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1.
Artículo en Inglés | MEDLINE | ID: mdl-39255120

RESUMEN

Cybersickness remains a major drawback of Virtual Reality (VR) headsets, as a breadth of stationary experiences with visual self-motion can result in visually-induced motion sickness. However, not everybody experiences the same intensity or type of adverse symptoms. Here we propose that prior experience with virtual environments can predict ones degree of cybersickness. Video gaming can enhance visuospatial abilities, which in-turn relate negatively to cybersickness - meaning that consistently engaging in virtual environments can result in protective habituation effects. In a controlled stationary VR experiment, we found that 'VR-naive' video gamers experienced significantly less cybersickness in a virtual tunnel-travel task and outperformed 'VR-naive' non-video gamers on a visual attention task. These findings strongly motivate the use of non-VR games for training VR cybersickness resilience, with future research needed to further understand the mechanism(s) by which gamers become cybersickness resilient - potentially expanding access to VR for even the most susceptible participants.

2.
Autism Res ; 17(5): 1041-1052, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38661256

RESUMEN

Research has shown that children on the autism spectrum and adults with high levels of autistic traits are less sensitive to audiovisual asynchrony compared to their neurotypical peers. However, this evidence has been limited to simultaneity judgments (SJ) which require participants to consider the timing of two cues together. Given evidence of partly divergent perceptual and neural mechanisms involved in making temporal order judgments (TOJ) and SJ, and given that SJ require a more global type of processing which may be impaired in autistic individuals, here we ask whether the observed differences in audiovisual temporal processing are task and stimulus specific. We examined the ability to detect audiovisual asynchrony in a group of 26 autistic adult males and a group of age and IQ-matched neurotypical males. Participants were presented with beep-flash, point-light drumming, and face-voice displays with varying degrees of asynchrony and asked to make SJ and TOJ. The results indicated that autistic participants were less able to detect audiovisual asynchrony compared to the control group, but this effect was specific to SJ and more complex social stimuli (e.g., face-voice) with stronger semantic correspondence between the cues, requiring a more global type of processing. This indicates that audiovisual temporal processing is not generally different in autistic individuals and that a similar level of performance could be achieved by using a more local type of processing, thus informing multisensory integration theory as well as multisensory training aimed to aid perceptual abilities in this population.


Asunto(s)
Percepción Auditiva , Trastorno Autístico , Juicio , Percepción Visual , Humanos , Masculino , Juicio/fisiología , Adulto , Percepción Visual/fisiología , Percepción Auditiva/fisiología , Adulto Joven , Trastorno Autístico/fisiopatología , Estimulación Luminosa/métodos , Señales (Psicología) , Estimulación Acústica/métodos , Percepción del Tiempo/fisiología , Adolescente
3.
Psychon Bull Rev ; 31(4): 1745-1758, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38273144

RESUMEN

When viewing the actions of others, we not only see patterns of body movements, but we also "see" the intentions and social relations of people. Experienced forensic examiners - Closed Circuit Television (CCTV) operators - have been shown to convey superior performance in identifying and predicting hostile intentions from surveillance footage than novices. However, it remains largely unknown what visual content CCTV operators actively attend to, and whether CCTV operators develop different strategies for active information seeking from what novices do. Here, we conducted computational analysis for the gaze-centered stimuli captured by experienced CCTV operators and novices' eye movements when viewing the same surveillance footage. Low-level image features were extracted by a visual saliency model, whereas object-level semantic features were extracted by a deep convolutional neural network (DCNN), AlexNet, from gaze-centered regions. We found that the looking behavior of CCTV operators differs from novices by actively attending to visual contents with different patterns of saliency and semantic features. Expertise in selectively utilizing informative features at different levels of visual hierarchy may play an important role in facilitating the efficient detection of social relationships between agents and the prediction of harmful intentions.


Asunto(s)
Fijación Ocular , Semántica , Humanos , Fijación Ocular/fisiología , Adulto , Televisión , Masculino , Femenino , Redes Neurales de la Computación , Adulto Joven , Percepción Visual/fisiología , Movimientos Oculares/fisiología , Percepción Social
4.
Autism ; 28(2): 498-509, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37294012

RESUMEN

LAY ABSTRACT: Autism is a condition comprised of difficulties in social and communication contexts, sensory sensitivities as well as restrictive and repetitive behaviours. Many theories have tried to explain all the symptoms and behaviours associated with autism. We focus on one recent theory - High, Inflexible Precision of Prediction Errors in Autism (HIPPEA). We aim to understand how much this theory fits the experiences of autistic individuals. We collected data through 21 online questionnaires and 8 follow-up interviews. One of our participants was a parent of an autistic child, and the remaining were adults who reported a diagnosis of autism. We analysed the data by thinking about how it fitted with what we already knew and by looking for new insights which came up. Our results suggest that autistic individuals can make generalisations but that this happens more slowly across both social and non-social areas. These generalisations are very reliant on detail - in computer terms, they are 'pixelated'. This is in line with what HIPPEA suggests. We also showed that autistic individuals can be motivated to explore and engage socially, something that needs more consideration within HIPPEA. Overall, this study shows that HIPPEA can explain many autistic experiences, but that further refinement is needed.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Trastornos Generalizados del Desarrollo Infantil , Adulto , Niño , Humanos , Conducta Estereotipada , Comunicación
5.
Psychiatry Res Neuroimaging ; 336: 111728, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37939431

RESUMEN

Major depressive disorder (MDD) is associated with biased perception of human movement. Gesture is important for communication and in this study we investigated neural correlates of gesture perception in MDD. We hypothesised different neural activity between individuals with MDD and typical individuals when viewing instrumental and expressive gestures that were negatively or positively valenced. Differences were expected in brain areas associated with gesture perception, including superior temporal, frontal, and emotion processing regions. We recruited 12 individuals with MDD and 12 typical controls matched on age, gender, and handedness. They viewed gestures displayed by stick figures while functional magnetic resonance imaging (fMRI) was performed. Results of a random effects three-way mixed ANOVA indicated that individuals with MDD had greater activity in the right claustrum compared to controls, regardless of gesture type or valence. Additionally, we observed main effects of gesture type and valence, regardless of group. Perceiving instrumental compared to expressive gestures was associated with greater activity in the left cuneus and left superior temporal gyrus, while perceiving negative compared to positive gestures was associated with greater activity in the right precuneus and right lingual gyrus. We also observed a two-way interaction between gesture type and valence in various brain regions.


Asunto(s)
Trastorno Depresivo Mayor , Humanos , Trastorno Depresivo Mayor/diagnóstico por imagen , Gestos , Depresión , Mapeo Encefálico , Imagen por Resonancia Magnética/métodos , Percepción
6.
Cogn Res Princ Implic ; 8(1): 55, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37589891

RESUMEN

A commonplace sight is seeing other people walk. Our visual system specializes in processing such actions. Notably, we are not only quick to recognize actions, but also quick to judge how elegantly (or not) people walk. What movements appear appealing, and why do we have such aesthetic experiences? Do aesthetic preferences for body movements arise simply from perceiving others' positive emotions? To answer these questions, we showed observers different point-light walkers who expressed neutral, happy, angry, or sad emotions through their movements and measured the observers' impressions of aesthetic appeal, emotion positivity, and naturalness of these movements. Three experiments were conducted. People showed consensus in aesthetic impressions even after controlling for emotion positivity, finding prototypical walks more aesthetically pleasing than atypical walks. This aesthetic prototype effect could be accounted for by a computational model in which walking actions are treated as a single category (as opposed to multiple emotion categories). The aesthetic impressions were affected both directly by the objective prototypicality of the movements, and indirectly through the mediation of perceived naturalness. These findings extend the boundary of category learning, and hint at possible functions for action aesthetics.


Asunto(s)
Ira , Emociones , Humanos , Consenso , Estética , Felicidad
7.
J Cogn Neurosci ; 35(6): 1045-1060, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37043235

RESUMEN

Visual perception and mental imagery have been shown to share a hierarchical topological visual structure of neural representation, despite the existence of dissociation of neural substrate between them in function and structure. However, we have limited knowledge about how the visual hierarchical cortex is involved in visual perception and visual imagery in a unique and shared fashion. In this study, a data set including a visual perception and an imagery experiment with human participants was used to train 2 types of voxel-wise encoding models. These models were based on Gabor features and voxel activity patterns of high-level visual cortex (i.e., fusiform face area, parahippocampal place area, and lateral occipital complex) to predict activity in the early visual cortex (EVC, i.e., V1, V2, V3) during perception, and then tested with respect to the generalization of these models to mental imagery. Our results showed that during perception and imagery, activities in the EVC could be independently predicted by the Gabor features and activity of high-level visual cortex via voxel-wise encoding models, which suggested that perception and imagery might share neural representation in the EVC. We further found Gabor-specific and non-Gabor-specific patterns of neural response to stimuli in the EVC, which were shared by perception and imagery. These findings provide insight into the mechanisms of how visual perception and imagery share representation in the EVC.


Asunto(s)
Imaginación , Corteza Visual , Humanos , Imaginación/fisiología , Percepción Visual/fisiología , Corteza Visual/diagnóstico por imagen , Corteza Visual/fisiología , Imagen por Resonancia Magnética
8.
Comput Intell Neurosci ; 2022: 8744982, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36082347

RESUMEN

Objective: The potential of neurofeedback to alter the M1-cerebellum connectivity was explored using motor imagery-based rt-fMRI. These regions were chosen due to their importance in motor performance and motor rehabilitation. Methods: Four right-handed individuals were recruited to examine the potential to change the M1-cerebellum neurofeedback link. The University of Glasgow Cognitive Neuroimaging Centre used a 3T MRI scanner from January 2019 to January 2020 to conduct this prospective study. Everyone participated in each fMRI session, which included six NF training runs. Participants were instructed to imagine complicated hand motions during the NF training to raise a thermometer bar's height. To contrast the correlation coefficients between the initial and last NF runs, a t-test was performed post hoc. Results: The neurofeedback connection between M1 and the cerebellum was strengthened in each participant. Motor imagery strategy was a significant task in training M1-cerebellum connectivity as participants used it successfully to enhance the activation level between these regions during M1-cerebellum modulation using real-time fMRI. The t-test and linear regression, on the other hand, showed this increase to be insignificant. Conclusion: A novel technique to manipulate M1-cerebellum connectivity was discovered using real-time fMRI NF. This study showed that each participant's neurofeedback connectivity between M1 and cerebellum was enhanced. This increase, on the other hand, was insignificant statistically. The results showed that the connectivity between both areas increased positively. Through the integration of fMRI and neurofeedback, M1-cerebellum connectivity can be positively affected.


Asunto(s)
Neurorretroalimentación , Mapeo Encefálico/métodos , Cerebelo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Neurorretroalimentación/fisiología , Estudios Prospectivos
9.
Front Neurosci ; 16: 921489, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36148146

RESUMEN

We use functional Magnetic Resonance Imaging (fMRI) to explore synchronized neural responses between observers of audiovisual presentation of a string quartet performance during free viewing. Audio presentation was accompanied by visual presentation of the string quartet as stick figures observed from a static viewpoint. Brain data from 18 musical novices were obtained during audiovisual presentation of a 116 s performance of the allegro of String Quartet, No. 14 in D minor by Schubert played by the 'Quartetto di Cremona.' These data were analyzed using intersubject correlation (ISC). Results showed extensive ISC in auditory and visual areas as well as parietal cortex, frontal cortex and subcortical areas including the medial geniculate and basal ganglia (putamen). These results from a single fixed viewpoint of multiple musicians are greater than previous reports of ISC from unstructured group activity but are broadly consistent with related research that used ISC to explore listening to music or watching solo dance. A feature analysis examining the relationship between brain activity and physical features of the auditory and visual signals yielded findings of a large proportion of activity related to auditory and visual processing, particularly in the superior temporal gyrus (STG) as well as midbrain areas. Motor areas were also involved, potentially as a result of watching motion from the stick figure display of musicians in the string quartet. These results reveal involvement of areas such as the putamen in processing complex musical performance and highlight the potential of using brief naturalistic stimuli to localize distinct brain areas and elucidate potential mechanisms underlying multisensory integration.

10.
Comput Intell Neurosci ; 2022: 7589493, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35669664

RESUMEN

Neuroimaging researchers increasingly take advantage of the known functional properties of brain regions to localize motor regions in the brain and investigate changes in their activity under various conditions. Using this noninvasive functional MRI (fMRI) method makes it possible to identify and localize brain activation. There are many localizers that can be used to identify brain areas, namely, motor areas such as functional localizer, anatomical localizer, or Atlas mask. Eighteen right-handed participants were recruited for this research to test the reliability of five localizers for primary motor cortex (M1), supplementary motor area (SMA), premotor cortex (PMC), motor cerebellum, and motor thalamus. Motor execution task, namely, hand clenching was used to activate M1, SMA, and motor cerebellum. A combined action observation and motor imagery (AOMI) task was used to functionally activate PMC. Finally, a mask based on Talairach coordinates Atlas was created and used to identify the motor thalamus. Our results show that all localizers were successfully activated in the desired regions of interest. Motor execution successfully activated M1, SMA, and motor cerebellum. A novel localizer based on AOMI was successfully activated in PMC, and the motor thalamus mask obtained from the thalamus mask was successfully implemented on each participant. In conclusion, all five localizers tested in this research were reliable and can be used for rt-fMRI neurofeedback research to define the regions of interest.


Asunto(s)
Corteza Motora , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Mapeo Encefálico/métodos , Humanos , Imagen por Resonancia Magnética/métodos , Corteza Motora/fisiología , Reproducibilidad de los Resultados
11.
Psychon Bull Rev ; 29(5): 1803-1811, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35501545

RESUMEN

"People watching" is a ubiquitous component of human activities. An important aspect of such activities is the aesthetic experience that arises naturally from seeing how elegant people move their bodies in performing different actions. What makes some body movements look better than others? We examine how the human visual system gives rise to aesthetic experience from observing actions, using "creatures" generated by spatially scrambling locations of a point-light walker's joints. Observers rated how aesthetically pleasing and lifelike creatures were when the trajectories of joints were generated either from an upright walker (thus exhibiting gravitational acceleration) or an inverted walker (thus defying gravity), and were either congruent to the direction of global body displacements or incongruent (as in the moonwalk). Observers gave both higher aesthetic and animacy ratings for creatures with upright compared to inverted trajectories, and congruent compared to incongruent movements. Moreover, after controlling for animacy, aesthetic preferences for causally plausible movements (those in accord with gravity and body displacement) persisted. This systematicity in aesthetic impressions, even in the absence of explicit recognition of the moving agents, suggests an important role of automatic perceptual mechanisms in determining aesthetic experiences.


Asunto(s)
Percepción de Movimiento , Estética , Gravitación , Humanos , Movimiento , Orientación Espacial
12.
IEEE J Biomed Health Inform ; 26(6): 2469-2480, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-34882567

RESUMEN

Virtual reality (VR) has the potential to induce cybersickness (CS), which impedes CS-susceptible VR users from the benefit of emerging VR applications. To better detect CS, the current study investigated whether/how the newly proposed human vestibular network (HVN) is involved in flagship consumer VR-induced CS by simultaneously recording autonomic physiological signals as well as neural signals generated in sensorimotor and cognitive domains. The VR stimuli were made up of one or two moderate CS-inducing entertaining task(s) as well as a mild CS-inducing cognitive task implemented before and after the moderate CS task(s). Results not only showed that CS impaired cognitive control ability, represented by the degree of attentional engagement, but also revealed that combined indicators from all three HVN domains could together establish the best regression relationship with CS ratings. More importantly, we found that every HVN domain had its unique advantage with the dynamic changes in CS severity and time. These results provide evidence for involvement of the HVN in CS and indicate the necessity of HVN-based CS detection.


Asunto(s)
Realidad Virtual , Humanos
13.
Neuropsychologia ; 163: 108070, 2021 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-34695420

RESUMEN

For autistic individuals, sensory stimulation can be experienced as overwhelming. Models of predictive coding postulate that cortical mechanisms disamplify predictable information and amplify prediction errors that surpass a defined precision level. In autism, the neuronal processing is putting an inflexibly high precision on prediction errors according to the HIPPEA theory (High, Inflexible Precision of Prediction Errors in Autism). We used an apparent motion paradigm to test this prediction. In apparent motion paradigms, the illusory motion of an object creates a prediction about where and when an internally generated token would be moving along the apparent motion trace. This illusion facilitates the perception of a flashing stimulus (target) appearing in-time with the apparent motion token and is perceived as a predictable event (predictable target). In contrast, a flashing stimulus appearing out-of-time with the apparent motion illusion is an unpredictable target that is less often detected even though it produces a prediction error signal. If a prediction error does not surpass a given precision threshold the stimulation event is discounted and therefore less often detected than predictable tokens. In autism, the precision threshold is lower and the same prediction errors (unpredictable target) triggers a detection similar to that of a predictable flash stimulus. To test this hypothesis, we recruited 11 autistic males and 9 neurotypical matched controls. The participants were tasked to detect flashing stimuli placed on an apparent motion trace either in-time or out-of-time with the apparent motion illusion. Descriptively, 66% (6/9) of neurotypical and 64% (7/11) of autistic participants were better at detecting predictable targets. The prediction established by illusory motion appears to assist autistic and neurotypical individuals equally in the detection of predictable over unpredictable targets. Importantly, 55% (6/11) of autistic participants had faster responses for unpredictable targets, whereas only 22% (2/9) of neurotypicals had faster responses to unpredictable compared to predictable targets. Hence, these tentative results suggest that for autistic participants, unpredictable targets produce an above threshold prediction error, which leads to faster response. This difference in unpredictable target detection can be encapsulated under the HIPPEA theory, suggesting that precision setting could be aberrant in autistic individuals with respect to prediction errors. These tentative results should be considered in light of the small sample. For this reason, we provide the full set of materials necessary to replicate and extend the results.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Ilusiones , Humanos , Masculino
14.
Neuropsychologia ; 161: 107997, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34425144

RESUMEN

In everyday life, emotional information is often conveyed by both the face and the voice. Consequently, information presented by one source can alter the way in which information from the other source is perceived, leading to emotional incongruence. Here, we used functional magnetic resonance imaging (fMRI) to examine neutral correlates of two different types of emotional incongruence in audiovisual processing, namely incongruence of emotion-valence and incongruence of emotion-presence. Participants were in two groups, one group with a low Autism Quotient score (LAQ) and one with a high score (HAQ). Each participant experienced emotional (happy, fearful) or neutral faces or voices while concurrently being exposed to emotional (happy, fearful) or neutral voices or faces. They were instructed to attend to either the visual or auditory track. The incongruence effect of emotion-valence was characterized by activation in a wide range of brain regions in both hemispheres involving the inferior frontal gyrus, cuneus, superior temporal gyrus, and middle frontal gyrus. The incongruence effect of emotion-presence was characterized by activation in a set of temporal and occipital regions in both hemispheres, including the middle occipital gyrus, middle temporal gyrus and inferior temporal gyrus. In addition, the present study identified greater recruitment of the right inferior parietal lobule in perceiving audio-visual emotional expressions in HAQ individuals, as compared to the LAQ individuals. Depending on face or voice-to-be attended, different patterns of emotional incongruence were found between the two groups. Specifically, the HAQ group tend to show more incidental processing to visual information whilst the LAQ group tend to show more incidental processing to auditory information during the crossmodal emotional incongruence decoding. These differences might be attributed to different attentional demands and different processing strategies between the two groups.


Asunto(s)
Trastorno Autístico , Trastorno Autístico/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Emociones , Expresión Facial , Humanos , Imagen por Resonancia Magnética
16.
eNeuro ; 8(1)2021.
Artículo en Inglés | MEDLINE | ID: mdl-33376115

RESUMEN

Functional magnetic resonance imaging (fMRI) neurofeedback (NF) is a promising tool to study the relationship between behavior and brain activity. It enables people to self-regulate their brain signal. Here, we applied fMRI NF to train healthy participants to increase activity in their supplementary motor area (SMA) during a motor imagery (MI) task of complex body movements while they received a continuous visual feedback signal. This signal represented the activity of participants' localized SMA regions in the NF group and a prerecorded signal in the control group (sham feedback). In the NF group only, results showed a gradual increase in SMA-related activity across runs. This upregulation was largely restricted to the SMA, while other regions of the motor network showed no, or only marginal NF effects. In addition, we found behavioral changes, i.e., shorter reaction times in a Go/No-go task after the NF training only. These results suggest that NF can assist participants to develop greater control over a specifically targeted motor region involved in motor skill learning. The results contribute to a better understanding of the underlying mechanisms of SMA NF based on MI with a direct implication for rehabilitation of motor dysfunctions.


Asunto(s)
Corteza Motora , Neurorretroalimentación , Mapeo Encefálico , Humanos , Imagen por Resonancia Magnética , Regulación hacia Arriba
17.
PLoS One ; 15(11): e0242808, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33237979

RESUMEN

This study aimed to extend previous research on the experiences and factors that impact law enforcement personnel when working with distressing materials such as child sexual abuse content. A sample of 22 law enforcement personnel working within one law enforcement organisation in England, United Kingdom participated in anonymous semi-structured interviews. Results were explored thematically and organised in the following headings: "Responses to the material", "Impact of working with distressing evidence", "Personal coping strategies" and "Risks and mitigating factors". Law enforcement professionals experienced heightened affective responses to personally relevant material, depictions of violence, victims' displays of emotions, norm violations and to various mediums. These responses dampened over time due to desensitisation. The stress experienced from exposure to the material sometimes led to psychological symptoms associated with Secondary Traumatic Stress. Job satisfaction, self-care activities, the coping strategies used when viewing evidence, detachment from work outside working hours, social support and reducing exposure to the material were found to mediate law enforcement professionals' resilience. Exposure to distressing material and the risks associated with this exposure were also influenced by specific organisational procedures implemented as a function of the funding available and workload. Recommendations for individual and organisational practices to foster resilience emerged from this research. These recommendations are relevant to all organisations where employees are required to view distressing content.


Asunto(s)
Adaptación Psicológica , Emociones/fisiología , Aplicación de la Ley , Policia/psicología , Adulto , Anciano , Niño , Maltrato a los Niños/psicología , Femenino , Humanos , Satisfacción en el Trabajo , Masculino , Persona de Mediana Edad , Profesionalismo , Apoyo Social , Reino Unido/epidemiología , Violencia/psicología
18.
Proc Natl Acad Sci U S A ; 117(34): 20868-20873, 2020 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-32764147

RESUMEN

Adaptive social behavior and mental well-being depend on not only recognizing emotional expressions but also, inferring the absence of emotion. While the neurobiology underwriting the perception of emotions is well studied, the mechanisms for detecting a lack of emotional content in social signals remain largely unknown. Here, using cutting-edge analyses of effective brain connectivity, we uncover the brain networks differentiating neutral and emotional body language. The data indicate greater activation of the right amygdala and midline cerebellar vermis to nonemotional as opposed to emotional body language. Most important, the effective connectivity between the amygdala and insula predicts people's ability to recognize the absence of emotion. These conclusions extend substantially current concepts of emotion perception by suggesting engagement of limbic effective connectivity in recognizing the lack of emotion in body language reading. Furthermore, the outcome may advance the understanding of overly emotional interpretation of social signals in depression or schizophrenia by providing the missing link between body language reading and limbic pathways. The study thus opens an avenue for multidisciplinary research on social cognition and the underlying cerebrocerebellar networks, ranging from animal models to patients with neuropsychiatric conditions.


Asunto(s)
Emociones/fisiología , Cinésica , Trastornos Mentales/fisiopatología , Adulto , Amígdala del Cerebelo/fisiología , Encéfalo/fisiología , Mapeo Encefálico/métodos , Corteza Cerebral/fisiología , Expresión Facial , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Vías Nerviosas/fisiología , Estimulación Luminosa/métodos
19.
Sci Rep ; 10(1): 5362, 2020 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-32210277

RESUMEN

Multivariate Pattern Analysis (MVPA) has grown in importance due to its capacity to use both coarse and fine scale patterns of brain activity. However, a major limitation of multivariate analysis is the difficulty of aligning features across brains, which makes MVPA a subject specific analysis. Recent work by Haxby et al. (2011) introduced a method called Hyperalignment that explored neural activity in ventral temporal cortex during object recognition and demonstrated the ability to align individual patterns of brain activity into a common high dimensional space to facilitate Between Subject Classification (BSC). Here we examined BSC based on Hyperalignment of motor cortex during a task of motor imagery of three natural actions (lift, knock and throw). To achieve this we collected brain activity during the combined tasks of action observation and motor imagery to a parametric action space containing 25 stick-figure blends of the three natural actions. From these responses we derived Hyperalignment transformation parameters that were used to map subjects' representational spaces of the motor imagery task in the motor cortex into a common model representational space. Results showed that BSC of the neural response patterns based on Hyperalignment exceeded both BSC based on anatomical alignment as well as a standard Within Subject Classification (WSC) approach. We also found that results were sensitive to the order in which participants entered the Hyperalignment algorithm. These results demonstrate the effectiveness of Hyperalignment to align neural responses across subject in motor cortex to enable BSC of motor imagery.


Asunto(s)
Percepción de Movimiento/fisiología , Corteza Motora/diagnóstico por imagen , Corteza Motora/fisiología , Adulto , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Experimentación Humana no Terapéutica
20.
Front Comput Neurosci ; 13: 30, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31143108

RESUMEN

It is believed that Mirror Visual Feedback (MVF) increases the interlimb transfer but the exact mechanism is still a matter of debate. The aim of this study was to compare between a bimanual task (BM) and a MVF task, within functionally rather than geometrically defined cortical domains. Measure Projection Analysis (MPA) approach was applied to compare the dynamic oscillatory activity (event-related synchronization/desynchronization ERS/ERD) between and within domains. EEG was recorded in 14 healthy participants performing a BM and an MVF task with the right hand. The MPA was applied on fitted equivalent current dipoles based on independent components to define domains containing functionally similar areas. The measure of intradomain similarity was a "signed mutual information," a parameter based on the coherence. Domain analysis was performed for joint tasks (BM and MVF) and for each task separately. MVF created 9 functional domains while MB task had only 4 functionally distinctive domains, two over the left hemispheres and two bilateraly. For all domains identified for BM task alone, similar domains could be identified in MVF and joint tasks analysis. In addition MVF had domains related to motor planning on the right hemisphere and to self-recognition of action. For joint tasks analysis, seven domains were identified, with similar functions for the left and the right hand with exception of a domain covering BA32 (self-recognition of action) of the left hand only. In joint task domain analysis, the ERD/ERS showed a larger difference between domains than between tasks. All domains which involved the sensory cortex had a visible beta ERS at the onset of movement, and post movement beta ERS. The frequency of ERD varied between domains. Largest difference between tasks existed in domains responsible for the awareness of action. In conclusion, functionally distinctive domains have different ERD/ERS patterns, similar for both tasks. MVF activates contralateral hemisphere in similar manner to BM movements, while at the same time also activating the ipsilateral hemisphere. Significance: Following stroke cortical activation and interhemispheric inhibition from the contralesional side is reduced. MVF creates stronger ipsilateral activity than BM, which is highly relevant of neurorehabilitation of movements.

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