1
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Eckmann S, Young EJ, Gjorgjieva J. Synapse-type-specific competitive Hebbian learning forms functional recurrent networks. Proc Natl Acad Sci U S A 2024; 121:e2305326121. [PMID: 38870059 PMCID: PMC11194505 DOI: 10.1073/pnas.2305326121] [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: 04/04/2023] [Accepted: 04/25/2024] [Indexed: 06/15/2024] Open
Abstract
Cortical networks exhibit complex stimulus-response patterns that are based on specific recurrent interactions between neurons. For example, the balance between excitatory and inhibitory currents has been identified as a central component of cortical computations. However, it remains unclear how the required synaptic connectivity can emerge in developing circuits where synapses between excitatory and inhibitory neurons are simultaneously plastic. Using theory and modeling, we propose that a wide range of cortical response properties can arise from a single plasticity paradigm that acts simultaneously at all excitatory and inhibitory connections-Hebbian learning that is stabilized by the synapse-type-specific competition for a limited supply of synaptic resources. In plastic recurrent circuits, this competition enables the formation and decorrelation of inhibition-balanced receptive fields. Networks develop an assembly structure with stronger synaptic connections between similarly tuned excitatory and inhibitory neurons and exhibit response normalization and orientation-specific center-surround suppression, reflecting the stimulus statistics during training. These results demonstrate how neurons can self-organize into functional networks and suggest an essential role for synapse-type-specific competitive learning in the development of cortical circuits.
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Affiliation(s)
- Samuel Eckmann
- Computation in Neural Circuits Group, Max Planck Institute for Brain Research, Frankfurt am Main60438, Germany
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, CambridgeCB2 1PZ, United Kingdom
| | - Edward James Young
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, CambridgeCB2 1PZ, United Kingdom
| | - Julijana Gjorgjieva
- Computation in Neural Circuits Group, Max Planck Institute for Brain Research, Frankfurt am Main60438, Germany
- School of Life Sciences, Technical University Munich, Freising85354, Germany
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2
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Goris RLT, Coen-Cagli R, Miller KD, Priebe NJ, Lengyel M. Response sub-additivity and variability quenching in visual cortex. Nat Rev Neurosci 2024; 25:237-252. [PMID: 38374462 DOI: 10.1038/s41583-024-00795-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2024] [Indexed: 02/21/2024]
Abstract
Sub-additivity and variability are ubiquitous response motifs in the primary visual cortex (V1). Response sub-additivity enables the construction of useful interpretations of the visual environment, whereas response variability indicates the factors that limit the precision with which the brain can do this. There is increasing evidence that experimental manipulations that elicit response sub-additivity often also quench response variability. Here, we provide an overview of these phenomena and suggest that they may have common origins. We discuss empirical findings and recent model-based insights into the functional operations, computational objectives and circuit mechanisms underlying V1 activity. These different modelling approaches all predict that response sub-additivity and variability quenching often co-occur. The phenomenology of these two response motifs, as well as many of the insights obtained about them in V1, generalize to other cortical areas. Thus, the connection between response sub-additivity and variability quenching may be a canonical motif across the cortex.
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Affiliation(s)
- Robbe L T Goris
- Center for Perceptual Systems, University of Texas at Austin, Austin, TX, USA.
| | - Ruben Coen-Cagli
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kenneth D Miller
- Center for Theoretical Neuroscience, Columbia University, New York, NY, USA
- Kavli Institute for Brain Science, Columbia University, New York, NY, USA
- Dept. of Neuroscience, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Morton B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
- Swartz Program in Theoretical Neuroscience, Columbia University, New York, NY, USA
| | - Nicholas J Priebe
- Center for Learning and Memory, University of Texas at Austin, Austin, TX, USA
| | - Máté Lengyel
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, UK
- Center for Cognitive Computation, Department of Cognitive Science, Central European University, Budapest, Hungary
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3
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Morton MP, Denagamage S, Hudson NV, Nandy AS. Non-uniform contextual interactions in the visual cortex place fundamental limits on spatial vision. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.15.553380. [PMID: 37645826 PMCID: PMC10462024 DOI: 10.1101/2023.08.15.553380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
A prevailing assumption in our understanding of how neurons in the primary visual cortex (V1) integrate contextual information is that such processes are spatially uniform. Conversely, perceptual phenomena such as visual crowding, the impaired ability to accurately recognize a target stimulus among distractors, suggest that interactions among stimuli are distinctly non-uniform. Prior studies have shown flankers at specific spatial geometries exert differential effects on target perception. To resolve this discrepancy, we investigated how flanker geometry impacted the representation of a target stimulus in the laminar microcircuits of V1. Our study reveals flanker location differentially impairs stimulus representation in excitatory neurons in the superficial and input layers of V1 by tuned suppression and untuned facilitation of orientation responses. Mechanistically, this effect can be explained by asymmetrical spatial kernels in a normalization model of cortical activity. Strikingly, these non-uniform modulations of neural representation mirror perceptual anisotropies. These results establish the non-uniform spatial integration of information in the earliest stages of cortical processing as a fundamental limitation of spatial vision.
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4
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Ambrosi P, Burr DC, Morrone MC. Investigating cross-orientation inhibition with continuous tracking. J Vis 2024; 24:2. [PMID: 38300555 PMCID: PMC10846342 DOI: 10.1167/jov.24.2.2] [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: 06/27/2023] [Accepted: 12/14/2023] [Indexed: 02/02/2024] Open
Abstract
We investigated cross-orientation inhibition with the recently developed continuous tracking technique. We designed an experiment where participants tracked the horizontal motion of a narrow vertical grating. The target was superimposed on one of three different backgrounds, in separate sessions: a uniform gray background or a sinusoidal grating oriented either parallel or orthogonal to the target. Both mask and target where phase reversed. We cross-correlated target and mouse movements and compared the peaks and lags of response with the different masks. Our results are in agreement with previous findings on cross-orientation inhibition: The orthogonal mask had a weak effect on the peaks and lags of correlation as a function of target contrast, consistently with a divisive effect of the mask, while the parallel mask acted subtractively on the response. Interestingly, lags of correlation decreased approximately linearly with contrast, with decrements of the order of 100 ms, even at 10 times the detection threshold, confirming that it is possible to investigate behavioral differences above threshold using the continuous tracking paradigm.
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Affiliation(s)
- Pierfrancesco Ambrosi
- Department of Neuroscience, Psychology, Pharmacology, and Child Health, University of Florence, Florence, Italy
- IRCCS Stella Maris, Pisa, Italy
| | - David Charles Burr
- Department of Neuroscience, Psychology, Pharmacology, and Child Health, University of Florence, Florence, Italy
- School of Psychology, University of Sydney, Sydney, NSW, Australia
| | - Maria Concetta Morrone
- IRCCS Stella Maris, Pisa, Italy
- Department of Translational Research in Medicine, University of Pisa, Pisa, Italy
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5
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Tring E, Dipoppa M, Ringach DL. A power law describes the magnitude of adaptation in neural populations of primary visual cortex. Nat Commun 2023; 14:8366. [PMID: 38102113 PMCID: PMC10724159 DOI: 10.1038/s41467-023-43572-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023] Open
Abstract
How do neural populations adapt to the time-varying statistics of sensory input? We used two-photon imaging to measure the activity of neurons in mouse primary visual cortex adapted to different sensory environments, each defined by a distinct probability distribution over a stimulus set. We find that two properties of adaptation capture how the population response to a given stimulus, viewed as a vector, changes across environments. First, the ratio between the response magnitudes is a power law of the ratio between the stimulus probabilities. Second, the response direction to a stimulus is largely invariant. These rules could be used to predict how cortical populations adapt to novel, sensory environments. Finally, we show how the power law enables the cortex to preferentially signal unexpected stimuli and to adjust the metabolic cost of its sensory representation to the entropy of the environment.
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Affiliation(s)
- Elaine Tring
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Mario Dipoppa
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Dario L Ringach
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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6
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Baker DH, Marinova D, Aveyard R, Hargreaves LJ, Renton A, Castellani R, Hall P, Harmens M, Holroyd G, Nicholson B, Williams EL, Hobson HM, Wade AR. Temporal dynamics of normalization reweighting. J Vis 2023; 23:6. [PMID: 37862008 PMCID: PMC10615141 DOI: 10.1167/jov.23.12.6] [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: 03/19/2023] [Accepted: 09/08/2023] [Indexed: 10/21/2023] Open
Abstract
For decades, neural suppression in early visual cortex has been thought to be fixed. But recent work has challenged this assumption by showing that suppression can be reweighted based on recent history; when pairs of stimuli are repeatedly presented together, suppression between them strengthens. Here we investigate the temporal dynamics of this process using a steady-state visual evoked potential (SSVEP) paradigm that provides a time-resolved, direct index of suppression between pairs of stimuli flickering at different frequencies (5 and 7 Hz). Our initial analysis of an existing electroencephalography (EEG) dataset (N = 100) indicated that suppression increases substantially during the first 2-5 seconds of stimulus presentation (with some variation across stimulation frequency). We then collected new EEG data (N = 100) replicating this finding for both monocular and dichoptic mask arrangements in a preregistered study designed to measure reweighting. A third experiment (N = 20) used source-localized magnetoencephalography and found that these effects are apparent in primary visual cortex (V1), consistent with results from neurophysiological work. Because long-standing theories propose inhibition/excitation differences in autism, we also compared reweighting between individuals with high versus low autistic traits, and with and without an autism diagnosis, across our three datasets (total N = 220). We find no compelling differences in reweighting that are associated with autism. Our results support the normalization reweighting model and indicate that for prolonged stimulation, increases in suppression occur on the order of 2-5 seconds after stimulus onset.
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Affiliation(s)
- Daniel H Baker
- Department of Psychology and York Biomedical Research Institute, University of York, York, UK
| | | | | | | | - Alice Renton
- Department of Psychology, University of York, York, UK
| | | | - Phoebe Hall
- Department of Psychology, University of York, York, UK
| | | | | | | | | | - Hannah M Hobson
- Department of Psychology and York Biomedical Research Institute, University of York, York, UK
| | - Alex R Wade
- Department of Psychology and York Biomedical Research Institute, University of York, York, UK
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7
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Mitchell BA, Carlson BM, Westerberg JA, Cox MA, Maier A. A role for ocular dominance in binocular integration. Curr Biol 2023; 33:3884-3895.e5. [PMID: 37657450 PMCID: PMC10530424 DOI: 10.1016/j.cub.2023.08.019] [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: 03/03/2023] [Revised: 06/07/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
Neurons in the primate primary visual cortex (V1) combine left- and right-eye information to form a binocular output. Controversy surrounds whether ocular dominance, the preference of these neurons for one eye over the other, is functionally relevant. Here, we demonstrate that ocular dominance impacts gain control during binocular combination. We recorded V1 spiking activity while monkeys passively viewed grating stimuli. Gratings were either presented to one eye (monocular), both eyes with the same contrasts (binocular balanced), or both eyes with different contrasts (binocular imbalanced). We found that contrast placed in a neuron's dominant eye was weighted more strongly than contrast placed in a neuron's non-dominant eye. This asymmetry covaried with neurons' ocular dominance. We then tested whether accounting for ocular dominance within divisive normalization improves the fit to neural data. We found that ocular dominance significantly improved model performance, with interocular normalization providing the best fits. These findings suggest that V1 ocular dominance is relevant for response normalization during binocular stimulation.
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Affiliation(s)
- Blake A Mitchell
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37235, USA
| | - Brock M Carlson
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37235, USA
| | - Jacob A Westerberg
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37235, USA
| | - Michele A Cox
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Alexander Maier
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37235, USA.
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8
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Carlson BM, Mitchell BA, Dougherty K, Westerberg JA, Cox MA, Maier A. Does V1 response suppression initiate binocular rivalry? iScience 2023; 26:107359. [PMID: 37520732 PMCID: PMC10382945 DOI: 10.1016/j.isci.2023.107359] [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: 03/13/2023] [Revised: 06/02/2023] [Accepted: 07/07/2023] [Indexed: 08/01/2023] Open
Abstract
During binocular rivalry (BR) only one eye's view is perceived. Neural underpinnings of BR are debated. Recent studies suggest that primary visual cortex (V1) initiates BR. One trigger might be response suppression across most V1 neurons at the onset of BR. Here, we utilize a variant of BR called binocular rivalry flash suppression (BRFS) to test this hypothesis. BRFS is identical to BR, except stimuli are shown with a ∼1s delay. If V1 response suppression was required to initiate BR, it should occur during BRFS as well. To test this, we compared V1 spiking in two macaques observing BRFS. We found that BRFS resulted in response facilitation rather than response suppression across V1 neurons. However, BRFS still reduces responses in a subset of V1 neurons due to the adaptive effects of asynchronous stimulus presentation. We argue that this selective response suppression could serve as an alternate initiator of BR.
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Affiliation(s)
- Brock M. Carlson
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
| | - Blake A. Mitchell
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
| | - Kacie Dougherty
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
- Department of Psychology, Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08540, USA
| | - Jacob A. Westerberg
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam 1105 BA, the Netherlands
| | - Michele A. Cox
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - Alexander Maier
- Department of Psychology, College of Arts and Science, Vanderbilt Vision Research Center, Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, TN 37235, USA
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9
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Tring E, Dipoppa M, Ringach DL. A power law of cortical adaptation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541834. [PMID: 37292876 PMCID: PMC10245856 DOI: 10.1101/2023.05.22.541834] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
How do neural populations adapt to the time-varying statistics of sensory input? To investigate, we measured the activity of neurons in primary visual cortex adapted to different environments, each associated with a distinct probability distribution over a stimulus set. Within each environment, a stimulus sequence was generated by independently sampling form its distribution. We find that two properties of adaptation capture how the population responses to a given stimulus, viewed as vectors, are linked across environments. First, the ratio between the response magnitudes is a power law of the ratio between the stimulus probabilities. Second, the response directions are largely invariant. These rules can be used to predict how cortical populations adapt to novel, sensory environments. Finally, we show how the power law enables the cortex to preferentially signal unexpected stimuli and to adjust the metabolic cost of its sensory representation to the entropy of the environment.
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Affiliation(s)
- Elaine Tring
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles
| | - Mario Dipoppa
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles
| | - Dario L Ringach
- Department of Psychology, David Geffen School of Medicine, University of California, Los Angeles
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles
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10
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Le Cong D, Sato D, Ikarashi K, Fujimoto T, Ochi G, Yamashiro K. Effect of whole-hand water flow stimulation on the neural balance between excitation and inhibition in the primary somatosensory cortex. Front Hum Neurosci 2022; 16:962936. [DOI: 10.3389/fnhum.2022.962936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Sustained peripheral somatosensory stimulations, such as high-frequency repetitive somatosensory stimulation (HF-RSS) and vibrated stimulation, are effective in altering the balance between excitation and inhibition in the somatosensory cortex (S1) and motor cortex (M1). A recent study reported that whole-hand water flow (WF) stimulation induced neural disinhibition in the M1. Based on previous results, we hypothesized that whole-hand WF stimulation would lead to neural disinhibition in the S1 because there is a strong neural connection between M1 and S1 and aimed to examine whether whole-hand WF stimulation would change the neural balance between excitation and inhibition in the S1. Nineteen healthy volunteers were studied by measuring excitation and inhibition in the S1 before and after each of the four 15-min interventions. The excitation and inhibition in the S1 were assessed using somatosensory evoked potentials (SEPs) and paired-pulse inhibition (PPI) induced by single- and paired-pulse stimulations, respectively. The four interventions were as follows: control, whole-hand water immersion, whole-hand WF, and HF-RSS. The results showed no significant changes in SEPs and PPI following any intervention. However, changes in PPI with an interstimulus interval (ISI) of 30 ms were significantly correlated with the baseline value before whole-hand WF. Thus, the present findings indicated that the whole-hand WF stimulation had a greater decreased neural inhibition in participants with higher neural inhibition in the S1 at baseline. Considering previous results on M1, the present results possibly show that S1 has lower plasticity than M1 and that the duration (15 min) of each intervention may not have been enough to alter the balance of excitation and inhibition in the S1.
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11
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Carriot J, McAllister G, Hooshangnejad H, Mackrous I, Cullen KE, Chacron MJ. Sensory adaptation mediates efficient and unambiguous encoding of natural stimuli by vestibular thalamocortical pathways. Nat Commun 2022; 13:2612. [PMID: 35551186 PMCID: PMC9098492 DOI: 10.1038/s41467-022-30348-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 04/26/2022] [Indexed: 11/09/2022] Open
Abstract
Sensory systems must continuously adapt to optimally encode stimuli encountered within the natural environment. The prevailing view is that such optimal coding comes at the cost of increased ambiguity, yet to date, prior studies have focused on artificial stimuli. Accordingly, here we investigated whether such a trade-off between optimality and ambiguity exists in the encoding of natural stimuli in the vestibular system. We recorded vestibular nuclei and their target vestibular thalamocortical neurons during naturalistic and artificial self-motion stimulation. Surprisingly, we found no trade-off between optimality and ambiguity. Using computational methods, we demonstrate that thalamocortical neural adaptation in the form of contrast gain control actually reduces coding ambiguity without compromising the optimality of coding under naturalistic but not artificial stimulation. Thus, taken together, our results challenge the common wisdom that adaptation leads to ambiguity and instead suggest an essential role in underlying unambiguous optimized encoding of natural stimuli.
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Affiliation(s)
- Jerome Carriot
- Department of Physiology, McGill University, Montréal, Canada
| | | | - Hamed Hooshangnejad
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA
| | | | - Kathleen E Cullen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, USA.,Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, USA.,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, USA.,Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, USA
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12
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Barbera D, Priebe NJ, Glickfeld LL. Feedforward mechanisms of cross-orientation interactions in mouse V1. Neuron 2022; 110:297-311.e4. [PMID: 34735779 PMCID: PMC8920535 DOI: 10.1016/j.neuron.2021.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/03/2021] [Accepted: 10/12/2021] [Indexed: 01/21/2023]
Abstract
Sensory neurons are modulated by context. For example, in mouse primary visual cortex (V1), neuronal responses to the preferred orientation are modulated by the presence of superimposed orientations ("plaids"). The effects of this modulation are diverse; some neurons are suppressed, while others have larger responses to a plaid than its components. We investigated whether this diversity could be explained by a unified circuit mechanism. We report that this masking is maintained during suppression of cortical activity, arguing against cortical mechanisms. Instead, the heterogeneity of plaid responses is explained by an interaction between stimulus geometry and orientation tuning. Highly selective neurons are uniformly suppressed by plaids, whereas the effects in weakly selective neurons depend on the spatial configuration of the stimulus, transitioning systematically between suppression and facilitation. Thus, the diverse responses emerge as a consequence of the spatial structure of feedforward inputs, with no need to invoke cortical interactions.
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Affiliation(s)
- Dylan Barbera
- Center for Learning and Memory, The University of Texas at Austin, 2415 Speedway, Austin, TX 78712, USA
| | - Nicholas J Priebe
- Center for Learning and Memory, The University of Texas at Austin, 2415 Speedway, Austin, TX 78712, USA.
| | - Lindsey L Glickfeld
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
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13
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Adibi M, Lampl I. Sensory Adaptation in the Whisker-Mediated Tactile System: Physiology, Theory, and Function. Front Neurosci 2021; 15:770011. [PMID: 34776857 PMCID: PMC8586522 DOI: 10.3389/fnins.2021.770011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 09/30/2021] [Indexed: 12/03/2022] Open
Abstract
In the natural environment, organisms are constantly exposed to a continuous stream of sensory input. The dynamics of sensory input changes with organism's behaviour and environmental context. The contextual variations may induce >100-fold change in the parameters of the stimulation that an animal experiences. Thus, it is vital for the organism to adapt to the new diet of stimulation. The response properties of neurons, in turn, dynamically adjust to the prevailing properties of sensory stimulation, a process known as "neuronal adaptation." Neuronal adaptation is a ubiquitous phenomenon across all sensory modalities and occurs at different stages of processing from periphery to cortex. In spite of the wealth of research on contextual modulation and neuronal adaptation in visual and auditory systems, the neuronal and computational basis of sensory adaptation in somatosensory system is less understood. Here, we summarise the recent finding and views about the neuronal adaptation in the rodent whisker-mediated tactile system and further summarise the functional effect of neuronal adaptation on the response dynamics and encoding efficiency of neurons at single cell and population levels along the whisker-mediated touch system in rodents. Based on direct and indirect pieces of evidence presented here, we suggest sensory adaptation provides context-dependent functional mechanisms for noise reduction in sensory processing, salience processing and deviant stimulus detection, shift between integration and coincidence detection, band-pass frequency filtering, adjusting neuronal receptive fields, enhancing neural coding and improving discriminability around adapting stimuli, energy conservation, and disambiguating encoding of principal features of tactile stimuli.
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Affiliation(s)
- Mehdi Adibi
- Department of Physiology and Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
- Department of Neuroscience and Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Ilan Lampl
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
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14
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Baker DH, Vilidaite G, Wade AR. Steady-state measures of visual suppression. PLoS Comput Biol 2021; 17:e1009507. [PMID: 34644292 PMCID: PMC8544832 DOI: 10.1371/journal.pcbi.1009507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/25/2021] [Accepted: 09/30/2021] [Indexed: 12/02/2022] Open
Abstract
In the early visual system, suppression occurs between neurons representing different stimulus properties. This includes features such as orientation (cross-orientation suppression), eye-of-origin (interocular suppression) and spatial location (surround suppression), which are thought to involve distinct anatomical pathways. We asked if these separate routes to suppression can be differentiated by their pattern of gain control on the contrast response function measured in human participants using steady-state electroencephalography. Changes in contrast gain shift the contrast response function laterally, whereas changes in response gain scale the function vertically. We used a Bayesian hierarchical model to summarise the evidence for each type of gain control. A computational meta-analysis of 16 previous studies found the most evidence for contrast gain effects with overlaid masks, but no clear evidence favouring either response gain or contrast gain for other mask types. We then conducted two new experiments, comparing suppression from four mask types (monocular and dichoptic overlay masks, and aligned and orthogonal surround masks) on responses to sine wave grating patches flickering at 5Hz. At the occipital pole, there was strong evidence for contrast gain effects in all four mask types at the first harmonic frequency (5Hz). Suppression generally became stronger at more lateral electrode sites, but there was little evidence of response gain effects. At the second harmonic frequency (10Hz) suppression was stronger overall, and involved both contrast and response gain effects. Although suppression from different mask types involves distinct anatomical pathways, gain control processes appear to serve a common purpose, which we suggest might be to suppress less reliable inputs.
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Affiliation(s)
- Daniel H. Baker
- Department of Psychology and York Biomedical Research Institute, University of York, York, United Kingdom
| | - Greta Vilidaite
- School of Psychology, University of Southampton, Southampton, United Kingdom
| | - Alex R. Wade
- Department of Psychology and York Biomedical Research Institute, University of York, York, United Kingdom
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15
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Hansen BC, Greene MR, Field DJ. Dynamic Electrode-to-Image (DETI) mapping reveals the human brain's spatiotemporal code of visual information. PLoS Comput Biol 2021; 17:e1009456. [PMID: 34570753 PMCID: PMC8496831 DOI: 10.1371/journal.pcbi.1009456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 10/07/2021] [Accepted: 09/16/2021] [Indexed: 11/18/2022] Open
Abstract
A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial and temporal limitations, they can each provide important insights into the visual code. While the BOLD signal of fMRI can be quite informative, the visual code is not static and this can be obscured by fMRI’s poor temporal resolution. In this study, we leveraged the high temporal resolution of EEG to develop an encoding technique based on the distribution of responses generated by a population of real-world scenes. This approach maps neural signals to each pixel within a given image and reveals location-specific transformations of the visual code, providing a spatiotemporal signature for the image at each electrode. Our analyses of the mapping results revealed that scenes undergo a series of nonuniform transformations that prioritize different spatial frequencies at different regions of scenes over time. This mapping technique offers a potential avenue for future studies to explore how dynamic feedforward and recurrent processes inform and refine high-level representations of our visual world. The visual information that we sample from our environment undergoes a series of neural modifications, with each modification state (or visual code) consisting of a unique distribution of responses across neurons along the visual pathway. However, current noninvasive neuroimaging techniques provide an account of that code that is coarse with respect to time or space. Here, we present dynamic electrode-to-image (DETI) mapping, an analysis technique that capitalizes on the high temporal resolution of EEG to map neural signals to each pixel within a given image to reveal location-specific modifications of the visual code. The DETI technique reveals maps of features that are associated with the neural signal at each pixel and at each time point. DETI mapping shows that real-world scenes undergo a series of nonuniform modifications over both space and time. Specifically, we find that the visual code varies in a location-specific manner, likely reflecting that neural processing prioritizes different features at different image locations over time. DETI mapping therefore offers a potential avenue for future studies to explore how each modification state informs and refines the conceptual meaning of our visual world.
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Affiliation(s)
- Bruce C. Hansen
- Colgate University, Department of Psychological & Brain Sciences, Neuroscience Program, Hamilton New York, United States of America
- * E-mail:
| | - Michelle R. Greene
- Bates College, Neuroscience Program, Lewiston, Maine, United States of America
| | - David J. Field
- Cornell University, Department of Psychology, Ithaca, New York, United States of America
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16
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Ramirez LD, Foster JJ, Ling S. Temporal attention selectively enhances target features. J Vis 2021; 21:6. [PMID: 34115108 PMCID: PMC8196420 DOI: 10.1167/jov.21.6.6] [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] [Indexed: 11/25/2022] Open
Abstract
Temporal attention, the allocation of attention to a moment in time, improves perception. Here, we examined the computational mechanism by which temporal attention improves perception, under a divisive normalization framework. Under this framework, attention can improve perception of a target signal in three ways: stimulus enhancement (increasing gain across all sensory channels), signal enhancement (selectively increasing gain in channels that encode the target stimulus), or external noise exclusion (reducing the gain in channels that encode irrelevant features). These mechanisms make diverging predictions when a target is embedded in varying levels of noise: stimulus enhancement improves performance only when noise is low, signal enhancement improves performance at all noise intensities, and external noise exclusion improves performance only when noise is high. To date, temporal attention studies have used noise-free displays. Therefore, it is unclear whether temporal attention acts via stimulus enhancement (amplifying both target features and noise) or signal enhancement (selectively amplifying target features) because both mechanisms predict improved performance in the absence of noise. To tease these mechanisms apart, we manipulated temporal attention using an auditory cue while parametrically varying external noise in a fine-orientation discrimination task. Temporal attention improved perceptual thresholds across all noise levels. Formal model comparisons revealed that this cuing effect was best accounted for by a combination of signal enhancement and stimulus enhancement, suggesting that temporal attention improves perceptual performance, in part, by selectively increasing gain for target features.
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Affiliation(s)
- Luis D Ramirez
- Graduate Program for Neuroscience, Boston University, Boston, MA, USA.,Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA.,Center for Systems Neuroscience, Boston University, Boston, MA, USA.,
| | - Joshua J Foster
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA.,Center for Systems Neuroscience, Boston University, Boston, MA, USA.,
| | - Sam Ling
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA.,Center for Systems Neuroscience, Boston University, Boston, MA, USA.,
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17
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Rhim I, Coello-Reyes G, Nauhaus I. Variations in photoreceptor throughput to mouse visual cortex and the unique effects on tuning. Sci Rep 2021; 11:11937. [PMID: 34099749 PMCID: PMC8184960 DOI: 10.1038/s41598-021-90650-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/12/2021] [Indexed: 11/24/2022] Open
Abstract
Visual input to primary visual cortex (V1) depends on highly adaptive filtering in the retina. In turn, isolation of V1 computations requires experimental control of retinal adaptation to infer its spatio-temporal-chromatic output. Here, we measure the balance of input to mouse V1, in the anesthetized setup, from the three main photoreceptor opsins-M-opsin, S-opsin, and rhodopsin-as a function of two stimulus dimensions. The first dimension is the level of light adaptation within the mesopic range, which governs the balance of rod and cone inputs to cortex. The second stimulus dimension is retinotopic position, which governs the balance of S- and M-cone opsin input due to the opsin expression gradient in the retina. The fitted model predicts opsin input under arbitrary lighting environments, which provides a much-needed handle on in-vivo studies of the mouse visual system. We use it here to reveal that V1 is rod-mediated in common laboratory settings yet cone-mediated in natural daylight. Next, we compare functional properties of V1 under rod and cone-mediated inputs. The results show that cone-mediated V1 responds to 2.5-fold higher temporal frequencies than rod-mediated V1. Furthermore, cone-mediated V1 has smaller receptive fields, yet similar spatial frequency tuning. V1 responses in rod-deficient (Gnat1-/-) mice confirm that the effects are due to differences in photoreceptor opsin contribution.
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Affiliation(s)
- I Rhim
- Department of Psychology, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA
- Center for Perceptual Systems, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA
| | - G Coello-Reyes
- Department of Psychology, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA
- Center for Perceptual Systems, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA
| | - I Nauhaus
- Department of Psychology, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA.
- Department of Neuroscience, University of Texas At Austin, 1 University Station, Stop C7000, Austin, TX, 78712, USA.
- Center for Perceptual Systems, University of Texas At Austin, 108 E. Dean Keeton, Austin, TX, 78712, USA.
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18
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Burg MF, Cadena SA, Denfield GH, Walker EY, Tolias AS, Bethge M, Ecker AS. Learning divisive normalization in primary visual cortex. PLoS Comput Biol 2021; 17:e1009028. [PMID: 34097695 PMCID: PMC8211272 DOI: 10.1371/journal.pcbi.1009028] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 06/17/2021] [Accepted: 04/30/2021] [Indexed: 11/18/2022] Open
Abstract
Divisive normalization (DN) is a prominent computational building block in the brain that has been proposed as a canonical cortical operation. Numerous experimental studies have verified its importance for capturing nonlinear neural response properties to simple, artificial stimuli, and computational studies suggest that DN is also an important component for processing natural stimuli. However, we lack quantitative models of DN that are directly informed by measurements of spiking responses in the brain and applicable to arbitrary stimuli. Here, we propose a DN model that is applicable to arbitrary input images. We test its ability to predict how neurons in macaque primary visual cortex (V1) respond to natural images, with a focus on nonlinear response properties within the classical receptive field. Our model consists of one layer of subunits followed by learned orientation-specific DN. It outperforms linear-nonlinear and wavelet-based feature representations and makes a significant step towards the performance of state-of-the-art convolutional neural network (CNN) models. Unlike deep CNNs, our compact DN model offers a direct interpretation of the nature of normalization. By inspecting the learned normalization pool of our model, we gained insights into a long-standing question about the tuning properties of DN that update the current textbook description: we found that within the receptive field oriented features were normalized preferentially by features with similar orientation rather than non-specifically as currently assumed.
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Affiliation(s)
- Max F. Burg
- Institute for Theoretical Physics and Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, Tübingen, Germany
- Institute of Computer Science and Campus Institute Data Science, University of Göttingen, Göttingen, Germany
- * E-mail:
| | - Santiago A. Cadena
- Institute for Theoretical Physics and Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, Tübingen, Germany
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas, United States of America
| | - George H. Denfield
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - Edgar Y. Walker
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
| | - Andreas S. Tolias
- Bernstein Center for Computational Neuroscience, Tübingen, Germany
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas, United States of America
| | - Matthias Bethge
- Institute for Theoretical Physics and Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Bernstein Center for Computational Neuroscience, Tübingen, Germany
- Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alexander S. Ecker
- Institute of Computer Science and Campus Institute Data Science, University of Göttingen, Göttingen, Germany
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
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19
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Wang B, Han C, Wang T, Dai W, Li Y, Yang Y, Yang G, Zhong L, Zhang Y, Wu Y, Wang G, Yu H, Xing D. Superimposed gratings induce diverse response patterns of gamma oscillations in primary visual cortex. Sci Rep 2021; 11:4941. [PMID: 33654121 PMCID: PMC7925546 DOI: 10.1038/s41598-021-83923-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 01/14/2021] [Indexed: 01/31/2023] Open
Abstract
Stimulus-dependence of gamma oscillations (GAMMA, 30-90 Hz) has not been fully understood, but it is important for revealing neural mechanisms and functions of GAMMA. Here, we recorded spiking activity (MUA) and the local field potential (LFP), driven by a variety of plaids (generated by two superimposed gratings orthogonal to each other and with different contrast combinations), in the primary visual cortex of anesthetized cats. We found two distinct narrow-band GAMMAs in the LFPs and a variety of response patterns to plaids. Similar to MUA, most response patterns showed that the second grating suppressed GAMMAs driven by the first one. However, there is only a weak site-by-site correlation between cross-orientation interactions in GAMMAs and those in MUAs. We developed a normalization model that could unify the response patterns of both GAMMAs and MUAs. Interestingly, compared with MUAs, the GAMMAs demonstrated a wider range of model parameters and more diverse response patterns to plaids. Further analysis revealed that normalization parameters for high GAMMA, but not those for low GAMMA, were significantly correlated with the discrepancy of spatial frequency between stimulus and sites' preferences. Consistent with these findings, normalization parameters and diversity of high GAMMA exhibited a clear transition trend and region difference between area 17 to 18. Our results show that GAMMAs are also regulated in the form of normalization, but that the neural mechanisms for these normalizations might differ from those of spiking activity. Normalizations in different brain signals could be due to interactions of excitation and inhibitions at multiple stages in the visual system.
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Affiliation(s)
- Bin Wang
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Chuanliang Han
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Tian Wang
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Weifeng Dai
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Yang Li
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Yi Yang
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Guanzhong Yang
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Lvyan Zhong
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Yange Zhang
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Yujie Wu
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
| | - Gang Wang
- grid.410318.f0000 0004 0632 3409Center of Brain Sciences, Beijing Institute of Basic Medical Sciences, Beijing, 100085 China
| | - Hongbo Yu
- grid.8547.e0000 0001 0125 2443Vision Research Laboratory, Center for Brain Science Research and School of Life Sciences, Fudan University, 2005 Songhu Road, Shanghai, 200433 China
| | - Dajun Xing
- grid.20513.350000 0004 1789 9964State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875 China
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20
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Das A, Ray S. Effect of Cross-Orientation Normalization on Different Neural Measures in Macaque Primary Visual Cortex. Cereb Cortex Commun 2021; 2:tgab009. [PMID: 34095837 PMCID: PMC8152940 DOI: 10.1093/texcom/tgab009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 11/14/2022] Open
Abstract
Divisive normalization is a canonical mechanism that can explain a variety of sensory phenomena. While normalization models have been used to explain spiking activity in response to different stimulus/behavioral conditions in multiple brain areas, it is unclear whether similar models can also explain modulation in population-level neural measures such as power at various frequencies in local field potentials (LFPs) or steady-state visually evoked potential (SSVEP) that is produced by flickering stimuli and popular in electroencephalogram studies. To address this, we manipulated normalization strength by presenting static as well as flickering orthogonal superimposed gratings (plaids) at varying contrasts to 2 female monkeys while recording multiunit activity (MUA) and LFP from the primary visual cortex and quantified the modulation in MUA, gamma (32-80 Hz), high-gamma (104-248 Hz) power, as well as SSVEP. Even under similar stimulus conditions, normalization strength was different for the 4 measures and increased as: spikes, high-gamma, SSVEP, and gamma. However, these results could be explained using a normalization model that was modified for population responses, by varying the tuned normalization parameter and semisaturation constant. Our results show that different neural measures can reflect the effect of stimulus normalization in different ways, which can be modeled by a simple normalization model.
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Affiliation(s)
- Aritra Das
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
| | - Supratim Ray
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
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21
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Jordan R, Keller GB. Opposing Influence of Top-down and Bottom-up Input on Excitatory Layer 2/3 Neurons in Mouse Primary Visual Cortex. Neuron 2020; 108:1194-1206.e5. [PMID: 33091338 PMCID: PMC7772056 DOI: 10.1016/j.neuron.2020.09.024] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/08/2020] [Accepted: 09/17/2020] [Indexed: 12/21/2022]
Abstract
Processing in cortical circuits is driven by combinations of cortical and subcortical inputs. These inputs are often conceptually categorized as bottom-up, conveying sensory information, and top-down, conveying contextual information. Using intracellular recordings in mouse primary visual cortex, we measured neuronal responses to visual input, locomotion, and visuomotor mismatches. We show that layer 2/3 (L2/3) neurons compute a difference between top-down motor-related input and bottom-up visual flow input. Most L2/3 neurons responded to visuomotor mismatch with either hyperpolarization or depolarization, and the size of this response was correlated with distinct physiological properties. Consistent with a subtraction of bottom-up and top-down input, visual and motor-related inputs had opposing influence on L2/3 neurons. In infragranular neurons, we found no evidence of a difference computation and responses were consistent with positive integration of visuomotor inputs. Our results provide evidence that L2/3 functions as a bidirectional comparator of top-down and bottom-up input. Layer 2/3 neurons show widespread subthreshold mismatch responses Mismatch response sign is predicted by visual flow and locomotion-related responses Layer 5/6 has a scarcity of depolarizing mismatch responses Visual flow and locomotion speed have opposing signs of influence only in layer 2/3
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Affiliation(s)
- Rebecca Jordan
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Georg B Keller
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
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22
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Hu JM, Qian MZ, Tanigawa H, Song XM, Roe AW. Focal Electrical Stimulation of Cortical Functional Networks. Cereb Cortex 2020; 30:5532-5543. [PMID: 32483588 DOI: 10.1093/cercor/bhaa136] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/30/2020] [Accepted: 04/27/2020] [Indexed: 01/11/2023] Open
Abstract
Abstract
Traditional electrical stimulation of brain tissue typically affects relatively large volumes of tissue spanning multiple millimeters. This low spatial resolution stimulation results in nonspecific functional effects. In addition, a primary shortcoming of these designs was the failure to take advantage of inherent functional organization in the cerebral cortex. Here, we describe a new method to electrically stimulate the brain which achieves selective targeting of single feature-specific domains in visual cortex. We provide evidence that this paradigm achieves mesoscale, functional network-specificity, and intensity dependence in a way that mimics visual stimulation. Application of this approach to known feature domains (such as color, orientation, motion, and depth) in visual cortex may lead to important functional improvements in the specificity and sophistication of brain stimulation methods and has implications for visual cortical prosthetic design.
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Affiliation(s)
- Jia Ming Hu
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Mei Zhen Qian
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Hisashi Tanigawa
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Xue Mei Song
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Anna Wang Roe
- Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Hangzhou 310029, China
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006 USA
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23
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Abstract
AbstractConvolutional neural networks (CNNs) lack robustness to test image corruptions that are not seen during training. In this paper, we propose a new layer for CNNs that increases their robustness to several types of corruptions of the input images. We call it a ‘push–pull’ layer and compute its response as the combination of two half-wave rectified convolutions, with kernels of different size and opposite polarity. Its implementation is based on a biologically motivated model of certain neurons in the visual system that exhibit response suppression, known as push–pull inhibition. We validate our method by replacing the first convolutional layer of the LeNet, ResNet and DenseNet architectures with our push–pull layer. We train the networks on original training images from the MNIST and CIFAR data sets and test them on images with several corruptions, of different types and severities, that are unseen by the training process. We experiment with various configurations of the ResNet and DenseNet models on a benchmark test set with typical image corruptions constructed on the CIFAR test images. We demonstrate that our push–pull layer contributes to a considerable improvement in robustness of classification of corrupted images, while maintaining state-of-the-art performance on the original image classification task. We released the code and trained models at the url http://github.com/nicstrisc/Push-Pull-CNN-layer.
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24
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Dynamic Signal Compression for Robust Motion Vision in Flies. Curr Biol 2020; 30:209-221.e8. [PMID: 31928873 DOI: 10.1016/j.cub.2019.10.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/17/2019] [Accepted: 10/18/2019] [Indexed: 12/16/2022]
Abstract
Sensory systems need to reliably extract information from highly variable natural signals. Flies, for instance, use optic flow to guide their course and are remarkably adept at estimating image velocity regardless of image statistics. Current circuit models, however, cannot account for this robustness. Here, we demonstrate that the Drosophila visual system reduces input variability by rapidly adjusting its sensitivity to local contrast conditions. We exhaustively map functional properties of neurons in the motion detection circuit and find that local responses are compressed by surround contrast. The compressive signal is fast, integrates spatially, and derives from neural feedback. Training convolutional neural networks on estimating the velocity of natural stimuli shows that this dynamic signal compression can close the performance gap between model and organism. Overall, our work represents a comprehensive mechanistic account of how neural systems attain the robustness to carry out survival-critical tasks in challenging real-world environments.
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25
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Bloem IM, Ling S. Normalization governs attentional modulation within human visual cortex. Nat Commun 2019; 10:5660. [PMID: 31827078 PMCID: PMC6906520 DOI: 10.1038/s41467-019-13597-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 11/12/2019] [Indexed: 12/02/2022] Open
Abstract
Although attention is known to increase the gain of visuocortical responses, its underlying neural computations remain unclear. Here, we use fMRI to test the hypothesis that a neural population’s ability to be modulated by attention is dependent on divisive normalization. To do so, we leverage the feature-tuned properties of normalization and find that visuocortical responses to stimuli sharing features normalize each other more strongly. Comparing these normalization measures to measures of attentional modulation, we demonstrate that subpopulations which exhibit stronger normalization also exhibit larger attentional benefits. In a converging experiment, we reveal that attentional benefits are greatest when a subpopulation is forced into a state of stronger normalization. Taken together, these results suggest that the degree to which a subpopulation exhibits normalization plays a role in dictating its potential for attentional benefits. Attention is known to enhance relevant information in our environment, yet its underlying neural computations remain unclear. Here, the authors provide evidence that the degree to which a neural population can normalize itself results in greater potential for attentional benefits.
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Affiliation(s)
- Ilona M Bloem
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA. .,Center for Systems Neuroscience, Boston University, Boston, MA, 02215, USA.
| | - Sam Ling
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, 02215, USA.,Center for Systems Neuroscience, Boston University, Boston, MA, 02215, USA
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26
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Strisciuglio N, Azzopardi G, Petkov N. Robust Inhibition-Augmented Operator for Delineation of Curvilinear Structures. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2019; 28:5852-5866. [PMID: 31247549 DOI: 10.1109/tip.2019.2922096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Delineation of curvilinear structures in images is an important basic step of several image processing applications, such as segmentation of roads or rivers in aerial images, vessels or staining membranes in medical images, and cracks in pavements and roads, among others. Existing methods suffer from insufficient robustness to noise. In this paper, we propose a novel operator for the detection of curvilinear structures in images, which we demonstrate to be robust to various types of noise and effective in several applications. We call it RUSTICO, which stands for RobUST Inhibition-augmented Curvilinear Operator. It is inspired by the push-pull inhibition in visual cortex and takes as input the responses of two trainable B-COSFIRE filters of opposite polarity. The output of RUSTICO consists of a magnitude map and an orientation map. We carried out experiments on a data set of synthetic stimuli with noise drawn from different distributions, as well as on several benchmark data sets of retinal fundus images, crack pavements, and aerial images and a new data set of rose bushes used for automatic gardening. We evaluated the performance of RUSTICO by a metric that considers the structural properties of line networks (connectivity, area, and length) and demonstrated that RUSTICO outperforms many existing methods with high statistical significance. RUSTICO exhibits high robustness to noise and texture.
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27
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Aschner A, Solomon SG, Landy MS, Heeger DJ, Kohn A. Temporal Contingencies Determine Whether Adaptation Strengthens or Weakens Normalization. J Neurosci 2018; 38:10129-10142. [PMID: 30291205 PMCID: PMC6246879 DOI: 10.1523/jneurosci.1131-18.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/30/2018] [Accepted: 09/19/2018] [Indexed: 11/21/2022] Open
Abstract
A fundamental and nearly ubiquitous feature of sensory encoding is that neuronal responses are strongly influenced by recent experience, or adaptation. Theoretical and computational studies have proposed that many adaptation effects may result in part from changes in the strength of normalization signals. Normalization is a "canonical" computation in which a neuron's response is modulated (normalized) by the pooled activity of other neurons. Here, we test whether adaptation can alter the strength of cross-orientation suppression, or masking, a paradigmatic form of normalization evident in primary visual cortex (V1). We made extracellular recordings of V1 neurons in anesthetized male macaques and measured responses to plaid stimuli composed of two overlapping, orthogonal gratings before and after prolonged exposure to two distinct adapters. The first adapter was a plaid consisting of orthogonal gratings and led to stronger masking. The second adapter presented the same orthogonal gratings in an interleaved manner and led to weaker masking. The strength of adaptation's effects on masking depended on the orientation of the test stimuli relative to the orientation of the adapters, but was independent of neuronal orientation preference. Changes in masking could not be explained by altered neuronal responsivity. Our results suggest that normalization signals can be strengthened or weakened by adaptation depending on the temporal contingencies of the adapting stimuli. Our findings reveal an interplay between two widespread computations in cortical circuits, adaptation and normalization, that enables flexible adjustments to the structure of the environment, including the temporal relationships among sensory stimuli.SIGNIFICANCE STATEMENT Two fundamental features of sensory responses are that they are influenced by adaptation and that they are modulated by the activity of other nearby neurons via normalization. Our findings reveal a strong interaction between these two aspects of cortical computation. Specifically, we show that cross-orientation masking, a form of normalization, can be strengthened or weakened by adaptation depending on the temporal contingencies between sensory inputs. Our findings support theoretical proposals that some adaptation effects may involve altered normalization and offer a network-based explanation for how cortex adjusts to current sensory demands.
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Affiliation(s)
- Amir Aschner
- Dominik Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461,
| | - Samuel G Solomon
- Department of Experimental Psychology, University College London, London, United Kingdom WC1H 0AP
| | - Michael S Landy
- Department of Psychology and Center for Neural Science, New York University, New York, New York 10003
| | - David J Heeger
- Department of Psychology and Center for Neural Science, New York University, New York, New York 10003
| | - Adam Kohn
- Dominik Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York 10461, and
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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28
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Abstract
The mechanisms underlying the emergence of orientation selectivity in the visual cortex have been, and continue to be, the subjects of intense scrutiny. Orientation selectivity reflects a dramatic change in the representation of the visual world: Whereas afferent thalamic neurons are generally orientation insensitive, neurons in the primary visual cortex (V1) are extremely sensitive to stimulus orientation. This profound change in the receptive field structure along the visual pathway has positioned V1 as a model system for studying the circuitry that underlies neural computations across the neocortex. The neocortex is characterized anatomically by the relative uniformity of its circuitry despite its role in processing distinct signals from region to region. A combination of physiological, anatomical, and theoretical studies has shed some light on the circuitry components necessary for generating orientation selectivity in V1. This targeted effort has led to critical insights, as well as controversies, concerning how neural circuits in the neocortex perform computations.
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Affiliation(s)
- Nicholas J Priebe
- Center for Learning and Memory, Center for Perceptual Systems, Department of Neuroscience, College of Natural Sciences, University of Texas, Austin, Texas 78712;
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29
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Nunez V, Shapley RM, Gordon J. Nonlinear dynamics of cortical responses to color in the human cVEP. J Vis 2017; 17:9. [PMID: 28973563 PMCID: PMC6894406 DOI: 10.1167/17.11.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The main finding of this paper is that the human visual cortex responds in a very nonlinear manner to the color contrast of pure color patterns. We examined human cortical responses to color checkerboard patterns at many color contrasts, measuring the chromatic visual evoked potential (cVEP) with a dense electrode array. Cortical topography of the cVEPs showed that they were localized near the posterior electrode at position Oz, indicating that the primary cortex (V1) was the major source of responses. The choice of fine spatial patterns as stimuli caused the cVEP response to be driven by double-opponent neurons in V1. The cVEP waveform revealed nonlinear color signal processing in the V1 cortex. The cVEP time-to-peak decreased and the waveform's shape was markedly narrower with increasing cone contrast. Comparison of the linear dynamics of retinal and lateral geniculate nucleus responses with the nonlinear dynamics of the cortical cVEP indicated that the nonlinear dynamics originated in the V1 cortex. The nature of the nonlinearity is a kind of automatic gain control that adjusts cortical dynamics to be faster when color contrast is greater.
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Affiliation(s)
- Valerie Nunez
- Center for Neural Science, New York University, New York, NY, USA.,Psychology Department, Hunter College, CUNY, New York, NY, USA
| | - Robert M Shapley
- Center for Neural Science, New York University, New York, NY, USA
| | - James Gordon
- Psychology Department, Hunter College, CUNY, New York, NY, USA.,Center for Neural Science, New York University, New York, NY, USA
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30
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Suppression and Contrast Normalization in Motion Processing. J Neurosci 2017; 37:11051-11066. [PMID: 29018158 DOI: 10.1523/jneurosci.1572-17.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/11/2017] [Accepted: 08/18/2017] [Indexed: 11/21/2022] Open
Abstract
Sensory neurons are activated by a range of stimuli to which they are said to be tuned. Usually, they are also suppressed by another set of stimuli that have little effect when presented in isolation. The interactions between preferred and suppressive stimuli are often quite complex and vary across neurons, even within a single area, making it difficult to infer their collective effect on behavioral responses mediated by activity across populations of neurons. Here, we investigated this issue by measuring, in human subjects (three males), the suppressive effect of static masks on the ocular following responses induced by moving stimuli. We found a wide range of effects, which depend in a nonlinear and nonseparable manner on the spatial frequency, contrast, and spatial location of both stimulus and mask. Under some conditions, the presence of the mask can be seen as scaling the contrast of the driving stimulus. Under other conditions, the effect is more complex, involving also a direct scaling of the behavioral response. All of this complexity at the behavioral level can be captured by a simple model in which stimulus and mask interact nonlinearly at two stages, one monocular and one binocular. The nature of the interactions is compatible with those observed at the level of single neurons in primates, usually broadly described as divisive normalization, without having to invoke any scaling mechanism.SIGNIFICANCE STATEMENT The response of sensory neurons to their preferred stimulus is often modulated by stimuli that are not effective when presented alone. Individual neurons can exhibit multiple modulatory effects, with considerable variability across neurons even in a single area. Such diversity has made it difficult to infer the impact of these modulatory mechanisms on behavioral responses. Here, we report the effects of a stationary mask on the reflexive eye movements induced by a moving stimulus. A model with two stages, each incorporating a divisive modulatory mechanism, reproduces our experimental results and suggests that qualitative variability of masking effects in cortical neurons might arise from differences in the extent to which such effects are inherited from earlier stages.
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31
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Ohshiro T, Angelaki DE, DeAngelis GC. A Neural Signature of Divisive Normalization at the Level of Multisensory Integration in Primate Cortex. Neuron 2017; 95:399-411.e8. [PMID: 28728025 DOI: 10.1016/j.neuron.2017.06.043] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/19/2017] [Accepted: 06/26/2017] [Indexed: 10/19/2022]
Abstract
Studies of multisensory integration by single neurons have traditionally emphasized empirical principles that describe nonlinear interactions between inputs from two sensory modalities. We previously proposed that many of these empirical principles could be explained by a divisive normalization mechanism operating in brain regions where multisensory integration occurs. This normalization model makes a critical diagnostic prediction: a non-preferred sensory input from one modality, which activates the neuron on its own, should suppress the response to a preferred input from another modality. We tested this prediction by recording from neurons in macaque area MSTd that integrate visual and vestibular cues regarding self-motion. We show that many MSTd neurons exhibit the diagnostic form of cross-modal suppression, whereas unisensory neurons in area MT do not. The normalization model also fits population responses better than a model based on subtractive inhibition. These findings provide strong support for a divisive normalization mechanism in multisensory integration.
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Affiliation(s)
- Tomokazu Ohshiro
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14611, USA; Department of Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan
| | - Dora E Angelaki
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gregory C DeAngelis
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14611, USA.
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32
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Sawada T, Petrov AA. The divisive normalization model of V1 neurons: a comprehensive comparison of physiological data and model predictions. J Neurophysiol 2017; 118:3051-3091. [PMID: 28835531 DOI: 10.1152/jn.00821.2016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 01/24/2023] Open
Abstract
The physiological responses of simple and complex cells in the primary visual cortex (V1) have been studied extensively and modeled at different levels. At the functional level, the divisive normalization model (DNM; Heeger DJ. Vis Neurosci 9: 181-197, 1992) has accounted for a wide range of single-cell recordings in terms of a combination of linear filtering, nonlinear rectification, and divisive normalization. We propose standardizing the formulation of the DNM and implementing it in software that takes static grayscale images as inputs and produces firing rate responses as outputs. We also review a comprehensive suite of 30 empirical phenomena and report a series of simulation experiments that qualitatively replicate dozens of key experiments with a standard parameter set consistent with physiological measurements. This systematic approach identifies novel falsifiable predictions of the DNM. We show how the model simultaneously satisfies the conflicting desiderata of flexibility and falsifiability. Our key idea is that, while adjustable parameters are needed to accommodate the diversity across neurons, they must be fixed for a given individual neuron. This requirement introduces falsifiable constraints when this single neuron is probed with multiple stimuli. We also present mathematical analyses and simulation experiments that explicate some of these constraints.
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Affiliation(s)
- Tadamasa Sawada
- School of Psychology, National Research University Higher School of Economics, Moscow, Russia; and
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33
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Comodulation Enhances Signal Detection via Priming of Auditory Cortical Circuits. J Neurosci 2017; 36:12299-12311. [PMID: 27927950 PMCID: PMC5148223 DOI: 10.1523/jneurosci.0656-16.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 08/25/2016] [Accepted: 08/29/2016] [Indexed: 11/21/2022] Open
Abstract
Acoustic environments are composed of complex overlapping sounds that the auditory system is required to segregate into discrete perceptual objects. The functions of distinct auditory processing stations in this challenging task are poorly understood. Here we show a direct role for mouse auditory cortex in detection and segregation of acoustic information. We measured the sensitivity of auditory cortical neurons to brief tones embedded in masking noise. By altering spectrotemporal characteristics of the masker, we reveal that sensitivity to pure tone stimuli is strongly enhanced in coherently modulated broadband noise, corresponding to the psychoacoustic phenomenon comodulation masking release. Improvements in detection were largest following priming periods of noise alone, indicating that cortical segregation is enhanced over time. Transient opsin-mediated silencing of auditory cortex during the priming period almost completely abolished these improvements, suggesting that cortical processing may play a direct and significant role in detection of quiet sounds in noisy environments. SIGNIFICANCE STATEMENT Auditory systems are adept at detecting and segregating competing sound sources, but there is little direct evidence of how this process occurs in the mammalian auditory pathway. We demonstrate that coherent broadband noise enhances signal representation in auditory cortex, and that prolonged exposure to noise is necessary to produce this enhancement. Using optogenetic perturbation to selectively silence auditory cortex during early noise processing, we show that cortical processing plays a crucial role in the segregation of competing sounds.
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34
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Jastrzebski NR, Hugrass LE, Crewther SG, Crewther DP. Surround-Masking Affects Visual Estimation Ability. Front Integr Neurosci 2017; 11:7. [PMID: 28360845 PMCID: PMC5352683 DOI: 10.3389/fnint.2017.00007] [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: 12/22/2016] [Accepted: 03/01/2017] [Indexed: 11/13/2022] Open
Abstract
Visual estimation of numerosity involves the discrimination of magnitude between two distributions or perceptual sets that vary in number of elements. How performance on such estimation depends on peripheral sensory stimulation is unclear, even in typically developing adults. Here, we varied the central and surround contrast of stimuli that comprised a visual estimation task in order to determine whether mechanisms involved with the removal of unessential visual input functionally contributes toward number acuity. The visual estimation judgments of typically developed adults were significantly impaired for high but not low contrast surround stimulus conditions. The center and surround contrasts of the stimuli also differentially affected the accuracy of numerosity estimation depending on whether fewer or more dots were presented. Remarkably, observers demonstrated the highest mean percentage accuracy across stimulus conditions in the discrimination of more elements when the surround contrast was low and the background luminance of the central region containing the elements was dark (black center). Conversely, accuracy was severely impaired during the discrimination of fewer elements when the surround contrast was high and the background luminance of the central region was mid level (gray center). These findings suggest that estimation ability is functionally related to the quality of low-order filtration of unessential visual information. These surround masking results may help understanding of the poor visual estimation ability commonly observed in developmental dyscalculia.
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Affiliation(s)
- Nicola R Jastrzebski
- Centre for Human Psychopharmacology, Faculty of Health, Arts and Design, Swinburne University of Technology Hawthorn, VIC, Australia
| | - Laila E Hugrass
- Centre for Human Psychopharmacology, Faculty of Health, Arts and Design, Swinburne University of Technology Hawthorn, VIC, Australia
| | - Sheila G Crewther
- School of Psychological Sciences, La Trobe University Bundoora, VIC, Australia
| | - David P Crewther
- Centre for Human Psychopharmacology, Faculty of Health, Arts and Design, Swinburne University of Technology Hawthorn, VIC, Australia
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35
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Hasegawa M, Majima K, Itokazu T, Maki T, Albrecht UR, Castner N, Izumo M, Sohya K, Sato TK, Kamitani Y, Sato TR. Selective Suppression of Local Circuits during Movement Preparation in the Mouse Motor Cortex. Cell Rep 2017; 18:2676-2686. [DOI: 10.1016/j.celrep.2017.02.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 01/08/2017] [Accepted: 02/14/2017] [Indexed: 10/20/2022] Open
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36
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Gheorghiu E, Kingdom FAA. Dynamics of contextual modulation of perceived shape in human vision. Sci Rep 2017; 7:43274. [PMID: 28230085 PMCID: PMC5322363 DOI: 10.1038/srep43274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/19/2017] [Indexed: 11/30/2022] Open
Abstract
In biological vision, contextual modulation refers to the influence of a surround pattern on either the perception of, or the neural responses to, a target pattern. One studied form of contextual modulation deals with the effect of a surround texture on the perceived shape of a contour, in the context of the phenomenon known as the shape aftereffect. In the shape aftereffect, prolonged viewing, or adaptation to a particular contour's shape causes a shift in the perceived shape of a subsequently viewed contour. Shape aftereffects are suppressed when the adaptor contour is surrounded by a texture of similarly-shaped contours, a surprising result given that the surround contours are all potential adaptors. Here we determine the motion and temporal properties of this form of contextual modulation. We varied the relative motion directions, speeds and temporal phases between the central adaptor contour and the surround texture and measured for each manipulation the degree to which the shape aftereffect was suppressed. Results indicate that contextual modulation of shape processing is selective to motion direction, temporal frequency and temporal phase. These selectivities are consistent with one aim of vision being to segregate contours that define objects from those that form textured surfaces.
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Affiliation(s)
- Elena Gheorghiu
- University of Stirling, Department of Psychology, Stirling, FK9 4LA, Scotland, United Kingdom
| | - Frederick A. A. Kingdom
- McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Qc, Canada
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37
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Hemberger M, Pammer L, Laurent G. Comparative approaches to cortical microcircuits. Curr Opin Neurobiol 2016; 41:24-30. [DOI: 10.1016/j.conb.2016.07.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 06/28/2016] [Accepted: 07/20/2016] [Indexed: 11/27/2022]
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38
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Cherniawsky AS, Mullen KT. The Whole is Other Than the Sum: Perceived Contrast Summation Within Color and Luminance Plaids. Iperception 2016; 7:2041669516672481. [PMID: 27822354 PMCID: PMC5081092 DOI: 10.1177/2041669516672481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The apparent contrast of a plaid is a reflection of the neural relationship between the responses to its two orthogonal component gratings. To investigate the perceived contrast summation of the responses to component gratings in plaids, we compared the apparent contrasts of monocular plaids to a component grating presented alone across chromaticity and spatial frequency. Observers performed a contrast-matching task for red–green color and luminance stimuli at low- and medium-spatial frequencies. Using the measured points of subjective equality between plaids and gratings, we evaluate perceived contrast summation across conditions, which may vary between 1 (no summation) and 2 (full summation). We show that achromatic plaids have higher perceived contrast summation than chromatic plaids. The greatest difference occurs at the medium-spatial frequency, with summation highest for achromatic plaids (1.87) and lowest for chromatic plaids (1.49), while at low-spatial frequencies, there is a smaller summation difference between achromatic (1.72) and chromatic (1.65) plaids. These results are consistent with recent theories of distinct cross-orientation suppression and summation mechanisms in color and luminance vision. Two control experiments for binocular versus monocular viewing, and the overall size of the stimulus patches did not reveal any differences from our main results.
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Affiliation(s)
- Avital S Cherniawsky
- McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada
| | - Kathy T Mullen
- McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada
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39
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Bruyns-Haylett M, Luo J, Kennerley AJ, Harris S, Boorman L, Milne E, Vautrelle N, Hayashi Y, Whalley BJ, Jones M, Berwick J, Riera J, Zheng Y. The neurogenesis of P1 and N1: A concurrent EEG/LFP study. Neuroimage 2016; 146:575-588. [PMID: 27646129 PMCID: PMC5312787 DOI: 10.1016/j.neuroimage.2016.09.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/19/2016] [Accepted: 09/15/2016] [Indexed: 10/29/2022] Open
Abstract
It is generally recognised that event related potentials (ERPs) of electroencephalogram (EEG) primarily reflect summed post-synaptic activity of the local pyramidal neural population(s). However, it is still not understood how the positive and negative deflections (e.g. P1, N1 etc) observed in ERP recordings are related to the underlying excitatory and inhibitory post-synaptic activity. We investigated the neurogenesis of P1 and N1 in ERPs by pharmacologically manipulating inhibitory post-synaptic activity in the somatosensory cortex of rodent, and concurrently recording EEG and local field potentials (LFPs). We found that the P1 wave in the ERP and LFP of the supragranular layers is determined solely by the excitatory post-synaptic activity of the local pyramidal neural population, as is the initial segment of the N1 wave across cortical depth. The later part of the N1 wave was modulated by inhibitory post-synaptic activity, with its peak and the pulse width increasing as inhibition was reduced. These findings suggest that the temporal delay of inhibition with respect to excitation observed in intracellular recordings is also reflected in extracellular field potentials (FPs), resulting in a temporal window during which only excitatory post-synaptic activity and leak channel activity are recorded in the ERP and evoked LFP time series. Based on these findings, we provide clarification on the interpretation of P1 and N1 in terms of the excitatory and inhibitory post-synaptic activities of the local pyramidal neural population(s).
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Affiliation(s)
- Michael Bruyns-Haylett
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
| | - Jingjing Luo
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
| | - Aneurin J Kennerley
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Sam Harris
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Luke Boorman
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Elizabeth Milne
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Nicolas Vautrelle
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Yurie Hayashi
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom
| | - Benjamin J Whalley
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom
| | - Myles Jones
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Jason Berwick
- Department of Psychology, University of Sheffield, Sheffield S10 2TP, United Kingdom
| | - Jorge Riera
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, United States of America
| | - Ying Zheng
- School of Systems Engineering, Whiteknights, University of Reading, Reading RG6 7AY, United Kingdom.
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40
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Abstract
Surround suppression is a well-known phenomenon in which the response to a visual stimulus is diminished by the presence of neighboring stimuli. This effect is observed in neural responses in areas such as primary visual cortex, and also manifests in visual contrast perception. Studies in animal models have identified at least two separate mechanisms that may contribute to surround suppression: one that is monocular and resistant to contrast adaptation, and another that is binocular and strongly diminished by adaptation. The current study was designed to investigate whether these two mechanisms exist in humans and if they can be identified psychophysically using eye-of-origin and contrast adaptation manipulations. In addition, we examined the prediction that the monocular suppression component is broadly tuned for orientation, while suppression between eyes is narrowly tuned. Our results confirmed that when center and surrounding stimuli were presented dichoptically (in opposite eyes), suppression was orientation-tuned. Following adaptation in the surrounding region, no dichoptic suppression was observed, and monoptic suppression no longer showed orientation selectivity. These results are consistent with a model of surround suppression that depends on both low-level and higher level components. This work provides a method to assess the separate contributions of these components during spatial context processing in human vision.
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41
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Kremkow J, Perrinet LU, Monier C, Alonso JM, Aertsen A, Frégnac Y, Masson GS. Push-Pull Receptive Field Organization and Synaptic Depression: Mechanisms for Reliably Encoding Naturalistic Stimuli in V1. Front Neural Circuits 2016; 10:37. [PMID: 27242445 PMCID: PMC4862982 DOI: 10.3389/fncir.2016.00037] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/25/2016] [Indexed: 11/13/2022] Open
Abstract
Neurons in the primary visual cortex are known for responding vigorously but with high variability to classical stimuli such as drifting bars or gratings. By contrast, natural scenes are encoded more efficiently by sparse and temporal precise spiking responses. We used a conductance-based model of the visual system in higher mammals to investigate how two specific features of the thalamo-cortical pathway, namely push-pull receptive field organization and fast synaptic depression, can contribute to this contextual reshaping of V1 responses. By comparing cortical dynamics evoked respectively by natural vs. artificial stimuli in a comprehensive parametric space analysis, we demonstrate that the reliability and sparseness of the spiking responses during natural vision is not a mere consequence of the increased bandwidth in the sensory input spectrum. Rather, it results from the combined impacts of fast synaptic depression and push-pull inhibition, the later acting for natural scenes as a form of “effective” feed-forward inhibition as demonstrated in other sensory systems. Thus, the combination of feedforward-like inhibition with fast thalamo-cortical synaptic depression by simple cells receiving a direct structured input from thalamus composes a generic computational mechanism for generating a sparse and reliable encoding of natural sensory events.
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Affiliation(s)
- Jens Kremkow
- Institut de Neurosciences de la Timone, UMR 7289, Centre National de la Recherche Scientifique - Aix-Marseille UniversitéMarseille, France; Neurobiology and Biophysics, Faculty of Biology, University of FreiburgFreiburg, Germany; Bernstein Center Freiburg, University of FreiburgFreiburg, Germany; Department of Biological Sciences, State University of New York (SUNY-Optometry)New York, NY, USA
| | - Laurent U Perrinet
- Institut de Neurosciences de la Timone, UMR 7289, Centre National de la Recherche Scientifique - Aix-Marseille Université Marseille, France
| | - Cyril Monier
- Unité de Neurosciences, Information et Complexité, UPR Centre National de la Recherche Scientifique 3293 Gif-sur-Yvette, France
| | - Jose-Manuel Alonso
- Department of Biological Sciences, State University of New York (SUNY-Optometry) New York, NY, USA
| | - Ad Aertsen
- Neurobiology and Biophysics, Faculty of Biology, University of FreiburgFreiburg, Germany; Bernstein Center Freiburg, University of FreiburgFreiburg, Germany
| | - Yves Frégnac
- Unité de Neurosciences, Information et Complexité, UPR Centre National de la Recherche Scientifique 3293 Gif-sur-Yvette, France
| | - Guillaume S Masson
- Institut de Neurosciences de la Timone, UMR 7289, Centre National de la Recherche Scientifique - Aix-Marseille Université Marseille, France
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42
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Rehmann R, Sczesny-Kaiser M, Lenz M, Gucia T, Schliesing A, Schwenkreis P, Tegenthoff M, Höffken O. Polarity-Specific Cortical Effects of Transcranial Direct Current Stimulation in Primary Somatosensory Cortex of Healthy Humans. Front Hum Neurosci 2016; 10:208. [PMID: 27242473 PMCID: PMC4860403 DOI: 10.3389/fnhum.2016.00208] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/22/2016] [Indexed: 11/13/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive stimulation method that has been shown to modulate the excitability of the motor and visual cortices in human subjects in a polarity dependent manner in previous studies. The aim of our study was to investigate whether anodal and cathodal tDCS can also be used to modulate the excitability of the human primary somatosensory cortex (S1). We measured paired-pulse suppression (PPS) of somatosensory evoked potentials in 36 right-handed volunteers before and after anodal, cathodal, or sham stimulation over the right non-dominant S1. Paired-pulse stimulation of the median nerve was performed at the dominant and non-dominant hand. After anodal tDCS, PPS was reduced in the ipsilateral S1 compared to sham stimulation, indicating an excitatory effect of anodal tDCS. In contrast, PPS in the stimulated left hemisphere was increased after cathodal tDCS, indicating an inhibitory effect of cathodal tDCS. Sham stimulation induced no pre-post differences. Thus, tDCS can be used to modulate the excitability of S1 in polarity-dependent manner, which can be assessed by PPS. An interesting topic for further studies could be the investigation of direct correlations between sensory changes and excitability changes induced by tDCS.
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Affiliation(s)
- Robert Rehmann
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | | | - Melanie Lenz
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | - Tomasz Gucia
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | - Annika Schliesing
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | - Peter Schwenkreis
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | - Martin Tegenthoff
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
| | - Oliver Höffken
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum Bochum, Germany
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43
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Abstract
Human contrast sensitivity for narrowband Gabor targets is suppressed when superimposed on narrowband masks of the same spatial frequency and orientation (referred to as overlay suppression), with suppression being broadly tuned to orientation and spatial frequency. Numerous behavioral and neurophysiological experiments have suggested that overlay suppression originates from the initial lateral geniculate nucleus (LGN) inputs to V1, which is consistent with the broad tuning typically reported for overlay suppression. However, recent reports have shown narrowly tuned anisotropic overlay suppression when narrowband targets are masked by broadband noise. Consequently, researchers have argued for an additional form of overlay suppression that involves cortical contrast gain control processes. The current study sought to further explore this notion behaviorally using narrowband and broadband masks, along with a computational neural simulation of the hypothesized underlying gain control processes in cortex. Additionally, we employed transcranial direct current stimulation (tDCS) in order to test whether cortical processes are involved in driving narrowly tuned anisotropic suppression. The behavioral results yielded anisotropic overlay suppression for both broadband and narrowband masks and could be replicated with our computational neural simulation of anisotropic gain control. Further, the anisotropic form of overlay suppression could be directly modulated by tDCS, which would not be expected if the suppression was primarily subcortical in origin. Altogether, the results of the current study provide further evidence in support of an additional overlay suppression process that originates in cortex and show that this form of suppression is also observable with narrowband masks.
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Stude P, Lenz M, Höffken O, Tegenthoff M, Dinse H. A single dose of lorazepam reduces paired-pulse suppression of median nerve evoked somatosensory evoked potentials. Eur J Neurosci 2016; 43:1156-60. [PMID: 26929110 DOI: 10.1111/ejn.13224] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 02/14/2016] [Accepted: 02/23/2016] [Indexed: 12/31/2022]
Abstract
Paired-pulse behaviour in the somatosensory cortex is an approach to obtain insights into cortical processing modes and to obtain markers of changes of cortical excitability attributable to learning or pathological states. Numerous studies have demonstrated suppression of the response to the stimulus that follows a first one after a short interval, but the underlying mechanisms remain elusive, although there is agreement that GABAergic mechanisms seem to play a crucial role. We therefore aimed to explore the influence of the GABAA agonist lorazepam on paired-pulse somatosensory evoked potentials (SEPs). We recorded and analysed SEPs after paired median nerve stimulation in healthy individuals before and after they had received a single dose of 2.5 mg of lorazepam as compared with a control group receiving placebo. Paired-pulse suppression was expressed as a ratio of the amplitudes of the second and the first peaks. We found that, after lorazepam application, paired-pulse suppression of the cortical N20 component remained unchanged, but suppression of the N20-P25 complex was significantly reduced, indicative of GABAergic involvement in intracortical processing. Our data suggest that lorazepam most likely enhances inhibition within the cortical network of interneurons responsible for creating paired-pulse suppression, leading to reduced inhibitory drive with a subsequently reduced amount of suppression. The results provide further evidence that GABAA -mediated mechanisms are involved in the generation of median nerve evoked paired-pulse suppression.
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Affiliation(s)
- Philipp Stude
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum, Buerkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Melanie Lenz
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum, Buerkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Oliver Höffken
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum, Buerkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Martin Tegenthoff
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum, Buerkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Hubert Dinse
- Department of Neurology, BG-Universitaetsklinikum Bergmannsheil Bochum, Buerkle-de-la-Camp-Platz 1, 44789, Bochum, Germany.,Neural Plasticity Laboratory, Institute for Neuroinformatics, Ruhr University, Bochum, Germany
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45
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Liu YJ, Hashemi-Nezhad M, Lyon DC. Contrast invariance of orientation tuning in cat primary visual cortex neurons depends on stimulus size. J Physiol 2015; 593:4485-98. [PMID: 26227285 DOI: 10.1113/jp271180] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/27/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The process of orientation tuning is an important and well-characterized feature of neurons in primary visual cortex. The combination of ascending and descending circuits involved is not only relevant to understanding visual processing but the function of neocortex in general. The classic feed-forward model of orientation tuning predicts a broadening effect due to increasing contrast; yet, experimental results consistently report contrast invariance. We show here that contrast invariance actually depends on stimulus size such that large stimuli extending beyond the neuron's receptive field engage circuits that promote invariance, whereas optimally sized, smaller stimuli result in contrast variance that is more in line with the classical orientation tuning model. These results illustrate the importance of optimizing stimulus parameters to best reflect the sensory pathways under study and provide new clues about different circuits that may be involved in variant and invariant response properties. ABSTRACT Selective response to stimulus orientation is a key feature of neurons in primary visual cortex, yet the underlying mechanisms generating orientation tuning are not fully understood. The combination of feed-forward and cortical mechanisms involved is not only relevant to understanding visual processing but the function of neocortex in general. The classic feed-forward model predicts that orientation tuning should broaden considerably with increasing contrast; however, experimental results consistently report contrast invariance. We show here, in primary visual cortex of anaesthetized cats under neuromuscular blockade, that contrast invariance occurs when visual stimuli are large enough to include the extraclassical surround (ECS), which is likely to involve circuits of suppression that may not be entirely feed-forward in origin. On the other hand, when stimulus size is optimized to the classical receptive field of each neuron, the population average shows a statistically significant 40% increase in tuning width at high contrast, demonstrating that contrast variance of orientation tuning can occur. Conversely, our results also suggest that the phenomenon of contrast invariance relies in part on the presence of the ECS. Moreover, these results illustrate the importance of optimizing stimulus parameters to best reflect the neural pathways under study.
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Affiliation(s)
- Yong-Jun Liu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, 364 Med Surge II, Irvine, CA, 92697, USA
| | - Maziar Hashemi-Nezhad
- Department of Anatomy and Neurobiology, School of Medicine, University of California, 364 Med Surge II, Irvine, CA, 92697, USA
| | - David C Lyon
- Department of Anatomy and Neurobiology, School of Medicine, University of California, 364 Med Surge II, Irvine, CA, 92697, USA
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46
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McTeague LM, Gruss LF, Keil A. Aversive learning shapes neuronal orientation tuning in human visual cortex. Nat Commun 2015. [PMID: 26215466 PMCID: PMC4518478 DOI: 10.1038/ncomms8823] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The responses of sensory cortical neurons are shaped by experience. As a result perceptual biases evolve, selectively facilitating the detection and identification of sensory events that are relevant for adaptive behaviour. Here we examine the involvement of human visual cortex in the formation of learned perceptual biases. We use classical aversive conditioning to associate one out of a series of oriented gratings with a noxious sound stimulus. After as few as two grating-sound pairings, visual cortical responses to the sound-paired grating show selective amplification. Furthermore, as learning progresses, responses to the orientations with greatest similarity to the sound-paired grating are increasingly suppressed, suggesting inhibitory interactions between orientation-selective neuronal populations. Changes in cortical connectivity between occipital and fronto-temporal regions mirror the changes in visuo-cortical response amplitudes. These findings suggest that short-term behaviourally driven retuning of human visual cortical neurons involves distal top–down projections as well as local inhibitory interactions. Sensory cortical tuning is shaped by experience to facilitate coding of features that are predictive of behaviourally relevant outcomes. Here the authors demonstrate that rapid behaviourally driven retuning of human visual cortex involves top–down projections as well as local inhibitory interactions.
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Affiliation(s)
- Lisa M McTeague
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | - L Forest Gruss
- 1] Department of Psychology, University of Florida, Gainesville, Florida 32611, USA [2] Center for the Study of Emotion and Attention, University of Florida, Gainesville, Florida 32611, USA
| | - Andreas Keil
- 1] Department of Psychology, University of Florida, Gainesville, Florida 32611, USA [2] Center for the Study of Emotion and Attention, University of Florida, Gainesville, Florida 32611, USA
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47
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Perry G. The effects of cross-orientation masking on the visual gamma response in humans. Eur J Neurosci 2015; 41:1484-95. [DOI: 10.1111/ejn.12900] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/18/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Gavin Perry
- Cardiff University Brain Imaging Centre (CUBRIC); School of Psychology; Cardiff University; 70 Park Place Cardiff CF10 3AT UK
- Institute of Psychological Medicine and Clinical Neurosciences; School of Medicine; Cardiff University; Cardiff UK
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48
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Sanayei M, Herrero JL, Distler C, Thiele A. Attention and normalization circuits in macaque V1. Eur J Neurosci 2015; 41:949-64. [PMID: 25757941 PMCID: PMC4402004 DOI: 10.1111/ejn.12857] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 01/13/2015] [Accepted: 01/22/2015] [Indexed: 11/30/2022]
Abstract
Attention affects neuronal processing and improves behavioural performance. In extrastriate visual cortex these effects have been explained by normalization models, which assume that attention influences the circuit that mediates surround suppression. While normalization models have been able to explain attentional effects, their validity has rarely been tested against alternative models. Here we investigate how attention and surround/mask stimuli affect neuronal firing rates and orientation tuning in macaque V1. Surround/mask stimuli provide an estimate to what extent V1 neurons are affected by normalization, which was compared against effects of spatial top down attention. For some attention/surround effect comparisons, the strength of attentional modulation was correlated with the strength of surround modulation, suggesting that attention and surround/mask stimulation (i.e. normalization) might use a common mechanism. To explore this in detail, we fitted multiplicative and additive models of attention to our data. In one class of models, attention contributed to normalization mechanisms, whereas in a different class of models it did not. Model selection based on Akaike's and on Bayesian information criteria demonstrated that in most cells the effects of attention were best described by models where attention did not contribute to normalization mechanisms. This demonstrates that attentional influences on neuronal responses in primary visual cortex often bypass normalization mechanisms.
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Affiliation(s)
- M Sanayei
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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49
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Abstract
How an object is perceived depends on the temporal context in which it is encountered. Sensory signals in the brain also depend on temporal context, a phenomenon often referred to as adaptation. Traditional descriptions of adaptation effects emphasize various forms of response fatigue in single neurons, which grow in strength with exposure to a stimulus. Recent work on vision, and other sensory modalities, has shown that this description has substantial shortcomings. Here we review our emerging understanding of how adaptation alters the balance between excitatory and suppressive signals, how effects depend on adaptation duration, and how adaptation influences representations that are distributed within and across multiple brain structures. This work points to a sophisticated set of mechanisms for adjusting to recent sensory experience, and suggests new avenues for understanding their function.
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Affiliation(s)
- Samuel G Solomon
- Institute for Behavioural Neuroscience, University College London, London, UK; Department of Experimental Psychology, University College London, London, UK.
| | - Adam Kohn
- Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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50
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Baker DH, Vilidaitė G. Broadband noise masks suppress neural responses to narrowband stimuli. Front Psychol 2014; 5:763. [PMID: 25076930 PMCID: PMC4098025 DOI: 10.3389/fpsyg.2014.00763] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 06/29/2014] [Indexed: 11/13/2022] Open
Abstract
White pixel noise is widely used to estimate the level of internal noise in a system by injecting external variance into the detecting mechanism. Recent work (Baker and Meese, 2012) has provided psychophysical evidence that such noise masks might also cause suppression that could invalidate estimates of internal noise. Here we measure neural population responses directly, using steady-state visual evoked potentials, elicited by target stimuli embedded in different mask types. Sinusoidal target gratings of 1 c/deg flickered at 5 Hz, and were shown in isolation, or with superimposed orthogonal grating masks or 2D white noise masks, flickering at 7 Hz. Compared with responses to a blank screen, the Fourier amplitude at the target frequency increased monotonically as a function of target contrast when no mask was present. Both orthogonal and white noise masks caused rightward shifts of the contrast response function, providing evidence of contrast gain control suppression. We also calculated within-observer amplitude variance across trials. This increased in proportion to the target response, implying signal-dependent (i.e., multiplicative) noise at the system level, the implications of which we discuss for behavioral tasks. This measure of variance was reduced by both mask types, consistent with the changes in mean target response. An alternative variety of noise, which we term zero-dimensional noise, involves trial-by-trial jittering of the target contrast. This type of noise produced no gain control suppression, and increased the amplitude variance across trials.
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