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Freund B, Nair D, Bulacio J, Najm I, Taylor K, Moosa AN. Pupillary constriction on stimulation of the parietal cortex-A novel finding. Epileptic Disord 2024. [PMID: 38943530 DOI: 10.1002/epd2.20252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 05/16/2024] [Accepted: 05/26/2024] [Indexed: 07/01/2024]
Abstract
Pupillary changes can be an important semiologic feature in focal epilepsy. Though the subcortical networks involving pupillomotor function have been described, cortical generators of pupillary dilation and constriction in humans are not well known. In this report, we describe a case of pupillary constriction occurring during seizures in a patient with drug resistant focal epilepsy. On stereoelectroencephalography, onset was noted within the posterior segment of the right intraparietal sulcus and direct cortical electrical stimulation of these electrode contacts reproduced pupillary constriction associated with habitual seizures. This is the first case report to describe ictal pupillary constriction during SEEG with confirmation of the cortical localization by direct cortical electrical stimulation. The posterior segment of the right intraparietal sulcus localization of pupillary constriction may aid in surgical evaluation patients with drug resistant focal epilepsy.
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Affiliation(s)
- Brin Freund
- Department of Neurology, Mayo Clinic Florida, Jacksonville, Florida, USA
| | - Dileep Nair
- Epilepsy Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Juan Bulacio
- Epilepsy Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Imad Najm
- Epilepsy Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Kenneth Taylor
- Epilepsy Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ahsan N Moosa
- Epilepsy Center, Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
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2
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Antoniades CA, Spering M. Eye movements in Parkinson's disease: from neurophysiological mechanisms to diagnostic tools. Trends Neurosci 2024; 47:71-83. [PMID: 38042680 DOI: 10.1016/j.tins.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/13/2023] [Accepted: 11/01/2023] [Indexed: 12/04/2023]
Abstract
Movement disorders such as Parkinson's disease (PD) impact oculomotor function - the ability to move the eyes accurately and purposefully to serve a multitude of sensory, cognitive, and secondary motor tasks. Decades of neurophysiological research in monkeys and behavioral studies in humans have characterized the neural basis of healthy oculomotor control. This review links eye movement abnormalities in persons living with PD to the underlying neurophysiological mechanisms and pathways. Building on this foundation, we highlight recent progress in using eye movements to gauge symptom severity, assess treatment effects, and serve as potential precision biomarkers. We conclude that whereas eye movements provide insights into PD mechanisms, based on current evidence they appear to lack sufficient sensitivity and specificity to serve as a standalone diagnostic tool. Their full potential may be realized when combined with other disease indicators in big datasets.
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Affiliation(s)
- Chrystalina A Antoniades
- Nuffield Department of Clinical Neurosciences, Medical Sciences Division, University of Oxford, Oxford, UK.
| | - Miriam Spering
- Department of Ophthalmology & Visual Sciences and Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, Canada.
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3
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Wang CA, Muggleton NG, Chang YH, Barquero C, Kuo YC. Time-on-task effects on human pupillary and saccadic metrics after theta burst transcranial magnetic stimulation over the frontal eye field. IBRO Neurosci Rep 2023; 15:364-375. [PMID: 38046886 PMCID: PMC10689284 DOI: 10.1016/j.ibneur.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/01/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Pupil size undergoes constant changes primarily influenced by ambient luminance. These changes are referred to as the pupillary light reflex (PLR), where the pupil transiently constricts in response to light. PLR kinematics provides valuable insights into autonomic nervous system function and have significant clinical applications. Recent research indicates that attention plays a role in modulating the PLR, and the circuit involving the frontal eye field (FEF) and superior colliculus is causally involved in controlling this pupillary modulation. However, there is limited research exploring the role of the human FEF in these pupillary responses, and its impact on PLR metrics remains unexplored. Additionally, although the protocol of continuous theta-burst stimulation (cTBS) is well-established, the period of disruption after cTBS is yet to be examined in pupillary responses. Our study aimed to investigate the effects of FEF cTBS on pupillary and saccadic metrics in relation to time spent performing a task (referred to as time-on-task). We presented a bright stimulus to induce the PLR in visual- and memory-delay saccade tasks following cTBS over the right FEF or vertex. FEF cTBS, compared to vertex cTBS, resulted in decreased baseline pupil size, peak constriction velocities, and amplitude. Furthermore, the time-on-task effects on baseline pupil size, peak amplitude, and peak time differed between the two stimulation conditions. In contrast, the time-on-task effects on saccadic metrics were less pronounced between the two conditions. In summary, our study provides the first evidence that FEF cTBS affects human PLR metrics and that these effects are modulated by time-on-task.
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Affiliation(s)
- Chin-An Wang
- Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
- Eye-Tracking Laboratory, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Neil G. Muggleton
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City, Taiwan
- Cognitive Intelligence and Precision Healthcare Center, National Central University, Taoyuan City, Taiwan
| | - Yi-Hsuan Chang
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City, Taiwan
| | - Cesar Barquero
- Eye-Tracking Laboratory, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City, Taiwan
- Department of Physical Activity and Sport Science, Universidad Peruana de Ciencias Aplicadas, Lima, Peru
| | - Ying-Chun Kuo
- Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
- Eye-Tracking Laboratory, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
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4
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Koevoet D, Strauch C, Naber M, der Stigchel SV. The Costs of Paying Overt and Covert Attention Assessed With Pupillometry. Psychol Sci 2023; 34:887-898. [PMID: 37314425 DOI: 10.1177/09567976231179378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
Attention can be shifted with or without an accompanying saccade (i.e., overtly or covertly, respectively). Thus far, it is unknown how cognitively costly these shifts are, yet such quantification is necessary to understand how and when attention is deployed overtly or covertly. In our first experiment (N = 24 adults), we used pupillometry to show that shifting attention overtly is more costly than shifting attention covertly, likely because planning saccades is more complex. We pose that these differential costs will, in part, determine whether attention is shifted overtly or covertly in a given context. A subsequent experiment (N = 24 adults) showed that relatively complex oblique saccades are more costly than relatively simple saccades in horizontal or vertical directions. This provides a possible explanation for the cardinal-direction bias of saccades. The utility of a cost perspective as presented here is vital to furthering our understanding of the multitude of decisions involved in processing and interacting with the external world efficiently.
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Affiliation(s)
- Damian Koevoet
- Experimental Psychology, Helmholtz Institute, Utrecht University
| | | | - Marnix Naber
- Experimental Psychology, Helmholtz Institute, Utrecht University
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5
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Hsu TY, Wang HY, Chen JT, Wang CA. Investigating the role of human frontal eye field in the pupil light reflex modulation by saccade planning and working memory. Front Hum Neurosci 2022; 16:1044893. [DOI: 10.3389/fnhum.2022.1044893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/02/2022] [Indexed: 11/18/2022] Open
Abstract
The pupil constricts in response to an increase in global luminance level, commonly referred to as the pupil light reflex. Recent research has shown that these reflex responses are modulated by high-level cognition. There is larger pupil constriction evoked by a bright stimulus when the stimulus location spatially overlaps with the locus of attention, and these effects have been extended to saccade planning and working memory (here referred to as pupil local-luminance modulation). Although research in monkeys has further elucidated a central role of the frontal eye field (FEF) and superior colliculus in the pupil local-luminance modulation, their roles remain to be established in humans. Through applying continuous theta-burst transcranial magnetic stimulation over the right FEF (and vertex) to inhibit its activity, we investigated the role of the FEF in human pupil local-luminance responses. Pupil light reflex responses were transiently evoked by a bright patch stimulus presented during the delay period in the visual- and memory-delay tasks. In the visual-delay task, larger pupil constriction was observed when the patch location was spatially aligned with the target location in both stimulation conditions. More interestingly, after FEF stimulation, larger pupil constriction was obtained when the patch was presented in the contralateral, compared to the ipsilateral visual field of the stimulation. In contrast, FEF stimulation effects were absence in the memory-delay task. Linear mixed model results further found that stimulation condition, patch location consistency, and visual field significantly modulated observed pupil constriction responses. Together, our results constitute the first evidence of FEF modulation in human pupil local-luminance responses.
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Karpouzian-Rogers T, Sweeney JA, Rubin LH, McDowell J, Clementz BA, Gershon E, Keshavan MS, Pearlson GD, Tamminga CA, Reilly JL. Reduced task-evoked pupillary response in preparation for an executive cognitive control response among individuals across the psychosis spectrum. Schizophr Res 2022; 248:79-88. [PMID: 35963057 DOI: 10.1016/j.schres.2022.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 04/29/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022]
Abstract
Task-evoked pupillary response (TEPR) is a measure of physiological arousal modulated by cognitive demand. Healthy individuals demonstrate greater TEPR prior to correct versus error antisaccade trials and correct antisaccade versus visually guided saccade (VGS) trials. The relationship between TEPR and antisaccade performance in individuals with psychotic disorders and their relatives has not been investigated. Probands with schizophrenia, schizoaffective disorder, psychotic bipolar disorder, their first-degree relatives, and controls from the B-SNIP study completed antisaccade and VGS tasks. TEPR prior to execution of responses on these tasks was evaluated among controls compared to probands and relatives according to diagnostic groups and neurobiologically defined subgroups (biotypes). Controls demonstrated greater TEPR on antisaccade correct versus error versus VGS trials. TEPR was not differentiated between antisaccade correct versus error trials in bipolar or schizophrenia probands, though was greater on antisaccade compared to prosaccade trials. There was no modulation of TEPR in schizoaffective probands. Relatives of schizophrenia and schizoaffective probands and those with elevated psychosis spectrum traits failed to demonstrate differential TEPR on antisaccade correct versus error trials. No proband or relative biotypes demonstrated differential TEPR on antisaccade correct versus error trials, and only proband biotype 3 and relative biotypes 3 and 2 demonstrated greater TEPR on antisaccade versus VGS trials. Our findings suggest that aberrant modulation of preparatory activity prior to saccade execution contributes to impaired executive cognitive control across the psychosis spectrum, including nonpsychotic relatives with elevated clinical risk. Reduced pupillary modulation under cognitive challenge may thus be a biomarker for the psychosis phenotype.
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Affiliation(s)
- Tatiana Karpouzian-Rogers
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America
| | - John A Sweeney
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
| | - Leah H Rubin
- Departments of Neurology and Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, United States of America; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Jennifer McDowell
- Department of Psychology, University of Georgia, Athens, GA, United States of America
| | - Brett A Clementz
- Department of Psychology, University of Georgia, Athens, GA, United States of America
| | - Elliot Gershon
- Psychiatry, University of Chicago, Chicago, IL, United States of America
| | - Matcheri S Keshavan
- Department of Psychiatry, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States of America
| | - Godfrey D Pearlson
- Departments of Psychiatry and Neurobiology, Yale University and Olin Neuropsychiatric Research Center, Hartford, CT, United States of America
| | - Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States of America
| | - James L Reilly
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, United States of America.
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7
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Chen JT, Kuo YC, Hsu TY, Wang CA. Fatigue and Arousal Modulations Revealed by Saccade and Pupil Dynamics. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159234. [PMID: 35954585 PMCID: PMC9367726 DOI: 10.3390/ijerph19159234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022]
Abstract
Saccadic eye movements are directed to the objects of interests and enable high-resolution visual images in the exploration of the visual world. There is a trial-to-trial variation in saccade dynamics even in a simple task, possibly attributed to arousal fluctuations. Previous studies have showed that an increase of fatigue level over time, also known as time-on-task, can be revealed by saccade peak velocity. In addition, pupil size, controlled by the autonomic nervous system, has long been used as an arousal index. However, limited research has been done with regards to the relation between pupil size and saccade behavior in the context of trial-to-trial variation. To investigate fatigue and arousal effects on saccadic and pupillary responses, we used bright and emotional stimuli to evoke pupillary responses in tasks requiring reactive and voluntary saccade generation. Decreased voluntary saccade peak velocities, reduced tonic pupil size and phasic pupillary responses were observed as time-on-task increased. Moreover, tonic pupil size affected saccade latency and dynamics, with steeper saccade main sequence slope as tonic pupil size increased. In summary, saccade dynamics and tonic pupil size were sensitive to fatigue and arousal level, together providing valuable information for the understanding of human behavior.
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Affiliation(s)
- Jui-Tai Chen
- Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
| | - Ying-Chun Kuo
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City 320, Taiwan;
- Cognitive Intelligence and Precision Healthcare Research Center, National Central University, Taoyuan City 320, Taiwan
| | - Tzu-Yu Hsu
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei 110, Taiwan;
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City 235, Taiwan
| | - Chin-An Wang
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City 320, Taiwan;
- Cognitive Intelligence and Precision Healthcare Research Center, National Central University, Taoyuan City 320, Taiwan
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei 110, Taiwan;
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City 235, Taiwan
- Correspondence:
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8
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Abstract
For over 100 years, eye movements have been studied and used as indicators of human sensory and cognitive functions. This review evaluates how eye movements contribute to our understanding of the processes that underlie decision-making. Eye movement metrics signify the visual and task contexts in which information is accumulated and weighed. They indicate the efficiency with which we evaluate the instructions for decision tasks, the timing and duration of decision formation, the expected reward associated with a decision, the accuracy of the decision outcome, and our ability to predict and feel confident about a decision. Because of their continuous nature, eye movements provide an exciting opportunity to probe decision processes noninvasively in real time. Expected final online publication date for the Annual Review of Vision Science, Volume 8 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Miriam Spering
- Department of Ophthalmology & Visual Sciences and the Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, Canada;
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9
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Strauch C, Wang CA, Einhäuser W, Van der Stigchel S, Naber M. Pupillometry as an integrated readout of distinct attentional networks. Trends Neurosci 2022; 45:635-647. [PMID: 35662511 DOI: 10.1016/j.tins.2022.05.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/15/2022] [Accepted: 05/09/2022] [Indexed: 10/18/2022]
Abstract
The course of pupillary constriction and dilation provides an easy-to-access, inexpensive, and noninvasive readout of brain activity. We propose a new taxonomy of factors affecting the pupil and link these to associated neural underpinnings in an ascending hierarchy. In addition to two well-established low-level factors (light level and focal distance), we suggest two further intermediate-level factors, alerting and orienting, and a higher-level factor, executive functioning. Alerting, orienting, and executive functioning - including their respective underlying neural circuitries - overlap with the three principal attentional networks, making pupil size an integrated readout of distinct states of attention. As a now widespread technique, pupillometry is ready to provide meaningful applications and constitutes a viable part of the psychophysiological toolbox.
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Affiliation(s)
- Christoph Strauch
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands.
| | - Chin-An Wang
- Institute of Cognitive Neuroscience, National Central University, Taoyuan City, Taiwan; Cognitive Intelligence and Precision Healthcare Center, National Central University, Taoyuan City, Taiwan
| | - Wolfgang Einhäuser
- Physics of Cognition Group, Chemnitz University of Technology, Chemnitz, Germany
| | | | - Marnix Naber
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
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10
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Covariations between pupil diameter and supplementary eye field activity suggest a role in cognitive effort implementation. PLoS Biol 2022; 20:e3001654. [PMID: 35617290 PMCID: PMC9135265 DOI: 10.1371/journal.pbio.3001654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 04/29/2022] [Indexed: 12/02/2022] Open
Abstract
In both human and nonhuman primates (NHP), the medial prefrontal region, defined as the supplementary eye field (SEF), can indirectly influence behavior selection through modulation of the primary selection process in the oculomotor structures. To perform this oculomotor control, SEF integrates multiple cognitive signals such as attention, memory, reward, and error. As changes in pupil responses can assess these cognitive efforts, a better understanding of the precise dynamics by which pupil diameter and medial prefrontal cortex activity interact requires thorough investigations before, during, and after changes in pupil diameter. We tested whether SEF activity is related to pupil dynamics during a mixed pro/antisaccade oculomotor task in 2 macaque monkeys. We used functional ultrasound (fUS) imaging to examine temporal changes in brain activity at the 0.1-s time scale and 0.1-mm spatial resolution concerning behavioral performance and pupil dynamics. By combining the pupil signals and real-time imaging of NHP during cognitive tasks, we were able to infer localized cerebral blood volume (CBV) responses within a restricted part of the dorsomedial prefrontal cortex, referred to as the SEF, an area in which antisaccade preparation activity is also recorded. Inversely, SEF neurovascular activity measured by fUS imaging was found to be a robust predictor of specific variations in pupil diameter over short and long-time scales. Furthermore, we directly manipulated pupil diameter and CBV in the SEF using reward modulations. These results bring a novel understanding of the physiological links between pupil and SEF, but it also raises questions about the role of anterior cingulate cortex (ACC), as CBV variations in the ACC seems to be negligible compared to CBV variations in the SEF. Ultrafast functional imaging reveals short- and long-term covariations between pupil diameter and activity in the Supplementary Eye Field (SEF) of awake behaving non-human primates, yielding a novel understanding of the physiological links between the pupil and SEF.
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11
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Wang CA, White B, Munoz DP. Pupil-linked Arousal Signals in the Midbrain Superior Colliculus. J Cogn Neurosci 2022; 34:1340-1354. [PMID: 35579984 DOI: 10.1162/jocn_a_01863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The orienting response evoked by the appearance of a salient stimulus is modulated by arousal; however, neural underpinnings for the interplay between orienting and arousal are not well understood. The superior colliculus (SC), causally involved in multiple components of the orienting response including gaze and attention shifts, receives not only multisensory and cognitive inputs but also arousal-regulated inputs from various cortical and subcortical structures. To investigate the impact of moment-by-moment fluctuations in arousal on orienting saccade responses, we used microstimulation of the monkey SC to trigger saccade responses, and we used pupil size and velocity to index the level of arousal at stimulation onset because these measures correlate with changes in brain states and locus coeruleus activity. Saccades induced by SC microstimulation correlated with prestimulation pupil velocity, with higher pupil velocities on trials without evoked saccades than with evoked saccades. In contrast, prestimulation absolute pupil size did not correlate with saccade behavior. However, pupil velocity correlated with evoked saccade latency and metrics. Together, our results demonstrated that small fluctuations in arousal, indexed by pupil velocity, can modulate the saccade response evoked by SC microstimulation in awake behaving monkeys.
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Affiliation(s)
| | - Brian White
- Queen's University, Kingston, Ontario, Canada
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12
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Kuraoka K, Nakamura K. Facial temperature and pupil size as indicators of internal state in primates. Neurosci Res 2022; 175:25-37. [PMID: 35026345 DOI: 10.1016/j.neures.2022.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/07/2022] [Indexed: 11/15/2022]
Abstract
Studies in human subjects have revealed that autonomic responses provide objective and biologically relevant information about cognitive and affective states. Measures of autonomic responses can also be applied to studies of non-human primates, which are neuro-anatomically and physically similar to humans. Facial temperature and pupil size are measured remotely and can be applied to physiological experiments in primates, preferably in a head-fixed condition. However, detailed guidelines for the use of these measures in non-human primates is lacking. Here, we review the neuronal circuits and methodological considerations necessary for measuring and analyzing facial temperature and pupil size in non-human primates. Previous studies have shown that the modulation of these measures primarily reflects sympathetic reactions to cognitive and emotional processes, including alertness, attention, and mental effort, over different time scales. Integrated analyses of autonomic, behavioral, and neurophysiological data in primates are promising methods that reflect multiple dimensions of emotion and could potentially provide tools for understanding the mechanisms underlying neuropsychiatric disorders and vulnerabilities characterized by cognitive and affective disturbances.
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Affiliation(s)
- Koji Kuraoka
- Department of Physiology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
| | - Kae Nakamura
- Department of Physiology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan.
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13
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Enlargement of female pupils when perceiving something cute. Sci Rep 2021; 11:23367. [PMID: 34862420 PMCID: PMC8642513 DOI: 10.1038/s41598-021-02852-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 11/22/2021] [Indexed: 11/08/2022] Open
Abstract
It is reported that women's pupils dilate when they see a baby; it is unclear if this pupillary response is caused by the perception of cuteness itself. Since many objects besides babies can be perceived as cute, we investigated whether the perception of cuteness, or the type of object observed, is related to pupil dilation. In the first experiment, female participants were requested to rate the subjective cuteness of greyscale pictures of objects such as animals and foods; their pupil sizes were measured. The results showed a significant positive correlation between perceived cuteness and participants' pupil dilation. In the second experiment, participants rated the cuteness of images of female faces. Results revealed a significant negative correlation between perceived cuteness and pupil dilation. In our study, perceiving cuteness enlarged female observers' pupils except when observing female faces. Positive reactions associated with cuteness may be premised on the existence of unconscious perceptual alterations and physical responses.
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14
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Meikle SJ, Wong YT. Neurophysiological considerations for visual implants. Brain Struct Funct 2021; 227:1523-1543. [PMID: 34773502 DOI: 10.1007/s00429-021-02417-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 10/17/2021] [Indexed: 11/26/2022]
Abstract
Neural implants have the potential to restore visual capabilities in blind individuals by electrically stimulating the neurons of the visual system. This stimulation can produce visual percepts known as phosphenes. The ideal location of electrical stimulation for achieving vision restoration is widely debated and dependent on the physiological properties of the targeted tissue. Here, the neurophysiology of several potential target structures within the visual system will be explored regarding their benefits and downfalls in producing phosphenes. These regions will include the lateral geniculate nucleus, primary visual cortex, visual area 2, visual area 3, visual area 4 and the middle temporal area. Based on the existing engineering limitations of neural prostheses, we anticipate that electrical stimulation of any singular brain region will be incapable of achieving high-resolution naturalistic perception including color, texture, shape and motion. As improvements in visual acuity facilitate improvements in quality of life, emulating naturalistic vision should be one of the ultimate goals of visual prostheses. To achieve this goal, we propose that multiple brain areas will need to be targeted in unison enabling different aspects of vision to be recreated.
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Affiliation(s)
- Sabrina J Meikle
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia
| | - Yan T Wong
- Department of Electrical and Computer Systems Engineering, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Department of Physiology and Biomedicine Discovery Institute, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
- Monash Vision Group, Monash University, 14 Alliance Lane, Clayton, Vic, 3800, Australia.
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15
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Wang CA, Nguyen KT, Juan CH. Linking Pupil Size Modulated by Global Luminance and Motor Preparation to Saccade Behavior. Neuroscience 2021; 476:90-101. [PMID: 34571085 DOI: 10.1016/j.neuroscience.2021.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/03/2021] [Accepted: 09/18/2021] [Indexed: 01/21/2023]
Abstract
Saccades are rapid eye movements that are used to move the high acuity fovea in a serial manner in the exploration of the visual scene. Stimulus contrast is known to modulate saccade latency and metrics possibly via changing visual activity in the superior colliculus (SC), a midbrain structure causally involved in saccade generation. However, the quality of visual signals should also be modulated by the amount of lights projected onto the retina, which is gated by the size of the pupil. Although absolute pupil size should modulate visual signals and in turn affect saccade responses, research examining this relationship is very limited. Besides, pupil size is associated with motor preparation. However, the role of pupil dilation in saccade metrics remains unexplored. Through varying peripheral background luminance level and target visual contrast in the saccade task, we investigated the role of absolute pupil size and baseline-corrected pupil dilation in saccade latency and metrics. Higher target detection accuracy was obtained with lower background luminance level, and larger absolute pupil diameter correlated with smaller saccade amplitude and higher saccade peak velocities. More interestingly, the comparable modulation between pupil dilation and stimulus contrast was obtained, showing larger pupil dilation (or higher contrast stimuli) correlating with faster saccade latencies, larger amplitude, higher peak velocities, and smaller endpoint deviation. Together, our results demonstrated the influence of absolute pupil size induced by global luminance level and baseline-corrected pupil dilation associated with motor preparation on saccade latency and metrics, implicating the role of the SC in this behavior.
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Affiliation(s)
- Chin-An Wang
- Institute of Cognitive Neuroscience, National Central University, Taoyuan City, Taiwan; Cognitive Intelligence and Precision Healthcare Center, National Central University, Taoyuan City, Taiwan.
| | - Kien Trong Nguyen
- Institute of Cognitive Neuroscience, National Central University, Taoyuan City, Taiwan; Faculty of Electronics Engineering, Posts and Telecommunications Institute of Technology, Ho Chi Minh City, Viet Nam
| | - Chi-Hung Juan
- Institute of Cognitive Neuroscience, National Central University, Taoyuan City, Taiwan; Cognitive Intelligence and Precision Healthcare Center, National Central University, Taoyuan City, Taiwan; Department of Psychology, Kaohsiung Medical University, Kaohsiung City, Taiwan
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16
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Lehmann SJ, Corneil BD. Completing the puzzle: Why studies in non-human primates are needed to better understand the effects of non-invasive brain stimulation. Neurosci Biobehav Rev 2021; 132:1074-1085. [PMID: 34742722 DOI: 10.1016/j.neubiorev.2021.10.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/29/2021] [Accepted: 10/31/2021] [Indexed: 11/27/2022]
Abstract
Brain stimulation is a core method in neuroscience. Numerous non-invasive brain stimulation (NIBS) techniques are currently in use in basic and clinical research, and recent advances promise the ability to non-invasively access deep brain structures. While encouraging, there is a surprising gap in our understanding of precisely how NIBS perturbs neural activity throughout an interconnected network, and how such perturbed neural activity ultimately links to behaviour. In this review, we will consider why non-human primate (NHP) models of NIBS are ideally situated to address this gap in knowledge, and why the oculomotor network that moves our line of sight offers a particularly valuable platform in which to empirically test hypothesis regarding NIBS-induced changes in brain and behaviour. NHP models of NIBS will enable investigation of the complex, dynamic effects of brain stimulation across multiple hierarchically interconnected brain areas, networks, and effectors. By establishing such links between brain and behavioural output, work in NHPs can help optimize experimental and therapeutic approaches, improve NIBS efficacy, and reduce side-effects of NIBS.
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Affiliation(s)
- Sebastian J Lehmann
- Department of Physiology and Pharmacology, Western University, London, Ontario, N6A 5B7, Canada.
| | - Brian D Corneil
- Department of Physiology and Pharmacology, Western University, London, Ontario, N6A 5B7, Canada; Department of Psychology, Western University, London, Ontario, N6A 5B7, Canada; Robarts Research Institute, London, Ontario, N6A 5B7, Canada.
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17
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Pandey P, Ray S. Pupil dynamics: A potential proxy of neural preparation for goal-directed eye movement. Eur J Neurosci 2021; 54:6587-6607. [PMID: 34510602 DOI: 10.1111/ejn.15453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/22/2021] [Accepted: 09/03/2021] [Indexed: 01/10/2023]
Abstract
The pupils reflexively constrict or dilate to regulate the influx of light on the retinae. Pupillary light reflex (PLR) is susceptible to many non-visual cognitive processes including covert orientation of attention and planning rapid saccadic eye movement. The frontal eye field (FEF) and superior colliculus (SC), which also send projections to the PLR pathway, are two important areas in primate's brain for planning saccade and orientation of attention. The saccadic reaction time (SRT) and the rate of increase in activity of movement neurons in these areas are inversely correlated. This study addressed how pupil dynamics, activity in the FEF and SC and SRT are related in a saccadic decision-making task. The rate of visually evoked pupil constriction was found inversely related to SRT. This was further verified by simulating a homeomorphic biomechanical model of pupillary muscle plants, wherein we projected signals similar to build-up activity in the FEF and SC to the parasympathetic (constriction) and sympathetic (dilation) division of the PLR pathway, respectively. A striking similarity between simulated and observed dynamics of pupil constriction suggests that PLR is a potential proxy of saccade planning by movement neurons in the FEF and SC. Indistinguishable pupil dynamics when planned saccades were elicited versus when they were cancelled eliminated the possibility that the obligatory pre-saccadic shift of attention alone influenced the rate of pupil constriction. Our study envisages a mechanism of how the oculomotor system influences the autonomic activity in an attempt to timely minimize saccadic visual transients by regulating the influx of light.
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Affiliation(s)
- Pragya Pandey
- Centre of Behavioural and Cognitive Sciences, University of Allahabad, Prayagraj, India
| | - Supriya Ray
- Centre of Behavioural and Cognitive Sciences, University of Allahabad, Prayagraj, India
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18
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Ayala N, Heath M. Pupillometry Reveals the Role of Arousal in a Postexercise Benefit to Executive Function. Brain Sci 2021; 11:1048. [PMID: 34439667 PMCID: PMC8394913 DOI: 10.3390/brainsci11081048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 12/05/2022] Open
Abstract
A single bout of aerobic exercise improves executive function; however, the mechanism(s) underlying this improvement remains unclear. Here, we employed a 20-min bout of aerobic exercise, and at pre- and immediate post-exercise sessions examined executive function via pro- (i.e., saccade to veridical target location) and anti-saccade (i.e., saccade mirror symmetrical to a target) performance and pupillometry metrics. Notably, tonic and phasic pupillometry responses in oculomotor control provided a framework to determine the degree that arousal and/or executive resource recruitment influence behavior. Results demonstrated a pre- to post-exercise decrease in pro- and anti-saccade reaction times (p = 0.01) concurrent with a decrease and increase in tonic baseline pupil size and task-evoked pupil dilations, respectively (ps < 0.03). Such results demonstrate that an exercise-induced improvement in saccade performance is related to an executive-mediated "shift" in physiological and/or psychological arousal, supported by the locus coeruleus norepinephrine system to optimize task engagement.
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Affiliation(s)
- Naila Ayala
- Department of Kinesiology, School of Kinesiology, University of Western Ontario, London, ON N6G 3K7, Canada;
- Graduate Program in Neuroscience, University of Western Ontario, London, ON N6G 3K7, Canada
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Matthew Heath
- Department of Kinesiology, School of Kinesiology, University of Western Ontario, London, ON N6G 3K7, Canada;
- Graduate Program in Neuroscience, University of Western Ontario, London, ON N6G 3K7, Canada
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19
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Capone F, Motolese F, Di Zazzo A, Antonini M, Magliozzi A, Rossi M, Marano M, Pilato F, Musumeci G, Coassin M, Di Lazzaro V. The effects of transcutaneous auricular vagal nerve stimulation on pupil size. Clin Neurophysiol 2021; 132:1859-1865. [PMID: 34147923 DOI: 10.1016/j.clinph.2021.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Mechanisms of action and optimal stimulation parameters of transcutaneous auricular vagus nerve stimulation (taVNS) are currently unknown. Pupil size has gained attention as a promising biomarker of vagal activation in different studies on animal models. The aim of this study is to investigate the effects of taVNS on pupil diameter in healthy subjects. METHODS All subjects received taVNS at the left external acoustic meatus and control stimulation at the left earlobe during the same experimental session. Different intensities (0.5 mA; 1.0 mA; 2.0 mA; 3.0 mA) for both conditions were tested. Tonic pupil size was recorded in both eyes at baseline and during each stimulation using an infrared-automated pupillometer in three different illuminance conditions (scotopic, mesopic, photopic). RESULTS In scotopic illuminance condition, a significant interaction between intensity and condition (real vs control) was found for the left eye. Post-Hoc analysis showed that during real taVNS at 2 mA, pupil size was significantly larger in comparison to baseline and 2 mA control stimulation. CONCLUSIONS Our study demonstrates that taVNS induces pupil dilation under specific illuminance conditions and at specific stimulation intensity. SIGNIFICANCE The effects of taVNS are strictly dependent on technical aspects, such as stimulation parameters and experimental set-up.
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Affiliation(s)
- Fioravante Capone
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy; NeXT: Neurophysiology and Neuroengineering of Human-Technology Interaction Research Unit, Campus Bio-Medico University, Rome, Italy.
| | - Francesco Motolese
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy; NeXT: Neurophysiology and Neuroengineering of Human-Technology Interaction Research Unit, Campus Bio-Medico University, Rome, Italy
| | - Antonio Di Zazzo
- Ophthalmology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Marco Antonini
- Ophthalmology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alessandro Magliozzi
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Mariagrazia Rossi
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Massimo Marano
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Fabio Pilato
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Gabriella Musumeci
- NeXT: Neurophysiology and Neuroengineering of Human-Technology Interaction Research Unit, Campus Bio-Medico University, Rome, Italy
| | - Marco Coassin
- Ophthalmology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Vincenzo Di Lazzaro
- Neurology, Neurophysiology and Neurobiology Unit, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
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20
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Jiménez EC, Sierra-Marcos A, Romeo A, Hashemi A, Leonovych O, Bustos Valenzuela P, Solé Puig M, Supèr H. Altered Vergence Eye Movements and Pupil Response of Patients with Alzheimer's Disease and Mild Cognitive Impairment During an Oddball Task. J Alzheimers Dis 2021; 82:421-433. [PMID: 34024820 DOI: 10.3233/jad-201301] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by progressive deterioration of cognitive functions and may be preceded by mild cognitive impairment (MCI). Evidence shows changes in pupil and vergence responses related to cognitive processing of visual information. OBJECTIVE Here we test the hypothesis that MCI and AD are associated with specific patterns in vergence and pupil responses. METHODS We employed a visual oddball task. In the distractor condition (80%of the trials), a blue stimulus was presented whereas in the target condition (20%of trials) it was red. Participants (23 Controls, 33 MCI patients, and 18 AD patients) were instructed to press a button when a target appeared. RESULTS Participants briefly converged their eyes 200 ms after stimulus presentation. In controls, this transient peak response was followed by a delay response to targets but not to distractor stimuli. In the patient groups, delay responses to distractors were noticed. Consequently, the differential vergence response was strong in the control group, weak in the MCI group, and absent in the AD group. Pupils started to dilate 500-600 ms after the appearance of a target but slightly contracted after the presentation of a distractor. This differential pupil response was strongest in the AD group. CONCLUSION Our findings support the idea of a role of vergence and pupil responses in attention and reveal altered responses in MCI and AD patients. Further studies should assess the value of vergence and pupil measurements as an objective support tool for early diagnosis of AD.
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Affiliation(s)
- Elizabeth Carolina Jiménez
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain.,University of Guadalajara, Jalisco, México
| | - Alba Sierra-Marcos
- Department of Neurology and Neurophysiology, Hospital Sanitas CIMA, Barcelona, Spain
| | - August Romeo
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain
| | - Amin Hashemi
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain
| | - Oleksii Leonovych
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain.,Braingaze SL, Mataró, Spain
| | - Patricia Bustos Valenzuela
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain
| | - Maria Solé Puig
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain
| | - Hans Supèr
- Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain.,Institute of Neurosciences of the University of Barcelona (UBNeuro), Barcelona, Spain.,Braingaze SL, Mataró, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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21
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Hsu TY, Hsu YF, Wang HY, Wang CA. Role of the frontal eye field in human pupil and saccade orienting responses. Eur J Neurosci 2021; 54:4283-4294. [PMID: 33901328 DOI: 10.1111/ejn.15253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 11/28/2022]
Abstract
The appearance of a salient stimulus evokes a series of orienting responses including saccades and pupil size to prepare the body for appropriate action. The midbrain superior colliculus (SC) that receives critical control signals from the frontal eye field (FEF) is hypothesized to coordinate all components of orienting. It has shown recently that the FEF, together with the SC, is also importantly involved in the control of pupil size, in addition to its well-documented role in eye movements. Although the role of the FEF in pupil size is demonstrated in monkeys, its role in human pupil responses and the coordination between pupil size and saccades remains to be established. Through applying continuous theta-burst stimulation over the right FEF and vertex, we investigated the role of the FEF in human pupil and saccade responses evoked by a salient stimulus, and the coordination between pupil size and saccades. Our results showed that neither saccade reaction times (SRT) nor pupil responses evoked by salient stimuli were modulated by FEF stimulation. In contrast, the correlation between pupil size and SRTs in the contralateral stimulus condition was diminished with FEF stimulation, but intact with vertex stimulation. Moreover, FEF stimulation effects between saccade and pupil responses associated with salient stimuli correlated across participants. This is the first transcranial magnetic stimulation (TMS) study on the pupil orienting response, and our findings suggest that human FEF was involved in coordinating pupil size and saccades, but not involved in the control of pupil orienting responses.
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Affiliation(s)
- Tzu-Yu Hsu
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City, Taiwan
| | - Yu-Fan Hsu
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City, Taiwan
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City, Taiwan
- Cognitive Intelligence and Precision Healthcare Research Center, National Central University, Taoyuan City, Taiwan
| | - Hsin-Yi Wang
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City, Taiwan
| | - Chin-An Wang
- Graduate Institute of Mind, Brain, and Consciousness (GIMBC), Taipei Medical University, Taipei, Taiwan
- Brain and Consciousness Research Center (BCRC), TMU-Shuang Ho Hospital, New Taipei City, Taiwan
- Institute of Cognitive Neuroscience, College of Health Science and Technology, National Central University, Taoyuan City, Taiwan
- Cognitive Intelligence and Precision Healthcare Research Center, National Central University, Taoyuan City, Taiwan
- Department of Anesthesiology, TMU-Shuang Ho Hospital, New Taipei City, Taiwan
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22
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Wang CA, Munoz DP. Coordination of Pupil and Saccade Responses by the Superior Colliculus. J Cogn Neurosci 2021; 33:919-932. [PMID: 33544056 DOI: 10.1162/jocn_a_01688] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The appearance of a salient stimulus evokes saccadic eye movements and pupil dilation as part of the orienting response. Although the role of the superior colliculus (SC) in saccade and pupil dilation has been established separately, whether and how these responses are coordinated remains unknown. The SC also receives global luminance signals from the retina, but whether global luminance modulates saccade and pupil responses coordinated by the SC remains unknown. Here, we used microstimulation to causally determine how the SC coordinates saccade and pupil responses and whether global luminance modulates these responses by varying stimulation frequency and global luminance in male monkeys. Stimulation frequency modulated saccade and pupil responses, with trial-by-trial correlations between the two responses. Global luminance only modulated pupil, but not, saccade responses. Our results demonstrate an integrated role of the SC on coordinating saccade and pupil responses, characterizing luminance independent modulation in the SC, together elucidating the differentiated pathways underlying this behavior.
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Affiliation(s)
- Chin-An Wang
- Queen's University, Kingston, Canada.,Taipei Medical University
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23
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Cherng YG, Crevecoeur F, Wang CA. Effects of pupillary light and darkness reflex on the generation of pro- And anti-saccades. Eur J Neurosci 2020; 53:1769-1782. [PMID: 33314426 DOI: 10.1111/ejn.15083] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/25/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022]
Abstract
Saccades are often directed toward a stimulus that provides useful information for observers to navigate the visual world. The quality of visual signals of a stimulus is influenced by global luminance, and the pupil constricts or dilates after a luminance increase or decrease, respectively, to optimize visual signals for further information processing. Although luminance level changes regularly in the real environment, saccades are mostly studied in the luminance-unchanged setup. Whether pupillary responses triggered by global luminance changes modulate saccadic behavior are yet to be explored. Through varying background luminance level in an interleaved pro- and anti-saccade paradigm, we investigated the modulation of pupillary luminance responses on the generation of reflexive and voluntary saccades. Subjects were instructed to either automatically look at the peripheral stimulus (pro-saccade) or to suppress the automatic response and voluntarily look in the opposite direction from the stimulus (anti-saccade). Level of background luminance was increased (light), decreased (dark), or unchanged (control) during the instructed fixation period. Saccade reaction time distributions of correct pro- and anti-saccades in the light and dark conditions were differed significantly from those in the control condition. Moreover, the luminance condition modulated saccade kinematics, showing reduced performances in the light condition than in the control condition, particularly in pro-saccades. Modeling results further suggested that both pupil diameter and pupil size derivative significantly modulated saccade behavior, though effect sizes were small and mainly mediated by intersubject differences. Together, our results demonstrated the influence of pupillary luminance responses on the generation of pro- and anti-saccades.
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Affiliation(s)
- Yih-Giun Cherng
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Anesthesiology, School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Frédéric Crevecoeur
- Institute of information Technologies, Electronics and Applied Mathematics (ICTEAM), Institute of Neuroscience, UCLouvain, Belgium.,Institute of Neuroscience, UCLouvain, Belgium
| | - Chin-An Wang
- Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,Research Center of Brain and Consciousness, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan
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24
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Ayala N, Niechwiej-Szwedo E. Effects of blocked vs. interleaved administration mode on saccade preparatory set revealed using pupillometry. Exp Brain Res 2020; 239:245-255. [PMID: 33145613 DOI: 10.1007/s00221-020-05967-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/21/2020] [Indexed: 12/01/2022]
Abstract
Eye movements have been used extensively to assess information processing and cognitive function. However, significant variability in saccade performance has been observed, which could arise from methodological variations across different studies. For example, prosaccades and antisaccades have been studied using either a blocked or interleaved design, which has a significant influence on error rates and latency. This is problematic as it makes it difficult to compare saccade performance across studies and may limit the ability to use saccades as a behavioural assay to assess neurocognitive function. Thus, the current study examined how administration mode influences saccade related preparatory activity by employing pupil size as a non-invasive proxy for neural activity related to saccade planning and execution. Saccade performance and pupil dynamics were examined in eleven participants as they completed pro- and antisaccades in blocked and interleaved paradigms. Results showed that administration mode significantly modulated saccade performance and preparatory activity. Reaction times were longer for both pro- and antisaccades in the interleaved condition, compared to the blocked condition (p < 0.05). Prosaccade pupil dilations were larger in the interleaved condition (p < 0.05), while antisaccade pupil dilations did not significantly differ between administration modes. Additionally, ROC analysis provided preliminary evidence that pupil size can effectively predict saccade directional errors prior to saccade onset. We propose that task-evoked pupil dilations reflect an increase in preparatory activity for prosaccades and the corresponding cognitive demands associated with interleaved administration mode. Overall, the results highlight the importance that administration mode plays in the design of neurocognitive tasks.
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Affiliation(s)
- Naila Ayala
- Department of Kinesiology, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 5G1, Canada
| | - Ewa Niechwiej-Szwedo
- Department of Kinesiology, University of Waterloo, 200 University Ave W., Waterloo, ON, N2L 5G1, Canada.
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25
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Background luminance effects on pupil size associated with emotion and saccade preparation. Sci Rep 2020; 10:15718. [PMID: 32973283 PMCID: PMC7515892 DOI: 10.1038/s41598-020-72954-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/07/2020] [Indexed: 11/16/2022] Open
Abstract
Pupil dilation is consistently evoked by affective and cognitive processing, and this dilation can result from sympathetic activation or parasympathetic inhibition. The relative contributions of the sympathetic and parasympathetic systems on the pupillary response induced by emotion and cognition may be different. Sympathetic and parasympathetic activity is regulated by global luminance level. Higher luminance levels lead to greater activation of the parasympathetic system while lower luminance levels lead to greater activation of the sympathetic system. To understand the contributions of the sympathetic and parasympathetic nervous systems to pupillary responses associated with emotion and saccade preparation, emotional auditory stimuli were presented following the fixation cue whose color indicated instruction to perform a pro- or anti-saccade while varying the background luminance level. Pupil dilation was evoked by emotional auditory stimuli and modulated by arousal level. More importantly, greater pupil dilation was observed with a dark background, compared to a bright background. In contrast, pupil dilation responses associated with saccade preparation were larger with the bright background than the dark background. Together, these results suggest that arousal-induced pupil dilation was mainly mediated by sympathetic activation, but pupil dilation related to saccade preparation was primarily mediated by parasympathetic inhibition.
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26
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Privitera M, Ferrari KD, von Ziegler LM, Sturman O, Duss SN, Floriou-Servou A, Germain PL, Vermeiren Y, Wyss MT, De Deyn PP, Weber B, Bohacek J. A complete pupillometry toolbox for real-time monitoring of locus coeruleus activity in rodents. Nat Protoc 2020; 15:2301-2320. [PMID: 32632319 DOI: 10.1038/s41596-020-0324-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/01/2020] [Indexed: 01/20/2023]
Abstract
The locus coeruleus (LC) is a region in the brainstem that produces noradrenaline and is involved in both normal and pathological brain function. Pupillometry, the measurement of pupil diameter, provides a powerful readout of LC activity in rodents, primates and humans. The protocol detailed here describes a miniaturized setup that can screen LC activity in rodents in real-time and can be established within 1-2 d. Using low-cost Raspberry Pi computers and cameras, the complete custom-built system costs only ~300 euros, is compatible with stereotaxic surgery frames and seamlessly integrates into complex experimental setups. Tools for pupil tracking and a user-friendly Pupillometry App allow quantification, analysis and visualization of pupil size. Pupillometry can discriminate between different, physiologically relevant firing patterns of the LC and can accurately report LC activation as measured by noradrenaline turnover. Pupillometry provides a rapid, non-invasive readout that can be used to verify accurate placement of electrodes/fibers in vivo, thus allowing decisions about the inclusion/exclusion of individual animals before experiments begin.
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Affiliation(s)
- Mattia Privitera
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Kim David Ferrari
- Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Experimental Imaging and Neuroenergetics, Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Lukas M von Ziegler
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Oliver Sturman
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Sian N Duss
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Amalia Floriou-Servou
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Pierre-Luc Germain
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Yannick Vermeiren
- Department of Biomedical Sciences, Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Wilrijk (Antwerp), Antwerpen, Belgium.,Department of Neurology and Alzheimer Center, University of Groningen and University Medical Center Groningen (UMCG), Groningen, the Netherlands
| | - Matthias T Wyss
- Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.,Experimental Imaging and Neuroenergetics, Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Peter P De Deyn
- Department of Biomedical Sciences, Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Wilrijk (Antwerp), Antwerpen, Belgium.,Department of Neurology and Alzheimer Center, University of Groningen and University Medical Center Groningen (UMCG), Groningen, the Netherlands.,Department of Neurology, Memory Clinic of Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Antwerp, Belgium
| | - Bruno Weber
- Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland. .,Experimental Imaging and Neuroenergetics, Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
| | - Johannes Bohacek
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland. .,Neuroscience Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland.
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Ayala N, Heath M. Executive Dysfunction after a Sport-Related Concussion Is Independent of Task-Based Symptom Burden. J Neurotrauma 2020; 37:2558-2568. [PMID: 32438897 DOI: 10.1089/neu.2019.6865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A sport-related concussion (SRC) results in short- and long-term deficits in oculomotor control; however, it is unclear whether this change reflects executive dysfunction and/or a performance decrement caused by an increase in task-based symptom burden. Here, individuals with a SRC - and age- and sex-matched controls - completed an antisaccade task (i.e., saccade mirror-symmetrical to a target) during the early (initial assessment ≤12 days) and later (follow-up assessment <30 days) stages of recovery. Antisaccades were used because they require top-down executive control and exhibit performance decrements following an SRC. Reaction time (RT) and directional errors were included with pupillometry, because pupil size in the antisaccade task has been shown to provide a neural proxy for executive control. In addition, the Sport-Concussion Assessment Tool (SCAT-5) symptom checklist was completed prior to and after each oculomotor assessment to identify a possible task-based increase in symptomology. The SRC group yielded longer initial assessment RTs, more directional errors, and larger task-evoked pupil dilations (TEPD) than the control group. At the follow-up assessment, RTs for the SRC and control group did not reliably differ; however, the former demonstrated more directional errors and larger TEPDs. SCAT-5 symptom severity scores did not vary from the pre- to post-oculomotor evaluation for either initial or follow-up assessments. Accordingly, an SRC imparts a persistent executive dysfunction to oculomotor planning independent of a task-based increase in symptom burden. These findings evince that antisaccades serve as an effective tool to identify subtle executive deficits during the early and later stages of SRC recovery.
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Affiliation(s)
- Naila Ayala
- School of Kinesiology, University of Western Ontario, London, Ontario, Canada.,Graduate Program in Neuroscience, University of Western Ontario, London, Ontario, Canada
| | - Matthew Heath
- School of Kinesiology, University of Western Ontario, London, Ontario, Canada.,Graduate Program in Neuroscience, University of Western Ontario, London, Ontario, Canada
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28
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Schwiedrzik CM, Sudmann SS. Pupil Diameter Tracks Statistical Structure in the Environment to Increase Visual Sensitivity. J Neurosci 2020; 40:4565-4575. [PMID: 32371603 PMCID: PMC7275858 DOI: 10.1523/jneurosci.0216-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/20/2020] [Accepted: 04/15/2020] [Indexed: 01/01/2023] Open
Abstract
Pupil diameter determines how much light hits the retina and, thus, how much information is available for visual processing. This is regulated by a brainstem reflex pathway. Here, we investigate whether this pathway is under the control of internal models about the environment. This would allow adjusting pupil dynamics to environmental statistics to augment information transmission. We present image sequences containing internal temporal structure to humans of either sex and male macaque monkeys. We then measure whether the pupil tracks this temporal structure not only at the rate of luminance variations, but also at the rate of statistics not available from luminance information alone. We find entrainment to environmental statistics in both species. This entrainment directly affects visual processing by increasing sensitivity at the environmentally relevant temporal frequency. Thus, pupil dynamics are matched to the temporal structure of the environment to optimize perception, in line with an active sensing account.SIGNIFICANCE STATEMENT When light hits the retina, the pupil reflexively constricts. This determines how much light and thus how much information is available for visual processing. We show that the rate at which the pupil constricts and dilates is matched to the temporal structure of our visual environment, although this information is not directly contained in the light variations that usually trigger reflexive pupil constrictions. Adjusting pupil diameter in accordance with environmental regularities optimizes information transmission at ecologically relevant temporal frequencies. We show that this is the case in humans and macaque monkeys, suggesting that the reflex pathways that regulate pupil diameter are under some degree of cognitive control across primate species.
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Affiliation(s)
- Caspar M Schwiedrzik
- Neural Circuits and Cognition Lab, European Neuroscience Institute Göttingen-A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, 37077 Göttingen, Germany
- Perception and Plasticity Group, German Primate Center, Leibniz Institute for Primate Research, 37077 Göttingen, Germany
| | - Sandrin S Sudmann
- Neural Circuits and Cognition Lab, European Neuroscience Institute Göttingen-A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, 37077 Göttingen, Germany
- Perception and Plasticity Group, German Primate Center, Leibniz Institute for Primate Research, 37077 Göttingen, Germany
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29
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Peinkhofer C, Knudsen GM, Moretti R, Kondziella D. Cortical modulation of pupillary function: systematic review. PeerJ 2019; 7:e6882. [PMID: 31119083 PMCID: PMC6510220 DOI: 10.7717/peerj.6882] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 03/26/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The pupillary light reflex is the main mechanism that regulates the pupillary diameter; it is controlled by the autonomic system and mediated by subcortical pathways. In addition, cognitive and emotional processes influence pupillary function due to input from cortical innervation, but the exact circuits remain poorly understood. We performed a systematic review to evaluate the mechanisms behind pupillary changes associated with cognitive efforts and processing of emotions and to investigate the cerebral areas involved in cortical modulation of the pupillary light reflex. METHODOLOGY We searched multiple databases until November 2018 for studies on cortical modulation of pupillary function in humans and non-human primates. Of 8,809 papers screened, 258 studies were included. RESULTS Most investigators focused on pupillary dilatation and/or constriction as an index of cognitive and emotional processing, evaluating how changes in pupillary diameter reflect levels of attention and arousal. Only few tried to correlate specific cerebral areas to pupillary changes, using either cortical activation models (employing micro-stimulation of cortical structures in non-human primates) or cortical lesion models (e.g., investigating patients with stroke and damage to salient cortical and/or subcortical areas). Results suggest the involvement of several cortical regions, including the insular cortex (Brodmann areas 13 and 16), the frontal eye field (Brodmann area 8) and the prefrontal cortex (Brodmann areas 11 and 25), and of subcortical structures such as the locus coeruleus and the superior colliculus. CONCLUSIONS Pupillary dilatation occurs with many kinds of mental or emotional processes, following sympathetic activation or parasympathetic inhibition. Conversely, pupillary constriction may occur with anticipation of a bright stimulus (even in its absence) and relies on a parasympathetic activation. All these reactions are controlled by subcortical and cortical structures that are directly or indirectly connected to the brainstem pupillary innervation system.
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Affiliation(s)
- Costanza Peinkhofer
- Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Medical Faculty, University of Trieste, Trieste, Italy
| | - Gitte M. Knudsen
- Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Neurobiology Research Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - Rita Moretti
- Medical Faculty, University of Trieste, Trieste, Italy
- Department of Medical, Surgical and Health Sciences, Neurological Unit, Trieste University Hospital, Cattinara, Trieste, Italy
| | - Daniel Kondziella
- Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroscience, Norwegian University of Technology and Science, Trondheim, Norway
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30
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Abstract
Phasic pupillary responses were used to track the active maintenance of information in working memory (WM). In seven experiments participants performed various change detection tasks while their pupils were continuously recorded. Across the experiments phasic pupillary responses increased as the number of maintained items increased up to around 4-5 items consistent with behavioral estimates of capacity. Combining data across experiments demonstrated that phasic pupillary responses were related to behavioral estimates of capacity. Furthermore, phasic pupillary responses demonstrated WM load-dependent relations only when active maintenance was required. When instructed to passively stare at the items or to drop items from WM, the pupil remained near baseline levels. These phasic pupillary responses also tracked the time course of maintenance demonstrating sustained responses early in the delay period, but declined thereafter. Finally, phasic pupillary responses tracked selection processes at encoding (filtering and pre-cues), but did not suggest evidence for item removal following retro-cues. These results are consistent with the notion that maintaining items in WM requires the allocation of effortful attention and further suggest that phasic pupillary responses can be used to track the active maintenance of items in WM.
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31
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Wang CA, Baird T, Huang J, Coutinho JD, Brien DC, Munoz DP. Arousal Effects on Pupil Size, Heart Rate, and Skin Conductance in an Emotional Face Task. Front Neurol 2018; 9:1029. [PMID: 30559707 PMCID: PMC6287044 DOI: 10.3389/fneur.2018.01029] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/14/2018] [Indexed: 11/18/2022] Open
Abstract
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 by the balanced activity of the parasympathetic and sympathetic systems, commonly indexed by heart rate (HR) and galvanic skin response (GSR), respectively. Although a growing number of studies have used pupil size to indicate the level of arousal, research that directly examines the relationship between pupil size and HR or GSR is limited. The goal of this study was to understand how pupil size is modulated by autonomic arousal. Human participants fixated various emotional face stimuli, of which low-level visual properties were carefully controlled, while their pupil size, HR, GSR, and eye position were recorded simultaneously. We hypothesized that a positive correlation between pupil size and HR or GSR would be observed both before and after face presentation. Trial-by-trial positive correlations between pupil diameter and HR and GSR were found before face presentation, with larger pupil diameter observed on trials with higher HR or GSR. However, task-evoked pupil responses after face presentation only correlated with HR. Overall, these results demonstrated a trial-by-trial relationship between pupil size and HR or GSR, suggesting that pupil size can be used as an index for arousal level involuntarily regulated by the autonomic nervous system.
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Affiliation(s)
- Chin-An Wang
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
- Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan
- Research Center of Brain and Consciousness, Taipei Medical University, Shuang Ho Hospital, New Taipei City, Taiwan
| | - Talia Baird
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Jeff Huang
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | | | - Donald C. Brien
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
| | - Douglas P. Munoz
- Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada
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32
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Peinkhofer C, Martens P, Grand J, Truelsen T, Knudsen GM, Kjaergaard J, Kondziella D. Influence of Strategic Cortical Infarctions on Pupillary Function. Front Neurol 2018; 9:916. [PMID: 30420833 PMCID: PMC6215832 DOI: 10.3389/fneur.2018.00916] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 10/09/2018] [Indexed: 11/13/2022] Open
Abstract
Objective: Cortical activity, including cognitive and emotional processes, may influence pupillary function. The exact pathways and the site of cortical pupillary innervation remain elusive, however. We investigated the effects of select cortical strokes, i.e. ischemic infarcts affecting the insular cortex and prefrontal eye field, on pupillary function. Methods: Seventy-four patients with acute ischemic stroke, consecutively admitted to our institution from March to July 2018, were assessed 24 h after endovascular recanalization therapy (i.e., day 2 after the stroke), using automated pupillometry. Stroke location and volume and clinical severity (estimated by the Alberta Stroke Program Early CT Score and National Institute of Health Stroke Scale) were recorded. We excluded patients with posterior circulation stroke, intracranial pathology other than ischemic stroke, midline shift on computed tomography exceeding 5 millimeters or a history of eye disease. Pupillometry data from 25 neurologically normal patients with acute myocardial infarction were acquired for control. Results: Fifty stroke patients after thrombectomy were included for analysis. Twenty-five patients (50%) had insular cortex or prefrontal eye field involvement (group 1, strategic infarcts); 25 patients had infarcts located in other cerebral areas (group 2, other infarcts). The pupillary light reflex, as measured by constriction velocity and maximal/minimal pupillary diameters, was within physiological limits in all patients, including controls. However, while pupillary size and constriction velocities were correlated in all subjects, the correlation of size and dilatation velocity was absent in right-hemispheric infarcts (left hemisphere infarcts, group 1 (r 2 = 0.15, p = 0.04), group 2 (r 2 = 0.41, p = 0.0007); right hemisphere infarcts, group 1 (r 2 = 0.008, p = 0.69); group 2 (r 2 = 0.12, p = 0.08); controls (r 2 = 0.29, p ≤ 0.0001). Conclusions: Cortical infarcts of the prefrontal eye field or insula do not impair the pupillary light reflex in humans. However, subtle changes may occur when the pupils dilate back to baseline, probably due to autonomic dysfunction. Replication is needed to explore the possible influence of hemispheric lateralization. We suggest that endovascular therapy for acute ischemic stroke may serve as a clinical research model for the study of acquired cortical lesions in humans.
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Affiliation(s)
- Costanza Peinkhofer
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,Medical Faculty, University of Trieste, Trieste, Italy
| | - Pernille Martens
- Department of Radiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Johannes Grand
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Thomas Truelsen
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Neurobiology Research Unit, Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Kjaergaard
- Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Daniel Kondziella
- Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
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Abstract
Spatial attention enables us to focus visual processing toward specific locations or stimuli before the next fixation. Recent evidence has suggested that local luminance at the spatial locus of attention or saccade preparation influences pupil size independent of global luminance levels. However, it remains to be determined which neural pathways produce this location-specific modulation of pupil size. The intermediate layers of the midbrain superior colliculus (SC) form part of the network of brain areas involved in spatial attention and modulation of pupil size. Here, we demonstrated that pupil size was altered according to local luminance level at the spatial location corresponding to a microstimulated location in the intermediate SC (SCi) map of monkeys. Moreover, local SCi inactivation through injection of lidocaine reversed this local luminance modulation. Our findings reveal a causal role of the SCi in preparing pupil size for local luminance conditions at the next saccadic goal.
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34
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Reduced pupil dilation during action preparation in schizophrenia. Int J Psychophysiol 2018; 128:111-118. [PMID: 29574231 DOI: 10.1016/j.ijpsycho.2018.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/30/2018] [Accepted: 03/19/2018] [Indexed: 11/22/2022]
Abstract
Impairments in cognitive control-the ability to exert control over thoughts and actions and respond flexibly to the environment-are well-documented in schizophrenia. However, the degree to which experimental task performance reflects true cognitive control impairments or more general alterations in effort, arousal and/or task preparedness is unclear. Pupillary responses can provide insight into these latter factors, as the pupil dilates with degree of cognitive effort and response preparation. In the current study, 16 medicated outpatients with schizophrenia (SZP) and 18 healthy controls performed a task that measures the ability to reactively inhibit and modify a planned action-the double-step task. In this task, participants were required to make a saccade to a visual target. Infrequently, the target jumped to a new location and participants were instructed to rapidly inhibit and change their eye movement plan. Applying a race model of performance, we have previously shown that SZP require more time to inhibit a planned action. In the current analysis, we measured pupil dilation associated with task preparation and found that SZP had a shallower increase in pupil size prior to the onset of the trial. Additionally, reduced magnitude of the pupil response was associated with negative symptom severity in patients. Based on primate neurophysiology and cognitive neuroscience work, we suggest that this blunted pupillary response may reflect abnormalities in a general orienting response or reduced motivational significance of a cue signifying the onset of a preparatory period and that these abnormalities might share an autonomic basis with negative symptoms.
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35
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Abstract
When observers search for a specific target, it is assumed that they activate a representation of the task relevant object in visual working memory (VWM). This representation – often referred to as the template – guides attention towards matching visual input. In two experiments we tested whether the pupil response can be used to differentiate stimuli that match the task-relevant template from irrelevant input. Observers memorized a target color to be searched for in a multi-color visual search display, presented after a delay period. In Experiment 1, one color appeared at the start of the trial, which was then automatically the search template. In Experiments 2, two colors were presented, and a retro-cue indicated which of these was relevant for the upcoming search task. Crucially, before the search display appeared, we briefly presented one colored probe stimulus. The probe could match either the relevant-template color, the non-cued color (irrelevant), or be a new color not presented in the trial. We measured the pupil response to the probe as a signature of task relevance. Experiment 1 showed significantly smaller pupil size in response to probes matching the search template than for irrelevant colors. Experiment 2 replicated the template matching effect and allowed us to rule out that it was solely due to repetition priming. Taken together, we show that the pupil responds selectively to participants’ target template prior to search.
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36
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Selective Modulation of the Pupil Light Reflex by Microstimulation of Prefrontal Cortex. J Neurosci 2017; 37:5008-5018. [PMID: 28432136 DOI: 10.1523/jneurosci.2433-16.2017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 03/14/2017] [Accepted: 03/15/2017] [Indexed: 11/21/2022] Open
Abstract
The prefrontal cortex (PFC) is thought to flexibly regulate sensorimotor responses, perhaps through modulating activity in other circuits. However, the scope of that control remains unknown: it remains unclear whether the PFC can modulate basic reflexes. One canonical example of a central reflex is the pupil light reflex (PLR): the automatic constriction of the pupil in response to luminance increments. Unlike pupil size, which depends on the interaction of multiple physiological and neuromodulatory influences, the PLR reflects the action of a simple brainstem circuit. However, emerging behavioral evidence suggests that the PLR may be modulated by cognitive processes. Although the neural basis of these modulations remains unknown, one possible source is the PFC, particularly the frontal eye field (FEF), an area of the PFC implicated in the control of attention. We show that microstimulation of the rhesus macaque FEF alters the magnitude of the PLR in a spatially specific manner. FEF microstimulation enhanced the PLR to probes presented within the stimulated visual field, but suppressed the PLR to probes at nonoverlapping locations. The spatial specificity of this effect parallels the effect of FEF stimulation on attention and suggests that FEF is capable of modulating visuomotor transformations performed at a lower level than was previously known. These results provide evidence of the selective regulation of a basic brainstem reflex by the PFC.SIGNIFICANCE STATEMENT The pupil light reflex (PLR) is our brain's first and most fundamental mechanism for light adaptation. Although it is often described in textbooks as being an immutable reflex, converging evidence suggests that the magnitude of the PLR is modulated by cognitive factors. The neural bases of these modulations are unknown. Here, we report that microstimulation in the prefrontal cortex (PFC) modulates the gain of the PLR, changing how a simple reflex circuit responds to physically identical stimuli. These results suggest that control structures such as the PFC can add complexity and flexibility to even a basic brainstem circuit.
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37
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Peysakhovich V, Vachon F, Dehais F. The impact of luminance on tonic and phasic pupillary responses to sustained cognitive load. Int J Psychophysiol 2016; 112:40-45. [PMID: 27979740 DOI: 10.1016/j.ijpsycho.2016.12.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 12/08/2016] [Accepted: 12/10/2016] [Indexed: 01/06/2023]
Abstract
Pupillary reactions independent of light conditions have been linked to cognition for a long time. However, the light conditions can impact the cognitive pupillary reaction. Previous studies underlined the impact of luminance on pupillary reaction, but it is still unclear how luminance modulates the sustained and transient components of pupillary reaction - tonic pupil diameter and phasic pupil response. In the present study, we investigated the impact of the luminance on these two components under sustained cognitive load. Fourteen participants performed a novel working memory task combining mathematical computations with a classic n-back task. We studied both tonic pupil diameter and phasic pupil response under low (1-back) and high (2-back) working memory load and two luminance levels (gray and white). We found that the impact of working memory load on the tonic pupil diameter was modulated by the level of luminance, the increase in tonic pupil diameter with the load being larger under lower luminance. In contrast, the smaller phasic pupil response found under high load remained unaffected by luminance. These results showed that luminance impacts the cognitive pupillary reaction - tonic pupil diameter (phasic pupil response) being modulated under sustained (respectively, transient) cognitive load. These findings also support the relationship between the locus-coeruleus system, presumably functioning in two firing modes - tonic and phasic - and the pupil diameter. We suggest that the tonic pupil diameter tracks the tonic activity of the locus-coeruleus while phasic pupil response reflects its phasic activity. Besides, the designed novel cognitive paradigm allows the simultaneous manipulation of sustained and transient components of the cognitive load and is useful for dissociating the effects on the tonic pupil diameter and phasic pupil response.
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38
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Peel TR, Hafed ZM, Dash S, Lomber SG, Corneil BD. A Causal Role for the Cortical Frontal Eye Fields in Microsaccade Deployment. PLoS Biol 2016; 14:e1002531. [PMID: 27509130 PMCID: PMC4980061 DOI: 10.1371/journal.pbio.1002531] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/15/2016] [Indexed: 11/19/2022] Open
Abstract
Microsaccades aid vision by helping to strategically sample visual scenes. Despite the importance of these small eye movements, no cortical area has ever been implicated in their generation. Here, we used unilateral and bilateral reversible inactivation of the frontal eye fields (FEF) to identify a cortical drive for microsaccades. Unexpectedly, FEF inactivation altered microsaccade metrics and kinematics. Such inactivation also impaired microsaccade deployment following peripheral cue onset, regardless of cue side or inactivation configuration. Our results demonstrate that the FEF provides critical top-down drive for microsaccade generation, particularly during the recovery of microsaccades after disruption by sensory transients. Our results constitute the first direct evidence, to our knowledge, for the contribution of any cortical area to microsaccade generation, and they provide a possible substrate for how cognitive processes can influence the strategic deployment of microsaccades. Our eyes are constantly in motion. This study shows that the frontal eye fields (an area of the frontal cortex) contribute to the strategic deployment of microsaccades, which aid vision by precisely translating retinal images by a few photoreceptors. Microsaccades are small, fixational eye movements that precisely relocate the visual axis. Despite evidence that microsaccades can be strategically controlled in high-acuity visual tasks, impacting visual processing, and considerable knowledge about how microsaccades are generated by the oculomotor brainstem, little is known about the cortical substrates that control microsaccades. To address this gap, we examined microsaccades generated by non-human primates before, during, and after large-volume reversible unilateral or bilateral inactivation of the frontal eye fields, a key oculomotor area in the frontal cortex. In support of a role for the frontal eye fields in microsaccades, microsaccade metrics and kinematics were altered during frontal eye fields inactivation. More surprisingly, frontal eye fields inactivation also impaired the generation of microsaccades following presentation of peripheral cues, regardless of the side of the cue or inactivation configuration. To our knowledge, our results constitute the first direct evidence for the contribution of any cortical area to microsaccade generation and suggest that the frontal eye fields can provide the top-down signals to the oculomotor brainstem needed to strategically guide microsaccades.
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Affiliation(s)
- Tyler R. Peel
- The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- Graduate Program in Neuroscience, University of Western Ontario, London, Ontario, Canada
| | - Ziad M. Hafed
- Physiology of Active Vision Laboratory, Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany
| | - Suryadeep Dash
- The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- Department of Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Stephen G. Lomber
- The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- Department of Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada
- Department of Psychology, University of Western Ontario, London, Ontario, Canada
| | - Brian D. Corneil
- The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- Department of Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada
- Department of Psychology, University of Western Ontario, London, Ontario, Canada
- Robarts Research Institute, London, Ontario, Canada
- * E-mail:
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