Correction: Performance Deficits in a Voluntary Saccade Task in Chinese “Express Saccade Makers”

82.3% of the traumatic brain injuries that U.S. Service Members and civilians sustain are concussions, also termed mild traumatic brain injuries (mTBI). Although the effects of concussion are relatively easy to diagnose in the acute phase, diagnosis remains difficult during the chronic phase. Here, we present data demonstrating improved sensitivity to oculomotor deficits of chronic mTBI through the use of a normorbaric hypoxic stress paradigm that approximates the partial pressure of oxygen encountered at about 13,000 feet above mean sea level. Saccadic performance was compared between mTBI and healthy control groups across normoxia, hypoxia, and finally upon return to normoxia. When compared to healthy controls at initial normoxia, the mTBI group showed a trend to poorer performance. At hypoxia and on return-to-normoxia, the difference between the groups increased to become statistically significant. Thus, hypoxia resulted in an increased saccadic impairment in the mTBI group, and, perhaps more importantly, the mTBI group evidenced a delayed recovery upon return to normoxia.

Download Full-text

The role of fixation disengagement and oculomotor preparation in gap saccade task is gap-duration dependent

Journal of Neurophysiology ◽

10.1152/jn.00259.2021 ◽

2021 ◽

Author(s):

Bing Li ◽

Jing Guang ◽

Mingsha Zhang

Keyword(s):

Spatial Information ◽

Brain State ◽

Primary Role ◽

Express Saccade ◽

Long Latency ◽

Theory Versus ◽

Saccade Direction ◽

Saccade Task ◽

Disengagement Theory ◽

Fixational Saccades

The influence of internal brain state on behavioral performance is well illustrated by the gap-saccade task, in which saccades might be initiated with short latency (express saccade) or with long latency (regular saccade) even though the external visual condition is identical. Accumulated evidence has demonstrated that the internal brain state is different before the initiation of an express saccade than of a regular saccade. However, the reported origin of the fluctuation of internal brain state is disputed among previous studies, e.g., the fixation disengagement theory versus the oculomotor preparation theory. In the present study, we examined these two theories by analyzing the rate and direction of fixational saccades, i.e., small amplitude saccades during fixation period, because they could be modulated by internal brain state. Since fixation disengagement is not spatially tuned, it might affect the rate but not direction of fixational saccade. In contrast, oculomotor preparation can contain the spatial information for upcoming saccade, thus, it might have a distinct effect on fixational saccade direction. We found that the different spatiotemporal characteristics of fixational saccades among tasks with different gap durations reveals different driven force to change the internal brain state. Under short gap duration (100 ms), fixation disengagement plays a primary role in switching internal brain state. Conversely, under medium (200 ms) and long (400 ms) gap durations, oculomotor preparation plays a primary role. These results suggest that both fixation disengagement and oculomotor preparation can change the internal brain state, but their relative contributions are gap-duration dependent.

Download Full-text

Human express saccade makers are impaired at suppressing visually evoked saccades

Journal of Neurophysiology ◽

10.1152/jn.1996.76.1.199 ◽

1996 ◽

Vol 76 (1) ◽

pp. 199-214 ◽

Cited By ~ 44

Author(s):

M. Biscaldi ◽

B. Fischer ◽

V. Stuhr

Keyword(s):

Human Subjects ◽

Brain Regions ◽

Express Saccades ◽

Express Saccade ◽

Oculomotor Behavior ◽

Control Subjects ◽

Latency Range ◽

Saccade Task ◽

Reflexive Saccades ◽

Fixation System

1. We report the oculomotor behavior of human subjects who produce unusually high numbers (> 30%) of express saccades (latency range 85-135 ms) in the overlap saccade task, where express saccades are usually absent or small in number (< 15%). We refer to these subjects as "express saccade makers" (ES makers). 2. We tested the hypothesis that ES makers have difficulties in maintaining fixation and in suppressing unwanted saccades to a suddenly appearing peripheral target by comparing the performances of 10 ES makers and 10 control subjects in gap and overlap antisaccade tasks and in a memory-guided saccade task. 3. The ES makers produced between 35% and 95% incorrect saccades toward the stimulus (prosaccades) in the antisaccade tasks, compared with control subjects, who produced < 20%. Their correct antisaccades appeared to be normal. 4. We further tested the ability of ES makers to maintain fixation and to avoid reflexive saccades to the onset of a target in the memory-guided saccade task. ES makers tended to glance to the briefly presented cue in many trials (4 of them in 50-80% of the trials) instead of delaying the saccade until fixation point offset. Most of the inappropriate saccades had latencies in the range of express saccades. 5. These results can be associated with the finding of fixation related neurons in different cortical and subcortical brain regions (e.g., inferior-parietal and frontal cortex, basal ganglia, superior colliculus). The unusual number of express saccades made by the ES makers in the standard overlap and gap tasks, and their unwanted short-latency reflexive saccades to the target in the memory-guided saccade task, are reminiscent of the performance in these tasks of monkeys whose collicular fixation neurons were chemically deactivated. The collicular fixation neurons are probably the final common pathway in the control of active fixation, and are in mutual inhibitory relationship with the saccade cells. 6. The decreased saccadic control observed in the ES makers suggests that saccade execution in humans is also gated by a fixation system. These ES makers may have reduced voluntarily control over saccade generation as a result of a defect or poor development of their fixation system.

Download Full-text

Inhibition of Voluntary Saccadic Eye Movement Commands by Abrupt Visual Onsets

Journal of Neurophysiology ◽

10.1152/jn.90708.2008 ◽

2009 ◽

Vol 101 (3) ◽

pp. 1222-1234 ◽

Cited By ~ 32

Author(s):

Jay A. Edelman ◽

Kitty Z. Xu

Keyword(s):

Visual Stimulus ◽

Saccadic Eye Movements ◽

Saccade Target ◽

Visual Response ◽

Express Saccade ◽

Voluntary Saccade ◽

The Face ◽

Visible Target ◽

Random Location ◽

Made In

Saccadic eye movements are made both to explore the visual world and to react to sudden sensory events. We studied the ability for humans to execute a voluntary (i.e., nonstimulus-driven) saccade command in the face of a suddenly appearing visual stimulus. Subjects were required to make a saccade to a memorized location when a central fixation point disappeared. At varying times relative to fixation point disappearance a visual distractor appeared at a random location. When the distractor appeared at locations distant from the target virtually no saccades were initiated in a 30- to 40-ms interval beginning 70–80 ms after appearance of the distractor. If the distractor was presented slightly earlier relative to saccade initiation then saccades tended to have smaller amplitudes, with velocity profiles suggesting that the distractor terminated them prematurely. In contrast, distractors appearing close to the saccade target elicited express saccade-like movements 70–100 ms after their appearance, although the saccade endpoint was generally scarcely affected by the distractor. An additional experiment showed that these effects were weaker when the saccade was made to a visible target in a delayed task and still weaker when the saccade itself was made in response to the abrupt appearance of a visual stimulus. A final experiment revealed that the effect is smaller, but quite evident, for very small stimuli. These results suggest that the transient component of a visual response can briefly but almost completely suppress a voluntary saccade command, but only when the stimulus evoking that response is distant from the saccade goal.

Download Full-text

Investigating Arousal, Saccade Preparation, and Global Luminance Effects on Microsaccade Behavior

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.602835 ◽

2021 ◽

Vol 15 ◽

Cited By ~ 1

Author(s):

Jui-Tai Chen ◽

Rachel Yep ◽

Yu-Fan Hsu ◽

Yih-Giun Cherng ◽

Chin-An Wang

Keyword(s):

Cognitive Processes ◽

Saccadic Eye Movements ◽

Emotional Arousal ◽

Luminance Level ◽

Peripheral Stimulus ◽

Voluntary Saccade ◽

Affective Processes ◽

Saccade Task ◽

Saccade Preparation

Microsaccades, small saccadic eye movements occurring during fixation, have been suggested to be modulated by various sensory, cognitive, and affective processes relating to arousal. Although the modulation of fatigue-related arousal on microsaccade behavior has previously been characterized, the influence of other aspects of arousal, such as emotional arousal, is less understood. Moreover, microsaccades are modulated by cognitive processes (e.g., voluntary saccade preparation) that could also be linked to arousal. To investigate the influence of emotional arousal, saccade preparation, and global luminance levels on microsaccade behavior, emotional auditory stimuli were presented prior to the onset of a fixation cue whose color indicated to look either at the peripheral stimulus (pro-saccade) or in the opposite direction of the stimulus (anti-saccade). Microsaccade behavior was found to be significantly modulated by saccade preparation and global luminance level, but not emotional arousal. In the pro- and anti-saccade task, microsaccade rate was lower during anti-saccade preparation as compared to pro-saccade preparation, though microsaccade dynamics were comparable during both trial types. Our results reveal a differential role of arousal linked to emotion, fatigue, saccade preparation, and global luminance level on microsaccade behavior.

Download Full-text

Face and Word Recognition in Patients with Left and Right Hemispheric Lesions: Evidence from Reaction Times and ERPs

Zeitschrift für Neuropsychologie ◽

10.1024//1016-264x.13.1.69 ◽

2002 ◽

Vol 13 (1) ◽

pp. 69-83 ◽

Cited By ~ 1

Author(s):

Stefan R. Schweinberger ◽

Thomas Klos ◽

Werner Sommer

Keyword(s):

Slow Wave ◽

Reaction Times ◽

Memory Search ◽

Event Related Potentials ◽

Performance Deficits ◽

Set Size ◽

Left Brain ◽

Related Potentials ◽

Abstract Words ◽

Left Brain Damage

Abstract: We recorded reaction times (RTs) and event-related potentials (ERPs) in patients with unilateral lesions during a memory search task. Participants memorized faces or abstract words, which were then recognized among new ones. The RT deficit found in patients with left brain damage (LBD) for words increased with memory set size, suggesting that their problem relates to memory search. In contrast, the RT deficit found in patients with RBD for faces was apparently related to perceptual encoding, a conclusion also supported by their reduced P100 ERP component. A late slow wave (720-1720 ms) was enhanced in patients, particularly to words in patients with LBD, and to faces in patients with RBD. Thus, the slow wave was largest in the conditions with most pronounced performance deficits, suggesting that it reflects deficit-related resource recruitment.

Download Full-text