Weight Perception Research Papers - Academia.edu (original) (raw)

Man, even though he may sometimes dream of being a pure spirit free from all material constraints, actually exists as a body in a world which is itself essentially constructed as a spatialized system of bodies; and in this constructed... more

Man, even though he may sometimes dream of being a pure spirit free from all material constraints, actually exists as a body in a world which is itself essentially constructed as a spatialized system of bodies; and in this constructed world features such as resistance, impenetrability, inertia, weight and forces are not accidents or exceptions but the rule.
The reflexions presented in this work aim at elucidating on a phenomenological level the relation that man entertains with the tangible aspects of his environment, and the function that this relation plays in the construction of the different sectors of his existence. The first of the sectors is perception: the opening on an ambient world that is pregnant with organisation and meaning. On the one hand, we shall take into account and conceptualize the way in which the tangibility of the world (the testing experience that the individual can have of resistance of his environment in the frame of a direct bodily relation with that environment, but more generally the understanding that the individual possesses of the very possibility of such a relation) participates in setting up the rationality by which man renders his world intelligible. On the other hand, we shall identify the structures of “subjectivity” (to speak the language of psychology, the structures of cognition) which make possible the specific way in which man constructs his experience and understanding of tangible resistance – whether this resistance is perceived in the context of an actual bodily engagement, or whether it is envisaged “indirectly” in the guise of a “simple” possibility.
We shall show here, on the basis of phenomenological analyses as well as elements coming from empirical psychology (experimental psychology as well as neuropsychology), that the relation that man has with the resistance of his ambient world depends on an opening towards the possible; and that the organisation of the ambient world in the form of a space which can contain material structures, or structures capable of opposing a resistance to the body, depends on a rationality which consists of making phenomena intelligible by interpreting them with reference to those capacities for action and for passion which the body confers on us, to the power that the body provides us with and the constraints to which it submits us.
Thus, even though the realm of material things – tangible objects, bodies – functions as an archetype of “presence” and of “being” (indeed, what is more “real” than a body?), in the last resort it gains its phenomenal character from the fact that it crystallizes for the person who perceives it a stream of virtual possibilities; hence, the here-and-now presence of the “tangible world” is in an essential way indebted to the realm of that which is not actually realized.

The aim of this text is to question the use made by Heidegger, from the start to the end of his work, of the lexical field of weight to express the relationship of Dasein to being, a relationship thought under the modality of taking on a... more

The aim of this text is to question the use made by Heidegger, from the start to the end of his work, of the lexical field of weight to express the relationship of Dasein to being, a relationship thought under the modality of taking on a load. Having recalled the context and the passages in which Heidegger mobilises this lexical field, and having proposed an interpretation in the sphere of the conceptuality of the existential analytic, we shall attempt to bring to light the reasons that may have led him, somehow unwittingly, to place the relationship of Dasein to being under the heading of the phenomenon of weight. We shall seek in this regard to show from a phenomenological description of the experience of physical weight (weight of the body proper as well as the weight of objects) that this convocation of the phenomenon of weight to express the ontological experience constitutive of Dasein, far from being anodyne, is motivated by the very structure of this phenomenon – a phenomenon in which Dasein is led to experience in a privileged way the “that he is and has to be” in which his understanding of being is originally realised. (translated by J. Dudley)

Ce texte vise à mettre en place une série d’éléments devant servir de fondement à une interprétation phénoménologique de la pesanteur, à savoir une caractérisation de la pesanteur telle qu’elle se montre et fait sens pour l’individu dans... more

Ce texte vise à mettre en place une série d’éléments devant servir de fondement à une interprétation phénoménologique de la pesanteur, à savoir une caractérisation de la pesanteur telle qu’elle se montre et fait sens pour l’individu dans son rapport quotidien, « préréflexif », au monde. Bien que les réflexions ici proposées soient prioritairement à rattacher à la philosophie, nous convoquerons une série d’observations issues des sciences empiriques – au premier chef la psychologie – pour appuyer leur cheminement. Après avoir montré, sur la base d’un ensemble de résultats de la psychologie, que le poids d’un objet manipulé est spontanément évalué/perçu par l’individu sur la base de l’effort requis pour le soulever, et que l’amplitude de l’effort devant être fourni pour développer un niveau de force donné est elle-même proportionnée à la capacité de production de force variable dont dispose l’individu, nous proposerons une première caractérisation phénoménologique de la pesanteur. Nous chercherons à partir de là à mettre en lumière les structures qui, du côté du sujet percevant, rendent possible la manifestation de quelque chose de tel que le poids. Deux idées principales s’imposeront : d’une part, la pesanteur peut être comprise comme une des manières dont l’individu se rend intelligible son monde en référant l’objet qu’il manipule à la prise dont il dispose, au sens de la latitude de son pouvoir d’action ; d’autre part, parce que le poids n’est pas quelque chose que l’on voit mais quelque chose que l’on supporte, quelque chose qui pour être perçu doit être pris en charge, seul un percevant capable de se rapporter à soi comme à une puissance finie, un être en perpétuel épuisement, aura la conformation requise pour rencontrer quelque chose de tel que le poids – pour ouvrir un monde où règne la pesanteur.

In four experiments, a multidimensional signal detection analysis was used to determine the influence of length, diameter, and mass on haptically perceived heaviness with and without vision. This analysis allowed us to test for sensory... more

In four experiments, a multidimensional signal detection analysis was used to determine the influence of length, diameter, and mass on haptically perceived heaviness with and without vision. This analysis allowed us to test for sensory and perceptual interactions between mass and size. As in previous research, sensory interactions were apparent in all four experiments. A novel result was the appearance of perceptual interactions that became more prominent when diameter varied and when vision was allowed. Discussion focuses on how vision and the modalities of touch (i.e., haptic and dynamic) might influence which interactions appear in the data.

The present study investigated whether a specific aspect of proprioception, the sense of heaviness or weight is affected in PD. We determined detection thresholds for the perception of a gravito-inertial load in 10 PD patients and 11... more

The present study investigated whether a specific aspect of proprioception, the sense of heaviness or weight is affected in PD. We determined detection thresholds for the perception of a gravito-inertial load in 10 PD patients and 11 age-matched control subjects. A gradually increasing weight
was applied to the index finger by means of two slings of different width (low vs. high skin pressure). For the controls, mean detection thresholds were 31.3 g at skin high pressure and
33.0 g under low pressure. PD patients revealed significantly higher thresholds than the control group in both pressure conditions (mean high pressure,47.7 g; mean low pressure, 52.3 g; group effect, P 0.001). Thresholds of PD patients tended to increase with disease severity as measured by the Unified Parkinson’s Disease Rating Scale Motor score (r 0.55) but did not correlate significantly with levodopa equivalent dosage. The results demonstrate that the perception of heaviness or weight is already affected in the early stages of PD. These findings underline the growing evidence that proprioceptive and possibly haptic dysfunction is a common feature of PD.

Disordered eating behaviors and substance use are two risk factors for the development of serious psychopathology and health concerns in adulthood. Despite the negative outcomes associated with these risky behaviors, few studies have... more

Disordered eating behaviors and substance use are two risk factors for the development of serious psychopathology and health concerns in adulthood. Despite the negative outcomes associated with these risky behaviors, few studies have examined potential associations between these risk factors as they occur during adolescence. The importance of accurate or inaccurate weight perception among adolescents has received increased interest given documented associations with nutritional beliefs and weight management strategies. This study examined the associations among the perceptions of weight and substance use with disordered eating behaviors among a diverse sample of normal weight and overweight adolescent males and females. Data came from the 2007 National Youth Risk Behavior Survey (YRBS). The sample consisted of 11,103 adolescents (53.4% female; 44% Caucasian, 21% African American; 13% Hispanic; age responses ranged from 12 and under to 18 and over), with 31.5% meeting criteria for being either at-risk for obesity or already obese (i.e., overweight). As hypothesized, overestimation of weight among normal weight adolescents and accurate perceptions of weight among overweight adolescents were associated with higher rates of disordered eating behaviors. In normal weight adolescents, use of all three substances (tobacco, binge drinking, and cocaine) was associated with each disordered eating behavior. In contrast, findings revealed differences for overweight adolescents between the type of substance use and disordered eating behavior. Post hoc analyses revealed that gender moderated some of these relationships among overweight individuals. Implications for the development and implementation of secondary prevention programs aimed at reducing disordered eating behaviors, substance use, and obesity risk among normal and overweight adolescents are considered.

To evaluate parental perceptions of and concern about child's body weight and general health in children in a European cohort. Cross-sectional multi-centre study in eight European countries. 16,220 children, ages 2-9 years. Parents... more

To evaluate parental perceptions of and concern about child's body weight and general health in children in a European cohort. Cross-sectional multi-centre study in eight European countries. 16,220 children, ages 2-9 years. Parents completed a questionnaire regarding children's health and weight and concern about overweight and underweight. Objective children's weight categories from the International Obesity Task Force were used. Logistic regression models were utilized to identify predictors of accurate weight perception. Parental weight perception corresponded overall to children's mean body mass index (BMI) z-scores, with important exceptions. About one-third of the total indicated concern about underweight, paradoxically most often parents of children in the overweight or obesity categories. In 63%, parents of children in the overweight category marked 'proper weight'. The strongest predictor for accurate parental weight perception for children with over...

Aim: To determine the prevalence of misperception of body weight status among Tunisian adults in the region of Sousse and examine its associated factors. Materials and Methods: The studied population was randomly selected from three... more

Aim: To determine the prevalence of misperception of body weight status among Tunisian adults in the region of Sousse and examine its associated factors.
Materials and Methods: The studied population was randomly selected from three districts of the region of Sousse. Our sample was composed of all adults aged from 18 to 65 years living in these selected districts. An interviewer-administered questionnaire was used to collect socio-demographic data, and self-reported weight and height. We collected biometric measures of height and weight. For multivariate analysis, we used Multinomial regression where reference group was composed of participants who well or over estimated their weight status.
Results: Prevalence of obesity based on self-reported weight and height was 15.2%. The prevalence of measured obesity was 31.7% (p < 0.001). Correct estimation of weight status was 74.3%, 65.5% and 90.9% respectively among participants who reported being normal weight, overweight and obese. Underestimation of weight status was 9.4% among overweight and 9.1% among obese according to their reported weight and height. Multivariate analysis showed that obese participants had higher risk of under estimation. However students had lower risk of under estimation of weight status.
Conclusion: We should take into account social circumstances when designing obesity preventive and treatment interventions.

This study examined the relationship between interoceptive sensitivity and the behavioral self-regulation of physical load. According to their performance in a heartbeat detection task, 34 participants were classified as good or poor... more

This study examined the relationship between interoceptive sensitivity and the behavioral self-regulation of physical load. According to their performance in a heartbeat detection task, 34 participants were classified as good or poor heartbeat perceivers. Participants pedaled on a bicycle ergometer for 15 min and were free to choose the tempo of their cycling. Good heartbeat perceivers covered a significantly shorter distance and showed a significantly smaller increase in mean heart rate, stroke volume, and cardiac output. There were significant negative correlations between heartbeat perception score and covered distance, changes in heart rate, changes in stroke volume, and changes in cardiac output. These results were not explained by differences in physical fitness level (PWC150). The findings suggest that good heartbeat perceivers show a more finely tuned behavioral self-regulation of physical load than poor heartbeat perceivers.

The accuracy of force perception by human subjects in the absence of voluntary motor command was evaluated by exploring how they perceived isometric twitches of wrist extensor muscles produced by external stimulation. Twelve normal... more

The accuracy of force perception by human subjects in the absence of voluntary motor command was evaluated by exploring how they perceived isometric twitches of wrist extensor muscles produced by external stimulation. Twelve normal subjects and a well-known patient lacking large-diameter afferent fibres (GL) performed estimation, production and reproduction tasks. Magnetic stimulation of the radial nerve and, in normal subjects, transcranial magnetic stimulation (TMS) of the motor cortex were used to produce weak brief non-voluntary twitches. In estimation tasks, the subjects had to ascribe verbal marks on a 1–5 scale to the forces of stimulation-induced twitches. Loose covariations of marks and forces were observed, while directions of force variations between successive twitches were relatively well detected. GL did less well than normal subjects in detecting directions of force variations. In production tasks, subjects had to produce twitches matching verbal command marks in a 1–5 range, with or without visual feedback. Performances of normal subjects and GL resembled those of estimation tasks and were not improved by visual feedback. In reproduction tasks, subjects had to duplicate stimulation-induced test twitches: first without visual feedback, second with and third again without. Large errors were observed but all subjects did better with visual feedback. In the third step, improvement with respect to the first one was significantly more marked with TMS than with peripheral stimulation. GL improved her performance in the third step, possibly because she could use information provided by group III and group IV afferents still present in her nerves. Altogether, for normal subjects (1) the performances in estimation tasks are consistent with the known behaviour of Golgi tendon organs as observed in animal experiments, and (2) results observed in reproduction tasks suggest that cortical stimulation might elicit, in addition to corticospinal activation of motoneurones, collateral discharges that could be stored as a memory of motor command.

Bigger objects look heavier than smaller but otherwise identical objects. When hefted as well as seen, however, bigger objects feel lighter (the size-weight illusion), confirming that the association between visual size and weight has a... more

Bigger objects look heavier than smaller but otherwise identical objects. When hefted as well as seen, however, bigger objects feel lighter (the size-weight illusion), confirming that the association between visual size and weight has a perceptual component. Darker objects also look heavier than brighter but otherwise identical objects. It is uncertain, however, if this association also has a perceptual element, or if it simply reflects the fact that, in English at least, the same verbal label (light) is applied to both surface brightness and weight. To address this, we looked for a brightness equivalent of the size-weight illusion. Paired-comparison judgments of weight were obtained for balls differing only in color. Based on vision alone, darker objects were judged to be heavier. When the balls were hefted as well as seen, this association was reversed (i.e., a brightness-weight illusion), consistent with it having a perceptual component. To gauge the strength of the illusion (in grams), a white and a black ball (both 129 g) were each compared against a set of mid-gray balls varying in weight. When the balls were hefted as well as seen, the white ball felt approximately 8 g heavier than the black ball, a difference corresponding to 6.2% of their actual weight. Possible environmental origins of the association between surface lightness and weight are considered.