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1.
Science ; 373(6553)2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34437090

RESUMO

The ability to perceive and respond to environmental stimuli emerges in the absence of sensory experience. Spontaneous retinal activity prior to eye opening guides the refinement of retinotopy and eye-specific segregation in mammals, but its role in the development of higher-order visual response properties remains unclear. Here, we describe a transient window in neonatal mouse development during which the spatial propagation of spontaneous retinal waves resembles the optic flow pattern generated by forward self-motion. We show that wave directionality requires the same circuit components that form the adult direction-selective retinal circuit and that chronic disruption of wave directionality alters the development of direction-selective responses of superior colliculus neurons. These data demonstrate how the developing visual system patterns spontaneous activity to simulate ethologically relevant features of the external world and thereby instruct self-organization.


Assuntos
Fluxo Óptico , Retina/fisiologia , Células Ganglionares da Retina/fisiologia , Visão Ocular/fisiologia , Vias Visuais , Potenciais de Ação , Células Amácrinas/fisiologia , Animais , Animais Recém-Nascidos , Axônios/fisiologia , Proteínas do Citoesqueleto/genética , Camundongos , Movimento (Física) , Mutação , Piridazinas/farmacologia , Receptores de GABA-A/metabolismo , Retina/crescimento & desenvolvimento , Análise Espaço-Temporal , Colículos Superiores/fisiologia
2.
FASEB J ; 35(9): e21802, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34383984

RESUMO

Mutations in transcription factors often exhibit pleiotropic effects related to their complex expression patterns and multiple regulatory targets. One such mutation in the zinc finger homeobox 3 (ZFHX3) transcription factor, short circuit (Sci, Zfhx3Sci/+ ), is associated with significant circadian deficits in mice. However, given evidence of its retinal expression, we set out to establish the effects of the mutation on retinal function using molecular, cellular, behavioral and electrophysiological measures. Immunohistochemistry confirms the expression of ZFHX3 in multiple retinal cell types, including GABAergic amacrine cells and retinal ganglion cells including intrinsically photosensitive retinal ganglion cells (ipRGCs). Zfhx3Sci/+ mutants display reduced light responsiveness in locomotor activity and circadian entrainment, relatively normal electroretinogram and optomotor responses but exhibit an unexpected pupillary reflex phenotype with markedly increased sensitivity. Furthermore, multiple electrode array recordings of Zfhx3Sci/+ retina show an increased sensitivity of ipRGC light responses.


Assuntos
Ritmo Circadiano/fisiologia , Proteínas de Homeodomínio/metabolismo , Retina/metabolismo , Células Amácrinas/metabolismo , Animais , Luz , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estimulação Luminosa/métodos , Células Ganglionares da Retina/metabolismo , Visão Ocular/fisiologia
3.
Nat Commun ; 12(1): 4005, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183661

RESUMO

Synaptic inputs on cortical dendrites are organized with remarkable subcellular precision at the micron level. This organization emerges during early postnatal development through patterned spontaneous activity and manifests both locally where nearby synapses are significantly correlated, and globally with distance to the soma. We propose a biophysically motivated synaptic plasticity model to dissect the mechanistic origins of this organization during development and elucidate synaptic clustering of different stimulus features in the adult. Our model captures local clustering of orientation in ferret and receptive field overlap in mouse visual cortex based on the receptive field diameter and the cortical magnification of visual space. Including action potential back-propagation explains branch clustering heterogeneity in the ferret and produces a global retinotopy gradient from soma to dendrite in the mouse. Therefore, by combining activity-dependent synaptic competition and species-specific receptive fields, our framework explains different aspects of synaptic organization regarding stimulus features and spatial scales.


Assuntos
Visão Ocular/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Potenciais de Ação/fisiologia , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Dendritos/fisiologia , Furões , Camundongos , Modelos Neurológicos , Fatores de Crescimento Neural/metabolismo , Plasticidade Neuronal/fisiologia , Sinapses/fisiologia , Córtex Visual/anatomia & histologia
4.
Nat Commun ; 12(1): 4004, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183678

RESUMO

The superior colliculus (SC) receives diverse and robust cortical inputs to drive a range of cognitive and sensorimotor behaviors. However, it remains unclear how descending cortical input arising from higher-order associative areas coordinate with SC sensorimotor networks to influence its outputs. Here, we construct a comprehensive map of all cortico-tectal projections and identify four collicular zones with differential cortical inputs: medial (SC.m), centromedial (SC.cm), centrolateral (SC.cl) and lateral (SC.l). Further, we delineate the distinctive brain-wide input/output organization of each collicular zone, assemble multiple parallel cortico-tecto-thalamic subnetworks, and identify the somatotopic map in the SC that displays distinguishable spatial properties from the somatotopic maps in the neocortex and basal ganglia. Finally, we characterize interactions between those cortico-tecto-thalamic and cortico-basal ganglia-thalamic subnetworks. This study provides a structural basis for understanding how SC is involved in integrating different sensory modalities, translating sensory information to motor command, and coordinating different actions in goal-directed behaviors.


Assuntos
Colículos Superiores/anatomia & histologia , Colículos Superiores/fisiologia , Visão Ocular/fisiologia , Percepção Visual/fisiologia , Animais , Gânglios da Base/fisiologia , Cognição/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Visuais
5.
PLoS Biol ; 19(5): e3001241, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33951043

RESUMO

The study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant's report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness and may influence conclusions about the extent of unconscious processing and about the neural correlates of consciousness. We obtained functional magnetic resonance imaging (fMRI) measurements from 43 subjects while they viewed masked faces and houses that were either subjectively or objectively invisible. Even for objectively invisible (perceptually indiscriminable) stimuli, we found significant category information in both early, lower-level visual areas and in higher-level visual cortex, although representations in anterior, category-selective ventrotemporal areas were less robust. For subjectively invisible stimuli, similar to visible stimuli, there was a clear posterior-to-anterior gradient in visual cortex, with stronger category information in ventrotemporal cortex than in early visual cortex. For objectively invisible stimuli, however, category information remained virtually unchanged from early visual cortex to object- and category-selective visual areas. These results demonstrate that although both objectively and subjectively invisible stimuli are represented in visual cortex, the extent of unconscious information processing is influenced by the measurement approach. Furthermore, our data show that subjective and objective approaches are associated with different neural correlates of consciousness and thus have implications for neural theories of consciousness.


Assuntos
Conscientização/fisiologia , Visão Ocular/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Estado de Consciência/fisiologia , Feminino , Substância Cinzenta/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Estimulação Luminosa/métodos , Córtex Visual/fisiologia , Adulto Jovem
6.
Nat Med ; 27(5): 785-789, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33795869

RESUMO

Leber congenital amaurosis due to CEP290 ciliopathy is being explored by treatment with the antisense oligonucleotide (AON) sepofarsen. One patient who was part of a larger cohort (ClinicalTrials.gov NCT03140969 ) was studied for 15 months after a single intravitreal sepofarsen injection. Concordant measures of visual function and retinal structure reached a substantial efficacy peak near 3 months after injection. At 15 months, there was sustained efficacy, even though there was evidence of reduction from peak response. Efficacy kinetics can be explained by the balance of AON-driven new CEP290 protein synthesis and a slow natural rate of CEP290 protein degradation in human foveal cone photoreceptors.


Assuntos
Antígenos de Neoplasias/genética , Proteínas de Ciclo Celular/genética , Ciliopatias/terapia , Proteínas do Citoesqueleto/genética , Terapia Genética/métodos , Amaurose Congênita de Leber/terapia , Oligonucleotídeos Antissenso/uso terapêutico , Antígenos de Neoplasias/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ciliopatias/genética , Proteínas do Citoesqueleto/metabolismo , Humanos , Amaurose Congênita de Leber/genética , Amaurose Congênita de Leber/fisiopatologia , Células Fotorreceptoras/metabolismo , Visão Ocular/fisiologia , Campos Visuais/fisiologia
7.
Am J Ophthalmol ; 227: 240-244, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33823159

RESUMO

PURPOSE: Multifocal intraocular lenses (MIOLs) are effective in treating presbyopia before cataracts develop. This study measured health-related quality of life (HRQoL) and vision-related quality of life (VRQoL) after clear lens extraction (CLE) and MIOL implantation. DESIGN: Before-and-after study METHODS: Patients were treated in Medilaser Coronaria, CorGroup, Oulu, Finland. HRQoL was measured by a generic 15-dimension (15D) instrument. VRQoL was measured with Visual Function Index-14 (VF-14) questionnaire. RESULTS: CLE and MIOL implantation was performed in 137 patients. The patient age was 57 ± 6.2 years (mean ± standard deviation), and 58% were women. The near add was 2.1±0.3 diopters (D). The overall HRQoL 15D score increased from 0.938±0.058 to 0.955±0.057 at 6 months (P < .0001 vs baseline) and to 0.948±0.060 at 1 year (P = .02 vs baseline). The VRQoL VF14 score increased from 85.32±15.57 to 96.57±5.07 at 6 months (P < .0001 vs baseline) and to 96.61±6.48 at 1 year (P < .0001 vs baseline). The increase of HRQoL was correlated with the increase of VRQoL (P < .04). CONCLUSIONS: CLE and MIOL implantation improved HRQoL and VRQoL compared to spectacles in this 1-year follow-up study. Improvement of HRQoL was correlated with VRQoL.


Assuntos
Implante de Lente Intraocular , Cristalino/cirurgia , Lentes Intraoculares Multifocais , Facoemulsificação , Presbiopia/cirurgia , Qualidade de Vida/psicologia , Visão Ocular/fisiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Presbiopia/fisiopatologia , Presbiopia/psicologia , Estudos Prospectivos , Pseudofacia/fisiopatologia , Inquéritos e Questionários , Resultado do Tratamento , Acuidade Visual/fisiologia
8.
Nat Commun ; 12(1): 2065, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33824315

RESUMO

Convolutional neural networks (CNNs) are increasingly used to model human vision due to their high object categorization capabilities and general correspondence with human brain responses. Here we evaluate the performance of 14 different CNNs compared with human fMRI responses to natural and artificial images using representational similarity analysis. Despite the presence of some CNN-brain correspondence and CNNs' impressive ability to fully capture lower level visual representation of real-world objects, we show that CNNs do not fully capture higher level visual representations of real-world objects, nor those of artificial objects, either at lower or higher levels of visual representations. The latter is particularly critical, as the processing of both real-world and artificial visual stimuli engages the same neural circuits. We report similar results regardless of differences in CNN architecture, training, or the presence of recurrent processing. This indicates some fundamental differences exist in how the brain and CNNs represent visual information.


Assuntos
Encéfalo/fisiologia , Redes Neurais de Computação , Visão Ocular/fisiologia , Adolescente , Adulto , Humanos , Processamento de Imagem Assistida por Computador , Estimulação Luminosa , Adulto Jovem
9.
Optom Vis Sci ; 98(3): 266-271, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33771956

RESUMO

SIGNIFICANCE: Clinicians commonly either recommend patients begin contact lens (CL) wear full time or suggest that patients should gradually increase their wear times during the first few days of wear. This study found no differences between these two wear schedules, suggesting that patient preference may be the best schedule. PURPOSE: The purpose of this study was to determine if there are any clinical differences in neophyte, 2-week, reusable soft CL wearers who were randomized to either a full-time or a gradually increasing wear time schedule. METHODS: This was an investigator-masked, three-visit, randomized, clinical trial. Participants were randomized to wear their CLs full time starting on the first day or gradually starting with 2 hours of wear on the first day and increasing wear by 2 hours each day until 8 hours or more of wear per day was achieved. Symptoms (Ocular Surface Disease Index and visual analog scale) and ocular surface signs (tear breakup time, extent of corneal staining, and Schirmer test I) were evaluated at each visit. RESULTS: A total of 25 participants were randomized, with 21 participants completing at least 1 week of follow-up. Completed participants had a mean ± standard deviation age of 23.5 ± 3.0 years, and 48% were female. No significant between-group differences were found when comparing the full-time and gradual wear time schedule groups at 2 weeks (all, P > .32): Ocular Surface Disease Index (10.8 ± 8.5 vs. 16.3 ± 18.8), visual analog scale (89.0 ± 9.7 vs. 81.8 ± 18.7), tear breakup time (11.7 ± 7.0 vs. 9.8 ± 2.7), extent of corneal staining (0.0 ± 0.1 vs. 0.3 ± 0.5), or Schirmer test I (15.9 ± 8.8 vs. 21.2 ± 12.5). CONCLUSIONS: No between-group differences were found for any metric evaluated, which suggests that the best wear schedule may be the one that best suits the neophyte CL wearer's lifestyle.


Assuntos
Adaptação Ocular/fisiologia , Lentes de Contato Hidrofílicas , Ajuste de Prótese , Adulto , Feminino , Humanos , Masculino , Inquéritos e Questionários , Visão Ocular/fisiologia , Adulto Jovem
10.
Elife ; 102021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33722342

RESUMO

Spontaneous activity drives the establishment of appropriate connectivity in different circuits during brain development. In the mouse primary visual cortex, two distinct patterns of spontaneous activity occur before vision onset: local low-synchronicity events originating in the retina and global high-synchronicity events originating in the cortex. We sought to determine the contribution of these activity patterns to jointly organize network connectivity through different activity-dependent plasticity rules. We postulated that local events shape cortical input selectivity and topography, while global events homeostatically regulate connection strength. However, to generate robust selectivity, we found that global events should adapt their amplitude to the history of preceding cortical activation. We confirmed this prediction by analyzing in vivo spontaneous cortical activity. The predicted adaptation leads to the sparsification of spontaneous activity on a slower timescale during development, demonstrating the remarkable capacity of the developing sensory cortex to acquire sensitivity to visual inputs after eye-opening.


Assuntos
Adaptação Fisiológica , Córtex Visual/fisiologia , Animais , Mapeamento Encefálico/métodos , Camundongos , Modelos Neurológicos , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Retina/fisiologia , Sinapses/fisiologia , Visão Ocular/fisiologia , Córtex Visual/crescimento & desenvolvimento
11.
PLoS One ; 16(3): e0247254, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33724991

RESUMO

Having an optimal quality of vision as well as adequate cognitive capacities is known to be essential for driving safety. However, the interaction between vision and cognitive mechanisms while driving remains unclear. We hypothesized that, in a context of high cognitive load, reduced visual acuity would have a negative impact on driving behavior, even when the acuity corresponds to the legal threshold for obtaining a driving license in Canada, and that the impact observed on driving performance would be greater with the increase in the threshold of degradation of visual acuity. In order to investigate this relationship, we examined driving behavior in a driving simulator under optimal and reduced vision conditions through two scenarios involving different levels of cognitive demand. These were: 1. a simple rural driving scenario with some pre-programmed events and 2. a highway driving scenario accompanied by a concurrent task involving the use of a navigation device. Two groups of visual quality degradation (lower/ higher) were evaluated according to their driving behavior. The results support the hypothesis: A dual task effect was indeed observed provoking less stable driving behavior, but in addition to this, by statistically controlling the impact of cognitive load, the effect of visual load emerged in this dual task context. These results support the idea that visual quality degradation impacts driving behavior when combined with a high mental workload driving environment while specifying that this impact is not present in the context of low cognitive load driving condition.


Assuntos
Condução de Veículo/psicologia , Direção Distraída/psicologia , Tempo de Reação/fisiologia , Adulto , Atenção/fisiologia , Canadá , Cognição/fisiologia , Simulação por Computador , Feminino , Humanos , Masculino , Desempenho Psicomotor , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Percepção Visual/fisiologia
12.
Nat Commun ; 12(1): 1544, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750806

RESUMO

Electroretinogram examinations serve as routine clinical procedures in ophthalmology for the diagnosis and management of many ocular diseases. However, the rigid form factor of current corneal sensors produces a mismatch with the soft, curvilinear, and exceptionally sensitive human cornea, which typically requires the use of topical anesthesia and a speculum for pain management and safety. Here we report a design of an all-printed stretchable corneal sensor built on commercially-available disposable soft contact lenses that can intimately and non-invasively interface with the corneal surface of human eyes. The corneal sensor is integrated with soft contact lenses via an electrochemical anchoring mechanism in a seamless manner that ensures its mechanical and chemical reliability. Thus, the resulting device enables the high-fidelity recording of full-field electroretinogram signals in human eyes without the need of topical anesthesia or a speculum. The device, superior to clinical standards in terms of signal quality and comfortability, is expected to address unmet clinical needs in the field of ocular electrodiagnosis.


Assuntos
Lentes de Contato Hidrofílicas , Córnea/fisiologia , Eletrodiagnóstico/métodos , Sensação/fisiologia , Visão Ocular/fisiologia , Doenças da Córnea/diagnóstico , Eletrodiagnóstico/instrumentação , Eletrorretinografia/instrumentação , Eletrorretinografia/métodos , Humanos , Reprodutibilidade dos Testes , Dispositivos Eletrônicos Vestíveis
13.
J Vis ; 21(3): 3, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33651879

RESUMO

Hitting a baseball, one of the most difficult skills in all of sports, requires complex hand-eye coordination, but its link with basic visuomotor capabilities remains largely unknown. Here we examined basic visuomotor skills of baseball players and demographically matched nonathletes by measuring their ocular-tracking and manual-control performance. We further investigated how these two capabilities relate to batting performance in baseball players. Compared to nonathletes, baseball players showed better ocular-tracking and manual-control capabilities, which remain unchanged with increasing baseball experience. Both, however, become more correlated with batting accuracy with increasing experience. Ocular-tracking performance is predictive of batting skill, accounting for ≥ 70% of the variance in batting performance across players with ≥ 10 years of experience. A simple linear additive-noise cascade model with shared front-end visual noise that limits batting performance can explain many of our results. Our findings show that fundamental visuomotor capabilities can predict the complex, learned skill of baseball batting.


Assuntos
Desempenho Atlético/fisiologia , Beisebol/fisiologia , Visão Ocular/fisiologia , Adolescente , Adulto , Estudos de Casos e Controles , Tecnologia de Rastreamento Ocular , Feminino , Humanos , Modelos Lineares , Masculino , Desempenho Psicomotor/fisiologia , Adulto Jovem
14.
PLoS One ; 16(2): e0246606, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33544763

RESUMO

OBJECTIVE: The objective of this study was to assess and compare drivers' and non-drivers' outcomes in the Adult Developmental Eye Movement test (ADEM), a visual-verbal test that measures the time needed to read series of numbers in both a vertical and horizontal reading pattern. A set of driving parameters (i.e., experience, risk exposure, and day and night perceived difficulty) and demographic variables (i.e., age, gender, and academic level) were considered as potential predictors of the test performance. METHODS: For this cross-sectional study, 302 healthy subjects (age range 20 to 86 years old) completed a self-reported questionnaire aimed at retrieving data on the independent variables, and underwent the ADEM in order to obtain the dependent outcomes. 214 (70.9%) of the participants were drivers. Non-parametric analyses and multilevel linear regression were used to assess differences between the variables and a prediction model. Also, some correlations were evaluated through the Spearman test. RESULTS: Drivers showed significantly better test performance than non-drivers. The age, driving experience, and perceived difficulty in driving at night were obtained as potential predictors of the test performance with the applied linear regression model. CONCLUSION: The ADEM may be a practical, non-expensive, easy-to-apply tool in the assessment of drivers, useful for obtaining or renewing the driving license. This test may help in the detection of impairments in the saccadic efficiency that could have a detrimental effect on the driving performance.


Assuntos
Atenção/fisiologia , Condução de Veículo/normas , Movimentos Oculares/fisiologia , Visão Noturna/fisiologia , Visão Ocular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Luz , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Análise e Desempenho de Tarefas , Adulto Jovem
15.
PLoS One ; 16(2): e0229189, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33566851

RESUMO

INTRODUCTION: Retinal implants have now been approved and commercially available for certain clinical populations for over 5 years, with hundreds of individuals implanted, scores of them closely followed in research trials. Despite these numbers, however, few data are available that would help us answer basic questions regarding the nature and outcomes of artificial vision: what do recipients see when the device is turned on for the first time, and how does that change over time? METHODS: Semi-structured interviews and observations were undertaken at two sites in France and the UK with 16 recipients who had received either the Argus II or IRIS II devices. Data were collected at various time points in the process that implant recipients went through in receiving and learning to use the device, including initial evaluation, implantation, initial activation and systems fitting, re-education and finally post-education. These data were supplemented with data from interviews conducted with vision rehabilitation specialists at the clinical sites and clinical researchers at the device manufacturers (Second Sight and Pixium Vision). Observational and interview data were transcribed, coded and analyzed using an approach guided by Interpretative Phenomenological Analysis (IPA). RESULTS: Implant recipients described the perceptual experience produced by their epiretinal implants as fundamentally, qualitatively different than natural vision. All used terms that invoked electrical stimuli to describe the appearance of their percepts, yet the characteristics used to describe the percepts varied significantly between recipients. Artificial vision for these recipients was a highly specific, learned skill-set that combined particular bodily techniques, associative learning and deductive reasoning in order to build a "lexicon of flashes"-a distinct perceptual vocabulary that they then used to decompose, recompose and interpret their surroundings. The percept did not transform over time; rather, the recipient became better at interpreting the signals they received, using cognitive techniques. The process of using the device never ceased to be cognitively fatiguing, and did not come without risk or cost to the recipient. In exchange, recipients received hope and purpose through participation, as well as a new kind of sensory signal that may not have afforded practical or functional use in daily life but, for some, provided a kind of "contemplative perception" that recipients tailored to individualized activities. CONCLUSION: Attending to the qualitative reports of implant recipients regarding the experience of artificial vision provides valuable information not captured by extant clinical outcome measures.


Assuntos
Retina/fisiologia , Percepção Visual/fisiologia , Pessoas com Deficiência Visual/psicologia , Adulto , Inglaterra , Membrana Epirretiniana/metabolismo , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Implantação de Prótese/métodos , Visão Ocular/fisiologia , Próteses Visuais/tendências
16.
Nat Commun ; 12(1): 1120, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602925

RESUMO

The integration and interaction of vision, touch, hearing, smell, and taste in the human multisensory neural network facilitate high-level cognitive functionalities, such as crossmodal integration, recognition, and imagination for accurate evaluation and comprehensive understanding of the multimodal world. Here, we report a bioinspired multisensory neural network that integrates artificial optic, afferent, auditory, and simulated olfactory and gustatory sensory nerves. With distributed multiple sensors and biomimetic hierarchical architectures, our system can not only sense, process, and memorize multimodal information, but also fuse multisensory data at hardware and software level. Using crossmodal learning, the system is capable of crossmodally recognizing and imagining multimodal information, such as visualizing alphabet letters upon handwritten input, recognizing multimodal visual/smell/taste information or imagining a never-seen picture when hearing its description. Our multisensory neural network provides a promising approach towards robotic sensing and perception.


Assuntos
Biomimética , Redes Neurais de Computação , Reconhecimento Psicológico , Humanos , Imaginação , Aprendizagem , Neurônios/fisiologia , Olfato/fisiologia , Paladar/fisiologia , Tato/fisiologia , Visão Ocular/fisiologia
17.
Neurosci Lett ; 749: 135743, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33607204

RESUMO

Lightly touching an earth-fixed external surface with the forefinger provides somatosensory information that reduces the center of pressure (CoP) oscillations. If this surface were to move slowly, the central nervous system (CNS) would misinterpret its movement as body self-motion, and involuntary compensatory sway responses would appear, resulting in a significant coupling between finger and CoP motions. We designed a forefinger moving light-touch biofeedback based on this finding, which controls the surface velocity to drive the CoP towards a target position. Here, we investigate this biofeedback resistance to cognitive processes. In addition to a baseline, the experimental protocol includes four main conditions. In the first, participants were utterly naive about the feedback. Then, they received additional reliable sensory information. The third condition ensured their full awareness of the external nature of the surface motion. Finally, the experimenter notified them that the external motion drives their balance and asked them to reject its influence. Our investigation shows that despite the robustness of the proposed biofeedback, light-touch remains penetrable by cognitive processes. For participants to dramatically reduce the existing coupling between the finger and CoP motions, they should be aware of the external motion, how it impacts sway, and actively reject its influence. The main implication of our findings is that light-touch exhibits the same cognitive flexibility as vision when artificially stimulated. This could be interpreted as a defense mechanism to re-weight these two sensory inputs in a moving environment.


Assuntos
Biorretroalimentação Psicológica/fisiologia , Cognição/fisiologia , Movimento/fisiologia , Tato/fisiologia , Feminino , Dedos/fisiologia , Humanos , Masculino , Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Visão Ocular/fisiologia
18.
J Med Internet Res ; 23(2): e21037, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33616535

RESUMO

BACKGROUND: Facial expressions require the complex coordination of 43 different facial muscles. Parkinson disease (PD) affects facial musculature leading to "hypomimia" or "masked facies." OBJECTIVE: We aimed to determine whether modern computer vision techniques can be applied to detect masked facies and quantify drug states in PD. METHODS: We trained a convolutional neural network on images extracted from videos of 107 self-identified people with PD, along with 1595 videos of controls, in order to detect PD hypomimia cues. This trained model was applied to clinical interviews of 35 PD patients in their on and off drug motor states, and seven journalist interviews of the actor Alan Alda obtained before and after he was diagnosed with PD. RESULTS: The algorithm achieved a test set area under the receiver operating characteristic curve of 0.71 on 54 subjects to detect PD hypomimia, compared to a value of 0.75 for trained neurologists using the United Parkinson Disease Rating Scale-III Facial Expression score. Additionally, the model accuracy to classify the on and off drug states in the clinical samples was 63% (22/35), in contrast to an accuracy of 46% (16/35) when using clinical rater scores. Finally, each of Alan Alda's seven interviews were successfully classified as occurring before (versus after) his diagnosis, with 100% accuracy (7/7). CONCLUSIONS: This proof-of-principle pilot study demonstrated that computer vision holds promise as a valuable tool for PD hypomimia and for monitoring a patient's motor state in an objective and noninvasive way, particularly given the increasing importance of telemedicine.


Assuntos
Doença de Parkinson/complicações , Visão Ocular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Computadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Doença de Parkinson/fisiopatologia , Projetos Piloto
19.
Sci Rep ; 11(1): 375, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431972

RESUMO

Effective binocular vision is dependent on both motor and perceptual function. Young children undergo development of both components while interacting with their dynamic three-dimensional environment. When this development fails, eye misalignment and double vision may result. We compared the range of image disparities over which young children display reflex motor realignment of their eyes with the range over which they report a single versus double percept. In response to step changes in the disparity of a 2.2° wide stimulus, 5-year-olds generated an adult-like reflex vergence velocity tuning function peaking at 2° of disparity, with a mean latency of 210 ms. On average, they reported double vision for stimulus disparities of 3° and larger, compared to 1° in adult reports. Three-year-olds also generated reflex vergence tuning functions peaking at approximately 2° of disparity, but their percepts could not be assessed. These data suggest that, by age 5, reflex eye realignment responses and percepts driven by these brief stimuli are tightly coordinated in space and time to permit robust binocular function around the point of fixation. Importantly, the plastic neural processes maintaining this tight coordination during growth control the stability of visual information driving learning during childhood.


Assuntos
Movimentos Oculares/fisiologia , Reflexo/fisiologia , Disparidade Visual/fisiologia , Adulto , Fatores Etários , Criança , Pré-Escolar , Diplopia/fisiopatologia , Fixação Ocular/fisiologia , Humanos , Estimulação Luminosa , Tempo de Reação/fisiologia , Movimentos Sacádicos/fisiologia , Visão Binocular/fisiologia , Visão Ocular/fisiologia , Percepção Visual/fisiologia
20.
Curr Biol ; 31(2): R65-R66, 2021 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-33497630

RESUMO

The discoveries of the photopigment melanopsin and intrinsically photosensitive retinal ganglion cells (ipRGCs) have revealed novel mechanisms of light detection now known to control several kinds of non-image-forming vision, including regulation of mood, the circadian rhythm, and the pupillary light reflex (PLR). These remarkable discoveries have been made mostly on mammals, but many vertebrates express melanopsin and adjust the diameter of the pupil to the ambient light intensity to extend the operating range of vision and reduce spherical aberration1. We were curious to know whether a PLR controlled by melanopsin is also present in lamprey, which are members of the only remaining group of jawless vertebrates (agnathans) which diverged from all other vertebrates about 500 million years ago2. We now show that lamprey have a robust PLR mediated by melanopsin apparently without any contribution from signals of rods and cones, suggesting that non-image-forming perception emerged long before the radiation of present vertebrate lines and was already present in the late Cambrian.


Assuntos
Petromyzon/fisiologia , Reflexo Pupilar/fisiologia , Visão Ocular/fisiologia , Animais , Células Ganglionares da Retina/metabolismo , Células Horizontais da Retina/metabolismo , Opsinas de Bastonetes/metabolismo
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