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Considering that somatosensory impairments may impact motor performance in individuals with cerebral palsy (CP), a better understanding of these relations is relevant to planning interventions. To synthesize research evidence to date on the interrelationships between the somatosensory functions of touch and proprioception with motor functions in persons with CP, we systematically searched Embase, CINAHL, PsycINFO, and Medline databases for studies relating these variables that were published in English from the inception of these databases to November 2020. We targeted the following content categories in our literature search: (a) cerebral palsy; (b) sensory functions; (c) tactile functions; (d) proprioception functions; and (e) motor functions. The selection, data extraction, and methodological quality assessment of these studies were performed in duplicate. We retrieved and analyzed information regarding the studies’ methodological approaches and synthesized results. The 11 studies that met our inclusion criteria showed that, in individuals with CP, impairments in tactile discrimination, proprioception, and stereognosis are related to motor functions in terms of overall manual ability, grip strength, postural control and locomotion. Thus, clinical practitioners should attend to somatosensory aspects of motor impairment in individuals with CP. More research is needed to clarify the direction of these associations.

Providing a natural mapping between multi-touch gestures and manipulations of digital content is important for user-friendly interfaces. Although there are some guidelines for 2D digital content available in the literature, a guideline for manipulation of 3D content has yet to be developed. In this research, two sets of gestures were developed for experiments in the ease of manipulating 3D content on a touchscreen. As there typically are large differences between age groups in the ease of learning new interfaces, we compared a group of adults with a group of children. Each person carried out three tasks linked to rotating the digital model of a green turtle to inspect major characteristics of its body. Task completion time, subjective evaluations, and gesture changing frequency were measured. Results showed that using the conventional gestures for 2D object rotation was not appropriate in the 3D environment. Gestures that required multiple touch points hampered the real-time visibility of rotational effects on a large screen. While the cumulative effects of 3D rotations became complicated after intensive operations, simpler gestures facilitated the mapping between 2D control movements and 3D content displays. For rotation in Cartesian coordinates, moving one fingertip horizontally or vertically on a 2D touchscreen corresponded to the rotation angles of two axes for 3D content, while the relative movement between two fingertips was used to control the rotation angle of the third axis. Based on behavior analysis, adults and children differed in the diversity of gesture types and in the touch points with respect to the object's contours. Offering a robust mechanism for gestural inputs is necessary for universal control of such a system.

A horizontal, table-sized computer display was used to examine one- and two-finger search performances. 31 college students participated in a basic computer operation and target landmark search task. The mean completion times of the target landmark search task were analyzed by a repeated-measures analysis of variance with the following factors: input device, environmental familiarity, and cue. Compared to the mouse, directly touching the computer display with one finger was inefficient when the task required more precise human-computer interactions, such as selecting small objects, or complicated tasks such as searching for targets in a computerized geographic application. However, directly touching the computer display with two fingers, one finger of each hand, appears efficient in complicated tasks. Additionally, familiar and cued environments can aid in the target landmark search task especially when searching within the cued conditions. However, the unfavorable effect of using a one-finger touch technique in searching may eliminate such cue effects.

Fluency-enhancing speech feedback, originating from internally or externally generated sources via auditory or visual sensory modalities is not restricted to a specific sensory modality or signal origination. Research suggests that externally generated digital vibrotactile speech feedback serves as an effective fluency enhancer. The present purpose was to test the fluency-enhancing effects of self-generated digital vibrotactile speech feedback on stuttering frequency. Adults who stutter read passages aloud over the telephone, both with and without digital vibrotactile speech feedback. Digital vibrotactile speech feedback was operationally defined as feeling the vibrations of the thyroid cartilage with the thumb and index finger while speaking. Analysis indicated that self-generated digital vibrotactile speech feedback reduced overt stuttering frequency by an average of 72%. As the specific neural mechanisms associated with stuttering and fluency enhancement from tactile speech feedback remain unknown, theoretical implications and clinical applications were discussed.

A light finger touch can stabilize posture despite it not providing enough force to create mechanical support. The underlying mechanism may be due to the finger touch providing information in the axis with the greatest instability. The most appropriate way to test this hypothesis is a dual-axis paradigm, i.e., to remove sway-related information from touch in either anterior-posterior (AP) or medio-lateral (ML) axis and then measure postural sway in both axes when the standing posture is equally unstable in AP and ML axes. In this study, 16 participants stood in a feet-together stance, and center of pressure in both axes was measured. Apart from No touch and Stable conditions, the touch surface was manipulated to move in close synchrony with postural sway so as to remove information regarding postural sway in one axis (AP Sway-referenced) or two axes (AP-ML Sway-referenced). The results showed that AP Sway-referenced condition stabilized posture in both axes, whereas AP-ML Sway-referenced condition did not stabilize posture in either axis. The pilot results indicated that touch effects do not come from axis-specific sensory cues of postural sway.

This study evaluated the effects of the mode of grasping, chopstick materials, and the groove of the chopstick-tip on gripping performance of 32 participants, among whom 16 were accustomed to using chopsticks with a pliers-grasping mode and the other 16 with a scissors-grasping mode. Based on a random sequence, 8 kinds of chopsticks with different combinations (materials: bamboo, wood, plastic, and stainless steel, with and without grooves in the chopstick-tip) were used to carry out the action of gripping two different objects (peanuts and longan). The time to finish gripping 50 pieces of peanut and longan, the number which fell on the table when gripping, the subjective effort and the subjective preference were measures of efficiency of pinching for 8 kinds of chopsticks. Analysis showed that chopstick materials significantly affect time of gripping. The large object (such as longan) could be gripped more easily with the pliers-grasping mode or gripped with the grooved chopstick-tip. However, for small objects (such as peanuts), there was no significant difference in performance whether the chopstick-tip was grooved or not. A combination of bamboo chopsticks with grooved tips used with a pliers-grasping seem preferrable for more favorable gripping performance.

This study assessed step-up exercises appropriate for elderly persons ( M age = 70.7 yr., SD = 7.0). The group did several exercises in 7 sessions per month (average participants per session was 14, SD = 3). A 30-sec. chair-stand test (sit-to-stand), questionnaires on activities of daily living, and impressions of the exercises were examined. Activities of daily living were expected to differ on cluster analysis before and after exercise sessions. Each cluster was classified by basic and instrumental activities. The 30-sec. chair-stand test did not significantly improve. Subjects enjoyed doing exercises with touch. Appropriate exercises for elderly persons should promote activities of daily living. Functional movements with touch seem appropriate for maintaining physical fitness and social interaction.

Self-touching is defined as self-directed touches, e.g., scratching or rubbing, that have no apparent conscious motivation. Earlier research on self-touching focused on internal processes associated with self-touching, e.g., mental conflict, while more recent research has considered external motivators, such as an auditory or visual presentation of a provocative stimulus, e.g., leeches. Here, 110 undergraduate psychology students (68 women, 42 men; M age = 18.7 yr., SD = 1.0) were shown a video about chiggers to replicate previous findings, while simultaneously studying the social influence of self-touching modeled by the presenter. A significant interaction was found as modeled self-touching significantly increased participants' self-touching when they were also attending to the video about chiggers. The results are discussed in terms of potential processes underlying this behavior and directions for research.

Two experiments tested the adequacy of behavioral criteria to fractionate reaction time (RT) into independent premotor (cognitive) and motor components. Healthy participants performed an omitted stimulus reaction time task in which they responded to the termination of a train of lateralized visual, auditory or tactile stimuli. Exp. 1 with 48 participants (24 men) showed premotor RT was independent of motor RT in each sensory modality and did not differ as a function of side of presentation or sex. Repeated tests administered in Exp. 2 ( N = 12) also showed no significant association between the behaviorally fractionated measures. These results are comparable to those obtained using muscle potential to fractionate RT and suggest behaviorally fractionated premotor and motor RT could be a reliable, useful tool in the assessment of cognitive and motor processing in different sensory modalities of healthy people or those with brain injury, disease, or drug-induced disturbances.

Little is known about the mechanisms that underlie the pathophysiology involved in the development of cumulative trauma disorders. Musicians, specifically string players, may be a useful model to examine the cumulative effects of repetitive motion given the highly attended movements of their left hands and the stereotypical grasp of their right hands. Musculoskeletal disorders related to playing are experienced by 39% to 87% of musicians, making musicians a potentially good model for the study of factors involved in development of cumulative trauma disorders. Sensory thresholds for two-point discrimination and light touch were measured in all phalanges of each digit, of each hand. Comparisons were made within and between a control group of 10 nonmusicians who did not engage in repetitive motion and 10 healthy musicians who did. There were 5 violinists, 2 violists, and 3 cellists. The Non-musician group perceived two-points and light touch at significantly lower thresholds in the proximal phalanges of the left hand than the right hand. Significant differences were not present between right and left hands for the means of distal, middle, and proximal phalanges of the Musician group. This lack of significant difference may be due to higher sensory thresholds associated with repetitive use of the left hand of the musicians.

This investigation assessed two training methods to heighten awareness of the oral cavity in normal adult speakers of English. A pretest-posttest design was used. 40 subjects ( M age = 25.6 yr., SD = 8.7) who passed a speech and hearing screening were placed into two equal-sized groups. Each group received 10 hr. of training over 3 wk. The Experimental group received verbal instructions regarding how the phonemes of English are produced, including tongue height, location, and contact with other structures in the oral cavity. Subjects in the Experimental group also used a tongue blade to enhance lingual awareness. The Control group received instructions in articulatory placement only. The Lingual Awareness Test required subjects to imitate 7 English syllables and answer 4 multiple-choice questions regarding lingual contact for each syllable. Posttest scores for the Experimental group were significantly better for one phoneme. The Control group made no significant improvement.

Little is known about the relationship between perceptions of comfort and cognitive performance. In the present study, 40 subjects (20 men and 20 women) participated in a computerized cognitive task of visual vigilance. The computer task was completed under three conditions of clothing and tactile comfort: one condition was that of extreme discomfort, effected by the wearing of wool clothing material on the arms and neck in addition to each subject's normal clothing, including a short sleeve shirt; a second condition was that of minimal discomfort, effected by the wearing of cotton clothing material on the arms and neck, in addition to each subject's normal clothing, including a short sleeve shirt; and a third condition was a control, wherein no experimental material was added to each subject's normal clothing, including a short sleeve shirt. Comfort was assessed prior to, during, and after testing. Reaction time and accuracy of 400 trials of a visual vigilance task were assessed under each of these three conditions. Analysis indicated a significant difference in perceived comfort between the wool and each of the other conditions. In addition, both reaction time and accuracy declined in the wool condition. This study is among the first to identify a direct significant relationship between perceptions of clothing comfort and cognitive performance.

In certain situations it has been shown that touch has a positive effect on the compliance with a request expressed by a stranger. However, the difference between the effect of touch on request compliance between people who had noticed and those who had not noticed this contact has never been taken into account. In this experiment a female confederate asked 227 women to answer a questionnaire. When asking for their collaboration the forearm was or was not touched for a brief period of 1 to 2 seconds. Analysis showed that touch was associated with significantly higher compliance to the request but no difference was found between subjects who had noticed the tactual contact and subjects who had not noticed.

Ballroom dancing consists in the performance of rhythmic movements guided by music, which provide sensorimotor integration and stimulate feelings. The body schema is the unconscious sensorimotor representation that allows the individual to perceive his anatomical body in space. Comprising tactile, proprioceptive, kinesthetic, and environmental information, it is directly related to movement. The aim of this study was to investigate the influence of non-competitive practice of ballroom dancing on body perception. The projection point test was applied to 30 volunteers before and after a period of 3 mo.; 15 controls attended lectures on body perception and 15 participants took dance lessons. It was observed that ballroom dancing brought perceptual benefits for those who practiced it.

To assess whether lingual-tactile feedback is developmental 60 normally developing children formed two groups of 30. Group 1 were in Grades 1 and 2 ( M age = 6.6 yr.) and Group 2 in Grades 5 and 6 ( M age = 10.7 yr.). All children passed a speech, language, and hearing screening. They were asked to imitate the production of a syllable, then describe the location of the tongue during that production. Following this request, subjects were given four multiple-choice questions to answer regarding (a) tongue height (high to low), (b) tongue position (front to back), (c) contact with the teeth. and (d) contact with other structures within the oral cavity. Seven English phonemes ( t, k, sh, r, l, and th) were presented in a consonant vowel (CF) syllable with the central carat vowel (pronounced “uh”). Children were aided by a two-dimensional line drawing of the oral cavity. Mean scores for each syllable ranged from .8 to 2.0 (on a scale of 4.0). Total mean scores of 28 possible for older children ( M = 11.0) was significantly better ( t58 = −2.2, p58 of .30 ( p

Three studies explored whether young adults' preference for using a sense modality, e.g., hearing, correlated with presence or clarity of attributes of that sense modality in earliest memories from childhood, elementary school, or high school. In Study 1, 75 graduates or seniors in fine arts, fashion merchandising, music, conducting, or dance showed no greater frequency or clarity of any modality's sensory attributes. In Study 2, 213 beginning university students' ratings of current importance of activities emphasizing a sense modality correlated with sensory contents of recollections only for smell and taste. In Study 3, 102 beginning students' ratings of current enjoyment in using a sense modality and sensory contents of recollections were correlated and involved every modality except vision.

We studied spatial stimulus-response compatibility in the somatosensory modality by instructing 16 men and 16 women to press a key using the left or the right thumb in response to a nonnoxious electric stimulation delivered either to the left or to the right little finger or, in different blocks, to the left or to the right malleolar region. The task was performed in compatible (stimulus and key-response on the same side of the corporeal midline) and in incompatible conditions (stimulus and key-response on opposite sides of the corporeal midline). In Exp. 1 subjects were tested while keeping their limbs in anatomic position; in Exp. 2 subjects performed the task while keeping the left upper and lower limbs on the right side and the right limbs on the left side of the bodily midline (crossed position). The compatibility effect was observed in both experiments and was higher for stimuli delivered to the little finger than to the malleolar region. This suggests that the cost of inhibiting compatible responses is maximal when stimulated and responding body parts are contiguous. Moreover, in the spatially most demanding task (Exp. 2) men outperformed women for both speed and accuracy suggesting a sex-related specialisation in the spatial processing of somatosensory information.

Previous research has shown that nonverbal self-touching behaviors can be induced by external motivators such as videos and literary passages about insects. This study investigated whether the number of self-touching behaviors differed between presentation of what was assumed to be an anxiety-inducing stimulus (listening to the reading of a passage about leeches and answering questions) or a nonanxiety-inducing stimulus (a passage about canaries). It also investigated whether there was a difference in frequency of self-touching when subjects were passively listening to passages or actively answering questions. The difference in frequency of self-touching between men and women was also observed. Over-all, subjects did not perform significantly more self-touching gestures during the anxiety-inducing stimulus than during the nonanxiety-inducing, as previous research had indicated Subjects did touch themselves significantly more, however, while answering questions than while listening to the passage. Over-all, men performed significantly more self-touching behaviors than women. And, women touched themselves significantly more during the active anxiety-inducing cell than in any other condition.

Infants' preferential looking at novel objects and adults' preference for the familiar indicate that preference may be influenced by whether the objects have been experienced previously. Infants and adults may have opposite preferential tendencies; however, infants' preference for a familiar object which they have experienced orally casts doubt on this as a developmental process. To examine both the influences of experienced modalities and age on the relationship between preference and memory, tactile-visual preference and memory tests were employed in 4- and 5-yr.-olds. The results indicated the dissociation of preference by recognition only in 4-yr.-olds: those who recognized the objects preferred the familiar and the 4-yr.-olds who could not recognize them preferred the novel. The 5-yr.-olds tended to prefer the familiar objects regardless of recognition. The results may suggest an age effect on the relationship between preference and recognition.

An unobtrusive system, which provided corrective feedback (vibratory stimulation) for an incorrect direction, was used to help a woman with deafness and profound intellectual and visual disabilities during her indoor travel. The data showed that the woman used the system very effectively and reached destinations for performing activities independently. Implications of the findings are discussed.

Endogenous ultradian rhythms with periods of one or a few hours affect not only on physiological and behavioural functions but also perception and cognition. In particular, lateralized ultradian rhythms which seem to operate separately in the right and left hemispheres of the brain can be monitored by testing the tactile discrimination of the contralateral hand. The present paper is based on two subsequent studies: First, ultradian rhythms in tactile discrimination of either hand were examined in German subjects under laboratory conditions. Considerably different ultradian periods of right and left-handed tactile error rate were found in men but not in women. In a second study, a group of Kenyan Masai shepherds were tested while the subjects were leading herds on daily feeding routes through a savanna habitat. They showed ultradian periods of about 2 hours in tactile discrimination of either hand. Since the right hemisphere is specialized for visuospatial, the left for verbal processing lateralized ultradian rhythms may serve for a long-scale timing of neural processes underlying spatial and semantic mapping of the environment. Sex difference in German subjects and lateral differences found in left-handed (right-hemispheric) ultradian rhythms of German and Masai subjects are discussed from this point of view.

This experiment was designed to test the construct validity of psychometric analyses that suggested a strong functional association between the accuracy for toe graphaesthesia and selective activation of neurons within the medial prefrontal regions. Single Photon Emission Computerized Tomography (SPECT) profiles were obtained for three volunteers (2 men, 1 woman) after they had been exposed to a toe graphaesthesia task or had been exposed to the control setting. The two measurements for each participant were separated by at least one week. Qualitative evaluation, using criteria employed for clinical diagnoses, of serial coronal, sagittal, and horizontal sections clearly indicated a specific increase in uptake of tracer within the rostral one-third to one-half of the medial prefrontal cortices of all three subjects during the toe graphaesthesia task compared to that during baseline conditions. The results are consistent with our neuropsychological research which indicates that toe graphaesthesia may be an accurate and useful indicator of the functional integrity of the medial surfaces of the anterior cerebral hemispheres.

This study explored the issue of whether status and power differences are expressed in the way men and women hold hands. It was hypothesized that men's hands would be upper in heterosexual handholding couples significantly more often than women's Also, to explore the possibility that height differences of handholding partners might affect handholding position, all handholding couples observed in this study were classified as couples with men and women of equal height or couples where either the men or women were taller. A total of 1,006 handholding couples were observed, and men's hands were significantly more likely to be the upper one in couples when men were taller than women and in couples where men and women were of equal height, suggesting that, while height does matter, it is less important for this handholding pattern than sex differences.

Accuracies of two-point discriminations (successive 2-mm increments between 0 and 10 mm) for the middle fingers and the middle toes for 87 children from ages 7 through 15 years were measured to obtain normative data. The finer discriminative capacity for the fingers rather than the toes was evident. Whereas discriminative accuracy approached the asymptote with distances equal to or greater than 4 mm for the fingers, distances equal to or greater than 8 mm were required for the toes. For this ontogenetic range, the effects for toes vs fingers was much greater than the effect size for age.

Intuitive judgments about covariations of length, weight, and width were assessed in two experiments using a series of prepositional statements. In Exp. 1, only a priori judgments were rendered, whereas in Exp. 2 blindfolded participants physically manipulated and described a series of objects varying on these dimensions before rendering their judgments. Analyses indicated participants judged weight and width as positively correlated, length and weight as uncorrelated and, to some extent, length and width as negatively correlated. If judgments are rendered after the haptic exploradon phase, weight and width are (again) judged as positively correlated, and length and weight were still judged as uncorrelated. However, after the database intervention, length and width were judged as positively correlated. Results are discussed relative to research on reasoning about covariation and belief perseveration as well as perceived covariations between height, weight, and body fat.

The ability of blind and blindfolded sighted subjects to discriminate cubes of different heights was measured using the method of constant stimuli. Five male blind and 5 male blindfolded sighted students, ages 22 to 28 years, were subjects. All blind subjects had undergone orientation and mobility training at a school for the blind. The cubes, made of wood, were explored using a long cane. Subjects were presented the standard cube and a comparison cube and required to judge whether the comparison cube height was taller, the same, or shorter than the standard. Analysis showed that the difference thresholds of blind and blindfolded sighted subjects were 1.93 and 2.14 cm, respectively. No significant difference in accuracy of discrimination was found between the two groups. The blind subjects showed significantly better performance than the blindfolded sighted subjects on the discrimination task. The blind subjects performed the task significantly faster than the blindfolded sighted subjects. The results suggest that braille reading, use of a long cane, and daily physical activities which required prolonged haptic or proprioceptive learning, may enhance nonvisual motor skills.

The size of a netbook plays an important role in its success. Somehow, the viewing area on screen and ability to type fast were traded off for portability. To further investigate, this study compared the performances of different-sized touchpads, touchscreens, and keyboards of four-sized netbooks for five application tasks. Consequently, the 7″ netbook was significantly slower than larger netbooks in all the tasks except the 8.9” netbook touchpad (successive selecting and clicking) or keyboard tasks. Differences were non-significant for the operating times among the 8.9″, 10.1”, and 11.6″ netbooks in all the tasks except between the 8.9” and 11.6″ netbooks in keyboards tasks. For error rates, device-type effects rather than size effects were significant. Gender effects were not significant for operating times in all the tasks but for error rates in touchscreen (multi-direction touching) and keyboard tasks. Considering size effects, the 10.1” netbooks seemed to optimally balance between portability and productivity.

This study was designed to compare tactile sensitivity of children and adults on printed target stimuli covering a wide range of elevations and requiring different resolutions. A recognition-relief task using 9 digits at 6 levels of elevation from a surface (0.5, 0.4, 0.3, 0.2, 0.1, and 0.05 mm) was presented to 24 young adults and 24 children. As predicted, relief elevations as low as 0.05 mm were recognized above chance. As predicted, children performed significantly more poorly than the adults on recognition at all elevations, although the difference increased as elevation increased. Adults performed significantly better than children on high-resolution digit 8, but there was no reliable age difference on low-resolution digit 1. Recognition difference between the high- and low-resolution digits decreased nonlinearly as elevation increased, irrespective of age. Overall, the findings support previous research indicating greater tactile sensitivity in adults than in children, but the superiority was moderated by the elevation and resolution requirements of the stimuli.

Blindfolding candidates when testing their tactile performance may increase their anxiety. This study examined whether different visual barriers would influence tactile performance on timed tasks. It was hypothesised that candidates using a blindfold would be more anxious, but that they would benefit by the potentially positive effects of arousal on performance and not differ from candidates using a screen to limit visual access to task material. 200 participants (ages 19 to 30 years), randomly assigned to the two conditions, completed a tactile perception task, as well as an anxiety scale. In contrast to the expected outcome, the screen sample took significantly longer to complete the task. This was hypothesised to be the result of increased distraction given competing cross-modal attentional demands and the consequent visual and tactile attention switching. Practitioners may need to consider the influences of visual interference when assessing tactile performance.

Women have been reported to be more positive about same-gender touch, but cross-cultural information about this touch is limited. Male and female students from Chile (n = 26), Spain (n = 61), Malaysia (n = 32), and the US (n = 77) completed a same-gender touch scale. As in past studies, US women had more positive scores than US men. Malaysians had more negative scores than the other three groups. Spanish and US students had more positive scores than Chilean students. National differences in attitudes toward particular types of touch were also noted. The need for new methods for examining cross-cultural differences in touch was discussed.

30 children (18 boys and 12 girls) with a mean age of 4 yr., 8 mo. were subjects in an experiment testing the relative dominance of visual and tactual modalities in mirror-image shape discrimination. The sets of unfamiliar stimuli (written and wooden letters of the English alphabet, P, B, C, U, R, F) were presented to the children randomly. Children matched the stimulus with either another visual or another tactual shape. Analysis suggests touch is not inferior to vision in mirror-image shape discrimination. These results are different from those of previous reports comparing tactual and visual discrimination with nonmirror-image patterns.

The purpose of this study was to compare lingual vibrotactile thresholds of sensitivity obtained using individual subject adjustments of vibrator probecontactor to lingual surface, with thresholds obtained using a fixed vibrator probe-contactor position across 30 subjects ranging in age from 18 to 26 yr. ( M age = 20 yr.). Analysis showed minor (less than 5 dB SPL) differences in lingual vibrotactile thresholds of sensitivity between the two methods of vibrator probe-contactor alignment. For research purposes, the vibrator probe-contactor assembly should be adjusted to each individual's lingual surface, but for clinical-behavioral purposes, it might be sensible to use a fixed vibrator probe-contactor position across subjects, especially when performing research on young children, older adults, and the communicatively handicapped.

The purpose of this study was to investigate differences in function of the tactile sensory system between groups of normal-speaking children and children with articulation problems. This task was accomplished by studying possible tactile threshold shifts occurring during magnitude-estimation scaling of vibratory stimuli presented to the dorsal surface of the tongue. 10 normal-speaking children ( M age = 7.8 yr.) and 9 children with articulation problems ( M age = 7.5 yr.) participated. The normal-speaking children and articulatory defective children performed differently on the magnitude-estimation scaling task in which threshold was allowed to return to baseline after each stimulus presentation. These two groups of children also showed dissimilar threshold shifts for the suprathreshold intensities employed in the magnitude-estimation scaling.

Because of the vulnerability of the medial surfaces of the cerebral hemispheres to the consequences of shear forces, we hypothesized that quantitative sensorimotor deficits for the feet would be strong indicators of general brain dysfunction. On the basis of the Halstead-Reitan Impairment Index, 28 adults who had received closed head injuries were assigned to perfectly normal, normal, or (mildly to severely) impaired groups. Foot tap and finger tap as well as agnosia and graphaesthesia for the fingers and toes were measured. Deficits in toe graphaesthesia were the most powerful group discriminator. Potential usefulness of haptic/motor, finger/toe comparisons for recording the progress of degenerative diseases, such as AIDS, is also suggested.

To examine hand differences in the sensory feeling of texture, 35 subjects made sensory evaluations with the left and the right hands to a tactile stimulus (sponge rubber) and also marked on a 5-point Likert scale 50 adjectives which represented various tactual feelings. Factor analyses, applied to the data of 35 subjects, showed that the left hand related more to a keen and sharp dimension while the right hand related more to a mild and soft dimension of the tactile stimulus. Possible relations of these hand differences in sensitivity to hemisphere functioning were discussed.

To investigate the effect of sensory imagery on subsequent movement, a unilateral Feldenkrais lesson of imaging a soft bristle brush passing over one-half of the body and in which no movement occurred, was given to 12 naive subjects. Forward flexion for each side of the body was measured at a sit-and-reach box. For 8 and 10 subjects who reported the perception of a side as being longer and lighter following the sensory imagery, there was also a significant increase in the forward flexion range on that side.

Internal consistency reliabilities were calculated for the Tactual Performance Test Preferred Hand ( n = 300), Nonpreferred Hand ( n = 302), and Both Hands ( n = 314) trials, and Total Time. Reliabilities are reported for the total sample and three groups: normal, undiagnosed patients sent for assessment, and alcoholic persons. The reliability coefficients ranged from .59 to .90.

Pinch-sustaining tasks such as holding a pencil, fork, or key require the exertion of different levels of force. There is little information concerning normal subjects' ability to discriminate differences in their pinching force, so the purpose of this study was to evaluate the ability of 24 normal young women to discriminate differences in their self-generated isometric tip and lateral pinching force. Resistance forces of 10, 25, 50, and 75% of known normal maximum pinching force were selected as standards. Subjects were presented a series of paired resistance settings of which the first resistance in each pair was the standard and the second resistance a comparator of some greater amount. This procedure of paired comparisons was continued until subjects' threshold of discrimination between two pinching forces was established. The results indicated that subjects' pinch-force discrimination at the standard of 50% of reported maximum pinching force was significantly better for the tip condition than for the lateral condition. This study has described an instrumentation and the methodology for assessing individuals' ability to discriminate differences in their pinching force at submaximal levels.

Summary.-The purpose of this study was to investigate the effect of disruption of the auditory feedback channel on Lingual vibrotactile thresholds obtained under skilled and unskilled speaking conditions. Each of 22 adults was asked to read an English (skilled) and French (unskilled) passage under conditions of normal and altered auditory feedback. Bilateral presentation of masking noise was uiized to disrupt auditory feedback. Before each of the experimental sessions and immediately following a reading, lingual vibrotactile thresholds were obtained. Analysis indicated that the mean differences in the pre- and posrvibtucactile threshold measurements of the skilled auditory disrupted condition varied significantly from the mean differences in the pre- and postvibrotactile threshold measurements of the three other conditions. The role of feedback in the speech production of skilled and unskilled speakers is discussed. In 1970, Sussman explored the relationship between auditory-tactile and visual-tactile modalities in speech-related tasks. During the tasks involving auditory-tactile feedback, an interaction between the two modalities was found that was not evident between the visual-tactile feedback modalities. Sussman concluded that "the auditory feedback modality interacted with the lingual tactile modality in a unique fashion implicating a sensitive auditory-tactile synchronization mechanism for speech motor activities" (Sussman, 1970, p. 319). To gain more information concerning the relationship between feedback modalities of audition and taction, Fucci, Crary, Warren, and Bond (1977) studied the effects of auditory masking on lingual sensitivity during a reading task. Results indicated a significant increase in threshold (decrease in sensitivity) before and after speech production under exposure to auditory masking. The fact that auditory masking alone without production of speech and the production of speech under normal feedback did not result in a shift in threshold may suggest that the change in lingual sensitivity is primarily due to speech production under disturbed auditory feedback. The threshold shift found after speech production when auditory feedback was disrupted

A deaf woman learned to control her excessive vocal loudness through a portable feedback system, which provided vibratory stimulation when her voice was too loud. The mean percentage of excessively loud talking decreased from 45 prior to the use of feedback to 3 during the use of feedback. This improvement (documented by formal observation) was confirmed by normally hearing people sharing the work environment with the woman. The woman preferred a system with a contact microphone since this was virtually unaffected by environmental noise.

Two experiments were carried out to investigate contributions of voluntary manual exploration and vision to rod-bisection performance when the rod was placed in different spatial positions. Analysis showed both voluntary manual exploration and vision contributed to the accuracy of rod-bisection performance in healthy adults (Exp. 1: 12 men, 13 women; Exp. 2: 10 men, 11 women). Advantages of voluntary manual exploration were related to rod position and initial search direction. Results are discussed with regard to ecological approach to action and perception, two cortical systems (ventral and dorsal streams) for perception and control of actions, and the hemispheric activation hypothesis.

This paper described a pilot study and two follow-up experiments, using a device developed in the laboratory to study the human fingertip's discrimination and memory for softness perception. According to the pilot study, soft objects were easier to identify than hard ones. When subjects touched objects, the number of times seemed to be from 2 to 6. For most, the touch frequency ranged from 0.3 to 1.3 Hz. In Exp. 1, the method of constant stimuli was used to study the human fingertip's stiffness difference threshold for haptic perception. The estimated difference threshold averaged over 24 subjects was 33 N/m. And, the stiffness difference thresholds for most people were in the range of 20 N/m to 40 N/m. In Exp. 2, the haptic memory span was discussed according to the recall experiment. Human haptic memory span lay between three and four items.

A pilot study was performed with 13 children, 1 to 4 yr. of age, to explore an heretofore uninvestigated area. The effect of passive tactile stimulation was an increase in muscle activation and hence the muscle tone of 13 hypotonic, develop-mentally delayed children.

Summary.-The effect of stimulus orientation of letters presented either visually or vibmtactually was examined to obtain basic information on sensory substitution using the tactile sense. The reaction time (RT) to identify the letters F and R presented in normal or mirror-image form at four orientations each was measured. In addition, conditions of O0 and 270° of head rotation from vertical and arm rotation From the midline axis were employed. Data from 5 trained subjects showed that vibrotactile RTs were always longer than visual RTs. Stimulus rotation away from normal orientation increased visual RTs significantly but not vibrotactile RTs. Visual orientation effect then seemed to be determined by the body-coordinate system but not the vibrotactile orientation. Although further studies are warranted, from the results of this experiment, any convenient and constant stimulus orientation could be used with a wearable vibrotactile display system to exploit passive touch. Alternate information reception via the tactile modality is necessary for the visually or auditorily impaired person. A vibrotactile display which exploits passive touch is often used as a wearable type of sensory substitution. One of the important problems is to define the spatiotemporal relationship between the origind and the transformed information. This study concerns the effect of orientation of the presented stimulus on the vibrotactile display. Since the study of Shepard and Metzler (1971), the effect of stimulus orientation has been examined as the effects of "mental rotation." Cooper and Shepard (1973) indicated that rotation away from the normal orientation systematically increased visual reaction time (RT) to letter stimuli. The effects of the tactile modality were also examined. Marmor and Zaback (1976) used pattern stimd, and Carpenter and Eisenberg (1978) used letter stimuli. Just and Carpenter (1985) reviewed experiments on mental rotation and analyzed the role of the cognitive coordinate system in the spatial ability involved in mental rotation. Furthermore, Heller (1987) indicated superiority of normal orientation in reading both visud and tactual braille. However, the effect of orientation by vibrotactile stimuli using passive touch is not clear. To obtain basic information about designing a vibrotactile display for sensory substitution devices, the following experiments were performed in both visual and vibrotactile modahties.

The purpose of this study was to investigate differences in tactile sensory system function between men and women. This task was accomplished by studying the effects of possible tactile threshold shifts occurring during magnitude-estimation scaling of vibratory stimuli presented to the dorsal surface of the tongue. 12 men ( M age = 19.7 yr.) and 12 women ( M age = 19.3 yr.) participated. Analysis suggested that men and women have tactile sensory systems that operate similarly at both threshold and suprathreshold levels of stimulation. Men and women do, however, choose to use consistently different numerical responses to suprathreshold stimuli, suggesting that environmental and/or cultural-educational influences may be involved in numerical decision-making aspects of the scaling process.

Two research questions were posed on the homophily theory of customer-vendor interactions: (a) do vendors show any nonverbal preference for Euro-American or African-American customers?; (b) do vendors demonstrate any nonverbal preference for customers with which they share racial homophily? The results supported the homophily theory for Euro-American customers in that there were significant interaction effects by race in facial expression ( F = 5.33, p < .05), amount of speaking ( F = 6.76, p < .01), tone of voice ( F = 7.62, p < .01), and touching ( F = 4.57, p < .05). Vendor behavior varied when the customer was Euro-American, with Euro-American vendors smiling more frequently ( M = 4.05) than African-American vendors ( M = 3.69), speaking more frequently ( M = 3.57) than African-American vendors ( M = 3.09), using a more friendly tone of voice ( M = 3.59, and engaging in more touching behaviors ( M = 1.81) than African-American vendors ( M = 1.48). There was no significant difference in the behavior of Euro-American and African-American vendors when the customer was African-American.