perception of object motion as continuing in the same direction as in the past.



2000 ◽  
Vol 130 (4) ◽  
pp. 540-544 ◽  
Author(s):  
Robin Walker ◽  
David G. Walker ◽  
Masud Husain ◽  
Christopher Kennard
Keyword(s):  


2015 ◽  
Vol 2 (7) ◽  
pp. 150151 ◽  
Author(s):  
John Fennell ◽  
Charlotte Goodwin ◽  
Jeremy F. Burn ◽  
Ute Leonards

Everybody would agree that vision guides locomotion; but how does vision influence choice when there are different solutions for possible foot placement? We addressed this question by investigating the impact of perceptual grouping on foot placement in humans. Participants performed a stepping stone task in which pathways consisted of target stones in a spatially regular path of foot falls and visual distractor stones in their proximity. Target and distractor stones differed in shape and colour so that each subset of stones could be easily grouped perceptually. In half of the trials, one target stone swapped shape and colour with a distractor in its close proximity. We show that in these ‘swapped’ conditions, participants chose the perceptually groupable, instead of the spatially regular, stepping location in over 40% of trials, even if the distance between perceptually groupable steps was substantially larger than normal step width/length. This reveals that the existence of a pathway that could be traversed without spatial disruption to periodic stepping is not sufficient to guarantee participants will select it and suggests competition between different types of visual input when choosing foot placement. We propose that a bias in foot placement choice in favour of visual grouping exists as, in nature, sudden changes in visual characteristics of the ground increase the uncertainty for stability.



2006 ◽  
Vol 18 (4) ◽  
pp. 522-538 ◽  
Author(s):  
Christian C. Ruff ◽  
Jon Driver

Attending to the location of an expected visual target can lead to anticipatory activations in spatiotopic occipital cortex, emerging before target onset. But less is known about how the brain may prepare for a distractor at a known location remote from the target. In a psychophysical experiment, we found that trial-to-trial advance knowledge about the presence of a distractor in the target-opposite hemifield significantly reduced its behavioral cost. In a subsequent functional magnetic resonance imaging experiment with similar task and stimuli, we found anticipatory activations in the occipital cortex contralateral to the expected distractor, but no additional target modulation, when participants were given advance information about a distractor's subsequent presence and location. Several attention-related control structures (frontal eye fields and superior parietal cortex) were active during attentional preparation for all trials, whereas the left superior prefrontal and right angular gyri were additionally activated when a distractor was anticipated. The right temporoparietal junction showed stronger functional coupling with occipital regions during preparation for trials with an isolated target than for trials with a distractor expected. These results show that anticipation of a visual distractor at a known location, remote from the target, can lead to (1) a reduction in the behavioral cost of that distractor, (2) preparatory modulation of the occipital cortex contralateral to the location of the expected distractor, and (3) anticipatory activation of distinct parietal and frontal brain structures. These findings indicate that specific components of preparatory visual attention may be devoted to minimizing the impact of distractors, not just to enhancements of target processing.



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