Perception of Size of Movement Patterns

Physiological data suggest that perception and memory of kinesthesis may differ depending on whether a movement pattern is actively commanded or passively induced. An attempt was made to demonstrate a difference between these two types of movements by employing a cross-modal visual recognition test of size perception. Absolute and algebraic errors in the matching of kinesthesis with vision were measured. Positive algebraic errors were seen indicating that subjects’ perception for the size of kinesthetic movement patterns was magnified as compared to vision. Active kinesthesis was matched with vision more accurately than was passive kinesthesis, and the data yielded information about the differential contribution of active and passive muscle compartments to the global kinesthetic perception of voluntary movement. Cross-modal matching of kinesthesis with vision was in certain cases as accurate as visual intramodal matching. It was argued that active kinesthesis has internal references, and vision has external references to facilitate the similar-size recognition performance.     

Age differences in the relationship between visual movement imagery and performance on kinesthetic acuity tests

The Vividness of Movement Imagery Questionnaire was administered to 280 fourteen-year-olds and 186 ten-year-olds, who were then tested on measures of kinesthetic acuity. The relationship between visual movement imagery and kinesthetic acuity scores was significant in the older group: Those with high levels of visual movement imagery performed significantly better on measures of kinesthetic acuity than did those with low imagery. No such effect was found in the younger group. The results indicate that for adolescents, the confounding effect of visual imagery affects the researcher's ability to interpret kinesthetic acuity scores. The relationship between imagery and kinesthesis appears to develop over the period between 10 and 14 years, although such an interpretation may be premature because the measurement of visual movement imagery in the younger age group is problematic.     

An analysis of perceptions from changes in optical size

The allocation of perceived size and perceived motion or displacement in depth resulting from retinal size changes (changes in the visual angle of the stimulus) was investigated in situations in which all other cues of perceived changes in distance were absent. The allocation process was represented by the size—distance invariance hypothesis (SDIH), in which, for a given change in visual angle, the perceived depth was determined only by the amount of size constancy available. The changes in perceived size and perceived distance (perceived depth) were measured by kinesthetic observer (open-loop) adjustments in five situations. These situations consisted of optical expansions or contractions presented successively or simultaneously or as a mixture of successive and simultaneous presentations. The amounts of perceived motion or perceived displacement in depth obtained by kinesthetic measures were compared with those obtained from size constancy measures as applied to the SDIH. This latter measure accounted for more of the perceived depth obtained from simultaneous and mixed situations than it did for the perceived depth from the successive situations and more for the perceived depth obtained from the expansion than from the contraction situations, whether these were simultaneous or mixed. Perceived rigidity of the stimulus (perfect size constancy) clearly was not obtained in any of the situations. Significant partial size constancy and some predictive ability of the perceived sagittal motion was found using the SDIH in all the situations except in the successively presented contraction situation, with the predictive ability from the SDIH increasing with increases in the amount of size constancy. The difference between the observer’s measures of the perceived motion or displacement in depth and the amount of perceived motion or displacement predicted from the perceptions of linear size using the SDIH is asserted to be due to a cognitive process associated with the perception of the different stimulus sizes as off-sized objects.     

Watching a cursor distorts haptically guided reproduction of mouse movement

Participants moved a mouse along a force-feedback-defined linear path, either without vision or while watching a cursor set to 1 of 3 levels of visual:haptic gain (all >1:1). They attempted to haptically reproduce the movement without visual feedback. Errors increased with gain, reaching 70% overestimation at the highest gain. Forewarning participants about gain variability did not eliminate this effect. The gain level was potentially cued during the movement by the mismatch between visual feedback and kinesthetic feedback. Moreover, because participants did not achieve cursor-speed constancy across gain levels, visual speed was another cue to gain. Collectively, these cues failed to prevent visual distortion of movement reproduction.     

The relationship between eye position and egocentric visual direction.

Hering's model of egocentric visual direction assumes implicitly that the effect of eye position on direction is both linear and equal for the two eyes; these two assumptions were evaluated in the present experiment. Five subjects pointed (open-loop) to the apparent direction of a target seen under conditions in which the position of one eye was systematically varied while the position of the other eye was held constant. The data were analyzed through examination of the relationship between the variations in perceived egocentric direction and variations in expected egocentric direction based on the positions of the varying eye. The data revealed that the relationship between eye position and egocentric direction is indeed linear. Further, the data showed that, for some subjects, variations in the positions of the two eyes do not have equal effects on egocentric direction. Both the between-eye differences and the linear relationship may be understood in terms of individual differences in the location of the cyclopean eye, an unequal weighting of the positions of the eyes in the processing of egocentric direction, or some combination of these two factors.     

Spatial representation of a two-dimensional pattern

The purpose of this study was (a) to determine if vision and kinesthesis contribute differentially to the coding of a specific two-dimensional pattern and (b) to identify the effect of repetition on the spatial representation of this pattern. The reproductions of a specific pattern presented visually were compared with those of a pattern presented kinesthetically. The results showed that vision and kinesthesis had contributed equally to the coding of the directional components of the pattern. However, there was dominance of visual information over kinesthetic information when coding the distance between the intersecting points of the pattern, especially at the beginning of the process. Generally speaking, the visual or kinesthetic repetition, or both, have increased favourably the precision with which a specific pattern was reproduced in distance and direction.     

Fake hand in movement: Visual motion cues from the rubber hand are processed for kinesthesia

The feeling that a fake (e.g. rubber) hand belongs to a person's own body can be elicited by synchronously stroking the fake hand and the real hand, with the latter hidden from view. Here, we sought to determine whether visual motion signals from that incorporated rubber hand would provide relevant cues for sensing movement (i.e. kinesthesia). After 180 s of visuo-tactile synchronous or asynchronous stroking, the fake hand was moved along the lateral or the sagittal axis. After synchronous stroking, movement of the rubber hand induced illusory movement of the static (real) hand in the same direction; the illusion was slightly more frequent and more intense when the fake hand was moved along the sagittal axis. We therefore conclude that visual signals of motion originating from the rubber hand are integrated for kinesthesia by the central nervous system just as visual signals from the real hand are.     

Oral kinesthetic deficit in adults who stutter: a target-accuracy study

The current study was based on the hypothesis that chronic developmental stuttering in adults involves a deficiency in oral kinesthesia. The authors used a target-accuracy task to compare oral kinesthesia in adults who stutter (n = 17) and in normal speakers (n = 17). During the task, participants were instructed to make accurate jaw-opening movements in visual and nonvisual feedback conditions. The authors further contrasted oral movement control in a normal response time condition with that in a reaction time condition. Overall, the adults who stutter consistently made significantly less accurate and more variable movements than the control participants in the nonvisual condition, but particularly in the reaction time condition. In general, the present findings suggest that chronic developmental stuttering involves an oral kinesthetic deficiency, although without direct measures of somatosensory function, one cannot exclude a motor deficit interpretation.     

Tool characteristics in imagery of tool actions

Are tool characteristics represented in imagined tool actions? In two experiments participants imagined and executed coloring rectangles with a thick and a thin pen. In Experiment 2, an additional execution condition without visual feedback of coloring allowed us to dissociate between the relevance of kinesthetic and visual feedback. Pen thickness influenced coloring durations in all conditions, indicating that characteristics of a simple tool are represented during imagery. Imagination was shorter than execution, indicating that imagination may be less detailed than execution. Execution without visual feedback was even shorter than imagination, indicating that vision is more important than kinesthesis for differences between imagination and execution, and that either imagining the movement, inhibiting movement execution or imagining the progress of the action is effortful during imagery. In conclusion, characteristics of simple tools are represented in imagined tool actions but the representation of tools’ effects may not always be adequate.     

Eye movements and the span of the effective stimulus in visual search

The span of the effective stimulus during visual search through an unstructured alphanumeric array was investigated by using eye-contingent-display changes while the subjects searched for a target letter. In one condition, a window exposing the search array moved in synchrony with the subjects' eye movements, and the size of the window was varied. Performance reached asymptotic levels when the window was 5 degrees. In another condition, a foveal mask moved in synchrony with each eye movement, and the size of the mask was varied. The foveal mask conditions were much more detrimental to search behavior than the window conditions, indicating the importance of foveal vision during search. The size of the array also influenced performance, but performance reached asymptote for all array sizes tested at the same window size, and the effect of the foveal mask was the same for all array sizes. The results indicate that both acuity and difficulty of the search task influenced the span of the effective stimulus during visual search.     

Saccadic suppression of displacement is strongest in central vision

Perception of target displacement is severely degraded if the displacement occurs during a saccadic eye movement, but the variation of this effect across the visual field is unknown. A small target was displaced from a starting point at the midline, or 10 deg to the right or left, while the eye made a saccade from the 10 deg right position to the 10 deg left position. Saccades were detected and the target displaced on line. Assessed with a signal detection measure, suppression was stronger in central vision than in more peripheral locations for all three subjects. Leftward and rightward displacements yielded equal thresholds. The results complement the findings of others to reveal a picture of perceptual events during saccades, with both deeper saccadic suppression and faster correction of spatial values (the correspondences between retinal position and perceived egocentric direction), favouring more accurate spatial processing in central vision than in the periphery.     

The relationship between eye position and egocentric visual direction

Hering’s model of egocentric visual direction assumes implicitly that the effect of eye position on direction is both linear and equal for the two eyes; these two assumptions were evaluated in the present experiment. Five subjects pointed (open-loop) to the apparent direction of a target seen under conditions in which the position of one eye was systematically varied while the position of the other eye was held constant. The data were analyzed through examination of the relationship between the variations in perceived egocentric direction and variations inexpected egocentric direction based on the positions of the varying eye. The data revealed that the relationship between eye position and egocentric direction is indeed linear. Further, the data showed that, for some subjects, variations in the positions of the two eyes do not have equateffectsTjn egocentric direction. Both the between-eye differences and the linear relationship may be understood in terms of individual differences in the location of the cyclopean eye, an unequal weighting of the positions of the eyes in the processing of egocentric direction, or some combination of these two factors.     

An Informational Analysis of Active Kinesthesis as Measured by Amplitude of Movement

5 blindfolded Ss were required to make absolute judgments of the extent to which their extended right arm was voluntarily moved in the horizontal plane. The first experiment entailed the judgment of 20 different amplitudes and from these data a scale of equal discriminability was constructed for each S. From these individual scales amplitudes were selected for 5 additional absolute judgment experiments where the number of amplitudes were varied from 4 to 16. Analysis of the mean equal discriminability scale showed that kinesthetic sensitivity varied over the continuum of movements. The primary analysis of information transfer between number of amplitudes of movement and responses indicated that information transfer varied considerably over the 5 experiments with a maximum transfer of 2.48 bits occurring when 16 amplitudes were used. These results were discussed in terms of the possible cues involved in movement discrimination and whether kinesthetic cues could be used in a closed-loop model of voluntary movement control.     

The perception of size and distance under monocular observation

A relative-perceived-size hypothesis is proposed to account for the perception of size and distance under monocular observation in reduced-cue settings. This hypothesis is based on two assumptions. In primary processing, perceived size is determined by both proximal stimulation on the retina and distance information from primary cues such as oculomotor cues. In secondary processing, the relation of two primary perceived sizes determines another relation of secondary perceived distances, so that an object of smaller primary perceived size is judged to be further away. An experiment was designed to test this hypothesis, especially the assumption of secondary processing, by making ratio judgments of perceived size and perceived distance for two successively presented targets. The Standard square was presented at a constant distance and varied in visual angle; the variable square was presented with a constant visual angle in distance. The results showed that an inverse relation between size and distance estimates held regardless of whether the visual angles of the targets were the same or different.     

Time-dependent effects of kinesthetic input

Sensory input can be used by the nervous system to control the spatial parameters of motor responses (e.g., distance, velocity, and direction) by initializing these parameters before movement onset and then by adjusting these parameters during movement. Sensory input can also be used to trigger movements. In the experiments reported in this paper, we compared the effects of kinesthetic input on a triggered motor response when the kinesthetic input was generated at different times relative to the onset of the motor response. Human subjects responded to a visual stimulus by intentionally increasing elbow torque to a target level. Kinesthetic input was generated by unexpectedly rotating each subject's elbow 100 ms before the onset of the intentional torque response (early) or coincident with the onset of the intentional torque response (late). The effect of early kinesthetic input on the intentional torque response markedly differed from the effect of late kinesthetic input. The effect of early kinesthetic input was relatively independent of the direction of elbow rotation, had a different dependence on the amplitude of rotation, and required a shorter duration of rotation compared to the effect of late kinesthetic input. These differences in the effects of early and late kinesthetic input might be related to the initialization, triggering, and adjustment of motor responses.     

Perceived size and distance as a perceptual conflict between two processing modes

Three different sized squares were successively presented at the same physical distance under three observational conditions which provided different information about distance in the visual field. The 60 observers in each observational condition were asked to give verbal absolute judgments of perceived size and perceived distance for each of the squares. The results showed that in a full-cue situation a ratio of perceived absolute sizes is equal to that of the corresponding visual angles, with perceived distances appearing equal to each other; in a reduced-cue situation an object of smaller perceived size is judged to be farther away than one of larger perceived size, with the observers tending to assume the two objects as the same object or identically sized objects. These results were analyzed in terms of the perceptual conflict between primary perception and secondary perception.     

Adaptation in the constancy of visual direction tested by measuring the constancy of auditory direction

Modification of the constancy of visual direction was produced by partially adapting Ss to the displacements of the visual field caused by magnifying lenses during 1 h of continuous head turning. The adaptation effects were measured by determining the range of perceived target immobility before and after this adaptation period. A method for measuring the range of apparent immobility of an auditory signal during head movements was developed and employed to test whether a modification of the constancy of visual direction transfers to the constancy of auditory direction. No such transfer was found, and it was concluded that a modification of the constancy of visual direction does not consist in an altered evaluation of kinesthetic cues for head turning. The method and the equipment used in the investigation of the constancy of visual direction are described; knowledge of the previous brief publications on this topic is not needed.     

Application of the Theory of Signal Detectability to Kinesthetic Discrimination Tasks

The psychophysical methods of the theory of signal detectability were applied to the measurement of kinesthetic recognition sensitivity. Subjects (n = 12) were tested on a kinesthetic discrimination apparatus, and were randomly assigned to one of four treatment conditions. Each subject operated under five response criteria which were imposed through a priori probabilities of high and low kinesthetic stimuli. The fundamental assumptions of the theory of signal detectability were tested and the basic premises of normality and equality of variance observed in most cases. A subproblem investigated the relationship between kinesthetic recognition sensitivity and the two independent variables of direction and extent of forearm movement, but no relationship was observed. This study was conducted at Kansas State University under the direction of Richard H. Cox with technical assistance from Harold L. Hawkins. The study was funded by a Faculty Research Grant awarded by Kansas State University.     

See what you’ve done! Active touch affects the number of perceived visual objects

Previous research has shown that visual perception is affected by sensory information from other modalities. For example, sound can alter the visual intensity or the number of visual objects perceived. However, when touch and vision are combined, vision normally dominates—a phenomenon known asvisual capture. Here we report a cross-modal interaction between active touch and vision: The perceived number of brief visual events (flashes) is affected by the number of concurrently performed finger movements (keypresses). This sensorimotor illusion occurred despite little ambiguity in the visual stimuli themselves and depended on a close temporal proximity between movement execution and vision.     

Imagery ability and the acquisition and retention of movements

In this study, we examined the relationship between imagery ability, as measured by the Movement Imagery Questionnaire (MIQ), and the acquisition, retention, and reacquisition of movements. Based on their MIQ scores, 10 subjects were selected for the following imagery groups: high visual/high kinesthetic (HH), high visual/low kinesthetic (HL), and low visual/low kinesthetic (LL). The subjects learned four movements to a criterion level. Before each trial, subjects kinesthetically imaged the movement about to be produced. Following each acquisition trial, subjects were provided visual feedback. The acquisition phase was followed by a 2-day retention interval, a retention test consisting of three trials on each movement (no feedback provided), and a reacquisition phase. The HH group acquired the movements in the least number of trials, the LL group required the greatest number of trials, and the HL group required an intermediate number of trials. The data for the reacquisition phase showed the same trend. There was only weak evidence for a relationship between imagery ability and the retention of the movements. These findings support the position that high imagery ability facilitates the acquisition, but probably not the short term retention, of movements.