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Anxiety can alter an individual’s perception of their external sensory environment. Previous studies suggest that anxiety can increase the magnitude of neural responses to unexpected (or surprising) stimuli. Additionally, surprise responses are reported to be boosted during stable compared to volatile environments. Few studies, however, have examined how learning is impacted by both threat and volatility. To investigate these effects, we used threat-of-shock to transiently increase subjective anxiety in healthy adults during an auditory oddball task, in which the regularity could be stable or volatile, while undergoing functional Magnetic Resonance Imaging (fMRI) scanning. We then used Bayesian Model Selection (BMS) mapping to pinpoint the brain areas where different models of anxiety displayed the highest evidence. Behaviourally, we found that threat-of-shock eliminated the accuracy advantage conferred by environmental stability over volatility in the task at hand. Neurally, we found that threat-of-shock led to both attenuation and loss of volatility-attuning of neural activity evoked by surprising sounds across most subcortical and limbic brain regions including the thalamus, basal ganglia, claustrum, insula, anterior cingulate, hippocampal gyrus and also the superior temporal gyrus. Conversely, within two small clusters in the left medial frontal gyrus and extrastriate area, threat-of-shock boosted the neural activity (relative to the safe and volatile condition) to the levels observed during the safe and stable condition, while also inducing a loss of volatility-attuning. Taken together, our findings suggest that threat eliminates the learning advantage conferred by statistical stability compared to volatility. Thus, we propose that anxiety disrupts behavioural adaptation to environmental statistics, and that multiple subcortical and limbic regions are implicated in this process.

BACKGROUND: Williams syndrome (WS) is a neurodevelopmental disorder characterized by hypersociability, heightened auditory sensitivities, attention deficits, and strong musical interests despite differences in musical skills. Behavioral studies report individuals with WS exhibit variable beat and rhythm perception skills. METHODS: We sought to investigate the neural basis of beat tracking in individuals with WS using electroencephalography (EEG). Twenty-seven adults with WS and sixteen age-matched typically developing control subjects passively listened to musical rhythms with accents on either the first or second tone of the repeating pattern, leading to distinct beat percepts. RESULTS: Consistent with the role of beta and gamma oscillations in rhythm processing, individuals with WS and typically developing control subjects showed strong evoked neural activity in both beta (13-30 Hz) and gamma (31-55 Hz) frequency bands in response to beat onsets. This neural response was somewhat more distributed across the scalp for individuals with WS. Compared with typically developing control subjects, individuals with WS exhibited significantly greater amplitude of auditory evoked potentials (P1-N1-P2 complex) and modulations in evoked alpha (8-12 Hz) activity, reflective of sensory and attentional processes, compared to typically developing control subjects. Individuals with WS also exhibited markedly stable neural responses over the course of the experiment, and these were significantly more stable than those of controls. CONCLUSIONS: These results provide neurophysiological evidence for dynamic beat tracking in WS and coincide with the atypical auditory phenotype and attentional difficulties seen in this population.

Disability is an important facet of diversity. Although diversity in clinical training in health service psychology has improved considerably, training often neglects accessibility and inclusion for individuals with sensory disabilities. The limited research to date documents that trainees with sensory disabilities (TSD) report extensive barriers and are consistently under-represented in clinical settings. Further, few resources have been developed to guide accommodating TSD in clinical training. Accordingly, our goals in this article are two-fold: (1) to highlight the barriers in clinical training faced by TSD and (2) to provide recommendations for trainees, supervisors, clinical leadership, and directors of clinical training to improve accessibility and inclusion for TSD. We offer vignettes to illustrate barriers faced by TSD and suggest guidelines to improve access for TSD.

The purpose of this study was to create a detailed characterization of the nature of the sensory perceptions associated with after-death communication. A primary aim was to determine if perceptions of after-death communication (ADC) support one or more of three hypotheses: (1) they are the result of hallucinations or day-to-day thoughts about the deceased; (2) they are subjective phenomena reflecting the extrasensory perception of remote events; or (3) they constitute objective phenomena, perceived more solidly, as if within the physical world. Methods: The study included a quantitative analysis and qualitative first-person narrative description of part of the data set from a detailed questionnaire study (991 viable cases) investigating the phenomenology of spontaneous ADCs. Results and Conclusions: A majority of respondents reported that ADCs were distinctly different from simple thoughts about the deceased. Specifically, relative distribution of ADCs across the senses was 46% visual, 44% auditory, 48% touch, and 28% olfactory, with 34% sensing the presence of the deceased without input from the five senses. ADCs often were perceived as external and having properties of the material world (e.g., solidity, tactile qualities). Even the more nebulous 'sense of presence' cases were perceived as having a distinct location in space and as being identifiable as a specific deceased presence despite the lack of sensory cues. These elements are more compatible with hypotheses 2 and 3 than hypothesis 1.

Background: Interoceptive signals related to changes in heartbeat, respiration, and gastric functioning continuously feedback to the brain. The interpretation of these signals influences several co...

The understanding of the neural control of appetite sheds light on the pathogenesis of eating disorders such as anorexia nervosa and obesity. Both diseases are a result of maladaptive eating behaviors (overeating or undereating) and are associated with life-threatening health problems. The fine regulation of appetite involves genetic, physiological, and environmental factors, which are detected and integrated in the brain by specific neuronal populations. For centuries, the hypothalamus has been the center of attention in the scientific community as a key regulator of appetite. The hypothalamus receives and sends axonal projections to several other brain regions that are important for the integration of sensory and emotional information. These connections ensure that appropriate behavioral decisions are made depending on the individual’s emotional state and environment. Thus, the mechanisms by which higher-order brain regions integrate exteroceptive information to coordinate feeding is of great importance. In this review, we will focus on the functional and anatomical projections connecting the hypothalamus to the limbic system and higher-order brain centers in the cortex. We will also address the mechanisms by which specific neuronal populations located in higher-order centers regulate appetite and how maladaptive eating behaviors might arise from altered connections among cortical and subcortical areas with the hypothalamus.

Summary While animals navigating the real world face a barrage of complex sensory input, their brains have evolved to perceptually compress multidimensional information by selectively extracting the features relevant for survival. For instance, communication signals supporting social interactions in several mammalian species consist of acoustically complex sequences of vocalizations, however little is known about what information listeners extract from such time-varying sensory streams. Here, we utilize female mice’s natural behavioural response to male courtship songs to evaluate the relevant acoustic dimensions used in their social decisions. We found that females were highly sensitive to disruptions of song temporal regularity, and preferentially approached playbacks of intact male songs over rhythmically irregular versions of the songs. In contrast, female behaviour was invariant to manipulations affecting the songs’ sequential organization, or the spectrotemporal structure of individual syllables. The results reveal temporal regularity as a key acoustic cue extracted by mammalian listeners from complex vocal sequences during goal-directed social behaviour. Highlights - Natural behaviour is used to probe how mouse listeners encode vocal sequences - Listeners are highly sensitive to disruptions of the songs’ rhythmic regularity - Female behaviour is invariant to changes in song sequence - Approach behaviour is robust to the removal of syllable spectrotemporal dynamics

Neurons in parietal cortex exhibit task-related activity during decision-making tasks. However, it remains unclear how long-term training to perform different tasks over months or even years shapes neural computations and representations. We examine lateral intraparietal area (LIP) responses during a visual motion delayed-match-to-category task. We consider two pairs of male macaque monkeys with different training histories: one trained only on the categorization task, and another first trained to perform fine motion-direction discrimination (i.e., pretrained). We introduce a novel analytical approach—generalized multilinear models—to quantify low-dimensional, task-relevant components in population activity. During the categorization task, we found stronger cosine-like motion-direction tuning in the pretrained monkeys than in the category-only monkeys, and that the pretrained monkeys’ performance depended more heavily on fine discrimination between sample and test stimuli. These results suggest that sensory representations in LIP depend on the sequence of tasks that the animals have learned, underscoring the importance of considering training history in studies with complex behavioral tasks.

The question how the brain distinguishes between information about oneself and the rest of the world is of fundamental interest to both philosophy and neuroscience. This question can be approached empirically by investigating how associating stimuli with oneself leads to differences in neurocognitive processing. However, little is known about the brain network involved in forming such self-associations for, specifically, bodily stimuli. In this fMRI study, we sought to distinguish the neural substrates of representing a full-body movement as one’s movement and as someone else’s movement. Participants performed a delayed match-to-sample working memory task where a retained full-body movement (displayed using point-light walkers) was arbitrarily labelled as one’s own movement or as performed by someone else. By using arbitrary associations we aimed to address a limitation of previous studies, namely that our own movements are more familiar to us than movements of other people. A searchlight multivariate decoding analysis was used to test where information about types of movement and about self-association was coded. Movement specific activation patterns was found in a network of regions also involved in perceptual processing of movement stimuli, however not in early sensory regions. Information about whether a memorized movement was associated with the self or with another person was found to be coded by activity in the left middle frontal gyrus (MFG), left inferior frontal gyrus (IFG), bilateral supplementary motor area, and (at reduced threshold) in the left temporoparietal junction (TPJ). These areas are frequently reported as involved in action understanding (IFG, MFG) and domain-general self/other distinction (TPJ). Finally, in univariate analysis we found that selecting a self-associated movement for retention was related to increased activity in the ventral medial prefrontal cortex.

Perceptual adaptation is often studied within a single sense. However, our experience of the world is naturally multisensory. Here, we investigated cross-sensory (visual-vestibular) adaptation of self-motion perception. It was previously found that relatively long visual self-motion stimuli (≳ 15s) are required to adapt subsequent vestibular perception, and that shorter duration stimuli do not elicit cross-sensory (visual↔vestibular) adaptation. However, it is not known whether several discrete short-duration stimuli may lead to cross-sensory adaptation (even when their sum, if presented together, would be too short to elicit cross-sensory adaptation). This would suggest that the brain monitors and adapts to supra-modal statistics of events in the environment. Here we investigated whether cross-sensory (visual↔vestibular) adaptation occurs after experiencing several short (1s) self-motion stimuli. Forty-five participants discriminated the headings of a series of self-motion stimuli. To expose adaptation effects, the trials were grouped in 140 batches, each comprising three ‘prior’ trials, with headings biased to the right or left, followed by a single unbiased ‘test’ trial. Right, and left-biased batches were interleaved pseudo-randomly. We found significant adaptation in both cross-sensory conditions (visual prior and vestibular test trials, and vice versa), as well as both unisensory conditions (when prior and test trials were of the same modality – either visual or vestibular). Fitting the data with a logistic regression model revealed that adaptation was elicited by the prior stimuli (not prior choices). These results suggest that the brain monitors supra-modal statistics of events in the environment, even for short-duration stimuli, leading to functional (supra-modal) adaptation of perception.

Sensitive periods soon after birth seem to be crucial for mapping brain networks and enable the development of healthy sensory responses in adulthood. Affective tactile experiences are at the core of interpersonal interactions in the neonatal period and represent a scaffolding for early development of autonomic self-regulation, which then becomes part of more complex patterns of social exchanges and executive functions across the first years of life. In the present article we reviewed recent studies that investigated physiological and behavioural responses to tactile stimulations across development, supporting our claim that affective touch is an essential part of early emerging self-regulatory skills with important cascade effects on infants’ socio-emotional and cognitive developmental trajectories.

Just as for any other sensory system, researchers have long wanted to discriminate between the sensory discriminative and hedonic aspects of tactile perception. Supporting such a distinction, researchers have, in recent decades, uncovered the existence of a dedicated system of receptors in the hairy skin (C-Tactile, CT, afferents) that appear to be preferentially tuned to pleasant stroking (i.e. caressing) touch. No matter what kind of touch one is talking about, though, it is important to recognize that human perception is fundamentally multisensory, meaning that what we feel, not to mention what we think about the experience, is modulated by the inputs that are available to the other senses. This review summarizes the latest evidence concerning these multisensory contributions to tactile perception focusing, in particular, on the case of affective touch. Given that CT afferents for pleasant touch are far more common in the hairy (as compared to the glabrous) skin, the question is further raised as to whether the relative contribution of the various senses to tactile perception may differ as a function of the skin site stimulated (i.e. glabrous versus hairy skin) or the kind of judgment (sensory-discriminative versus hedonic) that is being made.

In 1992, the Laboratory of Human Physiology at the University of Parma (Italy) publish a study describing "mirror" neurons in the macaque that activate both when the monkey performs an action and when it observes an experimenter performing the same action. The research team behind this discovery postulates that the mirror neurons system is the neural basis of our ability to understand the actions of others, through the motor mapping of the observed action on the observer's motor repertory (direct-matching hypothesis). Nevertheless, this conception met serious criticism. These critics attempt to relativize their function by placing them within a network of neurocognitive and sensory interdependencies. In short, the essential characteristic of these neurons is to combine the processing of sensory information, especially visual, with that of motor information. Their elementary function would be to provide a motor simulation of the observed action, based on visual information from it. They can contribute, with other non-mirror areas, to the identification/prediction of the action goal and to the interpretation of the intention of the actor performing it. Studying the connectivity and high frequency synchronizations of the different brain areas involved in action observation would likely provide important information about the dynamic contribution of mirror neurons to "action understanding". The aim of this review is to provide an up-to-date analysis of the scientific evidence related to mirror neurons and their elementary functions, as well as to shed light on the contribution of these neurons to our ability to interpret and understand others' actions.

Humans need to be able to differentiate between signals they produce themselves and signals that arise from non-self-causes. It has long been discussed that the brain uses a copy of the motor command, an efference copy, to predict the sensory outcomes of one’s own action — and to attenuate these. While studies in humans suggest that cerebellum and supplementary motor area play crucial roles in the attenuation, a study in mice suggests a global suppression during self-touch. However, the sensory percepts of self-touch are not fully cancelled out. Humans touch themselves frequently suggesting a behavioral relevance of self-touch, as to refocus attention, to calm oneself down during stress, to itch or for self-enjoyment. We discuss studies on sensory attenuation as well as the behavioral relevance of self-touch and open questions for future research.

The primary sensory modality for probing spatial perception can vary among psychophysical paradigms. In the subjective visual vertical (SVV) task, the brain must account for the position of the eye within the orbit to generate an estimate of a visual line orientation, whereas in the subjective haptic vertical (SHV) task, the position of the hand is used to sense the orientation of a haptic bar. Here we investigated whether a hand sensory bias can affect SHV measurement. We measured SHV in 12 subjects (6 left-handed and 6 right-handed) with a forced-choice paradigm using their left and right hands separately. The SHV measurement was less accurate than the SVV measurements (-0.6 ± 0.7) and it was biased in the direction of the hand used in the task but was not affected by handedness; SHV left hand -6.8 ± 2.1° (left-handed -7.9 ± 3.6°, right-handed -5.8 ± 2.5°) and right hand 9.8 ± 1.5° (left-handed 7.4 ± 2.2°, right-handed 12.3 ± 1.8°). SHV measurement with the same hand was also affected by the haptic bar placement on the left or right side versus midline, showing a side effect (left vs midline -2.0 ± 1.3°, right vs midline 3.8 ± 1.7°). Midline SHV measures using the left and right hands were different, confirming a laterality effect (left hand -4.5 ± 1.7°, right hand 6.4 ± 2.0°). These results demonstrate a sensory bias in SHV measurement related to the effects of both hand-in-body (i.e., right vs left hand) and hand-in-space positions. Such modality-specific bias may result in disparity between SHV and SVV measurements, and therefore cannot be generalized to vertical or spatial perception.

Organizational aesthetics comprises a way of understanding organizational life based on immediate sensory reactions (i.e., sight, hearing, taste, smell, and touch) to the material components of organizing (e.g., artifacts, physical settings, and material practices). Despite the growing interest in the topic, however, research is fragmented across management areas. To advance scholarly knowledge in this field, we reviewed the empirical work dealing with aesthetics. Our review yields two major insights. First, we identify three perspectives on the role of aesthetics. Scholars have treated aesthetics as (1) a directed stimulus (that elicits product evaluation and work organization), (2) a knowledge tool (that is entwined with creative work and everyday tasks), or (3) an open-ended outcome (that serves as a personal experience). Second, we find that each perspective highlights emotional and cognitive mechanisms through which aesthetics is implicated in organizing. Building on these two insights, our review offers an integrative framework that provides a comprehensive picture of the state of the field, illuminating the work of aesthetics in and around organizations and providing avenues for future studies.

Understanding how cortical circuits generate complex behavior requires investigating the cell types that comprise them. Functional differences across pyramidal neuron (PyN) types have been observed within cortical areas, but it is not known whether these local differences extend throughout the cortex, nor whether additional differences emerge when larger-scale dynamics are considered. We used genetic and retrograde labeling to target pyramidal tract (PT), intratelencephalic (IT) and corticostriatal projection neurons and measured their cortex-wide activity. Each PyN type drove unique neural dynamics, both at the local and cortex-wide scale. Cortical activity and optogenetic inactivation during an auditory decision task also revealed distinct functional roles: all PyNs in parietal cortex were recruited during perception of the auditory stimulus, but, surprisingly, PT neurons had the largest causal role. In frontal cortex, all PyNs were required for accurate choices but showed distinct choice-tuning. Our results reveal that rich, cell-type-specific cortical dynamics shape perceptual decisions.

While it is well established that motivational factors such as earning more money for performing well improve motor performance, how the motor system implements this improvement remains unclear. For instance, feedback-based control, which uses sensory feedback from the body to correct for errors in movement, improves with greater reward. But feedback control encompasses many feedback loops with diverse characteristics such as the brain regions involved and their response time. Which specific loops drive these performance improvements with reward is unknown, even though their diversity makes it unlikely that they are contributing uniformly. This lack of mechanistic insight leads to practical limitations in applications using reward, such as clinical rehabilitation, athletic coaching, and brain-inspired robotics. We systematically tested the effect of reward on the latency (how long for a corrective response to arise?) and gain (how large is the corrective response?) of eight distinct sensorimotor feedback loops in humans. Only the feedback responses known to rely on prefrontal associative cortices showed sensitivity to reward, while feedback responses that relied mainly on premotor and sensorimotor cortex did not show sensitivity to reward. Our results may have implications regarding feedback control performance in pathologies showing a cognitive decline, or on athletic coaching. For instance, coaching methodologies that rely on reinforcement or "reward shaping" may need to specifically target aspects of movement that rely on reward-sensitive feedback responses.

BACKGROUND: Research about the experience of sexuality and intimacy for autistic people has largely excluded the potential influences of autistic sensory features, which are highly common. The aim of this study was to explore how autistic sensory features influence autistic people's experiences of sexuality and relationships, including the impact of low and high neurological threshold sensory patterns and regarding specific sensory modalities. METHODS: Utilizing a qualitative approach, we explored autistic people's perspectives about the influences of sensory features on their experiences of sexuality and relationships through existing publicly available narratives (5 books and 13 online forums containing messages from 72 unique usernames) and responses to an open-ended survey question (N = 49). We used deductive coding based on Dunn's model of sensory processing, as well as inductive coding to identify additional themes about autistic sensory features and sexuality. RESULTS: Our findings indicated that sexual and relationship experiences were related to both sensory sensitivity and sensation seeking (i.e., low and high threshold sensory patterns) across several sensory modalities, including touch, sight, sound, and smell. Sensory features influenced autistic people's sexual and relationship experiences in both positive and negative ways. Examined narratives revealed adaptations and strategies used by autistic people to enhance or enable engagement in sexual activity as well as implications for their sexual identity. CONCLUSIONS: Sensory features and their impact on the sexuality and relationship experiences of autistic people should be considered in clinical practice and educational programming. More research is needed to further understand the impact of autistic sensory features on experiences of sexuality and relationships, and to develop effective strategies to promote safe and satisfying engagement, when desired. LAY SUMMARY: WHY WAS THIS STUDY DONE? Autistic people often respond to sensations differently than other people, including being more sensitive to sensations and/or wanting more intense sensations (called “autistic sensory features” in this study). Many aspects of sexuality and relationships involve sensory input. However, we do not know much about how autistic sensory features influence sexuality and relationships for autistic people. WHAT WAS THE PURPOSE OF THIS STUDY? The purpose of this study was to explore how autistic sensory features influence autistic people's experiences of sexuality and relationships. WHAT DID THE RESEARCHERS DO? For this study, we used two different sources of data. The first was existing publicly available things written by autistic people, including books and posts on online forums. The second was answers provided on a survey question asking about autistic sensory features and sexuality. Overall, we looked at things written by over 120 autistic people. We reviewed all the information to explore what kinds of sensory responses (e.g., sensitivities and sensation seeking) and sensory modalities (e.g., touches, sights, sounds, and smells) they wrote about. We also looked more generally to see how autistic people described the ways that autistic sensory features influenced their sexuality and relationship experiences. WHAT WERE THE RESULTS OF THE STUDY? Our findings show that in the information we accessed, autistic people did write about how sensory features influence their sexual and relationship experiences. Some people who have sensory sensitivities described confusion, distress, and frustration with sexual experiences. Despite wanting to participate, people with sensitivities described negative reactions to many of the sights, sounds, smells, and textures that were involved in dating and sexual activities. Other people indicated that they avoided sexual activity because of their sensory features. However, we also found that some autistic people seek out more intense sensations in their sexual activities, and others that enjoy intimacy that promotes calming and self-regulation. People wrote about strategies they use in response to their autistic sensory features, such as communication with partners and the use of substances to dull sensations. WHAT DO THESE FINDINGS ADD TO WHAT WAS ALREADY KNOWN? There has not been much published research on this topic, so this study is a starting place. In books, as well as in online discussion boards, autistic people have been discussing the importance of sensory features to their sexuality and relationships. We accessed that information, and used theory and clinical experience to analyze their writings and help identify what other research is needed. WHAT ARE POTENTIAL WEAKNESSES IN THE STUDY? We used text already written by autistic people and responses on one survey question for this study. Therefore, we may not have gained a complete understanding of the ways that autistic sensory features influence sexuality and relationship experiences. HOW WILL THESE FINDINGS HELP AUTISTIC ADULTS NOW OR IN THE FUTURE? This study contributes to greater understanding of how autistic traits affect sexuality and relationships for autistic people. That information can be used to develop effective education and resources for autistic people, families, and service providers.

Very few studies today validate the use of various sensory tools among elderly subjects, although the population is ageing rapidly. This chapter deals with applied sensory assessment in the food sector. It first presents heterogeneity factors in this population: physical and psychological health and dependency, decrease of chemosensory capacities, changes in oral-motor skills and modifications of cognitive abilities. Then, a study aiming at comparing the capacity of young and more or less dependent elderly subjects to use a discrete scale (discriminatory power and repeatability) in a monadic sequential presentation is described. Finally, recommendations are given about the cases where a panel of elderly people should be necessary and the precautions to undertake during a sensory test among elderly subjects.

ObjectivesSensory methods use human senses to evaluate product attributes. This review provides an overview of the types of sensory methods used to evaluate the perception of flavour in tobacco and other nicotine-containing (ToNic) products and to discuss how sensory data could inform flavoured ToNic product policy.Data sourcesPubMed, Embase and Web of Science.Study selectionAll peer-reviewed studies evaluating ToNic products using a sensory method published before 23 May 2020.Data extractionTwo independent coders completed title/abstract and full-text screening to choose articles for inclusion (Cohen’s kappa=0.85, strong agreement). Each coder completed data extraction on half the articles, recording relevant information (eg, sensory methods used, results). The coders categorised sensory methods and generated overarching themes.Data synthesisOf 110 articles identified, we included 29 articles containing 35 studies that used sensory methods to investigate ToNic products. The sensory methods included analytic methods such as discrimination and descriptive tests and hedonic methods such as liking tests. Six themes emerged regarding how sensory methods can be used to understand consumer perception and liking of ToNic products and to inform ToNic product policy.ConclusionsThe identified studies highlight that sensory data can inform ToNic product policy. Analytic and sensory hedonic ratings can be used to assess a ToNic product’s ability to promote addiction in the user (ie, abuse liability). Lastly, hedonic ratings can provide information to assess potential use behaviours.

Sensory scientists typically focus most of their effort on measuring the sensations that products elicit, or measuring the pleasure provided by products. Far less effort is given to measuring consumer behavior with regard to intake or use. Implicitly or explicitly, sensations are assumed to influence liking, acceptance, and preference, which in turn influence use and intake. That is, we all assume formulation ultimately influences use; however, measurement error at each stage complicates efforts to build causal models of the chain from formulation to use. This chapter highlights sources of variability at various points, including biological differences, as well as measurement error in the putative path from formulation to use.

Purpose: Multimodal sensory integration in audiovisual (AV) speech perception is a naturally occurring phenomenon. Modality-specific responses such as auditory left, auditory right, and visual responses to dichotic incongruent AV speech stimuli help in understanding AV speech processing through each input modality. It is observed that distribution of activity in the frontal motor areas involved in speech production has been shown to correlate with how subjects perceive the same syllable differently or perceive different syllables. This study investigated the distribution of modality-specific responses to dichotic incongruent AV speech stimuli by simultaneously presenting consonant–vowel (CV) syllables with different places of articulation to the participant's left and right ears and visually. Design: A dichotic experimental design was adopted. Six stop CV syllables /pa/, /ta/, /ka/, /ba/, /da/, and /ga/ were assembled to create dichotic incongruent AV speech material. Participants included 40 native speakers of Norwegian (20 women, M age = 22.6 years, SD = 2.43 years; 20 men, M age = 23.7 years, SD = 2.08 years). Results: Findings of this study showed that, under dichotic listening conditions, velar CV syllables resulted in the highest scores in the respective ears, and this might be explained by stimulus dominance of velar consonants, as shown in previous studies. However, this study, with dichotic auditory stimuli accompanied by an incongruent video segment, demonstrated that the presentation of a visually distinct video segment possibly draws attention to the video segment in some participants, thereby reducing the overall recognition of the dominant syllable. Furthermore, the findings here suggest the possibility of lesser response times to incongruent AV stimuli in females compared with males. Conclusion: The identification of the left audio, right audio, and visual segments in dichotic incongruent AV stimuli depends on place of articulation, stimulus dominance, and voice onset time of the CV syllables.

It is widely believed that predicted action outcomes are perceptually attenuated. Such mechanisms would prioritise processing of unexpected events, enabling us to perform corrective actions and update models of the world. However, evidence that action predictions attenuate perception is sparse. The present experiments determined whether predictive mechanisms in fact generate attenuation, or instead enhance perception – as assumed in sensory cognition domains outside of action. Under these accounts, it is thought that we combine prior expectations and sensory input to generate percepts, resulting in upweighted perception of the expected. Such mechanisms would enable rapid generation of veridical percepts in the face of sensory noise. We therefore manipulated probabilistic expectations in a paradigm typically used to demonstrate sensory attenuation during action. Participants produced actions and rated the intensity of concurrent passive tactile forces. Experiment 1 first confirmed previous findings that action outcomes are perceived less intensely than similar passive stimulation, but demonstrated more intense perception when reducing the contribution of non-predictive gating processes. Experiments 2 and 3 manipulated prediction explicitly and found that expected outcomes are perceived more, not less, intensely than unexpected outcomes. Computational modelling suggested that expectations alter the way sensory evidence is integrated – increasing the gain afforded to expected tactile signals. These findings challenge a central tenet of prominent motor control theories and demonstrate that sensorimotor predictions do not exhibit a qualitatively distinct influence on perception. Significance Statement Perception of expected action outcomes is thought to be attenuated. Such a mechanism is reasoned to be adaptive because surprising inputs are more useful, e.g., signalling the need to take new courses of action. This mechanism is thought to explain why we cannot tickle ourselves and explain unusual aspects of action and awareness in clinical populations. However, we do not know whether action predictions really attenuate perception. We demonstrate here that in fact action predictions enhance, rather than attenuate, touch. These findings are consistent with prediction theories outside of action, thought to explain how we generate accurate representations of our noisy sensory world. Our data importantly thereby demonstrate that action predictions do not have a qualitatively distinct influence on perception.

Speech comprehension deficits constitute a major issue for an increasingly aged population, as they may lead older individuals to social isolation. Since conversation requires constant monitoring, updating and selecting information, auditory working memory decline, rather than impoverished hearing acuity, has been suggested a core factor. However, in stark contrast to the visual domain, the neurophysiological mechanisms underlying auditory working memory deficits in healthy aging remain poorly understood, especially those related to on-the-fly information processing under increasing load. Therefore, we investigated the behavioral costs and electrophysiological differences associated with healthy aging and working memory load during continuous auditory processing. We recorded EEG activity from 27 younger (∼25 years) and 29 older (∼70 years) participants during their performance on an auditory version of the n-back task with speech syllables and 2 workload levels (1-back; 2-back). Behavioral measures were analyzed as indices of function; event-related potentials as proxies for sensory and cognitive processes; and theta oscillatory power as a reflection of memory and central executive function. Our results show age-related differences in auditory information processing within a latency range that is consistent with a series of impaired functions, from sensory gating to cognitive resource allocation during constant information updating, especially under high load.

Food odors play an important role in sensory and food perception as they affect the hedonic and motivational processes and determine food preference and consumption. Neuroimaging approaches have become increasingly important in understanding how the brain functions, providing a unique perspective in probing the perception and processing of food odors. This article presents an overview of the most recent research on brain processing of food odors, using the functional magnetic resonance imaging (fMRI), electroencephalography (EEG), or functional near-infrared spectroscopy (fNIRS). The implications and opportunities of neuroimaging in sensory and consumer sciences were discussed, while noting some important challenges and limitations. The review highlights the uniqueness of neuroimaging techniques in deepen our understanding of the food odor characteristics and the cognitive influences on food odor processing, that have potentials in research fields of sensory and consumer science.

Three separate sensory systems — taste, smell, and chemesthesis — contribute to the overall flavor perception of foods and beverages. Modern psychophysical methods have led to quantitation of individual differences in perception, which have potentially important implications for food liking and intake, along with human health. Carefully designed studies using contemporary methods have allowed for the identification of novel relationships between variability in chemosensory and related genes with differences in perception, liking, and intake of foods and beverages. Here we summarize recent original research on relationships between chemosensory genetics and various measures of food liking and intake.

Age-related declines in executive control are commonly assessed with neuropsychological tests that also rely on sensory and motor processes that are not typically measured in those tasks. It is therefore difficult to isolate the cognitive contributions from sensorimotor contributions to performance impairments. Rapid motor decision-making tasks may also be sensitive to age differences in executive control but allow for the measurement of sensorimotor contributors to task performance. Recently developed object hit (OH) and object hit and avoid (OHA) tasks using a robotic manipulandum are sensitive to motor and cognitive aspects of performance in stroke and Parkinson's disease. However, the impact of healthy aging, and the specific cognitive mechanisms involved in these tasks has not been assessed. We administered the OH and OHA tasks to 77 younger and 59 healthy older adults to evaluate the relative age differences in the perceptual-motor/sensory, movement coordination, and cognitive measures of performance. The Trail Making Test (TMT) Parts A and B were administered to assess the extent to which the cognitive contributors to OHA task performance are associated with executive functioning. After controlling for hand movement speed, age differences were largest for cognitive measures, with smaller differences in perceptual-motor speed and sensory measures, and little differences in bimanual and spatial coordination measures of performance. The cognitive measures were associated with executive functioning measures from the TMT task. These findings provide evidence that rapid motor decision-making tasks are sensitive to age differences in executive control and can isolate the cognitive from the sensorimotor contributions to task performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Mismatch negativity (MMN) is a candidate biomarker for neuropsychiatric disease. Understanding the extent to which it reflects cognitive deviance-detection or purely sensory processes will assist practitioners in making informed clinical interpretations. This study compares the utility of deviance-detection and sensory-processing theories for describing MMN-like auditory responses of a common marmoset monkey during roving oddball stimulation. The following exploratory analyses were performed on an existing dataset: responses during the transition and repetition sequence of the roving oddball paradigm (standard -> deviant/S1 -> S2 -> S3) were compared; long-latency potentials evoked by deviant stimuli were examined using a double-epoch waveform subtraction; effects of increasing stimulus repetitions on standard and deviant responses were analyzed; and transitions between standard and deviant stimuli were divided into ascending and descending frequency changes to explore contributions of frequency-sensitivity. An enlarged auditory response to deviant stimuli was observed. This decreased exponentially with stimulus repetition, characteristic of sensory gating. A slow positive deflection was viewed over approximately 300–800 ms after the deviant stimulus, which is more difficult to ascribe to afferent sensory mechanisms. When split into ascending and descending frequency transitions, the resulting difference waveforms were disproportionally influenced by descending frequency deviant stimuli. This asymmetry is inconsistent with the general deviance-detection theory of MMN. These findings tentatively suggest that MMN-like responses from common marmosets are predominantly influenced by rapid sensory adaptation and frequency preference of the auditory cortex, while deviance-detection may play a role in long-latency activity.

Addictive drugs are habit-forming. Addiction is a learned behavior; repeated exposure to addictive drugs can stamp in learning. Dopamine-depleted or dopamine-deleted animals have only unlearned reflexes; they lack learned seeking and learned avoidance. Burst-firing of dopamine neurons enables learning—long-term potentiation (LTP)—of search and avoidance responses. It sets the stage for learning that occurs between glutamatergic sensory inputs and GABAergic motor-related outputs of the striatum; this learning establishes the ability to search and avoid. Independent of burst-firing, the rate of single-spiking—or “pacemaker firing”—of dopaminergic neurons mediates motivational arousal. Motivational arousal increases during need states and its level determines the responsiveness of the animal to established predictive stimuli. Addictive drugs, while usually not serving as an external stimulus, have varying abilities to activate the dopamine system; the comparative abilities of different addictive drugs to facilitate LTP is something that might be studied in the future.

The reality is full of new phenomena, and the existing ones are transformed. An example is the phenomenon of social maladjustment. There is an increase in the number of criminal acts and acts proving demoralization committed by children and adolescents. The situation forces us to take radical measures, preceded by an in-depth analysis of the mechanisms and causes of the problem. The analysis shows the diversification of the demoralization phenomenon and, most often, the accumulation of risk factors for the emergence of the problem of social maladjustment, with the scarcity of the so-called protective factors. People with disabilities are in a particularly disadvantaged situation, often with a low degree of adaptation, exposed to unfavorable social situations. The greater the danger, the less favorable the environmental conditions - family and lack of support.

The ability to make decisions based on external information, prior knowledge, and evidence is a crucial aspect of cognition and may determine the success and survival of an organism. Despite extensive work on decision-making mechanisms/models, understanding the effects of alertness on neural and cognitive processes remain limited. Here we use EEG and behavioral modeling to characterize cognitive and neural dynamics of perceptual decision-making in awake/low alertness periods in humans (14 male, 18 female) and characterize the compensatory mechanisms as alertness decreases. Well-rested human participants, changing between full-wakefulness and low alertness, performed an auditory tone-localization task, and its behavioral dynamics were quantified with psychophysics, signal detection theory, and drift-diffusion modeling, revealing slower reaction times, inattention to the left side of space, and a lower rate of evidence accumulation in periods of low alertness. Unconstrained multivariate pattern analysis (decoding) showed a ∼280 ms delayed onset driven by low alertness of the neural signatures differentiating between left and right decision, with a spatial reconfiguration from centroparietal to lateral frontal regions 150-360 ms. To understand the neural compensatory mechanisms with decreasing alertness, we connected the evidence-accumulation behavioral parameter to the neural activity, showing in the early periods (125-325 ms) a shift in the associated patterns from right parietal regions in awake, to right frontoparietal during low alertness. This change in the neurobehavioral dynamics for central accumulation-related cognitive processes defines a clear reconfiguration of the brain networks' regions and dynamics needed for the implementation of decision-making, revealing mechanisms of resilience of cognition when challenged by decreased alertness.SIGNIFICANCE STATEMENTMost living organisms make multiple daily decisions, and these require a degree of evidence from both the environment and the internal milieu. Such decisions are usually studied under sequential sampling models and involve making a behavioral choice based on sensory encoding, central accumulation, and motor implementation processes. Since there is little research on how decreasing alertness affects such cognitive processes, this study has looked at the cognitive and neural dynamics of perceptual decision-making in people while fully awake and in drowsy periods. Using computational modeling of behavior and neural dynamics on human participants performing an auditory tone-localization task, we reveal how low alertness modulates evidence accumulation-related processes and its corresponding compensatory neural signatures.

Sensorimotor brain areas have been implicated in the recognition of emotion expressed on the face and through nonverbal vocalizations. However, no previous study has assessed whether sensorimotor cortices are recruited during the perception of emotion in speech—a signal that includes both audio (speech sounds) and visual (facial speech movements) components. To address this gap in the literature, we recruited 24 participants to listen to speech clips produced in a way that was either happy, sad, or neutral in expression. These stimuli also were presented in one of three modalities: audio-only (hearing the voice but not seeing the face), video-only (seeing the face but not hearing the voice), or audiovisual. Brain activity was recorded using electroencephalography, subjected to independent component analysis, and source-localized. We found that the left presupplementary motor area was more active in response to happy and sad stimuli than neutral stimuli, as indexed by greater mu event-related desynchronization. This effect did not differ by the sensory modality of the stimuli. Activity levels in other sensorimotor brain areas did not differ by emotion, although they were greatest in response to visual-only and audiovisual stimuli. One possible explanation for the pre-SMA result is that this brain area may actively support speech emotion recognition by using our extensive experience expressing emotion to generate sensory predictions that in turn guide our perception.

Reward associations are known to shape the brain's processing of visual stimuli, but relatively less is known about how reward associations impact the processing of auditory stimuli. We leveraged the high-temporal resolution of electroencephalography (EEG) and event-related potentials (ERPs) to investigate the influence of low- and high-magnitude stimulus-reward associations in an auditory oddball task. We associated fast, correct detection of certain auditory target stimuli with larger monetary rewards, and other auditory targets with smaller rewards. We found enhanced attentional processing of the more highly rewarded target stimuli, as evidenced by faster behavioral detection of those stimuli compared with lower-rewarded stimuli. Neurally, higher-reward associations enhanced the early sensory processing of auditory targets. Targets associated with higher-magnitude rewards had higher amplitude N1 and mismatch negativity (MMN) ERP components than targets associated with lower-magnitude rewards. Reward did not impact the latency of these early components. Higher-reward magnitude also decreased the latency and increased the amplitude of the longer-latency P3 component, suggesting that reward also can enhance the final processing stages of auditory target stimuli. These results provide insight into how the sensory and attentional neural processing of auditory stimuli is modulated by stimulus-reward associations and the magnitude of those associations, with higher-magnitude reward associations yielding enhanced auditory processing at both early and late stages compared with lower-magnitude reward associations.

There are growing numbers of young children with complex life-limiting conditions as well as varying degrees of physical, sensory and cognitive limitations currently surviving birth.As a trainee ar...

Occupational Therapists often use interventions that support sensory processing. Interventions may include Ayres sensory integration, sensory based intervetnions or use of sensory input built into ...

Children with and without dyslexia differ in their behavioral responses to visual information, particularly when required to pool dynamic signals over space and time. Importantly, multiple processes contribute to behavioral responses. Here we investigated which processing stages are affected in children with dyslexia when performing visual motion processing tasks, by combining two methods that are sensitive to the dynamic processes leading to responses. We used a diffusion model which decomposes response time and accuracy into distinct cognitive constructs, and high-density EEG. Fifty children with dyslexia (24 male) and 50 typically developing children (28 male) 6-14 years of age judged the direction of motion as quickly and accurately as possible in two global motion tasks (motion coherence and direction integration), which varied in their requirements for noise exclusion. Following our preregistered analyses, we fitted hierarchical Bayesian diffusion models to the data, blinded to group membership. Unblinding revealed reduced evidence accumulation in children with dyslexia compared with typical children for both tasks. Additionally, we identified a response-locked EEG component which was maximal over centro-parietal electrodes which indicated a neural correlate of reduced drift rate in dyslexia in the motion coherence task, thereby linking brain and behavior. We suggest that children with dyslexia tend to be slower to extract sensory evidence from global motion displays, regardless of whether noise exclusion is required, thus furthering our understanding of atypical perceptual decision-making processes in dyslexia.SIGNIFICANCE STATEMENTReduced sensitivity to visual information has been reported in dyslexia, with a lively debate about whether these differences causally contribute to reading difficulties. In this large preregistered study with a blind modeling approach, we combine state-of-the art methods in both computational modeling and EEG analysis to pinpoint the stages of processing that are atypical in children with dyslexia in two visual motion tasks that vary in their requirement for noise exclusion. We find reduced evidence accumulation in children with dyslexia across both tasks, and identify a neural marker, allowing us to link brain and behavior. We show that children with dyslexia exhibit general difficulties with extracting sensory evidence from global motion displays, not just in tasks that require noise exclusion.

Цель работы - установить возрастные особенности показателей эффективности функции равновесия и сенсорной организации постурального баланса у женщин 85-95 лет. Были обследованы 68 женщин 85-95 лет (средний возраст - 89,3±3 года), которых разделили на две возрастные группы: 1-я - 37 женщин 85-89 лет (средний возраст - 86,9±1,6 года); 2-я - 31 женщина 90-95 лет (средний возраст - 92,1±1,4 года). Для оценки компонентов постурального баланса использовали компьютерный динамический постурографический (стабилометрический) комплекс «Smart Equitest Balance Manager». Проводили Sensory Organization Test (SOT). Сравнительная оценка показателей Equilibrium Score во всех функциональных пробах SOT, включая показатель Com posite of all Equilibrium Scores, не выявила статистически значимых различий между группами обследованных женщин. Сенсорный анализ также не выявил возрастных изменений соматосенсорной, зрительной и вестибулярной информации в контроле над балансом. При этом показатель сенсорного предпочтения (Ratio for Sensory Analysis-Patient Preference) был выше у женщин 90-95 лет (p=0,007). У женщин после 89 лет не наблюдали возрастных изменений сенсорной организации постурального контроля, эффективности подержания статического и статодинамического баланса, включая снижение общей производительности баланса, а также адаптационных возможностей их функции равновесия. При этом у женщин-долгожителей сохраняется эффективность процесса сенсорной интеграции для поддержания постурального баланса и чувства пространственной ориентации, что можно рассматривать как предиктор активного долголетия. Кроме этого, у женщин-долгожителей сохраняется способность пространственной и временной организации контроля постурального равновесия, а также степени и порядка набора задействованных мышц для снижения дисбаланса. Полученные результаты позволили обозначить параметры SOT, которые можно учитывать при прогнозировании постуральных изменений и продолжительности жизни у женщин в старческом возрасте. The purpose of this work is to establish the age-related indicators’ characteristics of the effectiveness of the balance function and the postural balance sensory organization in women 85-95 years old. We examined 68 women aged 85-95 years [mean age (M±SD) 89,3±3 years]. The first age group included 37 women whose calendar age ranged from 85 to 89 years (mean age 86,9±1,6 years). The second age group included 31 women of 90-95 years (mean age: 92,1±1,4). To assess the components of the postural balance, a computer-based dynamic posturographic complex «Smart Equitest Balance Manager» was used. The Sensory Organization Test (SOT) was performed. Comparative assessment of the Equilibrium Score indicators in all SOT functional tests, including the Composite of all equilibrium scores, did not reveal statistically significant differences between the examined groups of women. The sensory analysis did not reveal age-related changes in somatosensory, visual and vestibular information in the control over balance, either. At the same time, the indicator of sensory preference (Ratio for sensory analysis-patient Preference) was higher in women 90-95 years old (p=0,007). In women after 89 years of age, there are no age-related changes in the sensory organization of postural control or the effectiveness of maintaining static and static-dynamic balance. No decrease in overall balance performance, as well as the adaptive capabilities of their balance function, was noticed. At the same time, long-lived women retain the effectiveness of the sensory integration process to maintain postural balance and a sense of spatial orientation, which can be considered a predictor of active longevity. In addition, centenarians retain the ability of spatial and temporal organization of postural equilibrium control, as well as the degree and order of the muscles involved to reduce the imbalance recruitment. The results obtained made it possible to designate SOT parameters that can be taken into account when predicting postural changes and life expectancy in women in old age.

Recent evidence suggests that visual attention alternately samples two behaviourally relevant objects at approximately 4 Hz, rhythmically shifting between the objects. Whether similar attentional rhythms exist in other sensory modalities, however, is not yet clear. We therefore adapted and extended an established paradigm to investigate visual and potential auditory attentional rhythms, as well as possible interactions, on both a behavioural (detection performance, N = 33) and a neural level (EEG, N = 18). The results during unimodal attention demonstrate that both visual- and auditory-target detection fluctuate at frequencies of approximately 4-8 Hz, confirming that attentional rhythms are not specific to visual processing. The EEG recordings provided evidence of oscillatory activity that underlies these behavioural effects. At right and left occipital EEG electrodes, we detected counter-phasic theta-band activity (4-8 Hz), mirroring behavioural evidence of alternating sampling between the objects presented right and left of central fixation, respectively. Similarly, alpha-band activity as a signature of relatively suppressed sensory encoding showed a theta-rhythmic, counter-phasic change in power. Moreover, these theta-rhythmic changes in alpha power were predictive of behavioural performance in both sensory modalities. Overall, the present findings provide a new perspective on the multimodal rhythmicity of attention.

Two point discrimination (TPD) is used to distinguish the two point discriminative sense. TPD is most commonly used as neurosensory tests in clinical settings. In tactile sensation, the sensory receptors from the skin reach the somatosensory system and stimulate mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors to give the response to the respective stimuli. The present study was aim to assess the value of tactiles sensation by two point discrimination test among 18 years people. 18 years old people among the normal population were selected, consisting of 17 males and 33 females. 6 sensory areas were selected for the test. Test performed on six regions of the body like fingertips, fingers, palm, forehead, forearm, back of palm. The results were tabulated and statistically analyzed by independent t test. The ability to distinguish the two point discrimination was estimated in millimeters by using a simple hand operated device. The main findings of the study are that females were more sensitive than males in TPD perception.TPD perception was more among 18 years old. The TPD values are more in females when compared to males. The normative values of two point discrimination among 18 years people were established. This study concluded that fingertips in females were more sensitive than other parts of the body.

Sluggish cognitive tempo (SCT) has been suggested to be a separate disorder from any form of attention deficit hyperactivity disorder (ADHD). However, it is still unclear about the underlying neurophysiological and neuropsychological mechanism contributed to this condition. The aim of the present review is to examine the possibility to understand the nature of SCT through investigating the sensory modulation abilities in individuals with SCT. Sensory modulation abilities have been studied in previous researches of developmental disorders such as ADHD and autism in order to understand their heterogeneous symptoms in these disorders. Sensory modulation processes involve arousal regulation mechanism. Therefore, it is possible to examine the possible arousal regulation deficits in children with SCT using sensory challenging protocol which is commonly used in sensory modulation researches. Previous researches have shown that there is a linkage between brain arousal level and autonomic nervous system (ANS) activity. Through examining the ANS activities during exposure to sensory stimulus in individuals with SCT, we can find empirical evidence on the linkage between SCT symptoms and arousal dysregulation. A recent research examined the relationship between ANS activities during expose to auditory stimulus and SCT symptoms. The findings have shown that SCT symptoms were associated with abnormal ANS activities during sensory stimulation phrase. These results reflected the deficient arousal regulatory process in children with SCT symptoms. Implications of examining sensory modulation abilities in developmental disorders have been discussed. Examining the sensory modulation abilities in individuals with SCT can help us to further understand their neurophysiological deficits which contributed to the SCT symptoms. Previous research employed this approach has found that SCT symptoms were associated with abnormal ANS activities during sensory stimulation. Using SCT as an example, the current review discussed the potential benefits of investigating the sensory modulation abilities in developmental disorders.

We see stunning morphological diversity across the animal world. Less conspicuous but equally fascinating are the sensory and cognitive adaptations that determine animals’ interactions with their environments and each other. We discuss the development of the fields of sensory and cognitive ecology and the importance of integrating these fields to understand the evolution of adaptive behaviors. Bats, with their extraordinarily high ecological diversity, are ideal animals for this purpose. An explosion in recent research allows for better understanding of the molecular, genetic, neural, and behavioral bases for sensory ecology and cognition in bats. We give examples of studies that illuminate connections between sensory and cognitive features of information filtering, evolutionary trade-offs in sensory and cognitive processing, and multimodal sensing and integration. By investigating the selective pressures underlying information acquisition, processing, and use in bats, we aim to illuminate patterns and processes driving sensory and cognitive evolution.

Iconic strategies—methods of making iconic forms—have been mostly considered in terms of concrete semantic fields such as actions and objects. In this article, I investigate iconic strategies in lexical sensory signs—signs that semantically relate to the five senses (sight, touch, smell, sound, and taste) and to emotions (e.g., anger)—in Finnish Sign Language. The iconic strategy types I discuss are hand-action, entity, drawing, and locating. I also discuss the indexical strategy type (e.g., finger pointing). To gain as rich and broad a view as possible, the mixed methods in the research consist of three components: intuition based, intersubjective, and statistical analyses. The main findings are (1) that, in order from most preferred to least preferred strategy, the hand-action, the entity, the indexical, and the drawing were found in lexical sensory signs; the locating strategy was not found at all, and (2) that the interpretation of iconic strategies is not always unambiguous and absolute. In conclusion, I reflect on methodological issues, and suggest that the concept of cross-modal iconicity and indexicality should be further studied in sign language linguistics.

Perceptual experience in the recent past has been shown to alter subsequent perception. Recently, it has been suggested that this "serial dependence" effect is modulated by sensory uncertainty. In the current study, by overlaying three different levels of visual noise (i.e., no-, low-, or high-noise) on face stimuli, we investigated how serial dependence in face identity perception varies with sensory uncertainty. After learning two facial identities, the faces were combined at various morph levels and participants reported which identity was perceived while noise and noise-free presentations alternated over trials. Results showed that identity perception of noise-free faces was positively biased toward the past when the previous face was noise-free or highly noisy, but not when a low-noise was added. There were considerable individual differences in bias magnitude for trials preceded by high-noise stimuli which reflected individuals' general bias tendencies. When correlated with the other two conditions, a general bias tendency showed a significant relationship with low-noise trials, but not with no-noise trials. This indicates that the bias tendency of individuals manifests more strongly when the sensory information was uncertain. Therefore, the current findings suggest 1) that sensory uncertainty modulates serial dependence in face identity perception and 2) that an individual's general bias tendency interacts with sensory uncertainty to alter perception.

Background For people with lower-limb amputations, wearing a prosthetic limb helps restore their motor abilities for daily activities. However, the prosthesis's potential benefits are hindered by limited somatosensory feedback from the affected limb and its prosthesis. Previous studies have examined various sensory substitution systems to alleviate this problem; the prominent approach is to convert foot–ground interaction to tactile stimulations. However, positive outcomes for improving their postural stability are still rare. We hypothesized that the sensory substiution system based on surrogated tactile stimulus is capable of improving the standing stability among people with lower-limb amputations. Methods We designed a wearable device consisting of four pressure sensors and two vibrators and tested it among people with unilateral transtibial amputations (n = 7) and non-disabled participants (n = 8). The real-time measurements of foot pressure were fused into a single representation of foot–ground interaction force, which was encoded by varying vibration intensity of the two vibrators attached to the participants’ forearm. The vibration intensity followed a logarithmic function of the force representation, in keeping with principles of tactile psychophysics. The participants were tested with a classical postural stability task in which visual disturbances perturbed their quiet standing. Results With a brief familiarization of the system, the participants exhibited better postural stability against visual disturbances when switching on sensory substitution than without. The body sway was substantially reduced, as shown in head movements and excursions of the center of pressure. The improvement was present for both groups of participants and was particularly pronounced in more challenging conditions with larger visual disturbances. Conclusions Substituting otherwise missing foot pressure feedback with vibrotactile signals can improve postural stability for people with lower-limb amputations. The design of the mapping between the foot–ground interaction force and the tactile signals is essential for the user to utilize the surrogated tactile signals for postural control, especially for situations that their postural control is challenged.