Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 18.219
Filtrar
1.
J Neuroeng Rehabil ; 21(1): 99, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851741

RESUMO

PURPOSE: Accurate perception of tactile stimuli is essential for performing and learning activities of daily living. Through this scoping review, we sought to summarize existing examination approaches for identifying tactile deficits at the upper extremity in individuals with stroke. The goal was to identify current limitations and future research needs for designing more comprehensive examination tools. METHODS: A scoping review was conducted in accordance with the Joanna Briggs Institute methodological framework and the PRISMA for Scoping Reviews (PRISMA-ScR) guidelines. A database search for tactile examination approaches at the upper extremity of individuals with stroke was conducted using Medline (Ovid), The Cochrane Library (Wiley), CINAHL Plus with Full Text (Ebsco), Scopus (Elsevier), PsycInfo (Ebsco), and Proquest Dissertations and Theses Global. Original research and review articles that involved adults (18 years or older) with stroke, and performed tactile examinations at the upper extremity were eligible for inclusion. Data items extracted from the selected articles included: if the examination was behavioral in nature and involved neuroimaging, the extent to which the arm participated during the examination, the number of possible outcomes of the examination, the type(s) of tactile stimulation equipment used, the location(s) along the arm examined, the peripheral nerves targeted for examination, and if any comparison was made with the non-paretic arm or with the arms of individuals who are neurotypical. RESULTS: Twenty-two articles met the inclusion criteria and were accepted in this review. Most examination approaches were behavioral in nature and involved self-reporting of whether a tactile stimulus was felt while the arm remained passive (i.e., no volitional muscle activity). Typically, the number of possible outcomes with these behavioral approaches were limited (2-3), whereas the neuroimaging approaches had many more possible outcomes ( > 15 ). Tactile examinations were conducted mostly at the distal locations along the arm (finger or hand) without targeting any specific peripheral nerve. Although a majority of articles compared paretic and non-paretic arms, most did not compare outcomes to a control group of individuals who are neurotypical. DISCUSSION: Our findings noted that most upper extremity tactile examinations are behavioral approaches, which are subjective in nature, lack adequate resolution, and are insufficient to identify the underlying neural mechanisms of tactile deficits. Also, most examinations are administered at distal locations of the upper extremity when the examinee's arm is relaxed (passive). Further research is needed to develop better tactile examination tools that combine behavioral responses and neurophysiological outcomes, and allow volitional tactile exploration. Approaches that include testing of multiple body locations/nerves along the upper extremity, provide higher resolution of outcomes, and consider normative comparisons with individuals who are neurotypical may provide a more comprehensive understanding of the tactile deficits occurring following a stroke.


Assuntos
Acidente Vascular Cerebral , Extremidade Superior , Humanos , Extremidade Superior/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/diagnóstico , Percepção do Tato/fisiologia , Tato/fisiologia
2.
PLoS One ; 19(5): e0293164, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38758835

RESUMO

Unmyelinated C-Tactile (CT) fibres are activated by caress-like touch, eliciting a pleasant feeling that decreases for static and faster stroking. Previous studies documented this effect also for vicarious touch, hypothesising simulation mechanisms driving the perception and appreciation of observed interpersonal touch. Notably, less is known about appreciation of vicarious execution of touch, that is as referred to the one giving gentle touch. To address this issue, 53 healthy participants were asked to view and rate a series of videoclips displaying an individual being touched by another on hairy (i.e., hand dorsum) or glabrous (i.e., palm) skin sites, with touch being delivered at CT-optimal (5 cm/s) or non-CT optimal velocities (0 cm/s or 30 cm/s). Following the observation of each clip, participants were asked to rate self-referred desirability and model-referred pleasantness of vicarious touch for both executer (toucher-referred) and receiver (touchee-referred). Consistent with the CT fibres properties, for both self-referred desirability and model-referred pleasantness judgements of vicarious touch execution and reception, participants provided higher ratings for vicarious touch delivered at CT-optimal than other velocities, and when observed CT-optimal touch was delivered to the hand-dorsum compared to the palm. However, higher ratings were attributed to vicarious reception compared to execution of CT-optimal touch. Notably, individual differences in interoceptive trusting and attitude to interpersonal touch were positively correlated with, respectively, toucher- and touchee-related overall appraisal ratings of touch. These findings suggest that the appreciation of both toucher- and touchee-referred vicarious touch is specifically attuned to CT-optimal touch, even though they might rely on different neurocognitive mechanisms to understand affective information conveyed by interpersonal tactile interactions.


Assuntos
Percepção do Tato , Tato , Humanos , Masculino , Feminino , Adulto , Tato/fisiologia , Percepção do Tato/fisiologia , Adulto Jovem , Relações Interpessoais
3.
J Acoust Soc Am ; 155(5): 3101-3117, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38722101

RESUMO

Cochlear implant (CI) users often report being unsatisfied by music listening through their hearing device. Vibrotactile stimulation could help alleviate those challenges. Previous research has shown that musical stimuli was given higher preference ratings by normal-hearing listeners when concurrent vibrotactile stimulation was congruent in intensity and timing with the corresponding auditory signal compared to incongruent. However, it is not known whether this is also the case for CI users. Therefore, in this experiment, we presented 18 CI users and 24 normal-hearing listeners with five melodies and five different audio-to-tactile maps. Each map varied the congruence between the audio and tactile signals related to intensity, fundamental frequency, and timing. Participants were asked to rate the maps from zero to 100, based on preference. It was shown that almost all normal-hearing listeners, as well as a subset of the CI users, preferred tactile stimulation, which was congruent with the audio in intensity and timing. However, many CI users had no difference in preference between timing aligned and timing unaligned stimuli. The results provide evidence that vibrotactile music enjoyment enhancement could be a solution for some CI users; however, more research is needed to understand which CI users can benefit from it most.


Assuntos
Estimulação Acústica , Percepção Auditiva , Implantes Cocleares , Música , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Percepção Auditiva/fisiologia , Adulto Jovem , Preferência do Paciente , Implante Coclear/instrumentação , Percepção do Tato/fisiologia , Vibração , Tato
4.
ACS Appl Mater Interfaces ; 16(19): 25404-25414, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38692284

RESUMO

Liquid crystal elastomers (LCEs), as a classical two-way shape-memory material, are good candidates for developing artificial muscles that mimic the contraction, expansion, or rotational behavior of natural muscles. However, biomimicry is currently focused more on the actuation functions of natural muscles dominated by muscle fibers, whereas the tactile sensing functions that are dominated by neuronal receptors and synapses have not been well captured. Very few studies have reported the sensing concept for LCEs, but the signals were still donated by macroscopic actuation, that is, variations in angle or length. Herein, we develop a conductive porous LCE (CPLCE) using a solvent (dimethyl sulfoxide (DMSO))-templated photo-cross-linking strategy, followed by carbon nanotube (CNT) incorporation. The CPLCE has excellent reversible contraction/elongation behavior in a manner similar to the actuation functions of skeletal muscles. Moreover, the CPLCE shows excellent pressure-sensing performance by providing real-time electrical signals and is capable of microtouch sensing, which is very similar to natural tactile sensing. Furthermore, macroscopic actuation and tactile sensation can be integrated into a single system. Proof-of-concept studies reveal that the CPLCE-based artificial muscle is sensitive to external touch while maintaining its excellent actuation performance. The CPLCE with tactile sensation beyond reversible actuation is expected to benefit the development of versatile artificial muscles and intelligent robots.


Assuntos
Elastômeros , Cristais Líquidos , Nanotubos de Carbono , Cristais Líquidos/química , Elastômeros/química , Nanotubos de Carbono/química , Porosidade , Solventes/química , Tato/fisiologia , Órgãos Artificiais , Músculo Esquelético/fisiologia , Músculo Esquelético/química , Humanos
5.
Sci Rep ; 14(1): 11296, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760391

RESUMO

The body and the self change markedly during adolescence, but how does bodily self-consciousness, the pre-reflexive experience of being a bodily subject, change? We addressed this issue by studying embodiment towards virtual avatars in 70 girls aged 10-17 years. We manipulated the synchrony between participants' and avatars' touch or movement, as well as the avatar visual shape or size relative to each participant's body. A weaker avatar's embodiment in case of mismatch between the body seen in virtual reality and the real body is indicative of a more robust bodily self-consciousness. In both the visuo-tactile and the visuo-motor experiments, asynchrony decreased ownership feeling to the same extent for all participants, while the effect of asynchrony on agency feeling increased with age. In the visuo-tactile experiment, incongruence in visual appearance did not affect agency feeling but impacted ownership, especially in older teenage girls. These findings highlight the higher malleability of bodily self-consciousness at the beginning of adolescence and suggest some independence between body ownership and agency.


Assuntos
Imagem Corporal , Autoimagem , Humanos , Adolescente , Feminino , Criança , Imagem Corporal/psicologia , Estado de Consciência/fisiologia , Realidade Virtual , Percepção do Tato/fisiologia , Tato/fisiologia , Percepção Visual/fisiologia
6.
Behav Processes ; 218: 105041, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692460

RESUMO

A previous study demonstrated that rodents on an inclined square platform traveled straight vertically or horizontally and avoided diagonal travel. Through behavior they aligned their head with the horizontal plane, acquiring similar bilateral vestibular cues - a basic requirement for spatial orientation and a salient feature of animals in motion. This behavior had previously been shown to be conspicuous in Tristram's jirds. Here, therefore jirds were challenged by testing their travel behavior on a circular arena inclined at 0°-75°. Our hypothesis was that if, as typical to rodents, the jirds would follow the curved arena wall, they would need to display a compensating mechanism to enable traveling in such a path shape, which involves a tilted frontal head axis and unbalanced bilateral vestibular cues. We found that with the increase in inclination, the jirds remained more in the lower section of the arena (geotaxis). When tested on the steep inclinations, however, their travel away from the arena wall was strictly straight up or down, in contrast to the curved paths that followed the circular arena wall. We suggest that traveling along a circular path while maintaining contact with the wall (thigmotaxis), provided tactile information that compensated for the unbalanced bilateral vestibular cues present when traveling along such curved inclined paths. In the latter case, the frontal plane of the head was in a diagonal posture in relation to gravity, a posture that was avoided when traveling away from the wall.


Assuntos
Sinais (Psicologia) , Orientação Espacial , Vestíbulo do Labirinto , Animais , Vestíbulo do Labirinto/fisiologia , Orientação Espacial/fisiologia , Masculino , Tato/fisiologia , Postura/fisiologia , Percepção do Tato/fisiologia
7.
Sensors (Basel) ; 24(9)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38733054

RESUMO

The problem of supporting visually impaired and blind people in meaningful interactions with objects is often neglected. To address this issue, we adapted a tactile belt for enhanced spatial navigation into a bracelet worn on the wrist that allows visually impaired people to grasp target objects. Participants' performance in locating and grasping target items when guided using the bracelet, which provides direction commands via vibrotactile signals, was compared to their performance when receiving auditory instructions. While participants were faster with the auditory commands, they also performed well with the bracelet, encouraging future development of this system and similar systems.


Assuntos
Força da Mão , Tato , Pessoas com Deficiência Visual , Humanos , Masculino , Tato/fisiologia , Feminino , Força da Mão/fisiologia , Adulto , Cegueira/fisiopatologia , Cegueira/reabilitação , Movimento/fisiologia , Pessoa de Meia-Idade
8.
Dev Psychobiol ; 66(5): e22486, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38739111

RESUMO

Maternal deprivation, as a result of the artificial rearing (AR) paradigm, disturbs electrophysiological and histological characteristics of the peripheral sensory sural (SU) nerve of infant and adult male rats. Such changes are prevented by providing tactile or social stimulation during isolation. AR also affects the female rat's brain and behavior; however, it is unknown whether this early adverse experience also alters their SU nerve development or if tactile stimulation might prevent these possible developmental effects. To assess these possibilities, the electrophysiological and histological characteristics of the SU nerve from adult diestrus AR female rats that: (i) received no tactile stimulation (AR group), (ii) received tactile stimulation in the anogenital and body area (AR-Tactile group), or (iii) were mother reared (MR group) were determined. We found that the amplitude, but not the area, of the evoked compound action potential response in SU nerves of AR rats was lower than those of SU nerves of MR female rats. Tactile stimulation prevented these effects. Additionally, we found a reduction in the outer diameter and myelin thickness of axons, as well as a large proportion of axons with low myelin thickness in nerves of AR rats compared to the nerves of the MR and AR-Tactile groups of rats; however, tactile stimulation only partially prevented these effects. Our data indicate that maternal deprivation disturbs the development of sensory SU nerves in female rats, whereas tactile stimulation partially prevents the changes generated by AR. Considering that our previous studies have shown more severe effects of AR on male SU nerve development, we suggest that sex-associated factors may be involved in these processes.


Assuntos
Privação Materna , Nervo Sural , Tato , Animais , Feminino , Ratos , Nervo Sural/fisiologia , Tato/fisiologia , Estimulação Física , Ratos Wistar , Axônios/fisiologia , Potenciais de Ação/fisiologia , Bainha de Mielina/fisiologia
9.
Int J Qual Stud Health Well-being ; 19(1): 2348891, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38723246

RESUMO

PURPOSE: This article describes intensive care nurses` experiences of using communicative caring touch as stroking the patient`s cheek or holding his hand. Our research question: "What do intensive care nurses communicate through caring touch?" METHODS: In this qualitative hermeneutically based study data from two intensive care units at Norwegian hospitals are analysed. Eight specialist nurses shared experiences through individual, semi-structured interviews. RESULTS: The main theme, Communicating safety and presence has four sub-themes: Amplified presence, Communicating security, trust and care, Creating and confirming relationships and Communicating openness to a deeper conversation. Communicative caring touch is offered from the nurse due to the patient`s needs. Caring touch communicates person-centred care, invites to relationship while respecting the patient's dignity as a fellow human being. Caring touch conveys a human initiative in the highly technology environment. CONCLUSION: Caring touch is the silent way to communicate care, hope, strength and humanity to critical sick patients. This article provides evidence for a common, but poorly described phenomenon in intensive care nursing.


Assuntos
Comunicação , Enfermagem de Cuidados Críticos , Empatia , Unidades de Terapia Intensiva , Relações Enfermeiro-Paciente , Pesquisa Qualitativa , Tato , Humanos , Noruega , Feminino , Masculino , Adulto , Atitude do Pessoal de Saúde , Recursos Humanos de Enfermagem Hospitalar/psicologia , Assistência Centrada no Paciente , Pessoa de Meia-Idade , Confiança
10.
J Oleo Sci ; 73(5): 801-811, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38692901

RESUMO

Hair shape affects the frictional properties and tactile sensation of hair. In this study, we evaluated the friction associated with the rubbing of straight, curly, or wavy hair by a contact probe equipped in a sinusoidal motion friction evaluation system. This system provides dynamic information such as the velocity dependence and hysteresis of the frictional force. In the case of hair fibers fixed at 1 mm intervals on a glass plate, a stable friction pattern was observed, in which the friction coefficient was almost constant during the dynamic friction process. The friction coefficients in the inward direction toward the hair root for straight, curly, and wavy hair were 0.47 ± 0.04, 0.51 ± 0.02, and 0.54 ± 0.04, respectively. As wavy hair is thick and has a larger true contact area with the contact probe, the friction coefficient was larger. When the finger model rubbed the straight or curly hair bundle in the inward direction, an oscillation pattern was observed, with the friction coefficient fluctuating at 20 ms intervals and the kinetic friction coefficient evaluated at 0.67 and 0.64, respectively. For the surface of straight hair, containing densely arranged cuticles, a large oscillation was observed in the direction against the cuticles. Meanwhile, no oscillation phenomenon was observed in wavy hair, which is characterized by a smooth cuticle and complex hair flow. Because wavy hair, which is frizzy, has fewer points of contact between hairs, impeding the occurrence of cooperative fluctuations in the frictional force.


Assuntos
Fricção , Cabelo , Cabelo/fisiologia , Humanos , Tato/fisiologia
11.
Science ; 384(6699): 987-994, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38815009

RESUMO

Human skin sensing of mechanical stimuli originates from transduction of mechanoreceptors that converts external forces into electrical signals. Although imitating the spatial distribution of those mechanoreceptors can enable developments of electronic skins capable of decoupled sensing of normal/shear forces and strains, it remains elusive. We report a three-dimensionally (3D) architected electronic skin (denoted as 3DAE-Skin) with force and strain sensing components arranged in a 3D layout that mimics that of Merkel cells and Ruffini endings in human skin. This 3DAE-Skin shows excellent decoupled sensing performances of normal force, shear force, and strain and enables development of a tactile system for simultaneous modulus/curvature measurements of an object through touch. Demonstrations include rapid modulus measurements of fruits, bread, and cake with various shapes and degrees of freshness.


Assuntos
Mecanorreceptores , Tato , Humanos , Mecanorreceptores/fisiologia , Células de Merkel/fisiologia , Pele/inervação , Fenômenos Fisiológicos da Pele , Pele Artificial
12.
PLoS One ; 19(5): e0304008, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38814897

RESUMO

The current study investigated spatial scaling of tactile maps among blind adults and blindfolded sighted controls. We were specifically interested in identifying spatial scaling strategies as well as effects of different scaling directions (up versus down) on participants' performance. To this aim, we asked late blind participants (with visual memory, Experiment 1) and early blind participants (without visual memory, Experiment 2) as well as sighted blindfolded controls to encode a map including a target and to place a response disc at the same spot on an empty, constant-sized referent space. Maps had five different sizes resulting in five scaling factors (1:3, 1:2, 1:1, 2:1, 3:1), allowing to investigate different scaling directions (up and down) in a single, comprehensive design. Accuracy and speed of learning about the target location as well as responding served as dependent variables. We hypothesized that participants who can use visual mental representations (i.e., late blind and blindfolded sighted participants) may adopt mental transformation scaling strategies. However, our results did not support this hypothesis. At the same time, we predicted the usage of relative distance scaling strategies in early blind participants, which was supported by our findings. Moreover, our results suggested that tactile maps can be scaled as accurately and even faster by blind participants than by sighted participants. Furthermore, irrespective of the visual status, participants of each visual status group gravitated their responses towards the center of the space. Overall, it seems that a lack of visual imagery does not impair early blind adults' spatial scaling ability but causes them to use a different strategy than sighted and late blind individuals.


Assuntos
Cegueira , Humanos , Cegueira/fisiopatologia , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Percepção Espacial/fisiologia , Percepção do Tato/fisiologia , Adulto Jovem , Tato/fisiologia
13.
J Phys Chem Lett ; 15(22): 5862-5867, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38804506

RESUMO

An artificial tactile receptor is crucial for e-skin in next-generation robots, mimicking the mechanical sensing, signal encoding, and preprocessing functionalities of human skin. In the neural network, pressure signals are encoded in spike patterns and efficiently transmitted, exhibiting low power consumption and robust tolerance for bit error rates. Here, we introduce a highly sensitive artificial tactile receptor system integrating a pressure sensor, axon-hillock circuit, and neurotransmitter release device to achieve pressure signal coding with patterned spikes and controlled neurotransmitter release. Owing to the heightened sensitivity of the axon-hillock circuit to pressure-mediated current signals, the artificial tactile receptor achieves a detection limit of 10 Pa that surpasses the human tactile receptors, with a wide response range from 10 to 5 × 105 Pa. Benefiting from the appreciable pressure-responsive performance, the potential application of an artificial tactile receptor in robotic tactile perception has been demonstrated, encompassing tasks such as finger touch and human pulse detection.


Assuntos
Pressão , Tato , Humanos , Robótica , Receptores Artificiais/química , Receptores Artificiais/metabolismo , Neurotransmissores/química
14.
Proc Natl Acad Sci U S A ; 121(22): e2404007121, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38768347

RESUMO

Sensations of heat and touch produced by receptors in the skin are of essential importance for perceptions of the physical environment, with a particularly powerful role in interpersonal interactions. Advances in technologies for replicating these sensations in a programmable manner have the potential not only to enhance virtual/augmented reality environments but they also hold promise in medical applications for individuals with amputations or impaired sensory function. Engineering challenges are in achieving interfaces with precise spatial resolution, power-efficient operation, wide dynamic range, and fast temporal responses in both thermal and in physical modulation, with forms that can extend over large regions of the body. This paper introduces a wireless, skin-compatible interface for thermo-haptic modulation designed to address some of these challenges, with the ability to deliver programmable patterns of enhanced vibrational displacement and high-speed thermal stimulation. Experimental and computational investigations quantify the thermal and mechanical efficiency of a vertically stacked design layout in the thermo-haptic stimulators that also supports real-time, closed-loop control mechanisms. The platform is effective in conveying thermal and physical information through the skin, as demonstrated in the control of robotic prosthetics and in interactions with pressure/temperature-sensitive touch displays.


Assuntos
Tato , Realidade Virtual , Tecnologia sem Fio , Humanos , Tecnologia sem Fio/instrumentação , Tato/fisiologia , Pele , Robótica/instrumentação , Robótica/métodos
15.
Plant Signal Behav ; 19(1): 2360296, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38808631

RESUMO

Rainfall, wind and touch, as mechanical forces, were mimicked on 6-week-old soil-grown tomato and potato under controlled conditions. Expression level changes of xyloglucan endotransglucosylase/hydrolase genes (XTHs) of tomato (Solanum lycopersicum L. cv. Micro Tom; SlXTHs) and potato (Solanum tuberosum L. cv. Desirée; StXTHs) were analyzed in response to these mechanical forces. Transcription intensity of every SlXTHs of tomato was altered in response to rainfall, while the expression intensity of 72% and 64% of SlXTHs was modified by wind and touch, respectively. Ninety-one percent of StXTHs (32 out of 35) in potato responded to the rainfall, while 49% and 66% of the StXTHs were responsive to the wind and touch treatments, respectively. As previously demonstrated, all StXTHs were responsive to ultrasound treatment, and all were sensitive to one or more of the environmental mechanical factors examined in the current study. To our best knowledge, this is the first study to demonstrate that these ubiquitous mechanical environmental cues, such as rainfall, wind and touch, influence the transcription of most XTHs examined in both species.


Assuntos
Regulação da Expressão Gênica de Plantas , Chuva , Solanum lycopersicum , Solanum tuberosum , Vento , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Solanum tuberosum/fisiologia , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Tato/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genes de Plantas
16.
Sci Rep ; 14(1): 11766, 2024 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783038

RESUMO

Human tactile memory allows us to remember and retrieve the multitude of somatosensory experiences we undergo in everyday life. An unsolved question is how tactile memory mechanisms change with increasing age. We here use the ability to remember fine-grained tactile patterns passively presented to the fingertip to investigate age-related changes in tactile memory performance. In experiment 1, we varied the degree of similarity between one learned and several new tactile patterns to test on age-related changes in the "uniqueness" of a stored tactile memory trace. In experiment 2, we varied the degree of stimulus completeness of both known and new tactile patterns to test on age-related changes in the weighting between known and novel tactile information. Results reveal that older adults show only weak impairments in both precision and bias of tactile memories, however, they show specific deficits in reaching peak performance > 85% in both experiments. In addition, both younger and older adults show a pattern completion bias for touch, indicating a higher weighting of known compared to new information. These results allow us to develop new models on how younger and older adults store and recall tactile experiences of the past, and how this influences their everyday behavior.


Assuntos
Tato , Humanos , Idoso , Masculino , Feminino , Adulto , Adulto Jovem , Tato/fisiologia , Pessoa de Meia-Idade , Percepção do Tato/fisiologia , Envelhecimento/fisiologia , Memória/fisiologia , Transtornos da Memória/fisiopatologia , Idoso de 80 Anos ou mais
17.
Sci Rep ; 14(1): 11697, 2024 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-38777816

RESUMO

Allogrooming is a widespread, pervasive activity among non-human primates. Besides its hygienic function, it is thought to be instrumental in maintaining social bonds and establishing hierarchical structures within groups. However, the question arises as to whether the physiological and social benefits derived from social touch stem directly from body stimulation, or whether other mechanisms come into play. We address this question by analyzing an elaborate social behavior that we observed in two adult male macaques. This behavior demonstrates the existence of a persistent motivation to interact through a form of simulated grooming, as the animals were housed in adjacent enclosures separated by a glass panel preventing direct tactile contact. We find that such virtual grooming produces similar physiological sensations and social effects as allogrooming. We suggest that this behavior engages affective and reward brain circuits to the same extent as real social touch, and that this is probably achieved through high level processes similar to those involved in bodily illusions or synaesthetic phenomena previously described in humans. This observation reveals the unsuspected capacity of non-human primates to invent alternative, quasi-symbolic strategies to obtain effects similar to those provided by direct bodily interaction, which are so important for maintaining social bonds.


Assuntos
Asseio Animal , Comportamento Social , Animais , Masculino , Asseio Animal/fisiologia , Comportamento Animal/fisiologia , Tato/fisiologia , Macaca , Psicofisiologia
18.
PLoS One ; 19(5): e0300128, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38758733

RESUMO

Interpersonal touch plays a crucial role in human communication, development, and wellness. Mediated interpersonal touch (MIT), a technology to distance or virtually simulated interpersonal touch, has received significant attention to counteract the negative consequences of touch deprivation. Studies investigating the effectiveness of MIT have primarily focused on self-reporting or behavioral correlates. It is largely unknown how MIT affects neural processes such as interbrain functional connectivity during human interactions. Given how users exchange haptic information simultaneously during interpersonal touch, interbrain functional connectivity provides a more ecologically valid way of studying the neural correlates associated with MIT. In this study, a palm squeeze task is designed to examine interbrain synchrony associated with MIT using EEG-based hyperscanning methodology. The phase locking value (PLV) index is used to measure interbrain synchrony. Results demonstrate that MIT elicits a significant increase in alpha interbrain synchronization between participants' brains. Especially, there was a significant difference in the alpha PLV indices between no MIT and MIT conditions in the early stage (130-470 ms) of the interaction period (t-test, p < 0.05). Given the role that alpha interbrain synchrony plays during social interaction, a significant increase in PLV index during MIT interaction seems to indicate an effect of social coordination. The findings and limitations of this study are further discussed, and perspectives on future research are provided.


Assuntos
Encéfalo , Eletroencefalografia , Relações Interpessoais , Tato , Humanos , Encéfalo/fisiologia , Masculino , Feminino , Adulto Jovem , Tato/fisiologia , Adulto , Ritmo alfa/fisiologia , Percepção do Tato/fisiologia , Interação Social
19.
J Neuroeng Rehabil ; 21(1): 79, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38750521

RESUMO

A large proportion of stroke survivors suffer from sensory loss, negatively impacting their independence, quality of life, and neurorehabilitation prognosis. Despite the high prevalence of somatosensory impairments, our understanding of somatosensory interventions such as sensory electrical stimulation (SES) in neurorehabilitation is limited. We aimed to study the effectiveness of SES combined with a sensory discrimination task in a well-controlled virtual environment in healthy participants, setting a foundation for its potential application in stroke rehabilitation. We employed electroencephalography (EEG) to gain a better understanding of the underlying neural mechanisms and dynamics associated with sensory training and SES. We conducted a single-session experiment with 26 healthy participants who explored a set of three visually identical virtual textures-haptically rendered by a robotic device and that differed in their spatial period-while physically guided by the robot to identify the odd texture. The experiment consisted of three phases: pre-intervention, intervention, and post-intervention. Half the participants received subthreshold whole-hand SES during the intervention, while the other half received sham stimulation. We evaluated changes in task performance-assessed by the probability of correct responses-before and after intervention and between groups. We also evaluated differences in the exploration behavior, e.g., scanning speed. EEG was employed to examine the effects of the intervention on brain activity, particularly in the alpha frequency band (8-13 Hz) associated with sensory processing. We found that participants in the SES group improved their task performance after intervention and their scanning speed during and after intervention, while the sham group did not improve their task performance. However, the differences in task performance improvements between groups only approached significance. Furthermore, we found that alpha power was sensitive to the effects of SES; participants in the stimulation group exhibited enhanced brain signals associated with improved touch sensitivity likely due to the effects of SES on the central nervous system, while the increase in alpha power for the sham group was less pronounced. Our findings suggest that SES enhances texture discrimination after training and has a positive effect on sensory-related brain areas. Further research involving brain-injured patients is needed to confirm the potential benefit of our solution in neurorehabilitation.


Assuntos
Eletroencefalografia , Humanos , Masculino , Feminino , Adulto , Percepção do Tato/fisiologia , Reabilitação Neurológica/métodos , Estimulação Elétrica/métodos , Adulto Jovem , Tato/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos
20.
Sci Rep ; 14(1): 10164, 2024 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702338

RESUMO

Orientation processing is one of the most fundamental functions in both visual and somatosensory perception. Converging findings suggest that orientation processing in both modalities is closely linked: somatosensory neurons share a similar orientation organisation as visual neurons, and the visual cortex has been found to be heavily involved in tactile orientation perception. Hence, we hypothesized that somatosensation would exhibit a similar orientation adaptation effect, and this adaptation effect would be transferable between the two modalities, considering the above-mentioned connection. The tilt aftereffect (TAE) is a demonstration of orientation adaptation and is used widely in behavioural experiments to investigate orientation mechanisms in vision. By testing the classic TAE paradigm in both tactile and crossmodal orientation tasks between vision and touch, we were able to show that tactile perception of orientation shows a very robust TAE, similar to its visual counterpart. We further show that orientation adaptation in touch transfers to produce a TAE when tested in vision, but not vice versa. Additionally, when examining the test sequence following adaptation for serial effects, we observed another asymmetry between the two conditions where the visual test sequence displayed a repulsive intramodal serial dependence effect while the tactile test sequence exhibited an attractive serial dependence. These findings provide concrete evidence that vision and touch engage a similar orientation processing mechanism. However, the asymmetry in the crossmodal transfer of TAE and serial dependence points to a non-reciprocal connection between the two modalities, providing further insights into the underlying processing mechanism.


Assuntos
Adaptação Fisiológica , Percepção do Tato , Percepção Visual , Humanos , Masculino , Feminino , Adulto , Percepção do Tato/fisiologia , Percepção Visual/fisiologia , Adulto Jovem , Orientação/fisiologia , Tato/fisiologia , Orientação Espacial/fisiologia , Visão Ocular/fisiologia , Córtex Visual/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...