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1.
Nature ; 615(7954): 892-899, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36949190

RESUMO

The head direction (HD) system functions as the brain's internal compass1,2, classically formalized as a one-dimensional ring attractor network3,4. In contrast to a globally consistent magnetic compass, the HD system does not have a universal reference frame. Instead, it anchors to local cues, maintaining a stable offset when cues rotate5-8 and drifting in the absence of referents5,8-10. However, questions about the mechanisms that underlie anchoring and drift remain unresolved and are best addressed at the population level. For example, the extent to which the one-dimensional description of population activity holds under conditions of reorientation and drift is unclear. Here we performed population recordings of thalamic HD cells using calcium imaging during controlled rotations of a visual landmark. Across experiments, population activity varied along a second dimension, which we refer to as network gain, especially under circumstances of cue conflict and ambiguity. Activity along this dimension predicted realignment and drift dynamics, including the speed of network realignment. In the dark, network gain maintained a 'memory trace' of the previously displayed landmark. Further experiments demonstrated that the HD network returned to its baseline orientation after brief, but not longer, exposures to a rotated cue. This experience dependence suggests that memory of previous associations between HD neurons and allocentric cues is maintained and influences the internal HD representation. Building on these results, we show that continuous rotation of a visual landmark induced rotation of the HD representation that persisted in darkness, demonstrating experience-dependent recalibration of the HD system. Finally, we propose a computational model to formalize how the neural compass flexibly adapts to changing environmental cues to maintain a reliable representation of HD. These results challenge classical one-dimensional interpretations of the HD system and provide insights into the interactions between this system and the cues to which it anchors.


Assuntos
Sinais (Psicologia) , Cabeça , Neurônios , Orientação , Tálamo , Sinalização do Cálcio , Cabeça/fisiologia , Neurônios/citologia , Neurônios/fisiologia , Orientação/fisiologia , Orientação Espacial/fisiologia , Rotação , Tálamo/citologia , Tálamo/fisiologia
2.
Proc Natl Acad Sci U S A ; 120(9): e2214539120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36812198

RESUMO

The head-direction (HD) system, a key neural circuit for navigation, consists of several anatomical structures containing neurons selective to the animal's head direction. HD cells exhibit ubiquitous temporal coordination across brain regions, independently of the animal's behavioral state or sensory inputs. Such temporal coordination mediates a single, stable, and persistent HD signal, which is essential for intact orientation. However, the mechanistic processes behind the temporal organization of HD cells are unknown. By manipulating the cerebellum, we identify pairs of HD cells recorded from two brain structures (anterodorsal thalamus and retrosplenial cortex) that lose their temporal coordination, specifically during the removal of the external sensory inputs. Further, we identify distinct cerebellar mechanisms that participate in the spatial stability of the HD signal depending on sensory signals. We show that while cerebellar protein phosphatase 2B-dependent mechanisms facilitate the anchoring of the HD signal on the external cues, the cerebellar protein kinase C-dependent mechanisms are required for the stability of the HD signal by self-motion cues. These results indicate that the cerebellum contributes to the preservation of a single and stable sense of direction.


Assuntos
Orientação , Tálamo , Animais , Orientação/fisiologia , Tálamo/fisiologia , Giro do Cíngulo , Cerebelo , Neurônios/fisiologia , Cabeça/fisiologia , Movimentos da Cabeça/fisiologia
3.
PLoS Comput Biol ; 17(9): e1009434, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34570749

RESUMO

Environmental information is required to stabilize estimates of head direction (HD) based on angular path integration. However, it is unclear how this happens in real-world (visually complex) environments. We present a computational model of how visual feedback can stabilize HD information in environments that contain multiple cues of varying stability and directional specificity. We show how combinations of feature-specific visual inputs can generate a stable unimodal landmark bearing signal, even in the presence of multiple cues and ambiguous directional specificity. This signal is associated with the retrosplenial HD signal (inherited from thalamic HD cells) and conveys feedback to the subcortical HD circuitry. The model predicts neurons with a unimodal encoding of the egocentric orientation of the array of landmarks, rather than any one particular landmark. The relationship between these abstract landmark bearing neurons and head direction cells is reminiscent of the relationship between place cells and grid cells. Their unimodal encoding is formed from visual inputs via a modified version of Oja's Subspace Algorithm. The rule allows the landmark bearing signal to disconnect from directionally unstable or ephemeral cues, incorporate newly added stable cues, support orientation across many different environments (high memory capacity), and is consistent with recent empirical findings on bidirectional HD firing reported in the retrosplenial cortex. Our account of visual feedback for HD stabilization provides a novel perspective on neural mechanisms of spatial navigation within richer sensory environments, and makes experimentally testable predictions.


Assuntos
Modelos Neurológicos , Orientação/fisiologia , Navegação Espacial/fisiologia , Algoritmos , Animais , Biologia Computacional , Simulação por Computador , Sinais (Psicologia) , Meio Ambiente , Retroalimentação Sensorial/fisiologia , Giro do Cíngulo/fisiologia , Cabeça/fisiologia , Vias Neurais/fisiologia , Tálamo/fisiologia
4.
Nat Commun ; 12(1): 4745, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362883

RESUMO

Spatial processing by receptive fields is a core property of the visual system. However, it is unknown how spatial processing in high-level regions contributes to recognition behavior. As face inversion is thought to disrupt typical holistic processing of information in faces, we mapped population receptive fields (pRFs) with upright and inverted faces in the human visual system. Here we show that in face-selective regions, but not primary visual cortex, pRFs and overall visual field coverage are smaller and shifted downward in response to face inversion. From these measurements, we successfully predict the relative behavioral detriment of face inversion at different positions in the visual field. This correspondence between neural measurements and behavior demonstrates how spatial processing in face-selective regions may enable holistic perception. These results not only show that spatial processing in high-level visual regions is dynamically used towards recognition, but also suggest a powerful approach for bridging neural computations by receptive fields to behavior.


Assuntos
Face/fisiologia , Reconhecimento Facial/fisiologia , Orientação/fisiologia , Processamento Espacial/fisiologia , Adulto , Comportamento , Encéfalo , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Córtex Visual/fisiologia , Campos Visuais/fisiologia , Adulto Jovem
5.
Elife ; 92020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32618268

RESUMO

Unlike dogs and cats, people do not point their ears as they focus attention on novel, salient, or task-relevant stimuli. Our species may nevertheless have retained a vestigial pinna-orienting system that has persisted as a 'neural fossil' within in the brain for about 25 million years. Consistent with this hypothesis, we demonstrate that the direction of auditory attention is reflected in sustained electrical activity of muscles within the vestigial auriculomotor system. Surface electromyograms (EMGs) were taken from muscles that either move the pinna or alter its shape. To assess reflexive, stimulus-driven attention we presented novel sounds from speakers at four different lateral locations while the participants silently read a boring text in front of them. To test voluntary, goal-directed attention we instructed participants to listen to a short story coming from one of these speakers, while ignoring a competing story from the corresponding speaker on the opposite side. In both experiments, EMG recordings showed larger activity at the ear on the side of the attended stimulus, but with slightly different patterns. Upward movement (perking) differed according to the lateral focus of attention only during voluntary orienting; rearward folding of the pinna's upper-lateral edge exhibited such differences only during reflexive orienting. The existence of a pinna-orienting system in humans, one that is experimentally accessible, offers opportunities for basic as well as applied science.


Dogs, cats, monkeys and other animals perk their ears in the direction of sounds they are interested in. Humans and their closest ape relatives, however, appear to have lost this ability. Some humans are able to wiggle their ears, suggesting that some of the brain circuits and muscles that allow automatic ear movements towards sounds are still present. This may be a 'vestigial feature', an ability that is maintained even though it no longer serves its original purpose. Now, Strauss et al. show that vestigial movements of muscles around the ear indicate the direction of sounds a person is paying attention to. In the experiments, human volunteers tried to read a boring text while surprising sounds like a traffic jam, a baby crying, or footsteps played. During this exercise, Strauss et al. recorded the electrical activity in the muscles of their ears to see if they moved in response to the direction the sound came from. In a second set of experiments, the same electrical recordings were made as participants listened to a podcast while a second podcast was playing from a different direction. The individuals' ears were also recorded using high resolution video. Both sets of experiments revealed tiny involuntary movements in muscles surrounding the ear closest to the direction of a sound the person is listening to. When the participants tried to listen to one podcast and tune out another, they also made ear 'perking' movements in the direction of their preferred podcast. The results suggest that movements of the vestigial muscles in the human ear indicate the direction of sounds a person is paying attention to. These tiny movements could be used to develop better hearing aids that sense the electrical activity in the ear muscles and amplify sounds the person is trying to focus on, while minimizing other sounds.


Assuntos
Atenção , Orelha/fisiologia , Músculo Esquelético/fisiologia , Orientação/fisiologia , Localização de Som/fisiologia , Estimulação Acústica , Adulto , Idoso , Eletromiografia , Humanos , Pessoa de Meia-Idade , Adulto Jovem
6.
J Neurosci ; 40(3): 671-681, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31754009

RESUMO

It is unclear to what extent sensory processing areas are involved in the maintenance of sensory information in working memory (WM). Previous studies have thus far relied on finding neural activity in the corresponding sensory cortices, neglecting potential activity-silent mechanisms, such as connectivity-dependent encoding. It has recently been found that visual stimulation during visual WM maintenance reveals WM-dependent changes through a bottom-up neural response. Here, we test whether this impulse response is uniquely visual and sensory-specific. Human participants (both sexes) completed visual and auditory WM tasks while electroencephalography was recorded. During the maintenance period, the WM network was perturbed serially with fixed and task-neutral auditory and visual stimuli. We show that a neutral auditory impulse-stimulus presented during the maintenance of a pure tone resulted in a WM-dependent neural response, providing evidence for the auditory counterpart to the visual WM findings reported previously. Interestingly, visual stimulation also resulted in an auditory WM-dependent impulse response, implicating the visual cortex in the maintenance of auditory information, either directly or indirectly, as a pathway to the neural auditory WM representations elsewhere. In contrast, during visual WM maintenance, only the impulse response to visual stimulation was content-specific, suggesting that visual information is maintained in a sensory-specific neural network, separated from auditory processing areas.SIGNIFICANCE STATEMENT Working memory is a crucial component of intelligent, adaptive behavior. Our understanding of the neural mechanisms that support it has recently shifted: rather than being dependent on an unbroken chain of neural activity, working memory may rely on transient changes in neuronal connectivity, which can be maintained efficiently in activity-silent brain states. Previous work using a visual impulse stimulus to perturb the memory network has implicated such silent states in the retention of line orientations in visual working memory. Here, we show that auditory working memory similarly retains auditory information. We also observed a sensory-specific impulse response in visual working memory, while auditory memory responded bimodally to both visual and auditory impulses, possibly reflecting visual dominance of working memory.


Assuntos
Percepção Auditiva/fisiologia , Memória de Curto Prazo/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Adolescente , Adulto , Sinais (Psicologia) , Eletroencefalografia , Potenciais Evocados , Feminino , Generalização Psicológica , Humanos , Masculino , Rede Nervosa/fisiologia , Orientação/fisiologia , Estimulação Luminosa , Percepção da Altura Sonora , Desempenho Psicomotor/fisiologia , Adulto Jovem
7.
Neurol Med Chir (Tokyo) ; 60(2): 101-106, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31866665

RESUMO

The present study examined the kinematics and biomechanical parameters of the head of a person thrown forward by the judo technique 'Seoi-nage'. A judo expert threw an anthropomorphic test device (the POLAR dummy) five times. Kinematics data were obtained with a high-speed digital video camera. Linear and angular accelerations of the head were measured by accelerometers mounted at the center of gravity of the dummy's head. When Seoi-nage was performed, the dummy fell forward accompanied by contacting the anterior parietal regions of the head to the tatami, and the linear and angular accelerations of most axes reached peak values when the head contacted the tatami. Peak resultant linear and angular accelerations were 20.3 ± 9.8 G and 1890.1 ± 1151.9 rad/s2, respectively (means ± standard deviation). Peak values in linear and angular acceleration did not significantly differ between the three directional axes. Absolute angular accelerations in all axes observed in Seoi-nage were high and the resultant value was approximately equal to the already reported in Ouchi-gari, one of the predominant techniques causing judo-related acute subdural hematoma. However, the remarkable increase of linear acceleration in the longitudinal direction and/or angular acceleration in the sagittal plane, as previously reported in techniques being thrown backward (i.e., Ouchi-gari and Osoto-gari), was not detected. The likely mechanism of acute subdural hematoma caused by Seoi-nage is that a large angular acceleration causes large strains and deformations of the brain surface and subsequent rupture of cortical vessels.


Assuntos
Fenômenos Biomecânicos/fisiologia , Lesões Encefálicas/fisiopatologia , Encéfalo/irrigação sanguínea , Movimentos da Cabeça/fisiologia , Artes Marciais/lesões , Artes Marciais/fisiologia , Aceleração , Antropometria , Hematoma Subdural/fisiopatologia , Humanos , Modelos Anatômicos , Orientação/fisiologia , Postura/fisiologia
8.
Int J Psychophysiol ; 146: 85-100, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31654696

RESUMO

Involuntary attention allows for the detection and processing of novel and potentially relevant stimuli that lie outside of cognitive focus. These processes comprise change detection in sensory contexts, automatic orientation toward this change, and the selection of adaptive responses, including reorientation to the original goal in cases when the detected change is not relevant for task demands. These processes have been studied using the Event-Related Potential (ERP) technique and have been associated to the Mismatch Negativity (MMN), the P3a, and the Reorienting Negativity (RON) electrophysiological components, respectively. This has allowed for the objective evaluation of the impact of different neuropsychiatric pathologies on involuntary attention. Additionally, these ERP have been proposed as alternative measures for the early detection of disease and the tracking of its progression. The objective of this review was to integrate the results reported to date about MMN, P3a, and RON in different neurological and psychiatric disorders. We included experimental studies with clinical populations that reported at least two of these three components in the same experimental paradigm. Overall, involuntary attention seems to reflect the state of cognitive integrity in different pathologies in adults. However, if the main goal for these ERP is to consider them as biomarkers, more research about their pathophysiological specificity in each disorder is needed, as well as improvement in the general experimental conditions under which these components are elicited. Nevertheless, these ERP represent a valuable neurophysiological tool for early detection and follow-up of diverse clinical populations.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Potenciais Evocados P300/fisiologia , Transtornos Mentais/psicologia , Doenças do Sistema Nervoso/psicologia , Orientação/fisiologia , Estimulação Acústica/métodos , Humanos , Transtornos Mentais/fisiopatologia , Doenças do Sistema Nervoso/fisiopatologia
9.
PLoS One ; 14(7): e0220414, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31348807

RESUMO

This study explored gender differences in correct response rates and response times on a task involving left or right arrow selection and another involving the transformation of mental rotation of the hand. We recruited 15 healthy, right-handed men (age 24.5 ± 6.4) and 15 healthy, right-handed women (age 21.3 ± 4.9). For the tasks, we used pictures of left and right arrows and 32 hand pictures (left and right, palm and back) placed in cons (each at 45° from 0° to 315°). Hand and arrow pictures alternated and were shown at random. Participants decided as quickly as possible whether each picture was left or right. To compare the time taken for the transformation of mental rotation of the hand, we subtracted the average arrow response time from that for the left and right hand pictures for each participant. Correct response rates did not differ significantly between men and women or left and right for either arrow or hand pictures. Regardless of gender, the response time was longer for the left arrow picture than right arrow picture. The response time for the hand picture was longest for both men and women for pictures at rotation angles that were most difficult to align with participants' hands. While there was no difference between men's responses for left and right hand pictures, the responses of women were longer for left than right hand pictures and also than those of men. These findings suggest that both men and women mainly perform the hand mental rotation task with implicit motor imagery. On the other hand, the gender difference in performance might be explained by the difference in balance with other strategies, such as visual imagery, and by cognitive, neurophysiological, and morphological differences.


Assuntos
Mãos/fisiologia , Orientação/fisiologia , Tempo de Reação/fisiologia , Caracteres Sexuais , Adolescente , Adulto , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Desempenho Psicomotor , Rotação , Inquéritos e Questionários , Adulto Jovem
10.
J Back Musculoskelet Rehabil ; 32(1): 77-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30149438

RESUMO

PURPOSE: Working body schema (WBS) of the limbs may be indirectly assessed using left/right limb judgement (LRLJ) task performance. This study aimed to investigate if: 1) Total Knee Replacement (TKR) patients perform LRLJ tasks with reference to their WBS; 2) patients have a disrupted WBS following a TKR for the replaced knee compared to the contralateral knee; and 3) lower limb-based LRLJ task performance changes following post-surgical rehabilitation using change in upper limb-based LRLJ task performance as a control. METHODS: In a convenience sample (n= 18, age 69 ± 7 yrs, 12F 6M) of TKR patients < 1 month post-surgery, WBS was assessed using LRLJ task performance for the upper (pictures of the hand) and lower limb (pictures of the foot) before and after rehabilitation. Accuracy and response time (RT) were analysed using a series of 2 × 2 × 2 ANOVAs. RESULTS: LRLJ task performance for images corresponding with the operated and non-operated side were comparable for accuracy (p= 0.83) and RT (p= 0.28). Accuracy for hand images was comparable from baseline to post-rehabilitation (p= 0.54) whereas accuracy for feet images increased significantly (p= 0.03). Responses for awkward posture images were significantly slower than for more natural posture images (p= 0.001). CONCLUSIONS: LRLJ task performance data reflected the typical biomechanical constraints indicative of implicit motor imagery being performed by patients. There was no evidence of a disrupted LRLJ task performance for the replaced knee compared to the contralateral knee. Following post-surgical rehabilitation, patients' lower limb LRLJ task performance improved whilst upper limb LRLJ task performance remained unchanged. These findings are the first to show that WBS improves with rehabilitation following TKR, and this may explain some of the clinical improvements observed. Undertaking LRLJ tasks could theoretically be a useful adjunct to current post-TKR rehabilitation.


Assuntos
Artroplastia do Joelho , Dominância Cerebral/fisiologia , Extremidade Inferior/fisiologia , Desempenho Psicomotor/fisiologia , Idoso , Imagem Corporal , Feminino , Humanos , Masculino , Movimento/fisiologia , Orientação/fisiologia , Tempo de Reação/fisiologia , Estudos de Amostragem , Extremidade Superior/fisiologia
11.
J Neurophysiol ; 121(1): 4-37, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30379631

RESUMO

Head direction (HD) cells fire when the animal faces that cell's preferred firing direction (PFD) in the horizontal plane. The PFD response when the animal is oriented outside the earth-horizontal plane could result from cells representing direction in the plane of locomotion or as a three-dimensional (3D), global-referenced direction anchored to gravity. To investigate these possibilities, anterodorsal thalamic HD cells were recorded from restrained rats while they were passively positioned in various 3D orientations. Cell responses were unaffected by pitch or roll up to ~90° from the horizontal plane. Firing was disrupted once the animal was oriented >90° away from the horizontal plane and during inversion. When rolling the animal around the earth-vertical axis, cells were active when the animal's ventral surface faced the cell's PFD. However, with the rat rolled 90° in an ear-down orientation, pitching the rat and rotating it around the vertical axis did not produce directionally tuned responses. Complex movements involving combinations of yaw-roll, but usually not yaw-pitch, resulted in reduced directional tuning even at the final upright orientation when the rat had full visual view of its environment and was pointing in the cell's PFD. Directional firing was restored when the rat's head was moved back-and-forth. There was limited evidence indicating that cells contained conjunctive firing with pitch or roll positions. These findings suggest that the brain's representation of directional heading is derived primarily from horizontal canal information and that the HD signal is a 3D gravity-referenced signal anchored to a direction in the horizontal plane. NEW & NOTEWORTHY This study monitored head direction cell responses from rats in three dimensions using a series of manipulations that involved yaw, pitch, roll, or a combination of these rotations. Results showed that head direction responses are consistent with the use of two reference frames simultaneously: one defined by the surrounding environment using primarily visual landmarks and a second defined by the earth's gravity vector.


Assuntos
Percepção de Movimento/fisiologia , Neurônios/fisiologia , Orientação/fisiologia , Percepção Espacial/fisiologia , Tálamo/fisiologia , Potenciais de Ação , Animais , Feminino , Cabeça , Estimulação Física , Propriocepção/fisiologia , Ratos Long-Evans , Restrição Física
12.
Hippocampus ; 29(7): 619-629, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30561118

RESUMO

Head direction cells are critical for navigation because they convey information about which direction an animal is facing within an environment. To date, most studies on head direction encoding have been conducted on a horizontal two-dimensional (2D) plane, and little is known about how three-dimensional (3D) direction information is encoded in the brain despite humans and other animals living in a 3D world. Here, we investigated head direction encoding in the human brain while participants moved within a virtual 3D "spaceship" environment. Movement was not constrained to planes and instead participants could move along all three axes in volumetric space as if in zero gravity. Using functional magnetic resonance imaging (fMRI) multivoxel pattern similarity analysis, we found evidence that the thalamus, particularly the anterior portion, and the subiculum encoded the horizontal component of 3D head direction (azimuth). In contrast, the retrosplenial cortex was significantly more sensitive to the vertical direction (pitch) than to the azimuth. Our results also indicated that vertical direction information in the retrosplenial cortex was significantly correlated with behavioral performance during a direction judgment task. Our findings represent the first evidence showing that the "classic" head direction system that has been identified on a horizontal 2D plane also seems to encode vertical and horizontal heading in 3D space in the human brain.


Assuntos
Encéfalo/fisiologia , Orientação/fisiologia , Navegação Espacial/fisiologia , Adulto , Encéfalo/diagnóstico por imagem , Imagem Ecoplanar , Feminino , Neuroimagem Funcional , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Tálamo/diagnóstico por imagem , Tálamo/fisiologia , Interface Usuário-Computador , Adulto Jovem
13.
Pain Res Manag ; 2018: 6810412, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30154945

RESUMO

The aim of the study was to investigate the difference in response to a motor imagery task between individuals with and without painful temporomandibular disorders (TMDs). The participants were 24 adults with and without TMD (TMD and control group, resp.). A set of photographic images of the profile view of a person's head and neck and a hand and a foot were presented in a random order. The set consisted of six different orientations with rotations of each image at 0, 60, 120, 180, 240, and 300 degrees and included left and right representations. The participants were required to view the image and make a decision as to whether it was a left or a right side presented, that is, mental rotation (MR) task. Data were collected on 48 tasks (including left and right) at each orientation for each body part. Reaction times (RTs) for correct answers and accuracy in making the left or right judgements were recorded. The RT was slower in the TMD group than in the control group. The RT for the profile image was slower than those for the hand and foot images. For images that were 180 degrees, the RT was slower and the accuracy was lower than those for five of the other image orientations. The judgements made about the 180-degree rotated image were more inaccurate compared to images of all other orientations among all types of stimuli.


Assuntos
Dor Facial/complicações , Dor Facial/reabilitação , Imagens, Psicoterapia/métodos , Atividade Motora/fisiologia , Transtornos da Articulação Temporomandibular/complicações , Transtornos da Articulação Temporomandibular/reabilitação , Adulto , Idoso , Análise de Variância , Antropometria , Dor Facial/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Orientação/fisiologia , Medição da Dor , Estimulação Luminosa , Tempo de Reação/fisiologia , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Resultado do Tratamento
14.
IEEE Trans Neural Syst Rehabil Eng ; 26(8): 1508-1515, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29994123

RESUMO

In this paper, we investigated the performance of a multi-class brain-computer interface (BCI). The BCI system is based on the concept of somatosensory attentional orientation (SAO), in which the user shifts and maintains somatosensory attention by imagining the sensation of tactile stimulation of a body part. At the beginning of every trial, a vibration stimulus (200 ms) informed the subjects to prepare for the task. Four SAO tasks were performed following randomly presented cues: SAO of the left hand (SAO-LF), SAO of the right hand (SAO-RT), bilateral SAO (SAO-BI), and SAO suppressed or idle state (SAO-ID). Analysis of the event-related desynchronization and synchronization (ERD/ERS) in the EEG indicated that the four SAO tasks had different somatosensory cortical activation patterns. SAO-LF and SAO-RT exhibited stronger contralateral ERD, whereas bilateral ERD activation was indicative of SAO-BI, and bilateral ERS activation was associated with SAO-ID. By selecting the frequency bands and/or optimal classes, classification accuracy of the system reached 85.2%±11.2% for two classes, 69.5%±16.2% for three classes, and 55.9%±15.8% for four classes. The results validated a multi-class BCI system based on SAO, on a single trial basis. Somatosensory attention to different body parts induces diverse oscillatory dynamics within the somatosensory area of the brain, and the proposed SAO paradigm provided a new approach for a multiple-class BCI that is potentially stimulus independent.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia/métodos , Potenciais Somatossensoriais Evocados/fisiologia , Imaginação/fisiologia , Sensação/fisiologia , Adolescente , Atenção/fisiologia , Sinais (Psicologia) , Feminino , Lateralidade Funcional , Humanos , Masculino , Orientação/fisiologia , Reprodutibilidade dos Testes , Córtex Somatossensorial/fisiologia , Tato/fisiologia , Vibração , Adulto Jovem
15.
Cell Tissue Res ; 373(3): 541-556, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29789927

RESUMO

Orientation in space is a fundamental cognitive process relying on brain-wide neuronal circuits. Many neurons in the presubiculum in the parahippocampal region encode head direction and each head direction cell selectively discharges when the animal faces a specific direction. Here, we attempt to link the current knowledge of afferent and efferent connectivity of the presubiculum to the processing of the head direction signal. We describe the cytoarchitecture of the presubicular six-layered cortex and the morphological and electrophysiological intrinsic properties of principal neurons and interneurons. While the presubicular head direction signal depends on synaptic input from thalamus, the intra- and interlaminar information flow in the microcircuit of the presubiculum may contribute to refine directional tuning. The interaction of a specific interneuron type, the Martinotti cells, with the excitatory pyramidal cells may maintain the head direction signal in the presubiculum with attractor-like properties.


Assuntos
Interneurônios/química , Neurônios/química , Orientação/fisiologia , Giro Para-Hipocampal/anatomia & histologia , Giro Para-Hipocampal/fisiologia , Animais , Fenômenos Eletrofisiológicos , Humanos , Interneurônios/metabolismo , Modelos Teóricos , Neurônios/metabolismo , Técnicas de Patch-Clamp , Tálamo/anatomia & histologia , Tálamo/fisiologia
16.
J Manipulative Physiol Ther ; 41(2): 81-91, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29482829

RESUMO

OBJECTIVE: The purpose of this study was to test whether people with subclinical neck pain (SCNP) had altered visual, auditory, and multisensory response times, and whether these findings were consistent over time. METHODS: Twenty-five volunteers (12 SCNP and 13 asymptomatic controls) were recruited from a Canadian university student population. A 2-alternative forced-choice discrimination task with multisensory redundancy was used to measure response times to the presentation of visual (color filled circles), auditory (verbalization of the color words, eg, red or blue), and multisensory (simultaneous audiovisual) stimuli at baseline and 4 weeks later. RESULTS: The SCNP group was slower at both visual and multisensory tasks (P = .046, P = .020, respectively), with no change over 4 weeks. Auditory response times improved slightly but significantly after 4 weeks (P = .050) with no group difference. CONCLUSIONS: This is the first study to report that people with SCNP have slower visual and multisensory response times than asymptomatic individuals. These differences persist over 4 weeks, suggesting that the multisensory technique is reliable and that these differences in the SCNP group do not improve on their own in the absence of treatment.


Assuntos
Percepção Auditiva/fisiologia , Processos Mentais/fisiologia , Cervicalgia/fisiopatologia , Orientação/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Canadá , Feminino , Seguimentos , Humanos , Masculino , Tempo de Reação
17.
J Neurosci ; 38(11): 2854-2862, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29440554

RESUMO

The cerebral cortex is a major hub for the convergence and integration of signals from across the sensory modalities; sensory cortices, including primary regions, are no exception. Here we show that visual stimuli influence neural firing in the auditory cortex of awake male and female mice, using multisite probes to sample single units across multiple cortical layers. We demonstrate that visual stimuli influence firing in both primary and secondary auditory cortex. We then determine the laminar location of recording sites through electrode track tracing with fluorescent dye and optogenetic identification using layer-specific markers. Spiking responses to visual stimulation occur deep in auditory cortex and are particularly prominent in layer 6. Visual modulation of firing rate occurs more frequently at areas with secondary-like auditory responses than those with primary-like responses. Auditory cortical responses to drifting visual gratings are not orientation-tuned, unlike visual cortex responses. The deepest cortical layers thus appear to be an important locus for cross-modal integration in auditory cortex.SIGNIFICANCE STATEMENT The deepest layers of the auditory cortex are often considered its most enigmatic, possessing a wide range of cell morphologies and atypical sensory responses. Here we show that, in mouse auditory cortex, these layers represent a locus of cross-modal convergence, containing many units responsive to visual stimuli. Our results suggest that this visual signal conveys the presence and timing of a stimulus rather than specifics about that stimulus, such as its orientation. These results shed light on both how and what types of cross-modal information is integrated at the earliest stages of sensory cortical processing.


Assuntos
Córtex Auditivo/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica , Animais , Córtex Auditivo/citologia , Mapeamento Encefálico , Eletrodos , Potenciais Evocados Visuais/fisiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Optogenética , Orientação/fisiologia , Estimulação Luminosa , Córtex Visual/fisiologia
18.
Acta Psychol (Amst) ; 185: 96-103, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29438877

RESUMO

To date, crossmodal spatial cuing research has primarily investigated spatial attention modulated by the positioning of auditory cues, without addressing the question of the role played by sound parameters such as intensity change, waveform structure, or duration. Therefore in the present study, we investigated exogenous spatial cuing following the presentation of auditory cues having different intensity profiles (looming or receding), waveforms (triangular structured waveform or white noise), and durations (250 ms or 500 ms). Auditory cues were presented from one of four locations (front-left, front-right, rear-left, or rear-right). The participants had to make speeded elevation discrimination responses to visual targets presented from the front (on the left or right). The magnitude of the cuing effect was larger following the presentation of a structured looming auditory cue than a structured receding cue. On the other hand, there was no statistical difference between the magnitude of the cuing effect in the looming and in the receding intensity profiles when white noise cues were used. Such findings are consistent with previous reports. Furthermore, the magnitude of the cuing effect was larger when the cues were presented from the front than from the rear. On the contrary, other recent findings showed that the presentation of a 100 ms constant-intensity auditory cue exogenously oriented visual attention to the cued hemifield, regardless of whether the cues were presented from the front or rear. Therefore, the findings reported here demonstrated that sound parameters can modulate the exogenous orienting of crossmodal spatial attention.


Assuntos
Estimulação Acústica/métodos , Percepção Auditiva/fisiologia , Sinais (Psicologia) , Orientação Espacial/fisiologia , Estimulação Luminosa/métodos , Som , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Orientação/fisiologia , Distribuição Aleatória , Tempo de Reação/fisiologia , Percepção Espacial/fisiologia
19.
Psicothema (Oviedo) ; 30(1): 39-45, feb. 2018. tab
Artigo em Inglês | IBECS | ID: ibc-172597

RESUMO

Background: The right to educational inclusion for students with intellectual disability (SWID) requires the development of good assessment and intervention practices from holistic perspectives not exclusively focused on the academic limitations that SWID may present. These practices are settled in Spain, via regulations drawn up by each Autonomous Community (AC). The variety of existing regulations demands a critical review of the decisions taken to promote the inclusion of those students. Method: current regulations-in-force in each AC that regulate attention to diversity (AD) have been were analyzed by using a checklist that includes the variables that defining each stage of the AD process and the ways of providing supports that favor the development, learning and participation of SWID. Results: attention to diversity measures in each AC emphasize organizational and curricular issues, with no AC following holistic approaches in both assessment and intervention, but rather neglecting self-determination and the promotion of quality of life for SWID. Conclusions: guidelines for the development of new legal frameworks and professional practices based on the latest evidence-based models of attention to SWID and on the results are discussed (AU)


Antecedentes: el derecho a la inclusión educativa del alumnado con discapacidad intelectual (ACDI) requiere buenas prácticas de evaluación e intervención desde enfoques holísticos no exclusivamente centrados en las dificultades académicas que pueda presentar el alumno. Estas prácticas se regulan en España por la normativa de cada Comunidad Autónoma (CA). La variedad de regulaciones existentes demanda una revisión crítica de las decisiones adoptadas para favorecer la inclusión de este alumnado. Método: se ha analizado la normativa vigente que regula la atención a la diversidad (AD) en cada CA empleando una lista de comprobación que recoge las variables que definen cada fase de AD y los modos de prestar apoyos que favorecen el desarrollo, aprendizaje y participación. Resultados: las medidas de AD en cada CA enfatizan aspectos organizativos y curriculares, no habiendo ninguna CA que recoja enfoques holísticos tanto en la evaluación como en la intervención, descuidando la promoción de la autodeterminación y la calidad de vida del ACDI. Conclusiones: se discuten orientaciones para el desarrollo de nuevos marcos legales y práctica profesional partiendo de los enfoques basados en la evidencia de atención al ACDI y de los resultados del estudio (AU)


Assuntos
Humanos , Deficiência Intelectual/psicologia , Aprendizagem/fisiologia , Qualidade de Vida/psicologia , Ensino/psicologia , Psicometria/métodos , Saúde Holística , Orientação/fisiologia
20.
Bull Entomol Res ; 108(4): 423-433, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28944748

RESUMO

The tea green leafhopper, Empoasca vitis Göthe, is one of the most serious pests in tea growing areas. This study investigated the roles played by olfaction and vision in host orientation behavior. The compound eye of E. vitis was found to be a photopic eye; few olfactory sensilla were found on the antennae, while abundant gustatory sensilla were recorded on the mouthparts. Three opsin genes (EV_LWop, EV_UVop, EV_Bop) were isolated and found to be mainly expressed in the compound eye compared with other parts of the body. Immunolocalization indicated that the opsins mainly located in the different regions of rhabdom. The transcription levels of EV_LWop, EV_Bop and EV_UVop were reduced by 77.3, 70.0 and 40.0%, respectively, by RNA interference induced by being fed a special RNA-rich diet for 6 days. The rate of tropism to host color was effectively impaired by 67.6 and 29.5% in the dsEV_LWop and dsEV_Bop treatment groups, but there was no significant change in the dsEV_UVop group. The determination of the cause of the tropism indicated that odors from the host over long distances were unable to attract E. vitis and were only detected when the insects were close to the host. The developed compound eye of E. vitis plays a leading role in host location, and the long-wavelength opsin significantly affects the tropism to host color; the lack of olfactory sensilla results in long-distance odors not being able to be detected until the insect is near to the host-plant. The understanding of these behavioral mechanisms, especially the importance of opsin genes is expected to be useful for pest management.


Assuntos
Hemípteros/fisiologia , Olfato , Percepção Visual , Animais , Antenas de Artrópodes/anatomia & histologia , Olho/anatomia & histologia , Comportamento Alimentar , Feminino , Hemípteros/anatomia & histologia , Hemípteros/genética , Opsinas/genética , Opsinas/fisiologia , Orientação/fisiologia , Filogenia , Olfato/fisiologia , Chá , Percepção Visual/fisiologia
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