Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Weight Perception”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources

The influence of phonemic awareness development on acoustic cue weighting strategies in children's speech perception.

In speech perception, children give particular patterns of weight to different acoustic cues (their cue weighting). These patterns appear to change with increased linguistic experience. Previous speech perception research has found a positive correlation between more analytical cue weighting strategies and the ability to consciously think about and manipulate segment-sized units (phonemic awareness). That research did not, however, aim to address whether the relation is in any way causal or, if so, then in which direction possible causality might move. Causality in this relation could move in 1 of 2 ways: Either phonemic awareness development could impact on cue weighting strategies or changes in cue weighting could allow for the later development of phonemic awareness. The aim of this study was to follow the development of these 2 processes longitudinally to determine which of the above 2 possibilities was more likely. Five-year-old children were tested 3 times in 7 months on their cue weighting strategies for a /so/-/[symbol in text]o/ contrast, in which the 2 cues manipulated were the frequency of fricative spectrum and the frequency of vowel-onset formant transitions. The children were also tested at the same time on their phoneme segmentation and phoneme blending skills. Results showed that phonemic awareness skills tended to improve before cue weighting changed and that early phonemic awareness ability predicted later cue weighting strategies. These results suggest that the development of metaphonemic awareness may play some role in changes in cue weighting.

Adult↗

Independence and separability of volume and mass in the size-weight illusion.

Numerous size-weight illusion models were classified in the present article according to general recognition theory (Ashby & Townsend, 1986), wherein the illusion results from a lack of perceptual separability, perceptual independence, decisional separability, or a combination of the three. These options were tested in two experiments in which a feature-complete factorial design and multidimensional signal detection analysis were used (Kadlec & Townsend, 1992a, 1992b). With haptic touch alone, the illusion was associated with a lack of perceptual and decisional separability. When the participant viewed the stimulus in his or her hand, the illusion was associated only with a lack of decisional separability. Visual input appeared to improve the discrimination of mass, leaving only the response bias due to expectation.

Adult↗

Aberrant judgmental pattern of schizophrenic patients in weight discrimination.

Sixteen chronic schizophrenics and 16 normal controls were tested on a weight discrimination task in various categories and hand conditions. Schizophrenics made significantly more errors than normals when the 'equal' category was included, whereas schizophrenics' performance could approximate the normals' discriminations when the 'equal' category was excluded. In the former condition, the more inaccurate performance of schizophrenics was ascribed to the selective increase in the errors by the 'equal' judgments, which was not due to an increase in 'doubtful' judgments. These findings were assumed to reflect schizophrenics' preference to equal judgments, which seemed to be their fundamental cognitive attitude, because the same tendency was found on the various discrimination tasks of other sensory modalities. Furthermore, the present results supported neither left hemisphere dysfunction nor interhemispheric transfer deficit in schizophrenia, because schizophrenics failed to show consistently more errors in the right hand and the bimanual conditions.

Adult↗

Contribution of visually perceived size to the scaling of fingertip forces when lifting a 'small' object.

The effects of visually perceived size of an object on the scaling of fingertip forces during lifting tasks were investigated using a small and lightweight object. A grip apparatus was attached to the top surface of three different size boxes of equal weight. 15 healthy adults were asked to grasp the grip apparatus with the thumb and index finger, lift it to a height of 5 cm, hold it for 8 sec., and then put it down. Force transducers embedded in the grip apparatus measured grip and load forces. When subjects lifted the same size object repeatedly, there were no size effects on the grip and load forces used by each subject. When the size was pseudorandomly varied, however, the grip and load forces exerted by 7 subjects significantly increased with increased size, while there were no size effects for the remaining subjects (n = 8). These results suggest a smaller contribution of information on size to the force programming when lifting a small object than when lifting a larger and heavier object as used in previous studies.

Adult↗

Cognitive estimation in patients with probable Alzheimer's disease and alcoholic Korsakoff patients.

Cognitive estimation is an important function in daily living. In early studies it was proposed that estimation deficits are associated with frontal lobe damage and executive dysfunctions. In this study, we assessed Alzheimer patients and patients with alcoholic Korsakoff's syndrome with a newly developed cognitive estimation task. We compared their performance with respect to different dimensions of estimation ('size', 'weight', 'quantity', and 'time') and to various error types. Compared to healthy controls, both patient groups were strongly impaired in all tested estimation dimensions, with Alzheimer patients performing generally worse than Korsakoff patients, except for the dimension "time". Alzheimer as well as Korsakoff patients produced so-called 'bizarre errors' and errors in the choice of the correct unit of measurement. In both patient groups cognitive estimation correlated highly with general knowledge. The production of bizarre errors and unit errors correlated with general knowledge as well as with working memory and executive functions. Results support the main assumptions of a model of cognitive estimation, described in the discussion, that specific parts of the semantic memory system as well as executive functions, in form of a plausibility check of the generated answer, are involved in the process of cognitive estimation.

Aged↗

Worst-case prediction strategy in force programming when visual information is obstructed.

A person's strategy for applying force while lifting an object is dependent upon visual cues. This study investigated the alteration of strategy in force programming when visual information about an object's size was obstructed at the moment of lifting. Seven subjects were instructed to use a precision grip for repeated lifts of a cube-like grip apparatus attached to a box. The grip apparatus was a special device designed to measure grip and load forces. Three different-sized plastic boxes of equal weight were pseudorandomly presented by attaching them beneath the grip apparatus to the subjects in two visual conditions. In the Full-vision condition, subjects could view the box's size prior to lifting. In the Obstructed-vision condition, a screen prevented subjects from seeing the box size prior to lifting. In the Full-vision condition, the grip force and load force used by subjects on the grip apparatus increased with box size. In contrast, the subjects in the Obstructed-vision condition used forces appropriate for the largest box regardless of box size. The present results suggest that absence of size information may cause an alteration of strategy used to determine force output in that subjects may apply a maximum force adequate for the largest box, which could be called a "worst-case" prediction strategy, i.e., when there is doubt, the most secure lift may be selected for all possible cases.

Adult↗

Cognitive [correction of cognitve] estimation: comparison of two tests in nondemented parkinsonian patients.

The Time and Weight Estimation test (STEP) and the Cognitive Estimation Task (CET) are two recently devised tests for the assessment of cognitive estimation. In the present study, we compared their performance in 30 non-demented idiopathic parkinsonian (PD) patients, also evaluated with the Frontal Assessment Battery (FAB) as an index of executive impairment, with the aim of verifying the putative frontal circuitry of cognitive estimation processes. Six patients (20%) showed a pathological performance on either or both tests. After division of the PD sample into tertiles based on the FAB score, no significant difference was detected by either estimation test. Furthermore, the two questionnaires were unrelated to each other. Thus, deficits of cognitive estimation ability appear to be mild in PD without dementia and do not correlate with executive impairment. Unexpectedly, the CET and the STEP seem to have no unique underlying construct.

Aged↗

Weight gain on the combined pill--is it real?

Britain has one of the highest teenage pregnancy rates in Western Europe at 8.8 per 1000 live births. Adolescents are very preoccupied with body image and fear weight gain with use of the combined oral contraceptive (COC) pill. Compliance with contraception continues to be a major issue. Is there a real evidence of weight gain? Or are there discrepancies between adolescent perceptions of weight gain with COC use and available scientific evidence? We carried out a comprehensive literature search and did not find evidence for the purported weight gain with use of low dose COCs. Adolescents need reassurance by gynaecologists, general practitioners, family planning doctors and mass media to remove such misperceptions. This will contribute in some way to reduce the high unintended pregnancy rates.

Adolescent↗

Examining gender, racial, and age differences in weight concern among third, fifth, eighth, and eleventh graders.

Weight management and concern, body weight beliefs, and perceptions of friend's and family's weight concerns were examined in this study by race, grade, and gender. A stratified random sample was used to select schools within nine districts in South Carolina and an anonymous self-report paper-pencil questionnaire was completed by the students. The final sample included 3151 African American (42.3%) and White (57.7%) children (51.7% female) in the third (n=599), fifth (n=686), eighth (n=1168), and eleventh (n=698) grades. White girls were more likely to report being overweight (P=.0042), having higher personal weight concerns (P<.0001), and perceiving higher friend (P<.0001) and family weight concerns (P<.0001) than the African American girls. Using multiple regression, 29.8% of the variance in the children's personal weight concern scores was explained by perceptions of family's weight concerns (R(2)=.1659), gender (R(2)=.0762), perceptions of friend's weight concerns (R(2)=.0392), grade (R(2)=.0094), a Race x Gender interaction (R(2)=.0042), and race (R(2)=.003). Most of the children, particularly the white girls, have personal weight concerns and dieting practices which place them at risk for possible health problems. These results support the need for nutrition interventions and education in early childhood. Programs to prevent obesity and eating disorders should be tailored for differences by gender, grade, and race.

Journal Article↗

Awareness of risks of overweight among rural Australians.

INTRODUCTION: Overweight and obesity are highly prevalent in rural areas and pose significant risks to health. The aim of this study was to investigate whether the rural public in central Queensland are aware of the health risks of overweight and to determine whether their perceptions of weight status and methods used to assess weight status correspond with those of health professionals. METHODS: Adults were randomly selected from shoppers in shopping centres in Central Queensland, Australia, to self-complete a questionnaire that assessed participants' understanding of the health risks of overweight, perception of current weight, methods used to assess current weight and understanding of the concepts of body mass index (BMI) and waist-to-hip ratio (WHR). Participants were also asked to provide demographic details and self-report their height and weight. RESULTS: The majority of participants were appropriately aware that, regardless of their degree of physical activity, overweight is associated with increased risk of heart disease (92%), type 2 diabetes (83%) and stroke (83%). A large proportion were also aware of the association of overweight with sleep apnoea (69%), fertility problems (68%) and arthritis (57%) but few were aware of the link with asthma (35%) and various types of cancer (14-32%). Knowledge of the health risks of overweight did not differ greatly across the BMI spectrum, with similar beliefs expressed by those who were classified overweight or obese (based on self-reported data) and those who were not. Women were more aware of the health risks of overweight for type 2 diabetes and fertility problems, less likely to be overweight, and to more accurately perceive their weight status compared with men. The majority of participants used subjective measures to assess weight status and few used or understood BMI or WHR. CONCLUSIONS: Rural people in central Queensland appear to be well aware of the health risks of overweight but many are unable to identify overweight in themselves and few understand how to accurately gauge their weight status. This exploratory study highlights the need to educate people in these communities about accurate and objective measures to assess overweight and obesity. Further studies are needed to assess how common misperception of weight status is among rural populations in Australia and to determine whether this contributes to a higher prevalence of overweight and obesity in rural communities compared with urban areas.

Adult↗

Grip force regulation during pinch grip lifts under somatosensory guidance: comparison between people with stroke and healthy controls.

OBJECTIVES: To compare the timing and grip force application in a pinch grip task performed under somatosensory guidance in stroke and matched controls and to identify characteristics of impaired grip force regulation after stroke. DESIGN: Matched-pairs control group. SETTING: University research laboratory. PARTICIPANTS: Forty-five people with stroke who could pick up a pen lid using a pinch grip and actively participated in rehabilitation and 45 adults without neurologic conditions or musculoskeletal or skin impairments affecting the hand, matched for age, sex, and hand dominance. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Timing and magnitude of grip forces applied during pinch grip lift and hold. RESULTS: Prolonged time to grip and lift objects, and excessive grip force prior to commencing the lift occurred in approximately half of the contralesional (involved) hands of people with stroke. Fluctuating irregular forces and reduced adaptation of the grip safety margin were also observed. Excessive safety margins were not predominant after stroke. Extreme slowing and disorganized sequencing of the grip and lifting forces and difficulty maintaining a stable grip characterized severe dysfunction. CONCLUSIONS: Delayed grip formulation and variable grip force application are key characteristics of grip dysfunction after stroke.

Adult↗

The influence of spectral distinctiveness on acoustic cue weighting in children's and adults' speech perception.

Children and adults appear to weight some acoustic cues differently in perceiving certain speech contrasts. One possible explanation for this difference is that children and adults make use of different strategies in the way that they process speech. An alternative explanation is that adult-child cue weighting differences are due to more general sensory (auditory) processing differences between the two groups. It has been proposed that children may be less able to deal with incomplete or insufficient acoustic information than are adults, and thus may require cues that are longer, louder, or more spectrally distinct to identify or discriminate between auditory stimuli. The current study tested this hypothesis by examining adults' and 3- to 7-year-old children's cue weighting for contrasts in which vowel-onset formant transitions varied from spectrally distinct (/no/-/mo/, /do/-/bo/, and /ta/-/da/) to spectrally similar (/ni/-/mi/, /de/-/be/, and /ti/-/di/). Spectrally distinct cues were more likely to yield different consonantal responses than were spectrally similar cues, for all listeners. Furthermore, as predicted by a sensory hypothesis, children were less likely to give different consonantal responses to stimuli distinguished by spectrally similar transitional cues than were adults. However, this pattern of behavior did not hold for all contrasts. Implications for theories of adult-child cue weighting differences are discussed.

Adult↗

The effects of subject arm position and initial experience on Chevreul pendulum responses.

Some clinicians maintain that responses to the Chevreul pendulum illusion are facilitated by resting one's elbow on a table. Others claim the reverse. We compared these two methods in a counterbalanced crossover design by having 32 university students perform the Chevreul pendulum illusion with their elbows supported on a table and with their elbows unsupported. Although there was no main effect for method (elbow supported versus elbow unsupported), subjects who rested their elbows on a table on the first trial were more successful in responding on both trials. This suggests that supporting the elbow does facilitate responding, but only on the initial trial. Performance on subsequent trials is determined by degree of success on the first trial. Similar data from a previous study comparing different hypnotic inductions suggests that this phenomenon is generalizable beyond the Chevreul pendulum illusion and supports the hypothesis that the test-retest reliability of suggestibility scales may be due to a stabilization of response expectancy by a person's first experience of imaginative suggestions.

Adult↗