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In a tradition of nature and mountain writing in which the solitary male intellectual has long dominated, Kathleen Jamie and Nan Shepherd stood out as offering a new way of writing about the natural world. Inherent in their writing is a repositioning of humanity that neither separates the human from the living world, nor determines anything that is perceived there. Instead, both Jamie and Shepherd focus on their sensed experience of the world, on their bodily perception, as a means by which to interpret that world and to express their part of it. I will draw primarily on the non-fiction prose of both writers to establish this privileging of the senses of the body, and to consider then the relationship that language has with the body and the role that it can play in what Shepherd calls the 'interpenetration' of place and mind. I will then consider how Jamie's and Shepherd's perspective shapes the writing of their texts, the journey from sensed experience of the living landscape, through its transformation into language, to the text formed by the writer, and the subsequent implications for the way in which nature writing connects with the living world from which it came. [ABSTRACT FROM AUTHOR]

Purpose: To explore how symptom perception affects functioning in patients with advanced cancer. Materials and methods: We conducted a cross-sectional observational study of 459 advanced cancer patients at the national cancer center. Functioning was assessed using the World Health Organization Disability Assessment Schedule (WHODAS) II, and symptoms were evaluated using the Memorial Symptom Assessment Scale-Short Form. Confirmatory factor analysis was conducted to develop a structural model based on different symptom perceptions, such as somatic sensation and experienced symptoms. Results: The structural model of disability revealed a significant direct pathway involving somatic sensation (β = 16.11, p < 0.001). Experienced symptoms significantly affected somatic sensations (β = 0.717, p < 0.001) but were not directly associated with disability. Unidimensional models exhibited a poor fit. In contrast, a complex model with first-order (somatic sensation) and second-order (experienced symptoms) factors provided an excellent fit, with comparative fit indexes (CFIs) and Tucker Lewis indexes (TLI) of more than 0.950 threshold. Conclusions: Our findings suggest that relationships to functioning may vary between somatic sensations versus experienced symptoms. The structure of symptoms is best conceptualized by direct somatic sensation and indirect experienced symptoms. A better understanding of symptom perception and the relationship between symptoms and function would facilitate the development of effective rehabilitation programs. [ABSTRACT FROM AUTHOR]

The experience of one's body as one's own is referred to as the sense of body ownership. This central part of human conscious experience determines the boundary between the self and the external environment, a crucial distinction in perception, action, and cognition. Although body ownership is known to involve the integration of signals from multiple sensory modalities, including vision, touch, and proprioception, little is known about the principles that determine this integration process, and the relationship between body ownership and perception is unclear. These uncertainties stem from the lack of a sensitive and rigorous method to quantify body ownership. Here, we describe a two-alternative forced-choice discrimination task that allows precise and direct measurement of body ownership as participants decide which of two rubber hands feels more like their own in a version of the rubber hand illusion. In two experiments, we show that the temporal and spatial congruence principles of multisensory stimulation, which determine ownership discrimination, impose tighter constraints than previously thought and that texture congruence constitutes an additional principle; these findings are compatible with theoretical models of multisensory integration. Taken together, our results suggest that body ownership constitutes a genuine perceptual multisensory phenomenon that can be quantified with psychophysics in discrimination experiments. [ABSTRACT FROM AUTHOR]

Classic and modern emotion theories suggest that the perception of bodily sensations, or interoception, is foundational to emotion processing. The present research examined whether interoception is enhanced among people high in ruminative tendencies, especially under stress. To test this notion, the present research examined the effects of a mild stressor on subjective and objective measures of interoception among people varying in ruminative tendencies. Under conditions of mild stress, rumination was positively associated with self-reported private body consciousness -a marker of interoceptive sensibility- in Study 1 (N = 312) and with heartbeat detection accuracy (especially in the presence of auditory interference) in Study 2 (N = 180). In both studies, rumination was not significantly associated with interoceptive sensibility or accuracy in the absence of stress. These findings suggest that stress-induced amplification of bodily sensations may be important in explaining emotional dysregulation among chronic ruminators. [ABSTRACT FROM AUTHOR]

The essay proposes a critique of a dominant model for structuring perception based on a fixed point of vision and stemming from Renaissance perspective, which grounds a sociality based on categorical splits. The essay proposes a new theory of movement and perception grounded on proprioception (the internal sense of movement of the body) linked to a new field-theory of movement. Finally, the essay proposes techniques and improvization practices to enact modes of relation and sociality grounded on this new account of movement and perception, associated to a co-sensing ethics proposing a series of meta-species, mestiza, neurodiverse, microsexual and swarming becomings. [ABSTRACT FROM AUTHOR]

This essay argues for a conception of poly-intentionality based on Merleau- Ponty's analysis of sense experience in his Phenomenology of Perception. I start by reviewing the tenuous status of sensation in Husserl's early work in order to prepare for a renewed conception of intentionality inspired by Merleau-Ponty--one that is grounded in the body's sense organs. I show how sensations accomplish a form of pre-reflective communication between the body and the world. Then, I explore how affect and the notion of a material a priori help resolve certain problems regarding sensation's alleged vagueness and unintelligibility. I conclude by advocating for Merleau-Ponty's notion of radical reflection and supplement it with insights gleaned from the analysis of poly-intentionality. [ABSTRACT FROM AUTHOR]

This essay explores the layering of perceptual information across the real and the virtual that occurs when bodies cohabit virtual environments using new commodity-priced virtual reality technologies. Specifically, we take an embodied somatic and dance perspective to better understand and characterise the perceptual gaps between how bodies are seen and how they are felt in virtual environments. Our discussion derives from observations and analysis of participant feedback obtained from a series of workshops run in July 2018 using a new multi-person VR framework. This research has opened up a fascinating fundamental question: can we harness VR's potential to awaken new modes of perception that enable people to better know their body? [ABSTRACT FROM AUTHOR]

The paper reviews and summarizes the history and the development of somatosensory amplification, a construct that plays a substantial role in symptom reports. Although the association with negative affect has been supported by empirical findings, another key elements of the original concept (i.e. body hypervigilance and the tendency of focusing on mild body sensations) have never been appropriately addressed. Recent findings indicate that somatosensory amplification is connected with phenomena that do not necessarily include symptoms (e.g. modern health worries, or expectations of symptoms and medication side effects), and also with the perception of external threats. In conclusion, somatosensory amplification appears to refer to the intensification of perceived external and internal threats to the integrity of the body ("somatic threat amplification") rather than amplification of perceived or actual bodily events only. Practical implications of this new approach are also discussed. [ABSTRACT FROM AUTHOR]

When one contrasts pain with the classic five senses, discussions generally focus on vision, which is taken as the paradigmatic example of perception. An intentionalist might argue that if the phenomenal difference between feeling and seeing bodily disturbances cannot be explained at the level of the content, it can be so at the level of the mode of presentation, and more particularly at the level of the structure of the spatial phenomenology of pain. Here I will argue that the spatial phenomenology of pain shares some key features with touch by contrast to sight, but these similarities should not make us neglect major differences between these two types of bodily sensations. I shall then draw the consequences of these differences for the awareness of one's body as one's own. In brief, to fix the boundaries of the body that one experiences as one's own, one must answer two questions: (i) where does the body stop, and the rest of world start? and (ii) what matters for self-preservation? I will suggest that touch primarily answers the first question, whereas pain primarily answers the second question. [ABSTRACT FROM AUTHOR]

Background: It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Body-powered prostheses (BPPs) provide the user with direct proprioceptive feedback. Currently available BPPs often require high cable operation forces, which complicates control of the forces at the terminal device. The aim of this study is to quantify the influence of high cable forces on object manipulation with voluntary-closing prostheses. Method: Able-bodied male subjects were fitted with a bypass-prosthesis with low and high cable force settings for the prehensor. Subjects were requested to grasp and transfer a collapsible object as fast as they could without dropping or breaking it. The object had a low and a high breaking force setting. Results: Subjects conducted significantly more successful manipulations with the low cable force setting, both for the low (33% more) and high (50%) object’s breaking force. The time to complete the task was not different between settings during successful manipulation trials. Conclusion: High cable forces lead to reduced pinch force control during object manipulation. This implies that low cable operation forces should be a key design requirement for voluntary-closing BPPs. [ABSTRACT FROM AUTHOR]

Background: Proprioception is important for proper motor control. As the central nervous system modulates how sensory information is processed during movement (sensory gating), proprioceptive tests performed at rest do not correlate well with performance during dynamic tasks such as walking. Proprioception therefore needs to be assessed during movement execution.Objectives: 1) To develop a test evaluating the ability to detect movement errors during walking, and its test-retest reliability; 2) to quantify the relationship between proprioceptive threshold (obtained with this new test) and performance in a standardized dynamic balance task.Method: Thirty healthy subjects walked on a treadmill while wearing a robotized ankle-foot orthosis (rAFO) for 2 bouts of 6min on 2 evaluation sessions (test-retest reliability). Force perturbations resisting ankle dorsiflexion during swing were applied to the ankle via the rAFO (150ms duration, variable amplitude). Participants pushed a button when they detected the perturbations. The Star Excursion Balance Test (SEBT) was used to evaluate dynamic balance.Analysis: Angular differences between perturbed and non-perturbed gait cycles were used to quantify movement error. Detection threshold was defined as the minimal movement error at which 50% of the perturbations were perceived. Intraclass correlation coefficients (ICCs) estimated test-retest reliability, and Pearson coefficients were used to determine the correlation between detection threshold and SEBT.Results: Detection threshold was 5.31±2.12°. Good reliability (ICC=0.70) and a moderate to strong correlation to SEBT (r=-0.57 to -0.76) were found.Conclusion: Force perturbations produced by the robotized AFO provides a reliable way of evaluating proprioception during walking. [ABSTRACT FROM AUTHOR]

We argue that bodily affects are in part constitutive of phenomenal consciousness. We find resources in Phenomenology, psychology, and neuroscience that point to the importance of bodily affects (e.g. hunger, fatigue, pain, as well as other various conscious and non-conscious bodily processes) for shaping not only our perceptions of arid judgments about the world, but the phenomenal 'something it is like' to experience such perceptions and judgments. [ABSTRACT FROM AUTHOR]

Oral somatosensory awareness refers to the somatic sensations arising within the mouth, and to the information these sensations provide about the state and structure of the mouth itself, and objects in the mouth. Because the oral tissues have a strong somatosensory innervation, they are the locus of some of our most intense and vivid bodily experiences. The salient pain of toothache, or the habit of running one's tongue over one's teeth when someone mentions “dentist”, provide two very different indications of the power of oral somatosensory awareness in human experience and behaviour. This paper aims to review the origins and structure of oral somatosensory awareness, focussing on quantitative, mechanistic studies in humans. We first extend a model of levels of bodily awareness to the specific case of the mouth. We then briefly summarise the sensory innervation of oral tissues, and their projections in the brain. We next describe how these peripheral inputs give rise to perceptions of objects in the mouth, such as foods, liquids and oral devices, and also of the mouth tissues themselves. Finally, we consider the concept of a conscious mouth image, and the somatosensory basis of “mouth feel”. The theoretical framework outlined in this paper is intended to facilitate scientific studies of this important site of human experience. [ABSTRACT FROM AUTHOR]

Objectives To investigate whether children with functional abdominal pain (FAP) show an attentional bias for their bodily activity, and whether receiving information about bodily activity influenced perception of bodily sensations. Methods A total of 30 children with FAP and 30 healthy children performed a dot-probe task, in which they were shown sham pictures about their bodily activity. Results Contrary to our hypotheses, no attentional bias for gut activity was found in either group. However, children with FAP were slower than healthy children on all supraliminal gut-activity trials, suggesting that pictures of gut activity distracted children with FAP from the task they were performing. Both groups showed an attention bias away from supraliminal pictures about heart activity. As hypothesized, more children with FAP than healthy children reported increases in pain after the experiment. Conclusions Children with FAP seemed more strongly influenced by information about gut activity than healthy children. The present study should be replicated for intervention purposes. [ABSTRACT FROM AUTHOR]

There is a growing body of research indicating that bodily sensation and behaviour strongly influences one?s emotional reaction towards certain situations or objects. On this background, a framework model of embodied affectivity1 is suggested: we regard emotions as resulting from the circular interaction between affective qualities or affordances in the environment and the subject?s bodily resonance, be it in the form of sensations, postures, expressive movements or movement tendencies. Motion and emotion are thus intrinsically connected: one is moved by movement (perception; impression; affection2) and moved to move (action; expression; e-motion). Through its resonance, the body functions as a medium of emotional perception: it colours or charges self-experience and the environment with affective valences while it remains itself in the background of one?s own awareness. This model is then applied to emotional social understanding or interaffectivity which is regarded as an intertwinement of two cycles of embodied affectivity, thus continuously modifying each partner?s affective affordances and bodily resonance. We conclude with considerations of how embodied affectivity is altered in psychopathology and can be addressed in psychotherapy of the embodied self. [ABSTRACT FROM AUTHOR]

Although flight phobia is very common in the general population, knowledge of the underlying mechanisms is limited. The aim of the current study is to determine whether hypoxia is selectively associated with flight anxiety. We wanted to explore levels of oxygen saturation (SpO2) and the associated subjective somatic sensations in flight phobics and controls. The data collected in this study were obtained from 103 participants: 54 had flight phobia, 49 were controls. SpO2as well as a subjective report of somatic sensations and anxiety were measured during short haul flights, both at ground level and at cruising altitude. Results indicated that both flight phobics and controls showed a comparable clinical significant decrease in SpO2from sea level to cruising altitude. Next, at ground level the flight phobic group reported more somatic sensations, most likely due to the elevated levels of anxiety at that point. However, at cruising altitude the flight phobic group still reported more somatic sensations while the level of anxiety was no longer significantly different from controls. This finding points to altered symptom perception in flight phobia and stresses the importance of somatic sensations in this particular phobia. [ABSTRACT FROM AUTHOR]

Background: ‘Self-objectification’ is the tendency to experience one's body principally as an object, to be evaluated for its appearance rather than for its effectiveness. Within objectification theory, it has been proposed that self-objectification accounts for the poorer interoceptive awareness observed in women, as measured by heartbeat perception. Our study is, we believe, the first specifically to test this relationship. Methodology/Principal Findings: Using a well-validated and reliable heartbeat perception task, we measured interoceptive awareness in women and compared this with their scores on the Self-Objectification Questionnaire, the Self-Consciousness Scale and the Body Consciousness Questionnaire. Interoceptive awareness was negatively correlated with self-objectification. Interoceptive awareness, public body consciousness and private body consciousness together explained 31% of the variance in self-objectification. However, private body consciousness was not significantly correlated with interoceptive awareness, which may explain the many nonsignificant results in self-objectification studies that have used private body consciousness as a measure of body awareness. Conclusions/Significance: We propose interoceptive awareness, assessed by heartbeat perception, as a measure of body awareness in self-objectification studies. Our findings have implications for those clinical conditions, in women, which are characterised by self-objectification and low interoceptive awareness, such as eating disorders. [ABSTRACT FROM AUTHOR]

Specialized, bimodal neural systems integrate visual and tactile information in the space near the hand. Here, we show that visuo-tactile representations allow attention to influence early perceptual processing, namely, figure-ground assignment. Regions that were reached toward were more likely than other regions to be assigned as foreground figures, and hand position competed with image-based information to bias figure-ground assignment. Our findings suggest that hand position allows attention to influence visual perceptual processing and that visual processes typically viewed as unimodal can be influenced by bimodal visuo-tactile representations. [ABSTRACT FROM PUBLISHER]

Abstract: The somatic sensation of the tongue is necessary for daily life, but it is difficult to know the underlying neural mechanisms. In particular, because of the vomiting reflex and several morphological problems, no neuroimaging studies have examined somatosensory processing by stimulating the posterior part of the tongue, except for two magnetoencephalographic studies (Sakamoto et al., 2008a,b). This is the first study to clarify the human cortical processing for sensory perception by the posterior part of the tongue with a newly developed device and functional magnetic resonance imaging (fMRI). Stimulation of the left and right postero-lateral parts of the tongue induced significant activity in the primary somatosensory cortex (SI) and Brodmann area 40 in the right hemisphere and the anterior cingulate cortex (ACC). In contrast, antero-lateral stimulation produced activity only in the right SI. The activated region in SI was significantly larger following stimulation of the posterior than anterior part. These results indicate that a clear difference exists in somatosensory processing between stimulation of the antero-lateral and postero-lateral parts of the tongue, and a right hemisphere is dominant for the stimulation of both antero-lateral and postero-lateral areas. The activity in BA 40 and ACC may imply that the posterior of the tongue belongs to the visceral system. [Copyright &y& Elsevier]

Abstract: There seems to be no dimension of bodily awareness that cannot be disrupted. To account for such variety, there is a growing consensus that there are at least two distinct types of body representation that can be impaired, the body schema and the body image. However, the definition of these notions is often unclear. The notion of body image has attracted most controversy because of its lack of unifying positive definition. The notion of body schema, onto which there seems to be a more widespread agreement, also covers a variety of sensorimotor representations. Here, I provide a conceptual analysis of the body schema contrasting it with the body image(s) as well as assess whether (i) the body schema can be specifically impaired, while other types of body representation are preserved; and (ii) the body schema obeys principles that are different from those that apply to other types of body representation. [Copyright &y& Elsevier]

A category of teder interaction is proposed as the main source of (mutual) mild touch stimuli in higher vertebrates. The somatosensory circuits for the perception of these stimuli in mammals and birds are discussed using data from the literature. In addition to the usual somatosensory areas of the brain, in mammals mild touch signals are also conducted to the insula, which is closely connected to the limbic system. This separate processing of mild touch stimuli lends more substance to the category of teder behaviour. The comparable neuroanatomy in birds is more difficult to interpret. There are some intriguing parallels between the relevant circuits of mammals and birds, though in the telencephalic parts in particular, conclusions are limited by uncertainties as to the homologies of the mammalian and avian brains. [ABSTRACT FROM AUTHOR]

Abstract: In a typical haptic search task, separate items are presented to individual fingertips. The time to find a specific item generally increases with the number of items, but is it the number of items or the number of fingers that determines search time? To find out, we conducted haptic search experiments in which horizontal lines made of swell paper were presented to either two, four or six of the participants’ fingertips. The task for the participant was to lift the finger under which they did not feel (part of) a line. In one of the conditions separate non-aligned lines were presented to the fingertips so that the number of items increased with the number of fingers used. In two other conditions the participants had to find an interruption in a single straight line under one of the fingertips. These conditions differed in the size of the gap. If only the number of items in the tactile display were important, search times would increase with the number of fingers in the first condition, but not depend on the number of fingers used in the other two conditions. In all conditions we found that the search time increased with the number of fingers used. However, this increase was smaller in the single line condition in which the gap was large enough for one finger to not make any contact with the line. Thus, the number of fingers involved determines the haptic search time, but search is more efficient when the stimulus can be interpreted as consisting of fewer items. [Copyright &y& Elsevier]

Evidence suggests that focusing on bodily symptoms increases perception of internal states. The interaction between situational (experimentally induced) symptom focusing and a disposition to focus on one's bodily symptoms is unclear. We assumed that situational symptom focusing increases perception of stress symptoms only in persons that usually do not focus on their bodily symptoms. Forty participants were divided into two groups (N=20) according to their disposition towards bodily symptom focusing (habitual symptom focusing, HSF+ and HSF-). Ten participants per group were instructed to focus on their neck muscle tension (situational symptom focusing, SSF+), while the others received a control instruction (SSF-). All participants underwent anticipation of a public speech, representing an emotional and mental stressor. There was a significant HSF×SSF interaction in reports on muscle tension and palpitation under stress. While HSF- participants reported more stress symptoms in the SSF+ condition, HSF+ participants reported less symptoms. However, no interaction was found in physiological measures including neck electromyogram, skin conductance reactions, heart rate and blood pressure. Our results indicate either that symptom perception is adjusted by symptom focusing, or that the instruction to use a habitual coping strategy reduces stress symptoms. [ABSTRACT FROM AUTHOR]

Age-related trends and predictors were explored with respect to three dimensions of adults’ body consciousness. Consistent with the notion that aging adults’ perceptions of their bodies are multidimensional and multidirectional, adults reported being more concerned about their external physical appearance (public body consciousness), more aware of their internal body sensations (private body consciousness), and more positive in their self-evaluations of their bodies (body competence). Moreover, consistent with the claim that such attitudes are multi-determined, the present research found that aging adults’ personal anxiety about aging and their subjective age identities were significant predictors of variations in their body consciousness. Moreover, the predictive value of these psychological variables rivaled the predictive value of chronological age. [ABSTRACT FROM AUTHOR]

The perception of the size and shape of one's body (body image) is a fundamental aspect of how we experience ourselves. We studied the neural correlates underlying perceived changes in the relative size of body parts by using a perceptual illusion in which participants felt that their waist was shrinking. We scanned the brains of the participants using functional magnetic resonance imaging. We found that activity in the cortices lining the left postcentral sulcus and the anterior part of the intraparietal sulcus reflected the illusion of waist shrinking, and that this activity was correlated with the reported degree of shrinking. These results suggest that the perceived changes in the size and shape of body parts are mediated by hierarchically higher-order somatosensory areas in the parietal cortex. Based on this finding we suggest that relative size of body parts is computed by the integration of more elementary somatic signals from different body segments. [ABSTRACT FROM AUTHOR]

Two experiments examined the integration of visual and proprioceptive information concerning the location of an unseen hand, using a mirror positioned along the midsagittal plane. In experiment 1, participants tapped the fingers of both hands in synchrony, while viewing the mirror-reflection of their left hand. After 6 s, participants made reaching movements to a target with their unseen right hand behind the mirror. Reaches were accurate when visually and proprioceptively specified hand positions were congruent prior to the reach, but significantly biased by vision when the visual location conflicted with the real location. This effect was independent of the target location and depended strongly upon the relative position of the mirror-reflected hand. In experiment 2, participants made reaching movements following 4, 8, or 12 s active visuomotor or passive visual exposure to the mirror, or following passive exposure without the mirror. Reaching was biased more by the visual location following active visuomotor compared to passive visual exposure, and this bias increased with the duration of visual exposure. These results suggest that the felt position of the hand depends upon an integrated, weighted sum of visual and proprioceptive information. Visual information is weighted more strongly under active visuomotor than passive visual exposure, and with increasing exposure duration to the mirror reflected hand. [ABSTRACT FROM AUTHOR]

A method for synergistic integration of multimodal sensor data is proposed in this paper. This method is based on two aspects of the integration process: (1) achieving synergistic integration of two or more sensory modalities, and (2) fusing the various information streams at particular moments during processing. Inspired by psychophysical experiments, we propose a self-supervised learning method for achieving synergy with combined representations. Evidence from temporal registration and binding experiments indicates that different cues are processed individually at specific time intervals. Therefore, an event-based temporal co-occurrence principle is proposed for the integration process. This integration method was applied to a mobile robot exploring unfamiliar environments. Simulations showed that integration enhanced route recognition with many perceptual similarities; moreover, they indicate that a perceptual hierarchy of knowledge about instant movement contributes significantly to short-term navigation, but that visual perceptions have bigger impact over longer intervals. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The integration of proprioception with vision, touch or audition is considered basic to the developmental formation of perceptions, conceptual objects and the creation of cognitive schemes. Thus, mapping of proprioceptive information processing is important in cognitive research. A stimulus of a brisk change of weight on a hand held load elicit a proprioceptive evoked potential (PEP). Here this is used to examine early and late information processing related to weight discrimination by event related potentials (ERP). Methods: A gating paradigm having 1s between the proprioceptive stimuli of 100g weight increase was recorded in 12 runs of 40 pairs and an 1:4 oddball task of discriminating between 40 and 100g weight increase was both recorded in 24 healthy men. The subjects were stratified in 3 groups according to their discrimination errors. Results: The proprioceptive event related potential (PERP) consisted of a contralateral parietal P60, frontal N70, midline P100, initial contralateral later widespread N160, vertex P200, parietal N290 and target related widespread P360 and posterior N500. The target related components were augmented in the best performers, while the bad performers had delayed P60 and attenuated N70. The amplitudes of N160, P200 and N290 were unrelated to performance. Gating was seen as attenuation of P100, N160 and P200 amplitude. Conclusions: The proprioceptive stimulus feature processing seem to be accomplished in the first 100ms, while later components are modified by context as expected from previous findings in the somatosensory modality. Significance: The PERP could be a useful research tool in the investigation of bodily information processing in neuropsychiatric disorders. [Copyright &y& Elsevier]

Previous research has shown that inertial cues resulting from passive transport through a large environment do not necessarily facilitate acquiring knowledge about its layout. Here we examine whether the additional body-based cues that result from active movement facilitate the acquisition of spatial knowledge. Three groups of participants learned locations along an 840-m route. One group walked the route during learning, allowing access to body-based cues (i.e., vestibular, proprioceptive, and efferent information). Another group learned by sitting in the laboratory, watching videos made from the first group. A third group watched a specially made video that minimized potentially confusing head-on-trunk rotations of the viewpoint. All groups were tested on their knowledge of directions in the environment as well as on its configural properties. Having access to body-based information reduced pointing error by a small but significant amount. Regardless of the sensory information available during learning, participants exhibited strikingly common biases. [ABSTRACT FROM AUTHOR]

The present study investigated the perceptual dimensions of everyday tactile textures and the semantics associated with touch experiences. In Experiment 1, the nature of the tactile descriptors present in the memory of 40 volunteers was investigated. Results suggested the existence of a limited but consensual tactile repertory. In Experiment 2, 20 volunteers used a free-sorting task to sort 24 car seat ‘ materials, with different tactile properties, on the basis of perceived similarity. Sorted groups were then characterized further by producing verbal labels. Multidimensional scaling and correspondence analysis indicated that the tactile texture space did not exceed four dimensions. The hypothesized perceptual dimensions were soft/harsh, thin/thick, relief and hardness. Further evidence for the relevance of these dimensions was provided in Experiment 3, in which participants were asked to evaluate the stimuli according to unipolar adjective scales corresponding to the previously derived dimensions. [Copyright &y& Elsevier]

An experiment investigated the mechanisms by which humans estimate Euclidean distances on the basis of kinaesthetic cues. Blindfolded participants followed straight and curvilinear paths with a hand-held stylus (encoding phase). Then, with a straight movement, they estimated the Euclidean distance between the start- and end-points of the path (response phase). The experiment contrasted an On-axis condition, in which encoding and response movements were spatially aligned, and an Off-axis condition, in which they were displaced laterally. Performances were slightly more accurate in the On-axis condition than in the Off-axis condition. In both conditions, however, errors were consistently smaller when the path covered a larger surface. The results showed that small paths yielded an overestimation of the Euclidean distance, the relative errors increasing with the length of curvilinear paths. The findings are compared with results of other studies in which distances were estimated on the basis of haptic cues. [ABSTRACT FROM AUTHOR]

Systematic deviations occur when blindfolded subjects set a test bar parallel to a reference bar in the horizontal plane using haptic information (Kappers and Koenderink 1999, Perception 28:781–795; Kappers 1999, Perception 28:1001–1012). These deviations are assumed to reflect the use of a combination of a biasing egocentric reference frame and an allocentric, more cognitive one (Kappers 2002, Acta Psychol 109:25–40). In two experiments, we have examined the effect of delay between the perception of a reference bar and the parallel setting of a test bar. In both experiments a 10-s delay improved performance. The improvement increased with a larger horizontal (left–right) distance between the bars. This improvement was interpreted as a shift from the egocentric towards the allocentric reference frame during the delay period. [ABSTRACT FROM AUTHOR]

By virtue of the direct coupling between circumoral skin and the underlying orofacial musculature, mechanosensation associated with precise orofacial force control may contribute significantly to processes associated with perception, proprioception, and sensorimotor control in this region. The purpose of this study was to assess lower lip (LL) vibratory detection thresholds of adult subjects during the simultaneous performance of a visually guided and continuous lip motor control task. Vibrotactile inputs were delivered to the right LL vermilion at test frequencies of 5, 10, 50, 150, 250, and 300 Hz. The psychophysical detection task was performed simultaneously with the three force control conditions: a null-force baseline condition, an active force control task performed with the right index finger, and an active force control task performed with the lip musculature. For the active tasks, subjects were instructed to use their analog force signal (lip or finger) to continuously perform a visually guided precision force task by tracking a 2 Hz sinusoidally moving target calibrated to a peak-to-peak force load of 0.2 N. Both the analog force signal and the target-tracking signal were displayed in real-time on an oscilloscope. Results showed a statistically significant elevation of LL vibrotactile detection thresholds for test frequencies below 50 Hz during the simultaneous performance of the lip force control task. Disassociating the site of motor control from the location of sensory stimulation (active control task) was effective in normalizing the elevations in LL vibrotactile thresholds, thus demonstrating that the threshold elevation during the lip force task was not solely an artifact of the added attentional load resulting from combining a perceptual task with a motor control requirement. These findings are discussed in relation to published reports of movement-related sensory gating in limb systems and the possible significance that this phenomenon may have for perception and proprioception in the orofacial system. [ABSTRACT FROM AUTHOR]

Vestibular functions are known to show some deterioration with age. Vestibular deterioration is often thought to be compensated for by an increase in neck proprioceptive gain. We studied this presumed compensatory mechanism by measuring psychophysical responses to vestibular (horizontal canal), neck and combined stimuli in 50 healthy human subjects as a function of age (range 15–76 years). After passive horizontal rotations of head and/or trunk (torso) in complete darkness (dominant frequencies 0.05, 0.1, and 0.4 Hz), subjects readjusted a visual target to its remembered prerotational location in space. (1) Vestibular-only stimulus (whole-body rotation); subjects' responses were shifted towards postrotatory body position, this only slightly at 0.4 Hz and pronounced at 0.1 and 0.05 Hz. These errors reflect the known physiological drop of vestibular gain at low rotational frequency. They exhibited a slight but significant increase with age. (2) Neck-only stimulus (trunk rotated, head stationary); the responses showed errors similar to those upon vestibular stimulation (with offset towards postrotatory trunk position) and this again slightly more with increasing age. (3) Vestibular-neck stimulus combination during head rotation on stationary trunk; the errors were close to zero, independent of stimulus frequency and the subjects' age. (4) Opposite stimulus combination (trunk rotated in the same direction as the head, but with double amplitude); the errors were clearly enhanced, essentially reflecting the sum of those with vestibular-only and neck-only stimulation. Taken together, we find a parallel increase in neck- and vestibular-related errors with age, in seeming contrast to previous studies. We explain our and the previous findings by a vestibular-neck interaction model in which two different neck signals are involved. One neck signal is used, in combination with the vestibular signal, for estimating trunk-in-space rotation. It is internally shaped to always match the vestibular signal, so that these two signals cancel each other out when summed during head rotation on stationary trunk. Because of this matching, perceived trunk stationariness during head rotation on the stationary trunk is independent of vestibular deterioration (related to stimulus frequency, age, ototoxic medication, etc.). The other neck proprioceptive signal, coding head-on-trunk rotation, is superimposed on the estimate of trunk-in-space rotation, thereby yielding a notion of head-in-space. This neck signal remains essentially unchanged with vestibular deterioration. Generally, we hold that the transformation of the vestibular signal from the head down to the trunk proceeds further to include the hip and the legs as well as the haptically perceived body support surface; by this, subjects yield a notion of support kinematics in space. As a consequence, spatial orientation is impaired by chronic vestibular deterioration only to the extent that the body support is moving in space, while it is unimpaired (determined by proprioception alone) during body motion with respect to a stationary support. [ABSTRACT FROM AUTHOR]

Focuses on the perceptual and psychophysical aspects of somesthesis. Peripheral sensory mechanisms and topics related to spatial and temporal pattern perception; Measures of spatial sensitivity; Use of touch as a possible channel of communication; Effect of aging on sensitivity and processing tactline stimuli; Aspects of haptics and kinesthesis affecting somesthesis.

Although there is little direct evidence available, there is a pervasive assumption that HR is easily detected during periods of physical stress or exertion. It has also been suggested that distance runners are keenly aware of their cardiac functioning. The present study assessed cardiac awareness while at rest and again following vigorous exercise for groups of subjects differing in physical fitness. Thirty-six subjects were solicited and composed groups of Sedentary, Tennis, and Distance Running groups. Each group was composed of equal numbers of male and female subjects. HR awareness was assessed using 35 10-sec discrimination trials. Veridical feedback was composed of light flashes triggered by EKG R-spikes whereas false feedback was composed of flashes at rates 10, 20, or 30 percent above or below their actual rate. At the end of each trial, subjects indicated the degree of certainty of their choice. Discrimination accuracy was measured at rest and again following exercise which raised HR level by 7 S percent. Analyses of variance indicated that male runners were significantly more accurate discriminators at rest than any other group. Similar superiority was not by the female runners. After exercise, the tennis and sedentary groups showed significant overall increases in awareness during augmented cardiac functioning. Exercise did not produce additional increments in awareness for the male runners. A battery of post experimental questionnaires largely failed to discriminate experimental groups. [ABSTRACT FROM AUTHOR]

• Distortions in visual perception preceding, or during, migraine are well known. • Other sensory distortions (hearing, touch, smell, taste) can also occur. • This study is the first to look at a range of sensory disturbances between attacks. • It also reports on distortions in the sense of the body, the environment and of time. • Some experiences are associated with reports of visual triggers and visual discomfort. Distortions in sensory experiences that precede a migraine attack have been extensively documented, the most well-known being the visual aura. Distortions in the experience of other senses are also reported as part of an aura, albeit less frequently, together with changes in the perception or ownership of the body or body parts. There are many examples of differences in aspects of visual perception between migraine and control groups, between attacks, but not as much on unusual experiences involving other senses, the sense of the body or the experience of the environment. Seventy-seven migraine (33 with aura) and 74 control participants took part. Anomalous perceptions were experienced by both migraine and control groups, but more with migraine experienced them and rated them as more distressing, intrusive and frequent. Associations with reports of visual triggers of migraine and visual discomfort are presented. This study is the first to show relationships between these factors. [ABSTRACT FROM AUTHOR]

The article examines the neural correlates underlying perceived changes in the relative size of body parts. Functional magnetic resonance imaging was used to investigate neural activity associated with perceptual changes of the size and shape of the waist known as the Pinocchio illusion. It is hypothesized that this illusion is the result of integration of conflicting somatic information from different body parts by the higher-order somatosensory areas in the parietal cortex. It is argued that these parietal areas are important for the construction of body image and how we experience ourselves.

Bodily self-consciousness consists of three components: the feeling of owning the body, the perceived location of yourself in space, and a first-person perspective. A recent study shows which neural areas subserve two components, body ownership and self-location, and crucially, how they can be integrated. [ABSTRACT FROM AUTHOR]

Support for the proposed dorsal-ventral distinction for the somatosensory system is not yet convincing, nor is the anatomical segregation of its pathways as clearly defined as the visual pathways. Consideration of alternative organizational principles might reveal critical differences across sensory processing systems. The role of attention and manipulations that modulate functional systems might also be worth considering. [ABSTRACT FROM AUTHOR]

Our commentary addresses two issues that are not developed enough in the target article. First, the model does not clearly address the distinction among external objects, external body parts, and internal bodies. Second, the authors could have discussed further the role of body schema with regard to its dynamic character, and its role in perspective and in imitation. [ABSTRACT FROM AUTHOR]

A general shortcoming of the localist, decompositional, approach to neuroscientific explanation that the target article exemplifies, is that it is incomplete unless supplemented with an account of how the hypothesized subsystems integrate in the normal case. Besides, a number of studies that show that object recognition is proprioception dependent and that cutaneous information affects motor performance make the existence of the proposed subsystems doubtful. [ABSTRACT FROM AUTHOR]

We review evidence for multifaceted functional specialization of somatosensory information processing, both within and outside classical somatosensory cortex. We argue that the nature of such specialization has not yet been clarified adequately to regard the proposed action/perception dichotomy as being established. However, we believe this is a good working hypothesis that can motivate further work. [ABSTRACT FROM AUTHOR]

There is a task-specificity in the visual-tactile interaction for perception: The polymodal posterior parietal cortex is related to the comparison of the shapes coded by different sensory modalities, whereas the lateral occipital complex is the part of the network for multimodal shape identification. These interactions may be mediated by some latent pathways potentiated by sensory deprivation or learning. [ABSTRACT FROM AUTHOR]

Dijkerman & de Haan (D&dH) propose a somatosensory perceptual pathway that informs a consciously accessible body image, and an action pathway that provides information to a body schema, which is not consciously accessible. We argue that the body schema may become accessible to consciousness in some circumstances, possibly resulting from cross talk, but that this may be detrimental to skilled movement production. [ABSTRACT FROM AUTHOR]

Dijkerman & de Haan (D&dH) study perception and action as two independent processes. However, in all daily activities the processes are completely intertwined, so it is difficult to separate one from the other. Humans perceive in order to move and also move in order to perceive. Understanding first how perception and action are coordinated, leads us then to determine how each component works independently. [ABSTRACT FROM AUTHOR]

Somatosensory processing for action guidance can be dissociated from perception and memory processing. The dorsal system has a global bias and the ventral system has a local processing bias. Autistics illustrate the point, showing a bias for part over wholes. Lateralized differences have also been noted in these modalities. The multi-modal dysfunction observed may suggest more an issue of interhemispheric communication. [ABSTRACT FROM AUTHOR]

The model developed in the target article is not as comprehensive as might be desired on two counts: (1) in that how the transition from proximal stimulation at the skin gives rise to the perception of external objects is taken for granted; and (2) in that another population of participants, the blind, constitute an important group from which we can understand somatosensoly processing and neural plasticity. [ABSTRACT FROM AUTHOR]