scholarly journals Coupling between Trigeminal-Induced Asymmetries in Locus Coeruleus Activity and Cognitive Performance

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1676
Author(s):  
Maria Paola Tramonti Tramonti Fantozzi ◽  
Ottavia Marconi ◽  
Federica Simoni ◽  
Vincenzo De De Cicco ◽  
Davide De De Cicco ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Cognitive Performance ◽  
Pupil Size ◽  
Cortical Excitability ◽  
Emg Activity ◽  
Performance Task ◽  
The Asymmetry ◽  
Spontaneous Fluctuations ◽  
Size Asymmetry ◽  
Average Pupil

In humans, the asymmetry in the masseter electromyographic (EMG) activity during clenching is positively correlated with the degree of pupil size asymmetry (anisocoria) at rest. Anisocoria reveals an asymmetry in LC activity, which may lead to an imbalance in cortical excitability, detrimental to performance. Hereby, we investigated, in individual subjects, the possibility that occlusal correction, which decreases EMG asymmetry, improves performance by balancing LC activity. Cognitive performance, task-related mydriasis, and pupil size at rest were modified by changing the occlusal condition. Occlusal-related changes in performance and mydriasis were negatively correlated with anisocoria changes in only 12/20 subjects. Within this population, spontaneous fluctuations in mydriasis and anisocoria also appeared negatively coupled. Occlusal-related changes in performance and mydriasis were negatively correlated with those in average pupil size (a proxy of average LC activity) in 19/20 subjects. The strongest association was observed for the pupil changes occurring on the side with higher EMG activity during clenching. These findings indicate that the effects of occlusal conditions on cognitive performance were coupled to changes in the asymmetry of LC activity in about half of the subjects, while they were related to changes in the average tonic LC activity in virtually all of them.

scholarly journals Chewing and Cognitive Improvement: The Side Matters

2021 ◽  
Vol 15 ◽  
Author(s):  
Maria Paola Tramonti Fantozzi ◽  
Vincenzo De Cicco ◽  
Davide De Cicco ◽  
Paola d’Ascanio ◽  
Enrico Cataldo ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Pupil Size ◽  
Simultaneous Increase ◽  
Emg Activity ◽  
Simultaneous Presence ◽  
Cognitive Improvement ◽  
Trigeminal Stimulation ◽  
Ascending Reticular Activating System ◽  
Before And After ◽  
Reticular Activating System

Chewing improves cognitive performance, which is impaired in subjects showing an asymmetry in electromyographic (EMG) masseter activity during clenching. In these subjects, the simultaneous presence of an asymmetry in pupil size (anisocoria) at rest indicates an imbalance in Ascending Reticular Activating System (ARAS) influencing arousal and pupil size. The aim of the present study was to verify whether a trigeminal EMG asymmetry may bias the stimulating effect of chewing on cognition. Cognitive performance and pupil size at rest were recorded before and after 1 min of unilateral chewing in 20 subjects with anisocoria, showing an EMG asymmetry during clenching. Unilateral chewing stimulated performance mainly when it occurred on the side of lower EMG activity (and smaller pupil size). Following chewing on the hypotonic side, changes in cognitive performance were negatively and positively correlated with those in anisocoria and pupil size, respectively. We propose that, following chewing on the hypotonic side, the arousing effects of trigeminal stimulation on performance are enhanced by a rebalancing of ARAS structures. At variance, following chewing on the hypertonic side, the arousing effect of trigeminal stimulation could be partially or completely prevented by the simultaneous increase in ARAS imbalance.

scholarly journals Pupil size, locus coeruleus, emotional intensity, and eye movements during unconstrained movie viewing

2019 ◽  
Vol 19 (10) ◽  
pp. 252c
Author(s):  
Sebastiaan Mathôt ◽  
Adina Wagner ◽  
Michael Hanke
Keyword(s):  
Eye Movements ◽  
Locus Coeruleus ◽  
Pupil Size ◽  
Emotional Intensity

scholarly journals Top-down coordination of local cortical state during selective attention

2020 ◽  
Author(s):  
Jochem van Kempen ◽  
Marc A. Gieselmann ◽  
Michael Boyd ◽  
Nicholas A. Steinmetz ◽  
Tirin Moore ◽  
...  
Keyword(s):  
Selective Attention ◽  
Cortical Excitability ◽  
Brain Regions ◽  
Global Changes ◽  
Top Down ◽  
Visual Hierarchy ◽  
Tightly Coupled ◽  
State Coordination ◽  
And Behavior ◽  
Spontaneous Fluctuations

AbstractSpontaneous fluctuations in cortical excitability influence sensory processing and behavior. These fluctuations, long known to reflect global changes in cortical state, were recently found to be modulated locally within a retinotopic map during spatially selective attention. We found that periods of vigorous (On) and faint (Off) spiking activity, the signature of cortical state fluctuations, were coordinated across brain areas along the visual hierarchy and tightly coupled to their retinotopic alignment. During top-down attention, this interareal coordination was enhanced and progressed along the reverse cortical hierarchy. The extent of local state coordination between areas was predictive of behavioral performance. Our results show that cortical state dynamics are shared across brain regions, modulated by cognitive demands and relevant for behavior.One Sentence SummaryInterareal coordination of local cortical state is retinotopically precise and progresses in a reverse hierarchical manner during selective attention.

scholarly journals Factors Influencing Saccadic Reaction Time: Effect of Task Modality, Stimulus Saliency, Spatial Congruency of Stimuli, and Pupil Size

2020 ◽  
Vol 14 ◽  
Author(s):  
Shimpei Yamagishi ◽  
Shigeto Furukawa
Keyword(s):  
Reaction Time ◽  
Locus Coeruleus ◽  
Pupil Size ◽  
Visual Target ◽  
Cognitive Task ◽  
Saccadic Reaction Time ◽  
Auditory Target ◽  
Target Condition ◽  
Related Factors ◽  
Stimulus Saliency

It is often assumed that the reaction time of a saccade toward visual and/or auditory stimuli reflects the sensitivities of our oculomotor-orienting system to stimulus saliency. Endogenous factors, as well as stimulus-related factors, would also affect the saccadic reaction time (SRT). However, it was not clear how these factors interact and to what extent visual and auditory-targeting saccades are accounted for by common mechanisms. The present study examined the effect of, and the interaction between, stimulus saliency and audiovisual spatial congruency on the SRT for visual- and for auditory-target conditions. We also analyzed pre-target pupil size to examine the relationship between saccade preparation and pupil size. Pupil size is considered to reflect arousal states coupling with locus-coeruleus (LC) activity during a cognitive task. The main findings were that (1) the pattern of the examined effects on the SRT varied between visual- and auditory-auditory target conditions, (2) the effect of stimulus saliency was significant for the visual-target condition, but not significant for the auditory-target condition, (3) Pupil velocity, not absolute pupil size, was sensitive to task set (i.e., visual-targeting saccade vs. auditory-targeting saccade), and (4) there was a significant correlation between the pre-saccade absolute pupil size and the SRTs for the visual-target condition but not for the auditory-target condition. The discrepancy between target modalities for the effect of pupil velocity and between the absolute pupil size and pupil velocity for the correlation with SRT may imply that the pupil effect for the visual-target condition was caused by a modality-specific link between pupil size modulation and the SC rather than by the LC-NE (locus coeruleus-norepinephrine) system. These results support the idea that different threshold mechanisms in the SC may be involved in the initiation of saccades toward visual and auditory targets.

scholarly journals More than Meets the Eye: the Relationship between Pupil Size and Locus Coeruleus Activity

Neuron ◽  
2016 ◽  
Vol 89 (1) ◽  
pp. 8-10 ◽  
Author(s):  
Vincent D. Costa ◽  
Peter H. Rudebeck
Keyword(s):  
Locus Coeruleus ◽  
Pupil Size ◽  
The Relationship

scholarly journals Effects of Sleep Deprivation on Brain Bioenergetics, Sleep, and Cognitive Performance in Cocaine-Dependent Individuals

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
George H. Trksak ◽  
Bethany K. Bracken ◽  
J. Eric Jensen ◽  
David T. Plante ◽  
David M. Penetar ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Cognitive Performance ◽  
Sleep Loss ◽  
Continuous Performance ◽  
Digit Symbol ◽  
Continuous Performance Task ◽  
Performance Task ◽  
Recovery Sleep ◽  
Symbol Substitution ◽  
Healthy Control

In cocaine-dependent individuals, sleep is disturbed during cocaine use and abstinence, highlighting the importance of examining the behavioral and homeostatic response to acute sleep loss in these individuals. The current study was designed to identify a differential effect of sleep deprivation on brain bioenergetics, cognitive performance, and sleep between cocaine-dependent and healthy control participants. 14 healthy control and 8 cocaine-dependent participants experienced consecutive nights of baseline, total sleep deprivation, and recovery sleep in the research laboratory. Participants underwent[31]P magnetic resonance spectroscopy (MRS) brain imaging, polysomnography, Continuous Performance Task, and Digit Symbol Substitution Task. Following recovery sleep,[31]P MRS scans revealed that cocaine-dependent participants exhibited elevated global brainβ-NTP (direct measure of adenosine triphosphate),α-NTP, and total NTP levels compared to those of healthy controls. Cocaine-dependent participants performed worse on the Continuous Performance Task and Digit Symbol Substitution Task at baseline compared to healthy control participants, but sleep deprivation did not worsen cognitive performance in either group. Enhancements of brain ATP levels in cocaine dependent participants following recovery sleep may reflect a greater impact of sleep deprivation on sleep homeostasis, which may highlight the importance of monitoring sleep during abstinence and the potential influence of sleep loss in drug relapse.

scholarly journals Pupil Size Reflects Exploration and Exploitation in Visual Search (and It’s Like Object-Based Attention)

2021 ◽  
Author(s):  
Franziska Regnath ◽  
Sebastiaan Mathôt
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Locus Coeruleus ◽  
Pupil Size ◽  
Search Task ◽  
Focused Attention ◽  
Exploration And Exploitation ◽  
Object Based ◽  
Exploration Behavior ◽  
Frequent Switching

AbstractThe adaptive gain theory (AGT) posits that activity in the locus coeruleus (LC) is linked to two behavioral modes: exploitation, characterized by focused attention on a single task; and exploration, characterized by a lack of focused attention and frequent switching between tasks. Furthermore, pupil size correlates with LC activity, such that large pupils indicate increased LC firing, and by extension also exploration behavior. Most evidence for this correlation in humans comes from complex behavior in game-like tasks. However, predictions of the AGT naturally extend to a very basic form of behavior: eye movements. To test this, we used a visual-search task. Participants searched for a target among many distractors, while we measured their pupil diameter and eye movements. The display was divided into four randomly generated regions of different colors. Although these regions were irrelevant to the task, participants were sensitive to their boundaries, and dwelled within regions for longer than expected by chance. Crucially, pupil size increased before eye movements that carried gaze from one region to another. We propose that eye movements that stay within regions (or objects) correspond to exploitation behavior, whereas eye movements that switch between regions (or objects) correspond to exploration behavior.Public Significance StatementWhen people experience increased arousal, their pupils dilate. The adaptive-gain theory proposes that pupil size reflects neural activity in the locus coeruleus (LC), which in turn is associated with two behavioral modes: a vigilant, distractible mode (“exploration”), and a calm, focused mode (“exploitation”). During exploration, pupils are larger and LC activity is higher than during exploitation. Here we show that the predictions of this theory generalize to eye movements: smaller pupils coincide with eye movements indicative of exploitation, while pupils slightly dilate just before make eye movements that are indicative of exploration.

Sign in / Sign up

Export Citation Format

Share Document