Arousal level changes constantly and it has a profound influence on performance during everyday activities. Fluctuations in arousal are regulated by the autonomic nervous system, which is mainly controlled balanced activity of parasympathetic sympathetic systems, commonly indexed heart rate (HR) galvanic skin response (GSR), respectively. Although growing number studies have used pupil size to indicate arousal, research that directly examines relationship between HR or GSR limited. The goal...

The orienting reflex is initiated by a salient stimulus and facilitates quick, appropriate action. It involves rapid shift of the eyes, head, attention other physiological responses such as changes in heart rate transient pupil dilation. SC critical structure midbrain that selects incoming stimuli based on saliency relevance to coordinate behaviors, particularly gaze shifts, but its causal role dilation remains poorly understood mammals. Here, we examined primate control dynamics. While...

The sudden appearance of a novel stimulus in the environment initiates series orienting responses that include coordinated shifts gaze and attention, also transient changes pupil size. Although numerous studies have identified significant effect saliency on effects size are less understood. To examine salience-evoked responses, we presented visual, auditory, or audiovisual stimuli while monkeys fixated central visual spot. Transient dilation was elicited after presentation regardless target...

Abstract The ability to generate flexible behaviors accommodate changing goals in response identical sensory stimuli is a signature that inherited humans and higher‐level animals. In the oculomotor system, this function has often been examined with anti‐saccade task, which subjects are instructed, prior stimulus appearance, either automatically look at peripheral (pro‐saccade) or suppress automatic voluntarily opposite direction from (anti‐saccade). Distinct neural preparatory activity...

Abstract The sudden appearance of a novel stimulus initiates series responses to orient the body for appropriate actions, including not only shifts gaze and attention, but also transient pupil dilation. Modulation dynamics by properties is less understood, although its effects on other components orienting have been extensively explored. Microstimulation superior colliculus evoked dilation, initial component dilation microstimulation was similar that elicited presentation salient sensory...

The appearance of a salient stimulus evokes saccadic eye movements and pupil dilation as part the orienting response. Although role superior colliculus (SC) in saccade has been established separately, whether how these responses are coordinated remains unknown. SC also receives global luminance signals from retina, but modulates by Here, we used microstimulation to causally determine coordinates varying stimulation frequency male monkeys. Stimulation modulated responses, with trial-by-trial...

Abstract Pupil dilation is consistently evoked by affective and cognitive processing, this can result from sympathetic activation or parasympathetic inhibition. The relative contributions of the systems on pupillary response induced emotion cognition may be different. Sympathetic activity regulated global luminance level. Higher levels lead to greater system while lower system. To understand nervous responses associated with saccade preparation, emotional auditory stimuli were presented...

Late-life depression (LLD) is a psychiatric disorder in older adults, characterized by high prevalence and significant mortality rates. Thus, it imperative to develop objective cost-effective methods for detecting LLD. Individuals with often exhibit disrupted levels of arousal, microsaccades, as type fixational eye movement that can be measured non-invasively, are known modulated arousal. This makes microsaccades promising candidate biomarkers In this study, we used high-resolution,...

Introduction This study aims to investigate the locus coeruleus-norepinephrine system (LC-NE) function in late-life depression (LLD) patients by examining task-evoked pupil dilation emotional face-word Stroop task, given recently established coupling between and LC-NE activation. Materials Methods Using video-based eye-tracking principal component analysis, we explored responses eye blinks LLD (N = 25) older healthy controls (CTRL) 29) determine whether there were alterations compared CTRL....

Abstract Achieving optimal performance requires effectively resolving emotional conflict arising from the interference of task‐irrelevant, emotionally salient stimuli. While microsaccade behavior has been linked to various cognitive and processes, whether affects responses remains be determined. Additionally, pupil dilation is known modulated by signals, both microsaccades are arguably mediated superior colliculus (SC). However, relationship between poorly understood. In this study, we...

Abstract Background Late-life depression (LLD) is a prevalent neuropsychiatric disorder in the older population. While LLD exhibits high mortality rates, depressive symptoms adults are often masked by physical health conditions. In younger adults, associated with deficits pupil light reflex and eye blink rate, suggesting potential use of these responses as biomarkers for LLD. Methods We conducted study using video-based eye-tracking to investigate patients ( n = 25), (OLD) healthy controls...

Significance The pupil regulates the amount of light entering eyes to optimize visual sensitivity and sharpness. system selects objects interest for future fixation, size can be adjusted object luminance before fixation. This study demonstrates that intermediate layers superior colliculus (SC), a phylogenetically conserved structure controlling eye movements spatial attention, coordinates this predictive response. By manipulating SC (SCi) excitability via microstimulation lidocaine...

Abstract Pupil size reflects a proxy for neural activity associated with global luminance, arousal and cognitive processing. Microsaccades are also modulated by Are these effects of signals on pupil microsaccades coordinated? If so, via what mechanisms? We hypothesized that if coordinately processes, immediately before microsaccade onset, as an index ongoing processing, should correlate responses during tasks alternating signals. Here, we examined the relationship between in included...

Saccadic eye movements are directed to the objects of interests and enable high-resolution visual images in exploration world. There is a trial-to-trial variation saccade dynamics even simple task, possibly attributed arousal fluctuations. Previous studies have showed that an increase fatigue level over time, also known as time-on-task, can be revealed by peak velocity. In addition, pupil size, controlled autonomic nervous system, has long been used index. However, limited research done with...

Abstract The locus coeruleus‐norepinephrine (LC‐NE) system, which regulates arousal levels, is important for cognitive control, including emotional conflict resolution. Additionally, the LC‐NE system implicated in P300 generation. If mediated by and considering established correlations between LC activity pupil dilation, amplitude should correlate with task‐evoked (phasic) dilation on a trial‐by‐trial basis. However, prior studies, predominantly utilizing oddball‐type paradigms, have not...

ABSTRACT Evidence has demonstrated that athletes exhibit superior cognitive performance associated with executive control. In the oculomotor system, this function been examined using interleaved pro‐saccade and anti‐saccade task (IPAST), wherein participants, prior to target appearance, are instructed either automatically look at peripheral (pro‐saccade) or suppress automatic response voluntarily in opposite direction (anti‐saccade). While IPAST provided much insight into sensorimotor...

Pupil size is a non-invasive index for autonomic arousal mediated by the locus coeruleus-norepinephrine (LC-NE) system. While pupil and its derivative (velocity) are increasingly used as indicators of arousal, limited research has investigated relationships between other well-known responses. Here, we simultaneously recorded pupillometry, heart rate, skin conductance, pulse wave amplitude, respiration signals during an emotional face-word Stroop task, in which task-evoked (phasic) dilation...