1
|
Karakose-Akbiyik S, Schubert TM, Caramazza A. Preserved recognition of basic visual features despite lack of awareness of shape: Evidence from a case of neglect. Cortex 2024; 176:62-76. [PMID: 38754211 DOI: 10.1016/j.cortex.2024.03.013] [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: 11/08/2023] [Revised: 01/27/2024] [Accepted: 03/26/2024] [Indexed: 05/18/2024]
Abstract
Human visual experience of objects comprises a combination of visual features, such as color, position, and shape. Spatial attention is thought to play a role in creating a coherent perceptual experience, integrating visual information coming from a given location, but the mechanisms underlying this process are not fully understood. Deficits of spatial attention in which this integration process does not occur normally, such as neglect, can provide insights regarding the mechanisms of spatial attention in visual object recognition. In this study, we describe a series of experiments conducted with an individual with neglect, DH. DH presents characteristic lack of awareness of the left side of individual objects, evidenced by poor object and face recognition, and impaired word reading. However, he exhibits intact recognition of color within the boundaries of the same objects he fails to recognize. Furthermore, he can also report the orientation and location of a colored region on the neglected left side despite lack of awareness of the shape of the region. Overall, DH shows selective lack of awareness of shape despite intact processing of basic visual features in the same spatial location. DH's performance raises intriguing questions and challenges about the role of spatial attention in the formation of coherent object percepts and visual awareness.
Collapse
Affiliation(s)
| | | | - Alfonso Caramazza
- Department of Psychology, Harvard University, Cambridge, MA, USA; Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, Italy; Faculty of Psychology and Educational Sciences, University of Coimbra, Portugal
| |
Collapse
|
2
|
Bhagwandin A, Molnár Z, Bertelsen MF, Karlsson KÆ, Alagaili AN, Bennett NC, Hof PR, Kaswera-Kyamakya C, Gilissen E, Jayakumar J, Manger PR. Where Do Core Thalamocortical Axons Terminate in Mammalian Neocortex When There Is No Cytoarchitecturally Distinct Layer 4? J Comp Neurol 2024; 532:e25652. [PMID: 38962882 DOI: 10.1002/cne.25652] [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: 03/15/2024] [Revised: 05/20/2024] [Accepted: 06/07/2024] [Indexed: 07/05/2024]
Abstract
Although the mammalian cerebral cortex is most often described as a hexalaminar structure, there are cortical areas (primary motor cortex) and species (elephants, cetaceans, and hippopotami), where a cytoarchitecturally indistinct, or absent, layer 4 is noted. Thalamocortical projections from the core, or first order, thalamic system terminate primarily in layers 4/inner 3. We explored the termination sites of core thalamocortical projections in cortical areas and in species where there is no cytoarchitecturally distinct layer 4 using the immunolocalization of vesicular glutamate transporter 2, a known marker of core thalamocortical axon terminals, in 31 mammal species spanning the eutherian radiation. Several variations from the canonical cortical column outline of layer 4 and core thalamocortical inputs were noted. In shrews/microchiropterans, layer 4 was present, but many core thalamocortical projections terminated in layer 1 in addition to layers 4 and inner 3. In primate primary visual cortex, the sublaminated layer 4 was associated with a specialized core thalamocortical projection pattern. In primate primary motor cortex, no cytoarchitecturally distinct layer 4 was evident and the core thalamocortical projections terminated throughout layer 3. In the African elephant, cetaceans, and river hippopotamus, no cytoarchitecturally distinct layer 4 was observed and core thalamocortical projections terminated primarily in inner layer 3 and less densely in outer layer 3. These findings are contextualized in terms of cortical processing, perception, and the evolutionary trajectory leading to an indistinct or absent cortical layer 4.
Collapse
Affiliation(s)
- Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK
| | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Karl Æ Karlsson
- Biomedical Engineering, Reykjavik University, Reykjavik, Iceland
| | | | - Nigel C Bennett
- South African Research Chair of Mammal Behavioural Ecology and Physiology, University of Pretoria, Pretoria, South Africa
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Center for Discovery and Innovation, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | | | - Emmanuel Gilissen
- Department of African Zoology, Royal Museum for Central Africa, Tervuren, Belgium
- Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, Brussels, Belgium
| | - Jaikishan Jayakumar
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai, India
- Center for Computational Brain Research, Indian Institute of Technology Madras, Chennai, India
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| |
Collapse
|
3
|
Szarka G, Ganczer A, Balogh M, Tengölics ÁJ, Futácsi A, Kenyon G, Pan F, Kovács-Öller T, Völgyi B. Gap junctions fine-tune ganglion cell signals to equalize response kinetics within a given electrically coupled array. iScience 2024; 27:110099. [PMID: 38947503 PMCID: PMC11214328 DOI: 10.1016/j.isci.2024.110099] [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: 01/04/2024] [Revised: 03/06/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
Retinal ganglion cells (RGCs) summate inputs and forward a spike train code to the brain in the form of either maintained spiking (sustained) or a quickly decaying brief spike burst (transient). We report diverse response transience values across the RGC population and, contrary to the conventional transient/sustained scheme, responses with intermediary characteristics are the most abundant. Pharmacological tests showed that besides GABAergic inhibition, gap junction (GJ)-mediated excitation also plays a pivotal role in shaping response transience and thus visual coding. More precisely GJs connecting RGCs to nearby amacrine and RGCs play a defining role in the process. These GJs equalize kinetic features, including the response transience of transient OFF alpha (tOFFα) RGCs across a coupled array. We propose that GJs in other coupled neuron ensembles in the brain are also critical in the harmonization of response kinetics to enhance the population code and suit a corresponding task.
Collapse
Affiliation(s)
- Gergely Szarka
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Alma Ganczer
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Márton Balogh
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Ádám Jonatán Tengölics
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| | - Anett Futácsi
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | | | - Feng Pan
- The Hong Kong Polytechnic University, Hong Kong, China
| | - Tamás Kovács-Öller
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
- SzKK Imaging Core Facility, Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Béla Völgyi
- University of Pécs, Szentágothai Research Centre, Pécs, Hungary
- University of Pécs, Department of Neurobiology, Pécs, Hungary
- MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary
- Center for Neuroscience, University of Pécs, Pécs, Hungary
| |
Collapse
|
4
|
Shapley R, Nunez V, Gordon J. Low luminance contrast's effect on the color appearance of S-cone patterns. Vision Res 2024; 222:108448. [PMID: 38906035 DOI: 10.1016/j.visres.2024.108448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/23/2024]
Abstract
There is a surprisingly strong effect on color appearance when low levels of luminance contrast are added to visual targets in which only S-cones are modulated. This phenomenon can be studied with checkerboard patterns composed of alternating S-cone-modulated checks and gray checks. + S checks look purple when surrounded by slightly brighter gray checks but look highly desaturated (lavender, almost white) when surrounded by darker gray checks. -S checks change in hue with luminance contrast; they look yellow when surrounded by darker gray checks but are greener when surrounded by lighter checks. Psychophysical paired comparisons confirm these perceptions. Furthermore, visual evoked potentials (VEPs) recorded from human posterior cortex indicate that signals evoked by low luminance contrast interact nonlinearly with S-cone-evoked signals in early cortical color processing. Our new psychophysics and electrophysiology results prove that human perception of color appearance is not based on neural computations within a separate, isolated color system. Rather, signals evoked by color contrast and luminance contrast interact to produce the colors we see.
Collapse
|
5
|
Phangwiwat T, Phunchongharn P, Wongsawat Y, Chatnuntawech I, Wang S, Chunharas C, Sprague TC, Woodman GF, Itthipuripat S. Sustained attention operates via dissociable neural mechanisms across different eccentric locations. Sci Rep 2024; 14:11188. [PMID: 38755251 PMCID: PMC11099062 DOI: 10.1038/s41598-024-61171-7] [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: 11/05/2023] [Accepted: 05/02/2024] [Indexed: 05/18/2024] Open
Abstract
In primates, foveal and peripheral vision have distinct neural architectures and functions. However, it has been debated if selective attention operates via the same or different neural mechanisms across eccentricities. We tested these alternative accounts by examining the effects of selective attention on the steady-state visually evoked potential (SSVEP) and the fronto-parietal signal measured via EEG from human subjects performing a sustained visuospatial attention task. With a negligible level of eye movements, both SSVEP and SND exhibited the heterogeneous patterns of attentional modulations across eccentricities. Specifically, the attentional modulations of these signals peaked at the parafoveal locations and such modulations wore off as visual stimuli appeared closer to the fovea or further away towards the periphery. However, with a relatively higher level of eye movements, the heterogeneous patterns of attentional modulations of these neural signals were less robust. These data demonstrate that the top-down influence of covert visuospatial attention on early sensory processing in human cortex depends on eccentricity and the level of saccadic responses. Taken together, the results suggest that sustained visuospatial attention operates differently across different eccentric locations, providing new understanding of how attention augments sensory representations regardless of where the attended stimulus appears.
Collapse
Affiliation(s)
- Tanagrit Phangwiwat
- Neuroscience Center for Research and Innovation (NX), Learning Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand
- Department of Computer Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
| | - Phond Phunchongharn
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand
- Department of Computer Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand
| | - Yodchanan Wongsawat
- Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Itthi Chatnuntawech
- National Nanotechnology Center, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Sisi Wang
- Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA
| | - Chaipat Chunharas
- Cognitive Clinical and Computational Neuroscience Center of Excellence, Department of Internal Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Chula Neuroscience Center, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Thomas C Sprague
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Geoffrey F Woodman
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA
| | - Sirawaj Itthipuripat
- Neuroscience Center for Research and Innovation (NX), Learning Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10140, Thailand.
- Big Data Experience Center (BX), King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, 10600, Thailand.
- Department of Psychology, Vanderbilt University, Nashville, TN, 37235, USA.
| |
Collapse
|
6
|
Song J, Breitmeyer BG, Brown JM. Further Examination of the Pulsed- and Steady-Pedestal Paradigms under Hypothetical Parvocellular- and Magnocellular-Biased Conditions. Vision (Basel) 2024; 8:28. [PMID: 38804349 PMCID: PMC11130818 DOI: 10.3390/vision8020028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/12/2024] [Accepted: 04/25/2024] [Indexed: 05/29/2024] Open
Abstract
The pulsed- and steady-pedestal paradigms were designed to track increment thresholds (ΔC) as a function of pedestal contrast (C) for the parvocellular (P) and magnocellular (M) systems, respectively. These paradigms produce contrasting results: linear relationships between ΔC and C are observed in the pulsed-pedestal paradigm, indicative of the P system's processing, while the steady-pedestal paradigm reveals nonlinear functions, characteristic of the M system's response. However, we recently found the P model fits better than the M model for both paradigms, using Gabor stimuli biased towards the M or P systems based on their sensitivity to color and spatial frequency. Here, we used two-square pedestals under green vs. red light in the lower-left vs. upper-right visual fields to bias processing towards the M vs. P system, respectively. Based on our previous findings, we predicted the following: (1) steeper ΔC vs. C functions with the pulsed than the steady pedestal due to different task demands; (2) lower ΔCs in the upper-right vs. lower-left quadrant due to its bias towards P-system processing there; (3) no effect of color, since both paradigms track the P-system; and, most importantly (4) contrast gain should not be higher for the steady than for the pulsed pedestal. In general, our predictions were confirmed, replicating our previous findings and providing further evidence questioning the general validity of using the pulsed- and steady-pedestal paradigms to differentiate the P and M systems.
Collapse
Affiliation(s)
- Jaeseon Song
- Department of Psychology, University of Georgia, Athens, GA 30602, USA;
| | | | - James M. Brown
- Department of Psychology, University of Georgia, Athens, GA 30602, USA;
| |
Collapse
|
7
|
Krug A, Eberhardt LV, Huckauf A. Transient attention does not alter the eccentricity effect in estimation of duration. Atten Percept Psychophys 2024; 86:392-403. [PMID: 37550478 PMCID: PMC10806013 DOI: 10.3758/s13414-023-02766-6] [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] [Accepted: 07/16/2023] [Indexed: 08/09/2023]
Abstract
Previous research investigating the influence of stimulus eccentricity on perceived duration showed an increasing duration underestimation with increasing eccentricity. Based on studies showing that precueing the stimulus location prolongs perceived duration, one might assume that this eccentricity effect is influenced by spatial attention. In the present study, we assessed the influence of transient covert attention on the eccentricity effect in duration estimation in two experiments, one online and one in a laboratory setting. In a duration estimation task, participants judged whether a comparison stimulus presented near or far from fixation with a varying duration was shorter or longer than a standard stimulus presented foveally with a constant duration. To manipulate transient covert attention, either a transient luminance cue was used (valid cue) to direct attention to the position of the subsequent peripheral comparison stimulus or all positions were marked by luminance (neutral cue). Results of both experiments yielded a greater underestimation of duration for the far than for the near stimulus, replicating the eccentricity effect. Although cueing was effective (i.e., shorter response latencies for validly cued stimuli), cueing did not alter the eccentricity effect on estimation of duration. This indicates that cueing leads to covert attentional shifts but does not account for the eccentricity effect in perceived duration.
Collapse
Affiliation(s)
- Alina Krug
- Department of General Psychology, Institute of Psychology and Education, Ulm University, 89069, Ulm, Germany.
| | - Lisa Valentina Eberhardt
- Department of General Psychology, Institute of Psychology and Education, Ulm University, 89069, Ulm, Germany
| | - Anke Huckauf
- Department of General Psychology, Institute of Psychology and Education, Ulm University, 89069, Ulm, Germany
| |
Collapse
|
8
|
Song J, Breitmeyer BG, Brown JM. Examining Increment thresholds as a function of pedestal contrast under hypothetical parvo- and magnocellular-biased conditions. Atten Percept Psychophys 2024; 86:213-220. [PMID: 38030820 DOI: 10.3758/s13414-023-02819-w] [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] [Accepted: 11/06/2023] [Indexed: 12/01/2023]
Abstract
Theoretically, the pulsed- and steady-pedestal paradigms are thought to track contrast-increment thresholds (ΔC) as a function of pedestal contrast (C) for the parvocellular (P) and magnocellular (M) systems, respectively, yielding linear ΔC versus C functions for the pulsed- and nonlinear functions for the steady-pedestal paradigm. A recent study utilizing these paradigms to isolate the P and M systems reported no evidence of the M system being suppressed by red light, contrary to previous physiological and psychophysical findings. Curious as to why this may have occurred, we examined how ΔC varies with C for the P and M systems using the pulsed- and steady-pedestal paradigms and stimuli biased towards the P or M systems based on their sensitivity to spatial frequency (SF) and color. We found no effect of color and little influence of SF. To explain this lack of color effects, we used a quantitative model of ΔC (as it changes with C) to obtain Csat and contrast-gain values. The contrast-gain values (i) contradicted the hypothesis that the steady-pedestal paradigm tracks the M-system response, and (ii) our obtained Csat values indicated strongly that both pulsed- and steady-pedestal paradigms track primarily the P-system response.
Collapse
Affiliation(s)
- Jaeseon Song
- Department of Psychology, University of Georgia, Athens, GA, 30602-3013, USA.
| | - Bruno G Breitmeyer
- Department of Psychology, University of Houston, Houston, TX, 77204-5022, USA
| | - James M Brown
- Department of Psychology, University of Georgia, Athens, GA, 30602-3013, USA
| |
Collapse
|
9
|
Di Dona G, Ronconi L. Beta oscillations in vision: a (preconscious) neural mechanism for the dorsal visual stream? Front Psychol 2023; 14:1296483. [PMID: 38155693 PMCID: PMC10753839 DOI: 10.3389/fpsyg.2023.1296483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Neural oscillations in alpha (8-12 Hz) and beta (13-30 Hz) frequency bands are thought to reflect feedback/reentrant loops and large-scale cortical interactions. In the last decades a main effort has been made in linking perception with alpha-band oscillations, with converging evidence showing that alpha oscillations have a key role in the temporal and featural binding of visual input, configuring the alpha rhythm a key determinant of conscious visual experience. Less attention has been historically dedicated to link beta oscillations and visual processing. Nonetheless, increasing studies report that task conditions that require to segregate/integrate stimuli in space, to disentangle local/global shapes, to spatially reorganize visual inputs, and to achieve motion perception or form-motion integration, rely on the activity of beta oscillations, with a main hub in parietal areas. In the present review, we summarize the evidence linking oscillations within the beta band and visual perception. We propose that beta oscillations represent a neural code that supports the functionality of the magnocellular-dorsal (M-D) visual pathway, serving as a fast primary neural code to exert top-down influences on the slower parvocellular-ventral visual pathway activity. Such M-D-related beta activity is proposed to act mainly pre-consciously, providing the spatial coordinates of vision and guiding the conscious extraction of objects identity that are achieved with slower alpha rhythms in ventral areas. Finally, within this new theoretical framework, we discuss the potential role of M-D-related beta oscillations in visuo-spatial attention, oculo-motor behavior and reading (dis)abilities.
Collapse
Affiliation(s)
- Giuseppe Di Dona
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
| | - Luca Ronconi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
10
|
Lawton T, Shelley-Tremblay J, Huang MX. Case report: Neural timing deficits prevalent in developmental disorders, aging, and concussions remediated rapidly by movement discrimination exercises. Front Neurol 2023; 14:898781. [PMID: 37818220 PMCID: PMC10560731 DOI: 10.3389/fneur.2023.898781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 09/04/2023] [Indexed: 10/12/2023] Open
Abstract
Background The substantial evidence that neural timing deficits are prevalent in developmental disorders, aging, and concussions resulting from a Traumatic Brain Injury (TBI) is presented. Objective When these timing deficits are remediated using low-level movement-discrimination training, then high-level cognitive skills, including reading, attention, processing speed, problem solving, and working memory improve rapidly and effectively. Methods In addition to the substantial evidence published previously, new evidence based on a neural correlate, MagnetoEncephalography physiological recordings, on an adult dyslexic, and neuropsychological tests on this dyslexic subject and an older adult were measured before and after 8-weeks of contrast sensitivity-based left-right movement-discrimination exercises were completed. Results The neuropsychological tests found large improvements in reading, selective and sustained attention, processing speed, working memory, and problem-solving skills, never before found after such a short period of training. Moreover, these improvements were found 4 years later for older adult. Substantial MEG signal increases in visual Motion, Attention, and Memory/Executive Control Networks were observed following training on contrast sensitivity-based left-right movement-discrimination. Improving the function of magnocells using figure/ground movement-discrimination at both low and high levels in dorsal stream: (1) improved both feedforward and feedback pathways to modulate attention by enhancing coupled theta/gamma and alpha/gamma oscillations, (2) is adaptive, and (3) incorporated cycles of feedback and reward at multiple levels. Conclusion What emerges from multiple studies is the essential role of timing deficits in the dorsal stream that are prevalent in developmental disorders like dyslexia, in aging, and following a TBI. Training visual dorsal stream function at low levels significantly improved high-level cognitive functions, including processing speed, selective and sustained attention, both auditory and visual working memory, problem solving, and reading fluency. A paradigm shift for treating cognitive impairments in developmental disorders, aging, and concussions is crucial. Remediating the neural timing deficits of low-level dorsal pathways, thereby improving both feedforward and feedback pathways, before cognitive exercises to improve specific cognitive skills provides the most rapid and effective methods to improve cognitive skills. Moreover, this adaptive training with substantial feedback shows cognitive transfer to tasks not trained on, significantly improving a person's quality of life rapidly and effectively.
Collapse
Affiliation(s)
- Teri Lawton
- Cognitive Neuroscience, Perception Dynamics Institute, Encinitas, CA, United States
| | | | - Ming-Xiong Huang
- Radiology Imaging Laboratory, Department of Radiology, University of California, San Diego, San Diego, CA, United States
| |
Collapse
|
11
|
Wang Q, So C, Zuo B, Banerjee S, Qiu C, Ting Z, Cheong AMY, Tse DYY, Pan F. Retinal ganglion cells encode differently in the myopic mouse retina? Exp Eye Res 2023; 234:109616. [PMID: 37580002 DOI: 10.1016/j.exer.2023.109616] [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: 03/07/2023] [Revised: 08/06/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
The etiology of myopia remains unclear. This study investigated whether retinal ganglion cells (RGCs) in the myopic retina encode visual information differently from the normal retina and to determine the role of Connexin (Cx) 36 in this process. Generalized linear models (GLMs), which can capture stimulus-dependent changes in real neurons with spike timing precision and reliability, were used to predict RGCs responses to focused and defocused images in the retinas of wild-type (normal) and Lens-Induced Myopia (LIM) mice. As the predominant subunit of gap junctions in the mouse retina and a plausible modulator in myopia development, Cx36 knockout (KO) mice were used as a control for an intact retinal circuit. The kinetics of excitatory postsynaptic currents (EPSCs) of a single αRGC could reflect projection of both focused and defocused images in the retinas of normal and LIM, but not in the Cx36 knockout mice. Poisson GLMs revealed that RGC encoding of visual stimuli in the LIM retina was similar to that of the normal retina. In the LIM retinas, the linear-Gaussian GLM model with offset was a better fit for predicting the spike count under a focused image than the defocused image. Akaike information criterion (AIC) indicated that nonparametric GLM (np-GLM) model predicted focused/defocused images better in both LIM and normal retinas. However, the spike counts in 33% of αRGCs in LIM retinas were better fitted by exponential GLM (exp-GLM) under defocus, compared to only 13% αRGCs in normal retinas. The differences in encoding performance between LIM and normal retinas indicated the possible amendment and plasticity of the retinal circuit in myopic retinas. The absence of a similar response between Cx36 KO mice and normal/LIM mice might suggest that Cx36, which is associated with myopia development, plays a role in encoding focused and defocused images.
Collapse
Affiliation(s)
- Qin Wang
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Chunghim So
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Bing Zuo
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Seema Banerjee
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - ChunTing Qiu
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Zhang Ting
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong; Hong Kong Polytechnic University Shenzhen Research Institute, Hong Kong
| | - Allen Ming-Yan Cheong
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Dennis Yan-Yin Tse
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
| | - Feng Pan
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong; Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong; Hong Kong Polytechnic University Shenzhen Research Institute, Hong Kong.
| |
Collapse
|
12
|
Zhu J, Zikopoulos B, Yazdanbakhsh A. A neural model of modified excitation/inhibition and feedback levels in schizophrenia. Front Psychiatry 2023; 14:1199690. [PMID: 37900297 PMCID: PMC10600455 DOI: 10.3389/fpsyt.2023.1199690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/20/2023] [Indexed: 10/31/2023] Open
Abstract
Introduction The strength of certain visual illusions, including contrast-contrast and apparent motion, is weakened in individuals with schizophrenia. Such phenomena have been interpreted as the impaired integration of inhibitory and excitatory neural responses, and impaired top-down feedback mechanisms. Methods To investigate whether and how these factors influence the perceived contrast-contrast and apparent motion illusions in individuals with schizophrenia, we propose a two-layer network, with top-down feedback from layer 2 to layer 1 that can model visual receptive fields (RFs) and their inhibitory and excitatory subfields. Results Our neural model suggests that illusion perception changes in individuals with schizophrenia can be influenced by altered top-down mechanisms and the organization of the on-center off-surround receptive fields. Alteration of the RF inhibitory surround and/or the excitatory center can replicate the difference of illusion precepts between individuals with schizophrenia within certain clinical states and normal controls. The results show that the simulated top-down feedback modulation enlarges the difference of the model illusion representations, replicating the difference between the two groups. Discussion We propose that the heterogeneity of visual and in general sensory processing in certain clinical states of schizophrenia can be largely explained by the degree of top-down feedback reduction, emphasizing the critical role of top-down feedback in illusion perception, and to a lesser extent on the imbalance of excitation/inhibition. Our neural model provides a mechanistic explanation for the modulated visual percepts of contrast-contrast and apparent motion in schizophrenia with findings that can explain a broad range of visual perceptual observations in previous studies. The two-layer motif of the current model provides a general framework that can be tailored to investigate subcortico-cortical (such as thalamocortical) and cortico-cortical networks, bridging neurobiological changes in schizophrenia and perceptual processing.
Collapse
Affiliation(s)
- Jiating Zhu
- Program in Brain, Behavior & Cognition, Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States
| | - Basilis Zikopoulos
- Human Systems Neuroscience Laboratory, Department of Health Sciences, Boston University, Boston, MA, United States
- Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
| | - Arash Yazdanbakhsh
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Computational Neuroscience and Vision Laboratory, Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States
| |
Collapse
|
13
|
Chien SE, Yeh SL, Yamashita W, Tsujimura SI. Enhanced human contrast sensitivity with increased stimulation of melanopsin in intrinsically photosensitive retinal ganglion cells. Vision Res 2023; 209:108271. [PMID: 37331304 DOI: 10.1016/j.visres.2023.108271] [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: 11/05/2022] [Revised: 05/15/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
The intrinsically photosensitive retinal ganglion cells (ipRGCs) are known to serve non-image-forming functions, such as photoentrainment of the circadian rhythm and pupillary light reflex. However, how they affect human spatial vision is largely unknown. The spatial contrast sensitivity function (CSF), which measures contrast sensitivity as a function of spatial frequency, was used in the current study to investigate the function of ipRGCs in pattern vision. To compare the effects of different background lights on the CSF, we utilized the silent substitution technique. We manipulated the stimulation level of melanopsin (i.e., the visual pigment of ipRGCs) from the background light while keeping the cone stimulations constant, or vice versa. We conducted four experiments to measure the CSFs at various spatial frequencies, eccentricities, and levels of background luminance. Results showed that melanopsin stimulation from the background light enhances spatial contrast sensitivity across different eccentricities and luminance levels. Our finding that melanopsin contributes to CSF, combined with the receptive field analysis, suggests a role for the magnocellular pathway and challenges the conventional view that ipRGCs are primarily responsible for non-visual functions.
Collapse
Affiliation(s)
- Sung-En Chien
- Department of Psychology, National Taiwan University, Taipei 10617, Taiwan; Ganzin Technology Inc., New Taipei City 23141, Taiwan
| | - Su-Ling Yeh
- Department of Psychology, National Taiwan University, Taipei 10617, Taiwan; Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei 10617, Taiwan; Neurobiology and Cognitive Science Center, National Taiwan University, Taipei 10617, Taiwan; Center for Advanced Studies in the Behavioral Sciences, Stanford University, Stanford, CA 94305, USA.
| | - Wakayo Yamashita
- Faculty of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan
| | - Sei-Ichi Tsujimura
- Faculty of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan; Faculty of Design and Architecture, Nagoya City University, Nagoya 467-8501, Japan.
| |
Collapse
|
14
|
Seemiller ES, Gaska J, O'Keefe E, Shoda E, Knapp J, Winterbottom M. Vision screening and vocational aptitude: A factor analysis approach. PLoS One 2023; 18:e0286513. [PMID: 37256907 DOI: 10.1371/journal.pone.0286513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/17/2023] [Indexed: 06/02/2023] Open
Abstract
For a good vision screening battery to quickly and accurately reflect the status of the human visual system it should be relevant, reliable, and streamlined. Because the early visual system has limited functional architecture, many simple measurements of the visual system may in fact be measuring the shared computations and parallel processes of other visual functions, making much of the measurement process redundant. This can make a screening battery repetitious and therefore inefficient. The purpose of this research is to investigate these redundancies in a large occupational screening dataset using factor analysis. 192 subjects participated in the Operational Based Vision Assessment (OBVA) Laboratory Automated Vision Testing (AVT) procedure. The AVT includes digital tests for visual acuity, luminance and cone contrast sensitivity, motion coherence, stereopsis, and binocular motor function. Psychometric thresholds and fusional ranges were collected from each subject and a factor analysis was utilized to investigate independent latent variables in the dataset. A promax rotation revealed 5 factors that explained 74% of the total variance: (1) medium and high spatial frequency vision, (2) stereoacuity and horizontal fusional range, (3) cone contrast sensitivity, (4) motion perception, and (5) low spatial frequency vision. Practically, these results suggest that the screening battery can be reduced to 5 independent measurements that capture much of the variance in the dataset. Furthermore, the factors predicted operational and vocational aptitude better than any single variable. More interestingly, these relationships also reiterate known computational processes within the human visual system, such as the parallel processing of low and high spatial frequency content.
Collapse
Affiliation(s)
- Eric S Seemiller
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, OH, United States of America
| | - James Gaska
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, OH, United States of America
| | | | | | - Jonelle Knapp
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, OH, United States of America
| | - Marc Winterbottom
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, OH, United States of America
| |
Collapse
|
15
|
Vanston JE, Boehm AE, Tuten WS, Roorda A. It's not easy seeing green: The veridical perception of small spots. J Vis 2023; 23:2. [PMID: 37133838 PMCID: PMC10166115 DOI: 10.1167/jov.23.5.2] [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: 11/16/2022] [Accepted: 03/26/2023] [Indexed: 05/04/2023] Open
Abstract
When single cones are stimulated with spots of 543-nm light presented against a white background, subjects report percepts that vary between predominately red, white, and green. However, light of the same spectral composition viewed over a large field under normal viewing conditions looks invariably green and highly saturated. It remains unknown what stimulus parameters are most important for governing the color appearance in the transition between these two extreme cases. The current study varied the size, intensity and retinal motion of stimuli presented in an adaptive optics scanning laser ophthalmoscope. Stimuli were either stabilized on target locations or allowed to drift across the retina with the eye's natural motion. Increasing both stimulus size and intensity led to higher likelihoods that monochromatic spots of light were perceived as green, whereas only higher intensities led to increases in perceived saturation. The data also show an interaction between size and intensity, suggesting that the balance between magnocellular and parvocellular activation may be critical factors for color perception. Surprisingly, under the range of conditions tested, color appearance did not depend on whether stimuli were stabilized. Sequential activation of many cones does not appear to drive hue and saturation perception as effectively as simultaneous activation of many cones.
Collapse
Affiliation(s)
- John Erik Vanston
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
| | - Alexandra E Boehm
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
| | - William S Tuten
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
| |
Collapse
|
16
|
Wang W, Zhou T, Chen L, Huang Y. A subcortical magnocellular pathway is responsible for the fast processing of topological properties of objects: A transcranial magnetic stimulation study. Hum Brain Mapp 2023; 44:1617-1628. [PMID: 36426867 PMCID: PMC9921224 DOI: 10.1002/hbm.26162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/16/2022] [Accepted: 11/11/2022] [Indexed: 11/26/2022] Open
Abstract
Rapid object recognition has survival significance. The extraction of topological properties (TP) is proposed as the starting point of object perception. Behavioral evidence shows that TP processing takes precedence over other geometric properties and can accelerate object recognition. However, the mechanism of the fast TP processing remains unclear. The magnocellular (M) pathway is well known as a fast route to convey "coarse" information, compared with the slow parvocellular (P) pathway. Here, we hypothesize that the fast processing of TP occurs in a subcortical M pathway. We applied single-pulse transcranial magnetic stimulation (TMS) over the primary visual cortex to temporarily disrupt cortical processing. Besides, stimuli were designed to preferentially engage M or P pathways (M- or P-biased conditions). We found that, when TMS disrupted cortical function at the early stages of stimulus processing, non-TP shape discrimination was strongly impaired in both M- and P-biased conditions, whereas TP discrimination was not affected in the M-biased condition, suggesting that early M processing of TP is independent of the visual cortex, but probably occurs in a subcortical M pathway. Using an unconscious priming paradigm, we further found that early M processing of TP can accelerate object recognition by speeding up the processing of other properties, e.g., orientation. Our findings suggest that the human visual system achieves efficient object recognition by rapidly processing TP in the subcortical M pathway.
Collapse
Affiliation(s)
- Wenbo Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China
| | - Tiangang Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China.,Hefei Comprehensive National Science Center, Institute of Artificial Intelligence, Hefei, China
| | - Lin Chen
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China.,Hefei Comprehensive National Science Center, Institute of Artificial Intelligence, Hefei, China
| | - Yan Huang
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences. University of Chinese Academy of Sciences, China, Shenzhen, China
| |
Collapse
|
17
|
Raghavan RT, Kelly JG, Hasse JM, Levy PG, Hawken MJ, Movshon JA. Contrast and Luminance Gain Control in the Macaque's Lateral Geniculate Nucleus. eNeuro 2023; 10:ENEURO.0515-22.2023. [PMID: 36858825 PMCID: PMC10035770 DOI: 10.1523/eneuro.0515-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 02/16/2023] [Indexed: 03/03/2023] Open
Abstract
There is substantial variation in the mean and variance of light levels (luminance and contrast) in natural visual scenes. Retinal ganglion cells maintain their sensitivity despite this variation using two adaptive mechanisms, which control how responses depend on luminance and on contrast. However, the nature of each mechanism and their interactions downstream of the retina are unknown. We recorded neurons in the magnocellular and parvocellular layers of the lateral geniculate nucleus (LGN) in anesthetized adult male macaques and characterized how their responses adapt to changes in contrast and luminance. As contrast increases, neurons in the magnocellular layers maintain sensitivity to high temporal frequency stimuli but attenuate sensitivity to low-temporal frequency stimuli. Neurons in the parvocellular layers do not adapt to changes in contrast. As luminance increases, both magnocellular and parvocellular cells increase their sensitivity to high-temporal frequency stimuli. Adaptation to luminance is independent of adaptation to contrast, as previously reported for LGN neurons in the cat. Our results are similar to those previously reported for macaque retinal ganglion cells, suggesting that adaptation to luminance and contrast result from two independent mechanisms that are retinal in origin.
Collapse
Affiliation(s)
- R T Raghavan
- Center for Neural Science, New York University, New York, New York 10003
| | - Jenna G Kelly
- Center for Neural Science, New York University, New York, New York 10003
| | - J Michael Hasse
- Center for Neural Science, New York University, New York, New York 10003
| | - Paul G Levy
- Center for Neural Science, New York University, New York, New York 10003
| | - Michael J Hawken
- Center for Neural Science, New York University, New York, New York 10003
| | - J Anthony Movshon
- Center for Neural Science, New York University, New York, New York 10003
| |
Collapse
|
18
|
Lyapunov SI, Shoshina II. A Model of the Broca–Sulzer Effect. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922060136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
|
19
|
In vivo chromatic and spatial tuning of foveolar retinal ganglion cells in Macaca fascicularis. PLoS One 2022; 17:e0278261. [PMID: 36445926 PMCID: PMC9707781 DOI: 10.1371/journal.pone.0278261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/13/2022] [Indexed: 11/30/2022] Open
Abstract
The primate fovea is specialized for high acuity chromatic vision, with the highest density of cone photoreceptors and a disproportionately large representation in visual cortex. The unique visual properties conferred by the fovea are conveyed to the brain by retinal ganglion cells, the somas of which lie at the margin of the foveal pit. Microelectrode recordings of these centermost retinal ganglion cells have been challenging due to the fragility of the fovea in the excised retina. Here we overcome this challenge by combining high resolution fluorescence adaptive optics ophthalmoscopy with calcium imaging to optically record functional responses of foveal retinal ganglion cells in the living eye. We use this approach to study the chromatic responses and spatial transfer functions of retinal ganglion cells using spatially uniform fields modulated in different directions in color space and monochromatic drifting gratings. We recorded from over 350 cells across three Macaca fascicularis primates over a time period of weeks to months. We find that the majority of the L vs. M cone opponent cells serving the most central foveolar cones have spatial transfer functions that peak at high spatial frequencies (20-40 c/deg), reflecting strong surround inhibition that sacrifices sensitivity at low spatial frequencies but preserves the transmission of fine detail in the retinal image. In addition, we fit to the drifting grating data a detailed model of how ganglion cell responses draw on the cone mosaic to derive receptive field properties of L vs. M cone opponent cells at the very center of the foveola. The fits are consistent with the hypothesis that foveal midget ganglion cells are specialized to preserve information at the resolution of the cone mosaic. By characterizing the functional properties of retinal ganglion cells in vivo through adaptive optics, we characterize the response characteristics of these cells in situ.
Collapse
|
20
|
Moradi F, Mirzajani A, Akbari MR, Khorrami-Nejad M, Abolghasemi J, Masoomian B. Binocular contrast sensitivity in patients with intermittent exotropia in relation to angle of strabismus and level of compensation. Strabismus 2022; 31:1-8. [PMID: 36415944 DOI: 10.1080/09273972.2022.2141272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Intermittent exotropia (IXT) causes photophobia, and photophobia has been studied by measurement of contrast sensitivity (CS). CS was reduced in children with IXT. We compared binocular CS (BCS) in patients with IXT and normal subjects in relation to the angle of strabismus and control of IXT. This case-control study was performed on 40 patients with IXT and 40 normal subjects who were examined with the CSV1000 CS device in mesopic (3 cd/m2) and photopic (85 cd/m2) conditions with and without a glare stimulus at 3, 6, 12, and 18 cycle/degree (cpd) spatial frequencies. The angle of strabismus and near stereoacuity were also measured. The patient's IXT compensation was graded based on the office control scale. The mean age for IXT and normal participants were 12.30 ± 0.60 (range, 6-18) and 11.00 ± 0.78 (range, 6-18) years, respectively (P = .34). The IXT patients had lower binocular CS than controls at all spatial frequencies (P < .001). The largest decrease in CS occurred at 6 cpd spatial frequency under mesopic condition (1.61 ± 0.07 vs 1.38 ± 0.15, P < .001) and photopic condition with glare (2.03 ± 0.06 vs 1.77 ± 0.13, P < .001). Patients with better control scores had higher levels of BCS; also, the score of BCS showed a significant decrease in patients with a deviation of 25 prism diopter or more, compared to those with less deviation. BCS correlated at 3 and 6 cpd with near stereoacuity (r = -0.652, P < .001 and r = -0.613, P < .001). Binocular CS in patients with IXT correlates with the angle of strabismus and level of compensation.
Collapse
Affiliation(s)
- Fatemeh Moradi
- Rehabilitation Research Center, Department of Optometry, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran
| | - Ali Mirzajani
- Rehabilitation Research Center, Department of Optometry, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran
| | - Mohammad Reza Akbari
- Translational research center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran
| | - Masoud Khorrami-Nejad
- Translational research center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran
- School of Rehabilitation, Tehran University of Medical Sciences, Tehran
| | - Jamileh Abolghasemi
- Biostatistics Department, School of Public Health, Iran University of Medical Sciences, Tehran
| | - Babak Masoomian
- Translational research center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran
| |
Collapse
|
21
|
Meng ZL, Liu ML, Bi HY. Spatial and temporal processing difficulties in Chinese children with developmental dyslexia: An ERP study. DYSLEXIA (CHICHESTER, ENGLAND) 2022; 28:416-430. [PMID: 35918880 DOI: 10.1002/dys.1723] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 06/25/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Magnocellular (M) deficit theory indicates that individuals with developmental dyslexia (DD) have low sensitivity to stimuli with high temporal frequencies (HTF) and low spatial frequencies (LSF). However, some studies found that temporal processing and spatial processing were correlated with different reading-related skills. Chinese is a logographic language, and visual skills are particularly important for reading in Chinese. It is necessary to investigate the temporal and spatial processing abilities in the M pathway of Chinese children with DD. Using electrophysiological recordings, the present study examined the mean amplitude and latency of P1 during a grating direction judgment task in 13 children with DD and 13 age-matched normal children. Dyslexic children showed a low amplitude and long latency of P1 in the HTF condition and LSF condition compared with age-matched children. In the HTF condition, the amplitude of P1 correlated with phonological awareness, and the latency of P1 correlated with reading fluency and rapid naming of digits. The amplitude of P1 in the LSF condition correlated with reading accuracy. This result suggested that Chinese children with DD had difficulties in both temporal and spatial processing in the M pathway. However, temporal processing and spatial processing played different roles in Chinese reading.
Collapse
Affiliation(s)
- Ze-Long Meng
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- Department of Psychology, School of Humanities and Social Sciences, Beijing Forestry University, Beijing, China
| | - Meng-Lian Liu
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Hong-Yan Bi
- CAS Key Laboratory of Behavioral Science, Center for Brain Science and Learning Difficulties, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
22
|
Lee BB, Swanson WH. Detection and discrimination of achromatic contrast: A ganglion cell perspective. J Vis 2022; 22:11. [PMID: 35848903 PMCID: PMC9308016 DOI: 10.1167/jov.22.8.11] [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: 11/24/2022] Open
Abstract
The magnocellular (MC) pathway in the primate has much higher achromatic contrast sensitivity than the parvocellular (PC) pathway, and is implicated in luminance contrast detection. But MC pathway responses tend to saturate at lower achromatic contrast than do PC pathway responses. It has been proposed that the PC pathway plays a major role in discriminating suprathreshold achromatic contrast, because the MC pathway is in saturation. This has been termed the pulsed-pedestal protocol. To test this hypothesis, responses of MC and PC pathway ganglion cells have been examined under suprathreshold conditions with stimulus configurations similar to those in psychophysical tests. For MC cells, response saturation was much less for flashed or moving edges than for sinusoidal modulation, and MC cell thresholds predicted for these stimuli were similar to psychophysical discrimination (and detection) data. Results suggest the protocol is not effective in segregating MC and PC function.
Collapse
Affiliation(s)
- Barry B Lee
- Graduate Center for Vision Research, Department of Biological Sciences, SUNY College of Optometry, New York, NY, USA.,Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,
| | | |
Collapse
|
23
|
Leung TW, Cheong AMY, Chan HHL. Deficits in the Magnocellular Pathway of People with Reading Difficulties. CURRENT DEVELOPMENTAL DISORDERS REPORTS 2022. [DOI: 10.1007/s40474-022-00248-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
24
|
Shooner C, Mullen KT. Linking perceived to physical contrast: Comparing results from discrimination and difference-scaling experiments. J Vis 2022; 22:13. [PMID: 35061001 PMCID: PMC8787651 DOI: 10.1167/jov.22.1.13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/29/2021] [Indexed: 11/24/2022] Open
Abstract
Psychophysical approaches that allow us to estimate how perceived stimulus intensity is linked to physical intensity are import tools for studying nonlinear transformations of visual signals within different visual pathways. Here, we investigated how stimulus contrast is encoded in achromatic and chromatic pathways using simple grating stimuli. We compared two experimental approaches to this question: contrast discrimination (increment detection thresholds measured on contrast pedestals) and the maximum likelihood difference scaling (MLDS) approach introduced by Maloney and Yang (2003). The results of both experiments are expressed using simple models that include a transducer function mapping physical contrast to an internal signal the observer uses in making judgments, and an estimate of the variability of this representation (internal "noise"). We found that the transducers derived from both experiments have a similar form, but occupy different ranges of physical contrast in different stimulus conditions, reflecting difference in contrast sensitivity. This is consistent with past discrimination results, and in the difference-scaling case provides new evidence supporting the idea that suprathreshold chromatic and achromatic contrast are processed similarly, once differences in contrast sensitivity are taken into account. Model estimates of internal noise were higher in the difference-scaling experiment than the discrimination experiment, a finding we attribute to a difference in task complexity. Finally, we fit an alternative version of the MLDS model in which internal noise increased with response level. This alternative was no better at predicting holdout data in a cross-validation analysis than the original constant-variance model.
Collapse
Affiliation(s)
- Christopher Shooner
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University Montreal, Quebec, Canada
| | - Kathy T Mullen
- McGill Vision Research, Department of Ophthalmology & Visual Sciences, McGill University Montreal, Quebec, Canada
| |
Collapse
|
25
|
Fernandes Costa M, Dutra Henriques L, Côrrea Pinho O. Development of a Spatio-temporal Contrast Sensitivity Test for Clinical Use. J Ophthalmic Vis Res 2022; 17:69-77. [PMID: 35194498 PMCID: PMC8850854 DOI: 10.18502/jovr.v17i1.10172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 03/11/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose We developed a contrast sensitivity test that considers an integrative approach of spatial and temporal frequencies to evaluate the psychophysical channels in processing two-dimensional stimulus for clinical use. Our new procedure provides a more efficient isolation of the magnocellular and parvocellular visual pathways supporting spatiotemporal contrast sensitivity processing. Methods We evaluated 36 participants of both sexes aged 18–30 years with 20/20 or better best-corrected visual acuity. Two spatial frequencies (0.5 cycles per degree [cpd] and 10 cpd), being in one of the three temporal frequencies (0.5 cycle per second [cps], 7.5 cps, and 15 cps), were presented in a high-resolution gamma corrected monitor. A two-alternative forced-choice procedure was conducted, and the staircase method was used to calculate the contrast sensitivity. Reliability was assessed using a retest procedure within a month (±5 days) under the same conditions. Results Results showed statistical significance in 0.5 cpd and 10 cpd spatial frequencies for 0.5 cps (F = 77.36; p< 0.001), 7.5 cps (F = 778.37; p< 0.001), and 15 cps (F = 827.23; p < 0.001) with a very high (η² = 0.89) effect size. No statistical differences were found between the first and second sessions for all spatial frequencies. For reliability, a significantly high correlation and high internal consistency were found in all spatiotemporal conditions. The limits were calculated for normality. Conclusion We developed an approach to investigate the spatiotemporal integration of contrast sensitivity designed for clinical purposes. The relative contribution of the low spatial frequencies/high temporal frequencies and the high spatial frequencies/low temporal frequencies of the psychophysical channels can also be evaluated separately.
Collapse
Affiliation(s)
- Marcelo Fernandes Costa
- Laboratório da Visão, Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, Brazil.,Núcleo de Neurociências Aplicada, Universidade de São Paulo, São Paulo, Brazil
| | - Leonardo Dutra Henriques
- Laboratório da Visão, Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, Brazil
| | - Otávio Côrrea Pinho
- Laboratório da Visão, Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
26
|
Differences in chromatic noise suppression of luminance contrast discrimination in young and elderly people. Vis Neurosci 2022; 39:E006. [DOI: 10.1017/s0952523822000050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract
Aging causes impairment of contrast sensitivity and chromatic discrimination, leading to changes in the perceptual interactions between color and luminance information. We aimed to investigate the influence of chromatic noise on luminance contrast thresholds in young and older adults. Forty participants were divided equally into Young (29.6 ± 6.3-year-old) and Elderly Groups (57.8 ± 6.6-year-old). They performed a luminance contrast discrimination task in the presence of chromatic noise maskers using a mosaic stimulus in a mosaic background. Four chromatic noise masking protocols were applied (protan, deutan, tritan, and no-noise protocols). We found that luminance contrast thresholds were significantly elevated by the addition of chromatic noise in both age groups (P < 0.05). In the Elderly group, but not the younger group, thresholds obtained in the tritan protocol were lower than those obtained from protan and deutan protocols (P < 0.05). For all protocols, the luminance contrast thresholds of elderly participants were higher than in young people (P < 0.01). Tritan chromatic noise was less effective in inhibiting luminance discrimination in elderly participants.
Collapse
|
27
|
Zhuang X, Tran T, Jin D, Philip R, Wu C. Aging effects on contrast sensitivity in visual pathways: A pilot study on flicker adaptation. PLoS One 2021; 16:e0261927. [PMID: 34972163 PMCID: PMC8719693 DOI: 10.1371/journal.pone.0261927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 12/13/2021] [Indexed: 11/18/2022] Open
Abstract
Contrast sensitivity is reduced in older adults and is often measured at an overall perceptual level. Recent human psychophysical studies have provided paradigms to measure contrast sensitivity independently in the magnocellular (MC) and parvocellular (PC) visual pathways and have reported desensitization in the MC pathway after flicker adaptation. The current study investigates the influence of aging on contrast sensitivity and on the desensitization effect in the two visual pathways. The steady- and pulsed-pedestal paradigms were used to measure contrast sensitivity under two adaptation conditions in 45 observers. In the non-flicker adaptation condition, observers adapted to a pedestal array of four 1°×1° squares presented with a steady luminance; in the flicker adaptation condition, observers adapted to a square-wave modulated luminance flicker of 7.5 Hz and 50% contrast. Results showed significant age-related contrast sensitivity reductions in the MC and PC pathways, with a significantly larger decrease of contrast sensitivity for individuals older than 50 years of age in the MC pathway but not in the PC pathway. These results are consistent with the hypothesis that sensitivity reduction observed at the overall perceptual level likely comes from both the MC and PC visual pathways, with a more dramatic reduction resulting from the MC pathway for adults >50 years of age. In addition, a similar desensitization effect from flicker adaptation was observed in the MC pathway for all ages, which suggests that aging may not affect the process of visual adaptation to rapid luminance flicker.
Collapse
Affiliation(s)
- Xiaohua Zhuang
- Illinois College of Optometry, Chicago, IL, United States of America
| | - Tam Tran
- Illinois College of Optometry, Chicago, IL, United States of America
| | - Doris Jin
- Illinois College of Optometry, Chicago, IL, United States of America
| | - Riya Philip
- Illinois College of Optometry, Chicago, IL, United States of America
| | - Chaorong Wu
- Study Design & Biostatistics Center, Division of Epidemiology, University of Utah, Salt Lake City, UT, United States of America
| |
Collapse
|
28
|
Roberts JW, Bennett SJ. Online control of rapid target-directed aiming using blurred visual feedback. Hum Mov Sci 2021; 81:102917. [PMID: 34954624 DOI: 10.1016/j.humov.2021.102917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/11/2021] [Accepted: 12/15/2021] [Indexed: 11/04/2022]
Abstract
The accuracy and precision of target-directed aiming is contingent upon the availability of online visual feedback. The present study aimed to examine the visual regulation of aiming with blurred vision. The aiming task was executed using a stylus on a graphics digitizing board, which was translated onto a screen in the form of a cursor (representing the moving limb) and target. The vision conditions involved the complete disappearance or blur of the cursor alone, target alone, and cursor+target. These conditions involved leaving the screen uncovered or covering with a diffusing sheet to induce blur. The distance between the screen and sheet was increased to make the blur progressively more severe (0 cm, 3 cm). Results showed significantly less radial and variable error under blurred compared to no vision of the cursor and cursor+target. These findings were corroborated by the movement kinematics including a shorter proportion of time to peak velocity, more negative within-participant correlation between the distances travelled to and after peak velocity, and lower spatial variability from peak velocity to the end of the movement under blurred vision. The superior accuracy and precision under the blurred compared to no vision conditions is consistent with functioning visual regulation of aiming, which is primarily contingent upon the online visual feedback of the moving limb. This outcome may be attributed to the processing of low spatial-high temporal frequencies. Potential implications for low vision diagnostics are discussed.
Collapse
Affiliation(s)
- James W Roberts
- Liverpool Hope University, Psychology, Action and Learning of Movement (PALM) Laboratory, School of Health Sciences, Liverpool L16 9JD, UK.
| | - Simon J Bennett
- Liverpool John Moores University, Research Institute of Sport & Exercise Sciences, Brain & Behaviour Research Group, Liverpool L3 5AF, UK
| |
Collapse
|
29
|
Rapid Analysis of Visual Receptive Fields by Iterative Tomography. eNeuro 2021; 8:ENEURO.0046-21.2021. [PMID: 34799410 PMCID: PMC8658541 DOI: 10.1523/eneuro.0046-21.2021] [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: 02/03/2021] [Revised: 11/02/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022] Open
Abstract
Many receptive fields in the early visual system show standard (center-surround) structure and can be analyzed using simple drifting patterns and a difference-of-Gaussians (DoG) model, which treats the receptive field as a linear filter of the visual image. But many other receptive fields show nonlinear properties such as selectivity for direction of movement. Such receptive fields are typically studied using discrete stimuli (moving or flashed bars and edges) and are modelled according to the features of the visual image to which they are most sensitive. Here, we harness recent advances in tomographic image analysis to characterize rapidly and simultaneously both the linear and nonlinear components of visual receptive fields. Spiking and intracellular voltage potential responses to briefly flashed bars are analyzed using non-negative matrix factorization (NNMF) and iterative reconstruction tomography (IRT). The method yields high-resolution receptive field maps of individual neurons and neuron ensembles in primate (marmoset, both sexes) lateral geniculate and rodent (mouse, male) retina. We show that the first two IRT components correspond to DoG-equivalent center and surround of standard [magnocellular (M) and parvocellular (P)] receptive fields in primate geniculate. The first two IRT components also reveal the spatiotemporal receptive field structure of nonstandard (on/off-rectifying) receptive fields. In rodent retina we combine NNMF-IRT with patch-clamp recording and dye injection to directly map spatial receptive fields to the underlying anatomy of retinal output neurons. We conclude that NNMF-IRT provides a rapid and flexible framework for study of receptive fields in the early visual system.
Collapse
|
30
|
Shoshina II, Hovis JK, Felisberti FM, Santos NA, Adreeva A, Butler PD, Fernandes TP. Visual processing and BDNF levels in first-episode schizophrenia. Psychiatry Res 2021; 305:114200. [PMID: 34653830 DOI: 10.1016/j.psychres.2021.114200] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 12/13/2022]
Abstract
Previous studies have shown that patients diagnosed with schizophrenia (SCZ) have deficits in early visual processing, namely contrast processing. The brain-derived neurotropic factor (BDNF) is an important measure to investigate neuroplasticity in some visual functions like visual perception. In this study, we investigated the relationship between visual processing and BDNF levels in first-episode SCZ patients. Thirty-nine healthy controls and 43 first-episode SCZ patients were enrolled. Contrast sensitivity measurements were conducted using low, mid- and high spatial frequencies. First-episode SCZ patients had higher contrast sensitivity than healthy controls for all frequencies, except for the middle spatial frequency. Negative correlations were found between BDNF, contrast sensitivity and clinical variables, mostly for middle and high spatial frequencies among females. Our results provide support for (i) the association of SCZ with alterations of magno- and parvocellular pathway functioning and (ii) decreased BDNF levels in first-episode SCZ patients. This study highlights the importance of using biomarkers along with other measures to investigate visual processing in SCZ and other disorders.
Collapse
Affiliation(s)
- Irina I Shoshina
- Pavlov Institute of Physiology, Russian Academy of Science, Department of Visual Physiology, Saint-Petersburg, Russian Federation; St. Petersburg State University, Department of Liberal Arts and Sciences, Saint-Petersburg, Russian Federation
| | - Jeffery K Hovis
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Fatima M Felisberti
- Department of Psychology, Kingston University London, London, United Kingdom
| | - Natanael A Santos
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil
| | - Anna Adreeva
- St. Petersburg State University, Department of Liberal Arts and Sciences, Saint-Petersburg, Russian Federation
| | - Pamela D Butler
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States; Department of Psychiatry, New York University School of Medicine, NY, USA
| | - Thiago P Fernandes
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil.
| |
Collapse
|
31
|
Nunez V, Gordon J, Shapley RM. A multiplicity of color-responsive cortical mechanisms revealed by the dynamics of cVEPs. Vision Res 2021; 188:234-245. [PMID: 34388605 DOI: 10.1016/j.visres.2021.07.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 10/20/2022]
Abstract
Our results connect higher-order color mechanisms deduced from psychophysics with the known diversity of populations of double-opponent, color-responsive cells in V1. We used the chromatic visual evoked potential, the cVEP, to study responses in human visual cortex to equiluminant color patterns. Stimuli were modulated along three directions in color space: the cardinal directions, L-M and S, and along the line in color space from the white point to the color of the Red LED in the display screen (the Red direction). The Red direction is roughly intermediate between L-M and S in DKL space in cone-contrast coordinates. While cVEP response amplitude, latency, and width--and their dependences on cone contrast-- were similar in the L-M and Red directions, the Transientness of the Red response was significantly greater than for responses to stimuli in the L-M direction and in the S direction. This difference in response dynamics supports the concept that there are multiple, distinct neuronal populations, so-called higher- order color mechanisms, for color perception within human V1 cortex.
Collapse
Affiliation(s)
- Valerie Nunez
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
| | - James Gordon
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA; Psychology Department, CUNY Hunter College, 695 Park Ave, New York, NY 10065, USA
| | - Robert M Shapley
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA
| |
Collapse
|
32
|
Gu Y, Chen ZS, Wang C, Song XM, Lu S, Cai YC. Spatial suppression of chromatic motion. Vision Res 2021; 188:227-233. [PMID: 34385078 DOI: 10.1016/j.visres.2021.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 07/03/2021] [Accepted: 07/20/2021] [Indexed: 10/20/2022]
Abstract
Center-surround antagonism, as a ubiquitous feature in visual processing, usually leads to inferior perception for a large stimulus compared to a small one. For example, it is more difficult to judge the motion direction of a large high-contrast pattern than that of a small one. However, this spatial suppression in the motion dimension was only reported for luminance motion, and was not found for chromatic motion. Given that center-surround suppression only occurs for strong visual inputs, we hypothesized that previous failure in finding spatial suppression of chromatic motion might be due to weak chromatic motion being induced with stimuli of limited parameters. In this study, we used phase-shift discrimination and motion-direction discrimination tasks to measure motion spatial suppression induced by stimuli of two spatial frequencies (0.5 and 2 cpd) and two contrasts (low and high). We found that spatial suppression of the chromatic motion was stably observed for stimuli of high spatial frequency (2 cpd) and high contrast and spatial summation occurred for stimuli of low spatial frequency (0.5 cpd). Intriguingly, there was no correlations between the motion spatial suppressions of luminance motion and chromatic motion, implying that the two types of spatial suppression are not originated from the same neural processing. Our findings indicate that spatial suppression also exists for chromatic motion, and the mechanisms underlying the spatial suppression of chromatic motion is different from that of luminance motion.
Collapse
Affiliation(s)
- Ye Gu
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, Zhejiang 310028, China
| | - Zhang-Shan Chen
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, Zhejiang 310028, China
| | - Ci Wang
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, Zhejiang 310028, China
| | - Xue-Mei Song
- Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Shena Lu
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, Zhejiang 310028, China.
| | - Yong-Chun Cai
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou, Zhejiang 310028, China.
| |
Collapse
|
33
|
Horwitz GD. Temporal filtering of luminance and chromaticity in macaque visual cortex. iScience 2021; 24:102536. [PMID: 34189430 PMCID: PMC8219838 DOI: 10.1016/j.isci.2021.102536] [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: 10/19/2020] [Revised: 03/02/2021] [Accepted: 05/11/2021] [Indexed: 11/23/2022] Open
Abstract
Contrast sensitivity peaks near 10 Hz for luminance modulations and at lower frequencies for modulations between equiluminant lights. This difference is rooted in retinal filtering, but additional filtering occurs in the cerebral cortex. To measure the cortical contributions to luminance and chromatic temporal contrast sensitivity, signals in the lateral geniculate nucleus (LGN) were compared to the behavioral contrast sensitivity of macaque monkeys. Long wavelength-sensitive (L) and medium wavelength-sensitive (M) cones were modulated in phase to produce a luminance modulation (L + M) or in counterphase to produce a chromatic modulation (L - M). The sensitivity of LGN neurons was well matched to behavioral sensitivity at low temporal frequencies but was approximately 7 times greater at high temporal frequencies. Similar results were obtained for L + M and L - M modulations. These results show that differences in the shapes of the luminance and chromatic temporal contrast sensitivity functions are due almost entirely to pre-cortical mechanisms.
Collapse
Affiliation(s)
- Gregory D. Horwitz
- Department of Physiology and Biophysics, Washington National Primate Research Center, University of Washington, 1959 N.E. Pacific Street, HSB I-714, Box 357290, Seattle, WA 98195, USA
| |
Collapse
|
34
|
Asher JM, O’Hare L, Hibbard PB. No Evidence of Reduced Contrast Sensitivity in Migraine-with-Aura for Large, Narrowband, Centrally Presented Noise-Masked Stimuli. Vision (Basel) 2021; 5:32. [PMID: 34205592 PMCID: PMC8293456 DOI: 10.3390/vision5020032] [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: 03/31/2021] [Revised: 05/28/2021] [Accepted: 06/16/2021] [Indexed: 11/25/2022] Open
Abstract
Individuals with migraine aura show differences in visual perception compared to control groups. Measures of contrast sensitivity have suggested that people with migraine aura are less able to exclude external visual noise, and that this relates to higher variability in neural processing. The current study compared contrast sensitivity in migraine with aura and control groups for narrow-band grating stimuli at 2 and 8 cycles/degree, masked by Gaussian white noise. We predicted that contrast sensitivity would be lower in the migraine with aura group at high noise levels. Contrast sensitivity was higher for the low spatial frequency stimuli, and decreased with the strength of the masking noise. We did not, however, find any evidence of reduced contrast sensitivity associated with migraine with aura. We propose alternative methods as a more targeted assessment of the role of neural noise and excitability as contributing factors to migraine aura.
Collapse
Affiliation(s)
- Jordi M. Asher
- Department of Psychology, University of Essex, Colchester CO4 3SQ, UK;
| | - Louise O’Hare
- Division of Psychology, Nottingham Trent University, Nottingham NG1 4FQ, UK;
| | - Paul B. Hibbard
- Department of Psychology, University of Essex, Colchester CO4 3SQ, UK;
| |
Collapse
|
35
|
Schottdorf M, Lee BB. A quantitative description of macaque ganglion cell responses to natural scenes: the interplay of time and space. J Physiol 2021; 599:3169-3193. [PMID: 33913164 DOI: 10.1113/jp281200] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/20/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Responses to natural scenes are the business of the retina. We find primate ganglion cell responses to such scenes consistent with those to simpler stimuli. A biophysical model confirmed this and predicted ganglion cell responses with close to retinal reliability. Primate ganglion cell responses to natural scenes were driven by temporal variations in colour and luminance over the receptive field centre caused by eye movements, and little influenced by interaction of centre and surround with structure in the scene. We discuss implications in the context of efficient coding of the visual environment. Much information in a higher spatiotemporal frequency band is concentrated in the magnocellular pathway. ABSTRACT Responses of visual neurons to natural scenes provide a link between classical descriptions of receptive field structure and visual perception of the natural environment. A natural scene video with a movement pattern resembling that of primate eye movements was used to evoke responses from macaque ganglion cells. Cell responses were well described through known properties of cell receptive fields. Different analyses converge to show that responses primarily derive from the temporal pattern of stimulation derived from eye movements, rather than spatial receptive field structure beyond centre size and position. This was confirmed using a model that predicted ganglion cell responses close to retinal reliability, with only a small contribution of the surround relative to the centre. We also found that the spatiotemporal spectrum of the stimulus is modified in ganglion cell responses, and this can reduce redundancy in the retinal signal. This is more pronounced in the magnocellular pathway, which is much better suited to transmit the detailed structure of natural scenes than the parvocellular pathway. Whitening is less important for chromatic channels. Taken together, this shows how a complex interplay across space, time and spectral content sculpts ganglion cell responses.
Collapse
Affiliation(s)
- Manuel Schottdorf
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, D-37077, Germany.,Max Planck Institute of Experimental Medicine, Göttingen, D-37075, Germany.,Princeton Neuroscience Institute, Princeton, NJ, 08544, USA
| | - Barry B Lee
- Graduate Center for Vision Research, Department of Biological Sciences, SUNY College of Optometry, 33 West 42nd St., New York, NY, 10036, USA.,Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, D-37077, Germany
| |
Collapse
|
36
|
Early recurrence enables figure border ownership. Vision Res 2021; 186:23-33. [PMID: 34023589 DOI: 10.1016/j.visres.2021.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/19/2022]
Abstract
Rubin's face-vase illusion demonstrates how one can switch back and forth between two different interpretations depending on how the figure outlines are assigned. In the primate visual system, assigning ownership along figure borders is encoded by neurons called the border ownership (BO) cells. Studies show that the responses of these neurons not only depend on the local features within their receptive fields, but also on contextual information. Despite two decades of studies on BO neurons, the ownership assignment mechanism in the brain is still unknown. Here, we propose a hierarchical recurrent model grounded on the hypothesis that neurons in the dorsal stream provide the context required for ownership assignment. Our proposed model incorporates early recurrence from the dorsal pathway as well as lateral modulations within the ventral stream. While dorsal modulations initiate the response difference to figure on either side of the border, lateral modulations enhance the difference. We found responses of our dorsally-modulated BO cells, similar to their biological counterparts, are invariant to size, position and solid/outlined figures. Moreover, our model BO cells exhibit comparable levels of reliability in the ownership signal to biological BO neurons. We found dorsal modulations result in high levels of accuracy and robustness for BO assignments in complex scenes compared to previous models based on ventral feedback. Finally, our experiments with illusory contours suggest that BO encoding could explain the perception of such contours in higher processing stages in the brain.
Collapse
|
37
|
Neural correlates of metacontrast masking across different contrast polarities. Brain Struct Funct 2021; 226:3067-3081. [PMID: 33779794 DOI: 10.1007/s00429-021-02260-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 03/16/2021] [Indexed: 01/01/2023]
Abstract
Metacontrast masking is a powerful illusion to investigate the dynamics of perceptual processing and to control conscious visual perception. However, the neural mechanisms underlying this fundamental investigative tool are still debated. In the present study, we examined metacontrast masking across different contrast polarities by employing a contour discrimination task combined with EEG (Electroencephalography). When the target and mask had the same contrast polarity, a typical U-shaped metacontrast function was observed. A change in mask polarity (i.e., opposite mask polarity) shifted this masking function to a monotonic increasing function such that the target visibility was strongly suppressed at stimulus onset asynchronies less than 50 ms. This transition in metacontrast function has been typically interpreted as an increase in intrachannel inhibition of the sustained activities functionally linked to object visibility and identity. Our EEG analyses revealed an early (160-300 ms) and a late (300-550 ms) spatiotemporal cluster associated with this effect of polarity. The early cluster was mainly over occipital and parieto-occipital scalp sites. On the other hand, the later modulations of the evoked activities were centered over parietal and centro-parietal sites. Since both of these clusters were beyond 160 ms, the EEG results point to late recurrent inhibitory mechanisms. Although the findings here do not directly preclude other proposed mechanisms for metacontrast, they highlight the involvement of recurrent intrachannel inhibition in metacontrast masking.
Collapse
|
38
|
Kremers J, Aher AJ, Parry NRA, Patel NB, Frishman LJ. Comparison of macaque and human L- and M-cone driven electroretinograms. Exp Eye Res 2021; 206:108556. [PMID: 33794198 DOI: 10.1016/j.exer.2021.108556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/05/2021] [Accepted: 03/22/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE The macaque retina is often used as a model for the human retina. However, there are only a handful of direct in vivo comparisons of the retinal physiology in humans and macaques. In the current study, ERG responses to luminance, L-cone isolating and M-cone isolating stimuli with sinusoidal, sawtooth and square wave temporal profiles were measured. The results were compared with those obtained from human observers. METHODS The responses from five anesthetized adult macaques were measured. Full field stimuli were created. L- and M-cone isolating stimuli were based on the triple silent substitution technique. Sinusoidal stimuli had temporal frequencies between 4 and 56 Hz in 4 Hz steps. Sawtooth stimuli with rapid-on ramp-off and with rapid-off ramp-on excitation profiles had a frequency of 4 Hz. Square stimuli were presented at 2 Hz. RESULTS Macaque and human ERGs in response to L- and M-cone isolating stimuli reflect L/M opponency and luminance activity. In responses to sine waves, cone opponency dominates at low temporal frequencies (4-12 Hz); luminance dominates at high temporal frequencies. The responses to sawtooth and square wave stimuli reflect a mixture of chromatic and luminance activity. L:M response ratios vary between individuals both in macaques and humans. Macaques show more complex responses, including greater second harmonic contributions than those in humans. CONCLUSIONS Macaque and human ERGs share basic underlying mechanisms reflecting L/M opponency and luminance activity. There may be quantitative differences possibly reflecting differences in contributions of inner retinal mechanisms to the ERGs.
Collapse
Affiliation(s)
- Jan Kremers
- Section for Retinal Physiology, University Hospital Erlangen, 91054, Erlangen, Germany.
| | - Avinash J Aher
- Section for Retinal Physiology, University Hospital Erlangen, 91054, Erlangen, Germany
| | - Neil R A Parry
- Vision Science Centre, Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Nimesh B Patel
- Department of Vision Sciences, College of Optometry, University of Houston, Houston, TX, USA
| | - Laura J Frishman
- Department of Vision Sciences, College of Optometry, University of Houston, Houston, TX, USA
| |
Collapse
|
39
|
Using perceptual tasks to selectively measure magnocellular and parvocellular performance: Rationale and a user's guide. Psychon Bull Rev 2021; 28:1029-1050. [PMID: 33742424 PMCID: PMC8367893 DOI: 10.3758/s13423-020-01874-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/26/2020] [Indexed: 11/24/2022]
Abstract
The visual system uses parallel pathways to process information. However, an ongoing debate centers on the extent to which the pathways from the retina, via the Lateral Geniculate nucleus to the visual cortex, process distinct aspects of the visual scene and, if they do, can stimuli in the laboratory be used to selectively drive them. These questions are important for a number of reasons, including that some pathologies are thought to be associated with impaired functioning of one of these pathways and certain cognitive functions have been preferentially linked to specific pathways. Here we examine the two main pathways that have been the focus of this debate: the magnocellular and parvocellular pathways. Specifically, we review the results of electrophysiological and lesion studies that have investigated their properties and conclude that while there is substantial overlap in the type of information that they process, it is possible to identify aspects of visual information that are predominantly processed by either the magnocellular or parvocellular pathway. We then discuss the types of visual stimuli that can be used to preferentially drive these pathways.
Collapse
|
40
|
Abstract
The retinal output is the sole source of visual information for the brain. Studies in non-primate mammals estimate that this information is carried by several dozens of retinal ganglion cell types, each informing the brain about different aspects of a visual scene. Even though morphological studies of primate retina suggest a similar diversity of ganglion cell types, research has focused on the function of only a few cell types. In human retina, recordings from individual cells are anecdotal or focus on a small subset of identified types. Here, we present the first systematic ex-vivo recording of light responses from 342 ganglion cells in human retinas obtained from donors. We find a great variety in the human retinal output in terms of preferences for positive or negative contrast, spatio-temporal frequency encoding, contrast sensitivity, and speed tuning. Some human ganglion cells showed similar response behavior as known cell types in other primate retinas, while we also recorded light responses that have not been described previously. This first extensive description of the human retinal output should facilitate interpretation of primate data and comparison to other mammalian species, and it lays the basis for the use of ex-vivo human retina for in-vitro analysis of novel treatment approaches.
Collapse
|
41
|
Creupelandt C, Maurage P, Lenoble Q, Lambot C, Geus C, D'Hondt F. Magnocellular and Parvocellular Mediated Luminance Contrast Discrimination in Severe Alcohol Use Disorder. Alcohol Clin Exp Res 2021; 45:375-385. [PMID: 33349930 DOI: 10.1111/acer.14541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Severe alcohol use disorder (SAUD) is associated with widespread cognitive impairments, including low-level visual processing deficits that persist after prolonged abstinence. However, the extent and characteristics of these visual deficits remain largely undetermined, impeding the identification of their underlying mechanisms and influence on higher-order processing. In particular, little work has been conducted to assess the integrity of the magnocellular (MC) and parvocellular (PC) visual pathways, namely the 2 main visual streams that convey information from the retina up to striate, extrastriate, and dorsal/ventral cerebral regions. METHODS We investigated achromatic luminance contrast processing mediated by inferred MC and PC pathways in 33 patients with SAUD and 32 matched healthy controls using 2 psychophysical pedestal contrast discrimination tasks that promote responses of inferred MC or PC pathways. We relied on a staircase procedure to assess participants' ability to detect small changes in luminance within an array of 4 gray squares that were either continuously presented (steady pedestal, MC-biased) or briefly flashed (pulsed pedestal, PC-biased). RESULTS We replicated the expected pattern of MC and PC contrast responses in healthy controls. We found preserved dissociation of MC and PC contrast signatures in SAUD but higher MC-mediated mean contrast discrimination thresholds combined with a steeper PC-mediated contrast discrimination slope compared with healthy controls. CONCLUSION These findings indicate altered MC-mediated contrast sensitivity and PC-mediated contrast gain, confirming the presence of early sensory disturbances in individuals with SAUD. Such low-level deficits, while usually overlooked, might influence higher-order abilities (e.g., memory, executive functions) in SAUD by disturbing the "coarse-to-fine" tuning of the visual system, which relies on the distinct functional properties of MC and PC pathways and ensures proper and efficient monitoring of the environment.
Collapse
Affiliation(s)
- Coralie Creupelandt
- Louvain Experimental Psychopathology Research Group (UCLEP), Psychological Sciences Research Institute (IPSY), UCLouvain, Louvain-la-Neuve, Belgium
| | - Pierre Maurage
- Louvain Experimental Psychopathology Research Group (UCLEP), Psychological Sciences Research Institute (IPSY), UCLouvain, Louvain-la-Neuve, Belgium
| | - Quentin Lenoble
- Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille, France
| | - Carine Lambot
- Clinique Regina Pacis, Le Beau Vallon, Saint-Servais, Belgium
| | - Christophe Geus
- Psychiatry Unit, Clinique Saint Pierre Ottignies, Ottignies, Belgium
| | - Fabien D'Hondt
- Univ. Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille, France.,CHU Lille, Clinique de Psychiatrie, CURE, Lille, France.,Centre National de Ressources et de Résilience Lille-Paris (CN2R), Lille, France
| |
Collapse
|
42
|
Schielen oder nicht Schielen? – Strabismus divergens intermittens, eine besondere Schielform. SPEKTRUM DER AUGENHEILKUNDE 2021. [DOI: 10.1007/s00717-020-00478-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Zusammenfassung
Hintergrund
Schielen tritt bei ca. 5–7 % der gesunden Kinder auf. Außenschielen ist mit 1,24 % weltweit seltener als Innenschielen. Der Strabismus divergens intermittens stellt mit 40–90 % die häufigste divergente Schielform dar. Das klinische Bild wurde von vielen AutorInnen beschrieben. Dennoch stellt es durch die Variabilität der Befunde eine therapeutische Herausforderung dar.
Material und Methode
Es wurden im Rahmen einer Literaturrecherche die Ergebnisse von Studien zum Strabismus divergens intermittens mit Fokus auf klinisches Bild, Untersuchungskriterien und Therapieansätze gesammelt und die Ergebnisse dargestellt.
Resultate
Der Strabismus divergens intermittens zeichnet sich durch eine besondere Binokularsituation und bisher ursächlich nicht vollends geklärte Symptome (Photophobie, Kneifen) aus. Konservative Therapien dienen der Entlastung des visuellen Systems, in vielen Fällen ist aber eine Schieloperation nötig. In der präoperativen Beurteilung ist der Stabilität des Schielwinkels besonderes Augenmerk zu schenken, als Entscheidungshilfe hinsichtlich Schieloperation hat sich der New Castle Control Score bewährt.
Schlussfolgerung
Die klinischen Charakteristika des Strabismus divergens intermittens sind klar beschrieben. Hinsichtlich therapeutischer Ansätze zeigen sich im internationalen Vergleich Unterschiede. Die Bedeutung der Einbeziehung der Eltern („shared decision making“) bei der Beurteilung der Schielhäufigkeit und bei der Operationsentscheidung ist zu betonen.
Collapse
|
43
|
Abstract
The response to contrast is one of the most important functions of the macaque primary visual cortex, V1, but up to now there has not been an adequate theory for it. To fill this gap in our understanding of cortical function, we built and analyzed a new large-scale, biologically constrained model of the input layer, 4Cα, of macaque V1. We called the new model CSY2. We challenged CSY2 with a three-parameter family of visual stimuli that varied in contrast, orientation, and spatial frequency. CSY2 accurately simulated experimental data and made many new predictions. It accounted for 1) the shapes of firing-rate-versus-contrast functions, 2) orientation and spatial frequency tuning versus contrast, and 3) the approximate contrast-invariance of cortical activity maps. Post-analysis revealed that the mechanisms that were needed to produce the successful simulations of contrast response included strong recurrent excitation and inhibition that find dynamic equilibria across the cortical surface, dynamic feedback between L6 and L4, and synaptic dynamics like inhibitory synaptic depression.
Collapse
|
44
|
Tootell RBH, Nasr S. Scotopic Vision Is Selectively Processed in Thick-Type Columns in Human Extrastriate Cortex. Cereb Cortex 2021; 31:1163-1181. [PMID: 33073288 PMCID: PMC7786355 DOI: 10.1093/cercor/bhaa284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/25/2020] [Accepted: 08/17/2020] [Indexed: 11/26/2022] Open
Abstract
In humans, visual stimuli can be perceived across an enormous range of light levels. Evidence suggests that different neural mechanisms process different subdivisions of this range. For instance, in the retina, stimuli presented at very low (scotopic) light levels activate rod photoreceptors, whereas cone photoreceptors are activated relatively more at higher (photopic) light levels. Similarly, different retinal ganglion cells are activated by scotopic versus photopic stimuli. However, in the brain, it remains unknown whether scotopic versus photopic information is: 1) processed in distinct channels, or 2) neurally merged. Using high-resolution functional magnetic resonance imaging at 7 T, we confirmed the first hypothesis. We first localized thick versus thin-type columns within areas V2, V3, and V4, based on photopic selectivity to motion versus color, respectively. Next, we found that scotopic stimuli selectively activated thick- (compared to thin-) type columns in V2 and V3 (in measurements of both overlap and amplitude) and V4 (based on overlap). Finally, we found stronger resting-state functional connections between scotopically dominated area MT with thick- (compared to thin-) type columns in areas V2, V3, and V4. We conclude that scotopic stimuli are processed in partially segregated parallel streams, emphasizing magnocellular influence, from retina through middle stages of visual cortex.
Collapse
Affiliation(s)
- Roger B H Tootell
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Radiology, Harvard Medical School, Boston, MA 02115, USA
| | - Shahin Nasr
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Radiology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
45
|
Kim US, Mahroo OA, Mollon JD, Yu-Wai-Man P. Retinal Ganglion Cells-Diversity of Cell Types and Clinical Relevance. Front Neurol 2021; 12:661938. [PMID: 34093409 PMCID: PMC8175861 DOI: 10.3389/fneur.2021.661938] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/06/2021] [Indexed: 11/24/2022] Open
Abstract
Retinal ganglion cells (RGCs) are the bridging neurons that connect the retinal input to the visual processing centres within the central nervous system. There is a remarkable diversity of RGCs and the various subtypes have unique morphological features, distinct functions, and characteristic pathways linking the inner retina to the relevant brain areas. A number of psychophysical and electrophysiological tests have been refined to investigate this large and varied population of RGCs. Technological advances, such as high-resolution optical coherence tomography imaging, have provided additional tools to define the pattern of RGC involvement and the chronological sequence of events in both inherited and acquired optic neuropathies. The mechanistic insights gained from these studies, in particular the selective vulnerability and relative resilience of particular RGC subtypes, are of fundamental importance as they are directly relevant to the development of targeted therapies for these invariably progressive blinding diseases. This review provides a comprehensive description of the various types of RGCs, the developments in proposed methods of classification, and the current gaps in our knowledge of how these RGCs are differentially affected depending on the underlying aetiology. The synthesis of the current body of knowledge on the diversity of RGCs and the pathways that are potentially amenable to therapeutic modulation will hopefully lead to much needed effective treatments for patients with optic neuropathies.
Collapse
Affiliation(s)
- Ungsoo Samuel Kim
- Kim's Eye Hospital, Seoul, South Korea
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- *Correspondence: Ungsoo Samuel Kim
| | - Omar A. Mahroo
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
- Section of Ophthalmology, King's College London, St. Thomas' Hospital Campus, London, United Kingdom
| | - John D. Mollon
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
| |
Collapse
|
46
|
Solomon SG. Retinal ganglion cells and the magnocellular, parvocellular, and koniocellular subcortical visual pathways from the eye to the brain. HANDBOOK OF CLINICAL NEUROLOGY 2021; 178:31-50. [PMID: 33832683 DOI: 10.1016/b978-0-12-821377-3.00018-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
In primates including humans, most retinal ganglion cells send signals to the lateral geniculate nucleus (LGN) of the thalamus. The anatomical and functional properties of the two major pathways through the LGN, the parvocellular (P) and magnocellular (M) pathways, are now well understood. Neurones in these pathways appear to convey a filtered version of the retinal image to primary visual cortex for further analysis. The properties of the P-pathway suggest it is important for high spatial acuity and red-green color vision, while those of the M-pathway suggest it is important for achromatic visual sensitivity and motion vision. Recent work has sharpened our understanding of how these properties are built in the retina, and described subtle but important nonlinearities that shape the signals that cortex receives. In addition to the P- and M-pathways, other retinal ganglion cells also project to the LGN. These ganglion cells are larger than those in the P- and M-pathways, have different retinal connectivity, and project to distinct regions of the LGN, together forming heterogenous koniocellular (K) pathways. Recent work has started to reveal the properties of these K-pathways, in the retina and in the LGN. The functional properties of K-pathways are more complex than those in the P- and M-pathways, and the K-pathways are likely to have a distinct contribution to vision. They provide a complementary pathway to the primary visual cortex, but can also send signals directly to extrastriate visual cortex. At the level of the LGN, many neurones in the K-pathways seem to integrate retinal with non-retinal inputs, and some may provide an early site of binocular convergence.
Collapse
Affiliation(s)
- Samuel G Solomon
- Department of Experimental Psychology, University College London, London, United Kingdom.
| |
Collapse
|
47
|
Zemon V, Herrera S, Gordon J, Revheim N, Silipo G, Butler PD. Contrast sensitivity deficits in schizophrenia: A psychophysical investigation. Eur J Neurosci 2020; 53:1155-1170. [DOI: 10.1111/ejn.15026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 01/07/2023]
Affiliation(s)
- Vance Zemon
- Ferkauf Graduate School of Psychology Yeshiva University Bronx NY USA
| | - Shaynna Herrera
- Ferkauf Graduate School of Psychology Yeshiva University Bronx NY USA
| | - James Gordon
- Hunter College of the City University of New York New York NY USA
| | - Nadine Revheim
- Nathan S. Kline Institute for Psychiatric Research Orangeburg NY USA
| | - Gail Silipo
- Nathan S. Kline Institute for Psychiatric Research Orangeburg NY USA
| | - Pamela D. Butler
- Nathan S. Kline Institute for Psychiatric Research Orangeburg NY USA
- Department of Psychiatry New York University School of Medicine New York NY USA
| |
Collapse
|
48
|
Masri RA, Grünert U, Martin PR. Analysis of Parvocellular and Magnocellular Visual Pathways in Human Retina. J Neurosci 2020; 40:8132-8148. [PMID: 33009001 PMCID: PMC7574660 DOI: 10.1523/jneurosci.1671-20.2020] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 09/22/2020] [Indexed: 12/18/2022] Open
Abstract
Two main subcortical pathways serving conscious visual perception are the midget-parvocellular (P), and the parasol-magnocellular (M) pathways. It is generally accepted that the P pathway serves red-green color vision, but the relative contribution of P and M pathways to spatial vision is a long-standing and unresolved issue. Here, we mapped the spatial sampling properties of P and M pathways across the human retina. Data were obtained from immunolabeled vertical sections of six postmortem male and female human donor retinas and imaged using high-resolution microscopy. Cone photoreceptors, OFF-midget bipolar cells (P pathway), OFF-diffuse bipolar (DB) types DB3a and DB3b (M pathway), and ganglion cells were counted along the temporal horizontal meridian, taking foveal spatial distortions (postreceptoral displacements) into account. We found that the density of OFF-midget bipolar and OFF-midget ganglion cells can support one-to-one connections to 1.05-mm (3.6°) eccentricity. One-to-one connections of cones to OFF-midget bipolar cells are present to at least 10-mm (35°) eccentricity. The OFF-midget ganglion cell array acuity is well-matched to photopic spatial acuity measures throughout the central 35°, but the OFF-parasol array acuity is well below photopic spatial acuity, supporting the view that the P pathway underlies high-acuity spatial vision. Outside the fovea, array acuity of both OFF-midget and OFF-DB cells exceeds psychophysical measures of photopic spatial acuity. We conclude that parasol and midget pathway bipolar cells deliver high-acuity spatial signals to the inner plexiform layer, but outside the fovea, this spatial resolution is lost at the level of ganglion cells.SIGNIFICANCE STATEMENT We make accurate maps of the spatial density and distribution of neurons in the human retina to aid in understanding human spatial vision, interpretation of diagnostic tests, and the implementation of therapies for retinal diseases. Here, we map neurons involved with the midget-parvocellular (P pathway) and parasol-magnocellular (M pathway) through human retina. We find that P-type bipolar cells outnumber M-type bipolar cells at all eccentricities. We show that cone photoreceptors and P-type pathway bipolar cells are tightly connected throughout the retina, but that spatial resolution is lost at the level of the ganglion cells. Overall, the results support the view that the P pathway is specialized to serve both high acuity vision and red-green color vision.
Collapse
Affiliation(s)
- Rania A Masri
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
| | - Ulrike Grünert
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
| | - Paul R Martin
- Faculty of Medicine and Health, Save Sight Institute and Discipline of Clinical Ophthalmology, The University of Sydney, Sydney, New South Wales 2000, Australia
- Australian Research Council Center of Excellence for Integrative Brain Function, The University of Sydney, Sydney, New South Wales 2000, Australia
| |
Collapse
|
49
|
Abstract
We as a couple spent 50 years working in visual psychophysics of color vision, temporal vision, and luminance adaptation. We sought collaborations with ophthalmologists, anatomists, physiologists, physicists, and psychologists, aiming to relate visual psychophysics to the underlying physiology of the primate retina. This review describes our journey and reflections in exploring the visual system.
Collapse
Affiliation(s)
- Joel Pokorny
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, Illinois 60637, USA;,
| | - Vivianne C. Smith
- Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, Illinois 60637, USA;,
| |
Collapse
|
50
|
Jokeit H, Blochwitz D. Neuro-aesthetics and the iconography in photography. Psych J 2020; 9:444-457. [PMID: 32851818 DOI: 10.1002/pchj.379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/03/2020] [Indexed: 11/09/2022]
Abstract
Can neurosciences explain art? No, but it can help us to understand why some images are more memorable and, thus, more successful than others. This article aims to identify certain factors that may influence the artistic success of photographic images. These factors are discussed within the contexts of basic neuropsychological concepts, visual perception, and visual memory. A new computational and neuroscientifically based model, the predictive coding theory, provides a powerful framework for integrating social and individual factors that influence aesthetic experience and activity. A case study of Dorothea Lange's iconic photograph Migrant Mother demonstrates the importance of identifiable factors that influence and determine a photograph's potential success. We are convinced that a future systemic approach will enable the complementary integration of neuroscientific, perceptual, cognitive, emotional, and sociopsychological insights through the framework of predictive coding theory with socioscientific, art-theoretical, and art-historical as well as neuro- and behavioral-economical models.
Collapse
Affiliation(s)
- Hennric Jokeit
- Department of Neuropsychology, University of Zurich and Swiss Epilepsy Centre, Zürich, Switzerland
| | | |
Collapse
|