1
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Xiao W, Sharma S, Kreiman G, Livingstone MS. Feature-selective responses in macaque visual cortex follow eye movements during natural vision. Nat Neurosci 2024; 27:1157-1166. [PMID: 38684892 PMCID: PMC11156562 DOI: 10.1038/s41593-024-01631-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 03/26/2024] [Indexed: 05/02/2024]
Abstract
In natural vision, primates actively move their eyes several times per second via saccades. It remains unclear whether, during this active looking, visual neurons exhibit classical retinotopic properties, anticipate gaze shifts or mirror the stable quality of perception, especially in complex natural scenes. Here, we let 13 monkeys freely view thousands of natural images across 4.6 million fixations, recorded 883 h of neuronal responses in six areas spanning primary visual to anterior inferior temporal cortex and analyzed spatial, temporal and featural selectivity in these responses. Face neurons tracked their receptive field contents, indicated by category-selective responses. Self-consistency analysis showed that general feature-selective responses also followed eye movements and remained gaze-dependent over seconds of viewing the same image. Computational models of feature-selective responses located retinotopic receptive fields during free viewing. We found limited evidence for feature-selective predictive remapping and no viewing-history integration. Thus, ventral visual neurons represent the world in a predominantly eye-centered reference frame during natural vision.
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Affiliation(s)
- Will Xiao
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
| | - Saloni Sharma
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Gabriel Kreiman
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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2
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Nelson R, Shelto E. Repetition blindness in a saccadic persistence of vision display. Perception 2024; 53:335-342. [PMID: 38483914 DOI: 10.1177/03010066241236403] [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: 05/12/2024]
Abstract
A form of repetition blindness in visually unimpaired individuals was found for objects presented during saccades. Observers were asked to draw their percepts after making saccades across an LED strip that "painted" an image on their retinas by presenting sequential columns of a bitmap at a speed to match a 30-degree saccade. During experimental trials, repetitions of a single letter (either "A," "X," "H," or "V") were presented across saccades. Although an average of six letters were presented across each saccade, observers typically indicated perceiving only a single instance of the letter in their drawings. This inability to perceive multiple instances of a letter was not due to a limited region of attentional processing, as it only attained for multiple instances along the axis of the saccade-horizontal saccades did not affect perception of multiple letters along the vertical axis. This effect is likely due to selective suppression of visual areas during saccades.
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3
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Weng G, Clark K, Akbarian A, Noudoost B, Nategh N. Time-varying generalized linear models: characterizing and decoding neuronal dynamics in higher visual areas. Front Comput Neurosci 2024; 18:1273053. [PMID: 38348287 PMCID: PMC10859875 DOI: 10.3389/fncom.2024.1273053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024] Open
Abstract
To create a behaviorally relevant representation of the visual world, neurons in higher visual areas exhibit dynamic response changes to account for the time-varying interactions between external (e.g., visual input) and internal (e.g., reward value) factors. The resulting high-dimensional representational space poses challenges for precisely quantifying individual factors' contributions to the representation and readout of sensory information during a behavior. The widely used point process generalized linear model (GLM) approach provides a powerful framework for a quantitative description of neuronal processing as a function of various sensory and non-sensory inputs (encoding) as well as linking particular response components to particular behaviors (decoding), at the level of single trials and individual neurons. However, most existing variations of GLMs assume the neural systems to be time-invariant, making them inadequate for modeling nonstationary characteristics of neuronal sensitivity in higher visual areas. In this review, we summarize some of the existing GLM variations, with a focus on time-varying extensions. We highlight their applications to understanding neural representations in higher visual areas and decoding transient neuronal sensitivity as well as linking physiology to behavior through manipulation of model components. This time-varying class of statistical models provide valuable insights into the neural basis of various visual behaviors in higher visual areas and hold significant potential for uncovering the fundamental computational principles that govern neuronal processing underlying various behaviors in different regions of the brain.
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Affiliation(s)
- Geyu Weng
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Kelsey Clark
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Amir Akbarian
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Behrad Noudoost
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
| | - Neda Nategh
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, United States
- Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, United States
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4
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Denagamage S, Morton MP, Hudson NV, Reynolds JH, Jadi MP, Nandy AS. Laminar mechanisms of saccadic suppression in primate visual cortex. Cell Rep 2023; 42:112720. [PMID: 37392385 PMCID: PMC10528056 DOI: 10.1016/j.celrep.2023.112720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 04/15/2023] [Accepted: 06/13/2023] [Indexed: 07/03/2023] Open
Abstract
Saccadic eye movements are known to cause saccadic suppression, a temporary reduction in visual sensitivity and visual cortical firing rates. While saccadic suppression has been well characterized at the level of perception and single neurons, relatively little is known about the visual cortical networks governing this phenomenon. Here we examine the effects of saccadic suppression on distinct neural subpopulations within visual area V4. We find subpopulation-specific differences in the magnitude and timing of peri-saccadic modulation. Input-layer neurons show changes in firing rate and inter-neuronal correlations prior to saccade onset, and putative inhibitory interneurons in the input layer elevate their firing rate during saccades. A computational model of this circuit recapitulates our empirical observations and demonstrates that an input-layer-targeting pathway can initiate saccadic suppression by enhancing local inhibitory activity. Collectively, our results provide a mechanistic understanding of how eye movement signaling interacts with cortical circuitry to enforce visual stability.
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Affiliation(s)
- Sachira Denagamage
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Mitchell P Morton
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA
| | - Nyomi V Hudson
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA
| | - John H Reynolds
- Systems Neurobiology Laboratories, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Monika P Jadi
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA; Department of Psychiatry, Yale University, New Haven, CT 06511, USA; Kavli Institute for Neuroscience, Yale University, New Haven, CT 06511, USA; Wu Tsai Institute, Yale University, New Haven, CT 06511, USA.
| | - Anirvan S Nandy
- Department of Neuroscience, Yale University, New Haven, CT 06511, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06511, USA; Kavli Institute for Neuroscience, Yale University, New Haven, CT 06511, USA; Wu Tsai Institute, Yale University, New Haven, CT 06511, USA.
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5
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Leszczynski M, Bickel S, Nentwich M, Russ BE, Parra L, Lakatos P, Mehta A, Schroeder CE. Saccadic modulation of neural excitability in auditory areas of the neocortex. Curr Biol 2023; 33:1185-1195.e6. [PMID: 36863343 PMCID: PMC10424710 DOI: 10.1016/j.cub.2023.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/25/2022] [Accepted: 02/03/2023] [Indexed: 03/04/2023]
Abstract
In natural "active" vision, humans and other primates use eye movements (saccades) to sample bits of information from visual scenes. In the visual cortex, non-retinal signals linked to saccades shift visual cortical neurons into a high excitability state as each saccade ends. The extent of this saccadic modulation outside of the visual system is unknown. Here, we show that during natural viewing, saccades modulate excitability in numerous auditory cortical areas with a temporal pattern complementary to that seen in visual areas. Control somatosensory cortical recordings indicate that the temporal pattern is unique to auditory areas. Bidirectional functional connectivity patterns suggest that these effects may arise from regions involved in saccade generation. We propose that by using saccadic signals to yoke excitability states in auditory areas to those in visual areas, the brain can improve information processing in complex natural settings.
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Affiliation(s)
- Marcin Leszczynski
- Departments of Psychiatry and Neurology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA; Translational Neuroscience Lab Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY 10962, USA; Cognitive Science Department, Institute of Philosophy, Jagiellonian University, Krakow 31-007, Poland.
| | - Stephan Bickel
- Translational Neuroscience Lab Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY 10962, USA; The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY 11030, USA; Departments of Neurosurgery and Neurology, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY 11549, USA
| | - Maximilian Nentwich
- Biomedical Engineering Department, City College, CUNY, New York, NY 10031, USA
| | - Brian E Russ
- Translational Neuroscience Lab Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY 10962, USA; Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Psychiatry, New York University at Langone, New York, NY 10016, USA
| | - Lucas Parra
- Biomedical Engineering Department, City College, CUNY, New York, NY 10031, USA
| | - Peter Lakatos
- Translational Neuroscience Lab Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY 10962, USA; Department of Psychiatry, New York University at Langone, New York, NY 10016, USA
| | - Ashesh Mehta
- The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY 11030, USA; Departments of Neurosurgery and Neurology, Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY 11549, USA
| | - Charles E Schroeder
- Departments of Psychiatry and Neurology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA; Translational Neuroscience Lab Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY 10962, USA.
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6
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Jensen O, Pan Y, Frisson S, Wang L. An oscillatory pipelining mechanism supporting previewing during visual exploration and reading. Trends Cogn Sci 2021; 25:1033-1044. [PMID: 34544653 PMCID: PMC7615059 DOI: 10.1016/j.tics.2021.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/24/2021] [Accepted: 08/25/2021] [Indexed: 11/15/2022]
Abstract
Humans have a remarkable ability to efficiently explore visual scenes and text using eye movements. Humans typically make eye movements (saccades) every ~250 ms. Since saccade initiation and execution take 100 ms, this leaves only ~150 ms to recognize the fixated object (or word) while simultaneously previewing candidates for the next saccade goal. We propose a pipelining mechanism where serial processing occurs within a specific brain region, whereas parallel processing occurs across different brain regions. The mechanism is timed by alpha oscillations that coordinate the saccades, visual recognition, and previewing in the cortical hierarchy. Consequently, the neuronal mechanism supporting natural vision and saccades must be studied in unison to uncover the brain mechanisms supporting visual exploration and reading.
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Affiliation(s)
- Ole Jensen
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK.
| | - Yali Pan
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Steven Frisson
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Lin Wang
- Department of Psychiatry and the Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA; Department of Psychology, Tufts University, Medford, MA 02155, USA
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7
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Akbarian A, Clark K, Noudoost B, Nategh N. A sensory memory to preserve visual representations across eye movements. Nat Commun 2021; 12:6449. [PMID: 34750376 PMCID: PMC8575989 DOI: 10.1038/s41467-021-26756-0] [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: 04/23/2021] [Accepted: 10/13/2021] [Indexed: 11/09/2022] Open
Abstract
Saccadic eye movements (saccades) disrupt the continuous flow of visual information, yet our perception of the visual world remains uninterrupted. Here we assess the representation of the visual scene across saccades from single-trial spike trains of extrastriate visual areas, using a combined electrophysiology and statistical modeling approach. Using a model-based decoder we generate a high temporal resolution readout of visual information, and identify the specific changes in neurons' spatiotemporal sensitivity that underly an integrated perisaccadic representation of visual space. Our results show that by maintaining a memory of the visual scene, extrastriate neurons produce an uninterrupted representation of the visual world. Extrastriate neurons exhibit a late response enhancement close to the time of saccade onset, which preserves the latest pre-saccadic information until the post-saccadic flow of retinal information resumes. These results show how our brain exploits available information to maintain a representation of the scene while visual inputs are disrupted.
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Affiliation(s)
- Amir Akbarian
- grid.223827.e0000 0001 2193 0096Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT USA
| | - Kelsey Clark
- grid.223827.e0000 0001 2193 0096Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT USA
| | - Behrad Noudoost
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA.
| | - Neda Nategh
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA. .,Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, USA.
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8
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Leszczynski M, Chaieb L, Staudigl T, Enkirch SJ, Fell J, Schroeder CE. Neural activity in the human anterior thalamus during natural vision. Sci Rep 2021; 11:17480. [PMID: 34471183 PMCID: PMC8410783 DOI: 10.1038/s41598-021-96588-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 08/11/2021] [Indexed: 12/23/2022] Open
Abstract
In natural vision humans and other primates explore environment by active sensing, using saccadic eye movements to relocate the fovea and sample different bits of information multiple times per second. Saccades induce a phase reset of ongoing neuronal oscillations in primary and higher-order visual cortices and in the medial temporal lobe. As a result, neuron ensembles are shifted to a common state at the time visual input propagates through the system (i.e., just after fixation). The extent of the brain’s circuitry that is modulated by saccades is not yet known. Here, we evaluate the possibility that saccadic phase reset impacts the anterior nuclei of the thalamus (ANT). Using recordings in the human thalamus of three surgical patients during natural vision, we found that saccades and visual stimulus onset both modulate neural activity, but with distinct field potential morphologies. Specifically, we found that fixation-locked field potentials had a component that preceded saccade onset. It was followed by an early negativity around 50 ms after fixation onset which is significantly faster than any response to visual stimulus presentation. The timing of these events suggests that the ANT is predictively modulated before the saccadic eye movement. We also found oscillatory phase concentration, peaking at 3–4 Hz, coincident with suppression of Broadband High-frequency Activity (BHA; 80–180 Hz), both locked to fixation onset supporting the idea that neural oscillations in these nuclei are reorganized to a low excitability state right after fixation onset. These findings show that during real-world natural visual exploration neural dynamics in the human ANT is influenced by visual and oculomotor events, which supports the idea that ANT, apart from their contribution to episodic memory, also play a role in natural vision.
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Affiliation(s)
- Marcin Leszczynski
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University Medical Center, 1051 Riverside Drive Kolb Annex Rm 561, New York, NY, 10032, USA. .,Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY, USA.
| | - Leila Chaieb
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Tobias Staudigl
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Juergen Fell
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Charles E Schroeder
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University Medical Center, 1051 Riverside Drive Kolb Annex Rm 561, New York, NY, 10032, USA.,Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute, Orangeburg, NY, USA
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9
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Spontaneous modulations of high-frequency cortical activity. Clin Neurophysiol 2021; 132:2391-2403. [PMID: 34454266 DOI: 10.1016/j.clinph.2021.06.020] [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: 04/14/2021] [Revised: 05/15/2021] [Accepted: 06/01/2021] [Indexed: 11/20/2022]
Abstract
OBJECTIVE We clarified the clinical and mechanistic significance of physiological modulations of high-frequency broadband cortical activity associated with spontaneous saccadic eye movements during a resting state. METHODS We studied 30 patients who underwent epilepsy surgery following extraoperative electrocorticography and electrooculography recordings. We determined whether high-gamma activity at 70-110 Hz preceding saccade onset would predict upcoming ocular behaviors. We assessed how accurately the model incorporating saccade-related high-gamma modulations would localize the primary visual cortex defined by electrical stimulation. RESULTS The dynamic atlas demonstrated transient high-gamma suppression in the striatal cortex before saccade onset and high-gamma augmentation subsequently involving the widespread posterior brain regions. More intense striatal high-gamma suppression predicted the upcoming saccade directed to the ipsilateral side and lasting longer in duration. The bagged-tree-ensemble model demonstrated that intense saccade-related high-gamma modulations localized the visual cortex with an accuracy of 95%. CONCLUSIONS We successfully animated the neural dynamics supporting saccadic suppression, a principal mechanism minimizing the perception of blurred vision during rapid eye movements. The primary visual cortex per se may prepare actively in advance for massive image motion expected during upcoming prolonged saccades. SIGNIFICANCE Measuring saccade-related electrocorticographic signals may help localize the visual cortex and avoid misperceiving physiological high-frequency activity as epileptogenic.
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10
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Schwenk JCB, Klingenhoefer S, Werner BO, Dowiasch S, Bremmer F. Perisaccadic encoding of temporal information in macaque area V4. J Neurophysiol 2021; 125:785-795. [PMID: 33502931 DOI: 10.1152/jn.00387.2020] [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] [Indexed: 11/22/2022] Open
Abstract
The accurate processing of temporal information is of critical importance in everyday life. Yet, psychophysical studies in humans have shown that the perception of time is distorted around saccadic eye movements. The neural correlates of this misperception are still poorly understood. Behavioral and neural evidence suggest that it is tightly linked to other known perisaccadic modulations of visual perception. To further our understanding of how temporal processing is affected by saccades, we studied the representations of brief visual time intervals during fixation and saccades in area V4 of two awake macaques. We presented random sequences of vertical bar stimuli and extracted neural responses to double-pulse stimulation at varying interstimulus intervals. Our results show that temporal information about very brief intervals of as brief as 20 ms is reliably represented in the multiunit activity in area V4. Response latencies were not systematically modulated by the saccade. However, a general increase in perisaccadic activity altered the ratio of response amplitudes within stimulus pairs compared with fixation. In line with previous studies showing that the perception of brief time intervals is partly based on response levels, this may be seen as a possible correlate of the perisaccadic misperception of time.NEW & NOTEWORTHY We investigated for the first time how temporal information on very brief timescales is represented in area V4 around the time of saccadic eye movements. Overall, the responses showed an unexpectedly precise representation of time intervals. Our finding of a perisaccadic modulation of relative response amplitudes introduces a new possible correlate of saccade-related perceptual distortions of time.
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Affiliation(s)
- Jakob C B Schwenk
- Department of Neurophysics, Philipps-Universität Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior (CMBB), Philipps-Universität Marburg and Justus-Liebig-University Giessen, Germany
| | | | - Björn-Olaf Werner
- Department of Neurophysics, Philipps-Universität Marburg, Marburg, Germany
| | - Stefan Dowiasch
- Department of Neurophysics, Philipps-Universität Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior (CMBB), Philipps-Universität Marburg and Justus-Liebig-University Giessen, Germany
| | - Frank Bremmer
- Department of Neurophysics, Philipps-Universität Marburg, Marburg, Germany
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11
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Neupane S, Guitton D, Pack CC. Perisaccadic remapping: What? How? Why? Rev Neurosci 2020; 31:505-520. [PMID: 32242834 DOI: 10.1515/revneuro-2019-0097] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/31/2019] [Indexed: 11/15/2022]
Abstract
About 25 years ago, the discovery of receptive field (RF) remapping in the parietal cortex of nonhuman primates revealed that visual RFs, widely assumed to have a fixed retinotopic organization, can change position before every saccade. Measuring such changes can be deceptively difficult. As a result, studies that followed have generated a fascinating but somewhat confusing picture of the phenomenon. In this review, we describe how observations of RF remapping depend on the spatial and temporal sampling of visual RFs and saccade directions. Further, we summarize some of the theories of how remapping might occur in neural circuitry. Finally, based on neurophysiological and psychophysical observations, we discuss the ways in which remapping information might facilitate computations in downstream brain areas.
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Affiliation(s)
- Sujaya Neupane
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Daniel Guitton
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A2B4, Canada
| | - Christopher C Pack
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A2B4, Canada
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12
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Barczak A, Haegens S, Ross DA, McGinnis T, Lakatos P, Schroeder CE. Dynamic Modulation of Cortical Excitability during Visual Active Sensing. Cell Rep 2020; 27:3447-3459.e3. [PMID: 31216467 PMCID: PMC6598687 DOI: 10.1016/j.celrep.2019.05.072] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/19/2019] [Accepted: 05/17/2019] [Indexed: 01/15/2023] Open
Abstract
Visual physiology is traditionally investigated by presenting stimuli with gaze held constant. However, during active viewing of a scene, information is actively acquired using systematic patterns of fixations and saccades. Prior studies suggest that during such active viewing, both nonretinal, saccade-related signals and “extra-classical” receptive field inputs modulate visual processing. This study used a set of active viewing tasks that allowed us to compare visual responses with and without direct foveal input, thus isolating the contextual eye movement-related influences. Studying nonhuman primates, we find strong contextual modulation in primary visual cortex (V1): excitability and response amplification immediately after fixation onset, transiting to suppression leading up to the next saccade. Time-frequency decomposition suggests that this amplification and suppression cycle stems from a phase reset of ongoing neuronal oscillatory activity. The impact of saccade-related contextual modulation on stimulus processing makes active visual sensing fundamentally different from the more passive processes investigated in traditional paradigms. By isolating contextual eye movement-related influences during active vision, Barczak et al. show that eye movements affect excitability in V1 such that responses are amplified immediately after fixation onset and suppressed as the next saccade approaches. This amplification and suppression cycle stems from a phase reset of ambient oscillatory activity in V1.
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Affiliation(s)
- Annamaria Barczak
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Saskia Haegens
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Departments of Neurological Surgery and Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA; Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen 6500HB, the Netherlands
| | - Deborah A Ross
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Tammy McGinnis
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
| | - Peter Lakatos
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Psychiatry, New York University School of Medicine, New York, NY 10016, USA
| | - Charles E Schroeder
- Translational Neuroscience Division, Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Departments of Neurological Surgery and Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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13
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Oprea L, Pack CC, Khadra A. Machine classification of spatiotemporal patterns: automated parameter search in a rebounding spiking network. Cogn Neurodyn 2020; 14:267-280. [PMID: 32399070 PMCID: PMC7203379 DOI: 10.1007/s11571-020-09568-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 11/20/2019] [Accepted: 01/03/2020] [Indexed: 12/20/2022] Open
Abstract
Various patterns of electrical activities, including travelling waves, have been observed in cortical experimental data from animal models as well as humans. By applying machine learning techniques, we investigate the spatiotemporal patterns, found in a spiking neuronal network with inhibition-induced firing (rebounding). Our cortical sheet model produces a wide variety of network activities including synchrony, target waves, and travelling wavelets. Pattern formation is controlled by modifying a Gaussian derivative coupling kernel through varying the level of inhibition, coupling strength, and kernel geometry. We have designed a computationally efficient machine classifier, based on statistical, textural, and temporal features, to identify the parameter regimes associated with different spatiotemporal patterns. Our results reveal that switching between synchrony and travelling waves can occur transiently and spontaneously without a stimulus, in a noise-dependent fashion, or in the presence of stimulus when the coupling strength and level of inhibition are at moderate values. They also demonstrate that when a target wave is formed, its wave speed is most sensitive to perturbations in the coupling strength between model neurons. This study provides an automated method to characterize activities produced by a novel spiking network that phenomenologically models large scale dynamics in the cortex.
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Affiliation(s)
- Lawrence Oprea
- Department of Physiology, McGill University, Montréal, QC Canada
| | - Christopher C. Pack
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC Canada
| | - Anmar Khadra
- Department of Physiology, McGill University, Montréal, QC Canada
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14
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Abstract
Most people easily learn to recognize new faces and places, and with more extensive practice they can become experts at visual tasks as complex as radiological diagnosis and action video games. Such perceptual plasticity has been thoroughly studied in the context of training paradigms that require constant fixation. In contrast, when observers learn under more natural conditions, they make frequent saccadic eye movements. Here we show that such eye movements can play an important role in visual learning. Observers performed a task in which they executed a saccade while discriminating the motion of a cued visual stimulus. Additional stimuli, presented simultaneously with the cued one, permitted an assessment of the perceptual integration of information across visual space. Consistent with previous results on perisaccadic remapping [M. Szinte, D. Jonikaitis, M. Rolfs, P. Cavanagh, H. Deubel, J. Neurophysiol. 116, 1592-1602 (2016)], most observers preferentially integrated information from locations representing the presaccadic and postsaccadic retinal positions of the cue. With extensive training on the saccade task, these observers gradually acquired the ability to perform similar motion integration without making eye movements. Importantly, the newly acquired pattern of spatial integration was determined by the metrics of the saccades made during training. These results suggest that oculomotor influences on visual processing, long thought to subserve the function of perceptual stability, also play a role in visual plasticity.
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15
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Zanos TP. Recording and Decoding of Vagal Neural Signals Related to Changes in Physiological Parameters and Biomarkers of Disease. Cold Spring Harb Perspect Med 2019; 9:a034157. [PMID: 30670469 PMCID: PMC6886457 DOI: 10.1101/cshperspect.a034157] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Our bodies have built-in neural reflexes that continuously monitor organ function and maintain physiological homeostasis. Whereas the field of bioelectronic medicine has mainly focused on the stimulation of neural circuits to treat various conditions, recent studies have started to investigate the possibility of leveraging the sensory arm of these reflexes to diagnose disease states. To accomplish this, neural signals emanating from the body's built-in biosensors and propagating through peripheral nerves must be recorded and decoded to identify the presence or levels of relevant biomarkers of disease. The process of acquiring these signals poses several technical challenges related to the neural interfaces, surgical techniques, and data-processing framework needed to record and analyze them. However, these challenges can be addressed with a rigorous experimental approach and new advances in implantable electrodes, signal processing, and machine learning methods. Outlined in this review are studies decoding vagus nerve activity as it related to inflammatory, metabolic, and cardiopulmonary biomarkers. Successfully decoding peripheral nerve activity related to disease states will not only enable the development of real-time diagnostic devices, but also help advancing truly closed-loop neuromodulation technologies.
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Affiliation(s)
- Theodoros P Zanos
- Center for Bioelectronic Medicine, The Feinstein Institute for Medical Research, Donald & Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, New York 11030
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16
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Brooks JX, Cullen KE. Predictive Sensing: The Role of Motor Signals in Sensory Processing. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:842-850. [PMID: 31401034 DOI: 10.1016/j.bpsc.2019.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022]
Abstract
The strategy of integrating motor signals with sensory information during voluntary behavior is a general feature of sensory processing. It is required to distinguish externally applied (exafferent) from self-generated (reafferent) sensory inputs. This distinction, in turn, underlies our ability to achieve both perceptual stability and accurate motor control during everyday activities. In this review, we consider the results of recent experiments that have provided circuit-level insight into how motor-related inputs to sensory areas selectively cancel self-generated sensory inputs during active behaviors. These studies have revealed both common strategies and important differences across systems. Sensory reafference is suppressed at the earliest stages of central processing in the somatosensory, vestibular, and auditory systems, with the cerebellum and cerebellum-like structures playing key roles. Furthermore, motor-related inputs can also suppress reafferent responses at higher levels of processing such as the cortex-a strategy preferentially used in visual processing. These recent findings have important implications for understanding how the brain achieves the flexibility required to continuously calibrate relationships between motor signals and the resultant sensory feedback, a computation necessary for our subjective awareness that we control both our actions and their sensory consequences.
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Affiliation(s)
- Jessica X Brooks
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - Kathleen E Cullen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland.
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17
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Grujic N, Brehm N, Gloge C, Zhuo W, Hafed ZM. Perisaccadic perceptual mislocalization is different for upward saccades. J Neurophysiol 2018; 120:3198-3216. [PMID: 30332326 DOI: 10.1152/jn.00350.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Saccadic eye movements, which dramatically alter retinal images, are associated with robust perimovement perceptual alterations. Such alterations, thought to reflect brain mechanisms for maintaining perceptual stability in the face of saccade-induced retinal image disruptions, are often studied by asking subjects to localize brief stimuli presented around the time of horizontal saccades. However, other saccade directions are not usually explored. Motivated by recently discovered asymmetries in upper and lower visual field representations in the superior colliculus, a structure important for both saccade generation and visual analysis, we observed significant differences in perisaccadic perceptual alterations for upward saccades relative to other saccade directions. We also found that, even for purely horizontal saccades, perceptual alterations differ for upper vs. lower retinotopic stimulus locations. Our results, coupled with conceptual modeling, suggest that perisaccadic perceptual alterations might critically depend on neural circuits, such as superior colliculus, that asymmetrically represent the upper and lower visual fields. NEW & NOTEWORTHY Brief visual stimuli are robustly mislocalized around the time of saccades. Such mislocalization is thought to arise because oculomotor and visual neural maps distort space through foveal magnification. However, other neural asymmetries, such as upper visual field magnification in the superior colliculus, may also exist, raising the possibility that interactions between saccades and visual stimuli would depend on saccade direction. We confirmed this behaviorally by exploring and characterizing perisaccadic perception for upward saccades.
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Affiliation(s)
- Nikola Grujic
- Graduate School of Neural and Behavioural Sciences, International Max Planck Research School, Tübingen University , Tübingen , Germany
| | - Nils Brehm
- Master's Program for Neurobiology, Tübingen University , Tübingen , Germany
| | - Cordula Gloge
- Master's Program for Neurobiology, Tübingen University , Tübingen , Germany
| | - Weijie Zhuo
- Master's Program for Neurobiology, Tübingen University , Tübingen , Germany
| | - Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, Tübingen University , Tübingen , Germany.,Hertie Institute for Clinical Brain Research, Tübingen University , Tübingen , Germany
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18
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Zanos TP, Silverman HA, Levy T, Tsaava T, Battinelli E, Lorraine PW, Ashe JM, Chavan SS, Tracey KJ, Bouton CE. Identification of cytokine-specific sensory neural signals by decoding murine vagus nerve activity. Proc Natl Acad Sci U S A 2018; 115:E4843-E4852. [PMID: 29735654 PMCID: PMC6003492 DOI: 10.1073/pnas.1719083115] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The nervous system maintains physiological homeostasis through reflex pathways that modulate organ function. This process begins when changes in the internal milieu (e.g., blood pressure, temperature, or pH) activate visceral sensory neurons that transmit action potentials along the vagus nerve to the brainstem. IL-1β and TNF, inflammatory cytokines produced by immune cells during infection and injury, and other inflammatory mediators have been implicated in activating sensory action potentials in the vagus nerve. However, it remains unclear whether neural responses encode cytokine-specific information. Here we develop methods to isolate and decode specific neural signals to discriminate between two different cytokines. Nerve impulses recorded from the vagus nerve of mice exposed to IL-1β and TNF were sorted into groups based on their shape and amplitude, and their respective firing rates were computed. This revealed sensory neural groups responding specifically to TNF and IL-1β in a dose-dependent manner. These cytokine-mediated responses were subsequently decoded using a Naive Bayes algorithm that discriminated between no exposure and exposures to IL-1β and TNF (mean successful identification rate 82.9 ± 17.8%, chance level 33%). Recordings obtained in IL-1 receptor-KO mice were devoid of IL-1β-related signals but retained their responses to TNF. Genetic ablation of TRPV1 neurons attenuated the vagus neural signals mediated by IL-1β, and distal lidocaine nerve block attenuated all vagus neural signals recorded. The results obtained in this study using the methodological framework suggest that cytokine-specific information is present in sensory neural signals within the vagus nerve.
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Affiliation(s)
- Theodoros P Zanos
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Harold A Silverman
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
- Center for Biomedical Sciences, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Todd Levy
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Tea Tsaava
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
- Center for Biomedical Sciences, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Emily Battinelli
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
- Center for Biomedical Sciences, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | | | - Jeffrey M Ashe
- General Electric Global Research US, Niskayuna, NY 12309
| | - Sangeeta S Chavan
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030
- Center for Biomedical Sciences, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Kevin J Tracey
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030;
- Center for Biomedical Sciences, Feinstein Institute for Medical Research, Manhasset, NY 11030
| | - Chad E Bouton
- Center for Bioelectronic Medicine, Feinstein Institute for Medical Research, Manhasset, NY 11030;
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19
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Akbarian A, Niknam K, Parsa M, Clark K, Noudoost B, Nategh N. Developing a Nonstationary Computational Framework With Application to Modeling Dynamic Modulations in Neural Spiking Responses. IEEE Trans Biomed Eng 2018; 65:241-253. [PMID: 29035203 PMCID: PMC5796416 DOI: 10.1109/tbme.2017.2762687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE This paper aims to develop a computational model that incorporates the functional effects of modulatory covariates (such as context, task, or behavior), which dynamically alter the relationship between the stimulus and the neural response. METHODS We develop a general computational approach along with an efficient estimation procedure in the widely used generalized linear model (GLM) framework to characterize such nonstationary dynamics in spiking response and spatiotemporal characteristics of a neuron at the level of individual trials. The model employs a set of modulatory components, which nonlinearly interact with other stimulus-related signals to reproduce such nonstationary effects. RESULTS The model is tested for its ability to predict the responses of neurons in the middle temporal cortex of macaque monkeys during an eye movement task. The fitted model proves successful in capturing the fast temporal modulations in the response, reproducing the spike response temporal statistics, and accurately accounting for the neurons' dynamic spatiotemporal sensitivities, during eye movements. CONCLUSION The nonstationary GLM framework developed in this study can be used in cases where a time-varying behavioral or cognitive component makes GLM-based models insufficient to describe the dependencies of neural responses on the stimulus-related covariates. SIGNIFICANCE In addition to being quite powerful in encoding time-varying response modulations, this general framework also enables a readout of the neural code while dissociating the influence of other nonstimulus covariates. This framework will advance our ability to understand sensory processing in higher brain areas when modulated by several behavioral or cognitive variables.
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20
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Golan T, Davidesco I, Meshulam M, Groppe DM, Mégevand P, Yeagle EM, Goldfinger MS, Harel M, Melloni L, Schroeder CE, Deouell LY, Mehta AD, Malach R. Increasing suppression of saccade-related transients along the human visual hierarchy. eLife 2017; 6. [PMID: 28850030 PMCID: PMC5576487 DOI: 10.7554/elife.27819] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 08/08/2017] [Indexed: 11/13/2022] Open
Abstract
A key hallmark of visual perceptual awareness is robustness to instabilities arising from unnoticeable eye and eyelid movements. In previous human intracranial (iEEG) work (Golan et al., 2016) we found that excitatory broadband high-frequency activity transients, driven by eye blinks, are suppressed in higher-level but not early visual cortex. Here, we utilized the broad anatomical coverage of iEEG recordings in 12 eye-tracked neurosurgical patients to test whether a similar stabilizing mechanism operates following small saccades. We compared saccades (1.3°−3.7°) initiated during inspection of large individual visual objects with similarly-sized external stimulus displacements. Early visual cortex sites responded with positive transients to both conditions. In contrast, in both dorsal and ventral higher-level sites the response to saccades (but not to external displacements) was suppressed. These findings indicate that early visual cortex is highly unstable compared to higher-level visual regions which apparently constitute the main target of stabilizing extra-retinal oculomotor influences.
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Affiliation(s)
- Tal Golan
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ido Davidesco
- Department of Psychology, New York University, New York, United States
| | - Meir Meshulam
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - David M Groppe
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States.,The Krembil Neuroscience Centre, Toronto, Canada
| | - Pierre Mégevand
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Erin M Yeagle
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Matthew S Goldfinger
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Michal Harel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Lucia Melloni
- Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany.,NYU Comprehensive Epilepsy Center, Department of Neurology, School of Medicine, New York University, New York, United States
| | - Charles E Schroeder
- Department of Neurosurgery, Columbia University College of Physicians and Surgeons, New York, United States.,Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute, Orangeburg, United States
| | - Leon Y Deouell
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Psychology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ashesh D Mehta
- Department of Neurosurgery, Hofstra Northwell School of Medicine, Manhasset, United States.,The Feinstein Institute for Medical Research, Manhasset, United States
| | - Rafael Malach
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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21
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Bellet J, Chen CY, Hafed ZM. Sequential hemifield gating of α- and β-behavioral performance oscillations after microsaccades. J Neurophysiol 2017; 118:2789-2805. [PMID: 28794193 DOI: 10.1152/jn.00253.2017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 08/08/2017] [Accepted: 08/08/2017] [Indexed: 11/22/2022] Open
Abstract
Microsaccades are tiny saccades that occur during gaze fixation. Even though visual processing has been shown to be strongly modulated close to the time of microsaccades, both at central and peripheral eccentricities, it is not clear how these eye movements might influence longer term fluctuations in brain activity and behavior. Here we found that visual processing is significantly affected and, in a rhythmic manner, even several hundreds of milliseconds after a microsaccade. Human visual detection efficiency, as measured by reaction time, exhibited coherent rhythmic oscillations in the α- and β-frequency bands for up to ~650-700 ms after a microsaccade. Surprisingly, the oscillations were sequentially pulsed across visual hemifields relative to microsaccade direction, first occurring in the same hemifield as the movement vector for ~400 ms and then the opposite. Such pulsing also affected perceptual detection performance. Our results suggest that visual processing is subject to long-lasting oscillations that are phase locked to microsaccade generation, and that these oscillations are dependent on microsaccade direction.NEW & NOTEWORTHY We investigated long-term microsaccadic influences on visual processing and found rhythmic oscillations in behavioral performance at α- and β-frequencies (~8-20 Hz). These oscillations were pulsed at a much lower frequency across visual hemifields, first occurring in the same hemifield as the microsaccade direction vector for ~400 ms before switching to the opposite hemifield for a similar interval. Our results suggest that saccades temporally organize visual processing and that such organization can sequentially switch hemifields.
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Affiliation(s)
- Joachim Bellet
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany.,Graduate School of Neural and Behavioural Sciences, International Max Planck Research School, Tuebingen University, Tuebingen, Germany; and.,Hertie Institute for Clinical Brain Research, Tuebingen University, Tuebingen, Germany
| | - Chih-Yang Chen
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany.,Graduate School of Neural and Behavioural Sciences, International Max Planck Research School, Tuebingen University, Tuebingen, Germany; and.,Hertie Institute for Clinical Brain Research, Tuebingen University, Tuebingen, Germany
| | - Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany; .,Hertie Institute for Clinical Brain Research, Tuebingen University, Tuebingen, Germany
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22
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Coherent alpha oscillations link current and future receptive fields during saccades. Proc Natl Acad Sci U S A 2017; 114:E5979-E5985. [PMID: 28673993 DOI: 10.1073/pnas.1701672114] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Oscillations are ubiquitous in the brain, and they can powerfully influence neural coding. In particular, when oscillations at distinct sites are coherent, they provide a means of gating the flow of neural signals between different cortical regions. Coherent oscillations also occur within individual brain regions, although the purpose of this coherence is not well understood. Here, we report that within a single brain region, coherent alpha oscillations link stimulus representations as they change in space and time. Specifically, in primate cortical area V4, alpha coherence links sites that encode the retinal location of a visual stimulus before and after a saccade. These coherence changes exhibit properties similar to those of receptive field remapping, a phenomenon in which individual neurons change their receptive fields according to the metrics of each saccade. In particular, alpha coherence, like remapping, is highly dependent on the saccade vector and the spatial arrangement of current and future receptive fields. Moreover, although visual stimulation plays a modulatory role, it is neither necessary nor sufficient to elicit alpha coherence. Indeed, a similar pattern of coherence is observed even when saccades are made in darkness. Together, these results show that the pattern of alpha coherence across the retinotopic map in V4 matches many of the properties of receptive field remapping. Thus, oscillatory coherence might play a role in constructing the stable representation of visual space that is an essential aspect of conscious perception.
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23
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Chen CY, Hafed ZM. A neural locus for spatial-frequency specific saccadic suppression in visual-motor neurons of the primate superior colliculus. J Neurophysiol 2017; 117:1657-1673. [PMID: 28100659 DOI: 10.1152/jn.00911.2016] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/17/2017] [Accepted: 01/17/2017] [Indexed: 11/22/2022] Open
Abstract
Saccades cause rapid retinal-image shifts that go perceptually unnoticed several times per second. The mechanisms for saccadic suppression have been controversial, in part because of sparse understanding of neural substrates. In this study we uncovered an unexpectedly specific neural locus for spatial frequency-specific saccadic suppression in the superior colliculus (SC). We first developed a sensitive behavioral measure of suppression in two macaque monkeys, demonstrating selectivity to low spatial frequencies similar to that observed in earlier behavioral studies. We then investigated visual responses in either purely visual SC neurons or anatomically deeper visual motor neurons, which are also involved in saccade generation commands. Surprisingly, visual motor neurons showed the strongest visual suppression, and the suppression was dependent on spatial frequency, as in behavior. Most importantly, suppression selectivity for spatial frequency in visual motor neurons was highly predictive of behavioral suppression effects in each individual animal, with our recorded population explaining up to ~74% of behavioral variance even on completely different experimental sessions. Visual SC neurons had mild suppression, which was unselective for spatial frequency and thus only explained up to ~48% of behavioral variance. In terms of spatial frequency-specific saccadic suppression, our results run contrary to predictions that may be associated with a hypothesized SC saccadic suppression mechanism, in which a motor command in the visual motor and motor neurons is first relayed to the more superficial purely visual neurons, to suppress them and to then potentially be fed back to cortex. Instead, an extraretinal modulatory signal mediating spatial-frequency-specific suppression may already be established in visual motor neurons.NEW & NOTEWORTHY Saccades, which repeatedly realign the line of sight, introduce spurious signals in retinal images that normally go unnoticed. In part, this happens because of perisaccadic suppression of visual sensitivity, which is known to depend on spatial frequency. We discovered that a specific subtype of superior colliculus (SC) neurons demonstrates spatial-frequency-dependent suppression. Curiously, it is the neurons that help mediate the saccadic command itself that exhibit such suppression, and not the purely visual ones.
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Affiliation(s)
- Chih-Yang Chen
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany.,Graduate School of Neural and Behavioural Sciences, International Max Planck Research School, Tuebingen University, Tuebingen, Germany; and.,Hertie Institute for Clinical Brain Research, Tuebingen, Germany
| | - Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen University, Tuebingen, Germany; .,Hertie Institute for Clinical Brain Research, Tuebingen, Germany
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