This is a review of the proprioceptive senses generated as a result of our own actions. They include the senses of position and movement of our limbs and trunk, the sense of effort, the sense of force, and the sense of heaviness. Receptors involved in proprioception are located in skin, muscles, and joints. Information about limb position and movement is not generated by individual receptors, but by populations of afferents. Afferent signals generated during a movement are processed to code for endpoint position of a limb. The afferent input is referred to a central body map to determine the location of the limbs in space. Experimental phantom limbs, produced by blocking peripheral nerves, have shown that motor areas in the brain are able to generate conscious sensations of limb displacement and movement in the absence of any sensory input. In the normal limb tendon organs and possibly also muscle spindles contribute to the senses of force and heaviness. Exercise can disturb proprioception, and this has implications for musculoskeletal injuries. Proprioceptive senses, particularly of limb position and movement, deteriorate with age and are associated with an increased risk of falls in the elderly. The more recent information available on proprioception has given a better understanding of the mechanisms underlying these senses as well as providing new insight into a range of clinical conditions.

The Proprioceptive Senses: Their Roles in Signaling Body Shape, Body Position and Movement, and Muscle Force

What determines what we see? In contrast to the traditional "modular" understanding of perception, according to which visual processing is encapsulated from higher-level cognition, a tidal wave of recent research alleges that states such as beliefs, desires, emotions, motivations, intentions, and linguistic representations exert direct top-down influences on what we see. There is a growing consensus that such effects are ubiquitous, and that the distinction between perception and cognition may itself be unsustainable. We argue otherwise: none of these hundreds of studies - either individually or collectively - provide compelling evidence for true top-down effects on perception, or "cognitive penetrability". In particular, and despite their variety, we suggest that these studies all fall prey to only a handful of pitfalls. And whereas abstract theoretical challenges have failed to resolve this debate in the past, our presentation of these pitfalls is empirically anchored: in each case, we show not only how certain studies could be susceptible to the pitfall (in principle), but how several alleged top-down effects actually are explained by the pitfall (in practice). Moreover, these pitfalls are perfectly general, with each applying to dozens of other top-down effects. We conclude by extracting the lessons provided by these pitfalls into a checklist that future work could use to convincingly demonstrate top-down effects on visual perception. The discovery of substantive top-down effects of cognition on perception would revolutionize our understanding of how the mind is organized; but without addressing these pitfalls, no such empirical report will license such exciting conclusions. Language: en

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Cognition does not affect perception: Evaluating the evidence for "top-down" effects.

Perception informs people about the opportu- nities for action and their associated costs. To this end, explicit awareness of spatial layout varies not only with relevant optical and ocular-motor variables, but also as a function of the costs associated with performing intended actions. Although explicit awareness is mutable in this respect, visually guided actions directed at the immediate environment are not. When the metabolic costs associated with walking an extent increase—perhaps because one is wearing a heavy backpack—hills appear steeper and distances to targets appear greater. When one is standing on a high balcony, the apparent distance to the ground is correlated with one's fear of falling. Perceiving spatial layout combines the geometry of the world with behavioral goals and the costs associated with achieving these goals.

Embodied Perception and the Economy of Action

Immersive virtual environment (IVE) technology has great promise as a tool for basic experimental research in psychology. IVE technology gives participants the experience of being surrounded by the computer-synthesized environment. We begin with a discussion of the various devices needed to implement immersive virtual environments, including object manipulation and social interaction. We review the benefits and drawbacks associated with virtual environment technology, in comparison with more conventional ways of doing basic experimental research. We then consider a variety of examples of research using IVE technology in the areas of perception, spatial cognition, and social interaction.

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Immersive virtual environment technology as a basic research tool in psychology.

This paper posits the usefulness of mental shifts of scale and perspective in thinking and communicating about spatial relations, and describes two experimental techniques for researching such cognitive activities. The first example involves mentally expanding a hand-sized piece of entangled string, a knot, so that following a portion of the string into a crossing resembles the act of walking along a path and over a bridge. The second example involves transforming experience and conceptions of the large-scale environment to small-scale representations through the act of mapmaking, and then translating the map to depictions of street-level views. When used in the context of clinical research methodologies, these techniques can help to elicit multimodal expressions of conceived topological relationships and geographical detail, with particular attention to individual differences.

Spatial Cognition II

In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

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Visual-motor recalibration in geographical slant perception.

People judged the inclination of hills viewed either out-of-doors or in a computer-simulated virtual environment Angle judgments were obtained by having people (1) provide verbal estimates, (2) adjust a representation of the hill’s cross-section, and (3) adjust a tilt board with their unseen hand Geographical slant was greatly overestimated according to the first two measures, but not the third Apparent slant judgments conformed to ratio scales, thereby enhancing sensitivity to the small inclines that must actually be traversed in everyday experience It is proposed that the perceived exaggeration of geographical slant preserves the relationship between distal inclination and people’s behavioral potential Hills are harder to traverse as people become tired; hence, apparent slant increased with fatigue Visually guided actions must be accommodated to the actual distal properties of the environment; consequently, the tilt board adjustments did not reflect apparent slant overestimations, nor were they influenced by fatigue Consistent with the fact that steep hills are more difficult to descend than to ascend, these hills appeared steeper when viewed from the top

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Perceiving geographical slant

The purpose of this study was to determine the intercorrelations between religiosity, perceived family support, and self-esteem in adolescents. Using convenience sampling, we recruited the participants from three high schools and one church youth group in Southeast Louisiana. There were 93 participants (32 male and 61 female) ranging in age from 14 to 18 years. The participants filled out a demographic questionnaire, the Rosenberg Self-Esteem Scale, a Religiosity Scale, and the Perceived Social Support Family Scale. No significant correlation was found between religiosity and self-esteem. However, perceived family support and self-esteem had a significant positive correlation, as did perceived family support and religiosity. Male adolescents had lower religiosity than female adolescents. Suggestions for future research include investigating a more diverse sample and other possible variables.

Relationship Among Adolescent Self-Esteem, Religiosity, and Perceived Family Support

Geographical slant perception: Dissociation and coordination between explicit awareness and visually guided actions

The effect of labels on recognition and identification of odors over time was assessed. 30 men and 30 women were presented 20 odors; half of the participants were also told a name for the odor as a label. Five min. and 60 min. later, all participants were given 20 odors (10 from the original set, 10 new) and asked whether each odor was new or old (odor recognition). The group given labels was also asked to recall the label provided (odor identification). Analysis indicated a significant effect of time on recognition. Significantly more odors were recognized at 5 min. than 60 min. The effect of label was also significant, with recognition being better for the Label condition than the No-Label condition. As for odor identification, women identified more labels than did men. Overall, odor recognition was better with labels soon after exposure, and the women were better at remembering the labels than the men.

Mukul Bhalla

Papers

Visual-motor recalibration in geographical slant perception.

Perceiving geographical slant

Relationship Among Adolescent Self-Esteem, Religiosity, and Perceived Family Support

Geographical slant perception: Dissociation and coordination between explicit awareness and visually guided actions

Odor recognition and identification: effect of labels over time.