SEARCH · PubMed Health

Results for “Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 901 records · Page 50Linked to original sources

PubMed2006

Reliability and validity of The Awareness of Social Inference Test (TASIT): a clinical test of social perception.

PURPOSE: The Awareness of Social Inference Test (TASIT) is an audiovisual tool designed for the clinical assessment of social perception with alternate forms for re-testing. Part 1 assesses emotion recognition, Parts 2 and 3 assess the ability to interpret conversational remarks meant literally (i.e., sincere remarks and lies) or non-literally (i.e., sarcasm) as well as the ability to make judgments about the thoughts, intentions and feelings of speakers. This paper aims to examine TASIT's reliability and validity. METHOD: Some 32 adults with severe, chronic brain injuries were administered Form A twice, one week apart. 38 adults with brain injuries were readministered alternate forms over a period of 5 - 26 weeks. Construct validity was examined in subsets of a sample of 116 adults with brain injuries by relating TASIT performance to standard tests of neuropsychological function and specific social perception measures. RESULTS: Test-retest reliability ranged from 0.74 - 0.88. Alternate forms reliability ranged from 0.62 - 0.83. TASIT performance was associated with face perception, information processing speed and working memory. Socially relevant new learning and executive tasks were significantly associated with TASIT performance whereas non-social tasks showed little association. Social perception tasks such as Ekman photos and theory of mind stories were also associated. CONCLUSIONS: TASIT has adequate psychometric properties as a clinical test of social perception. It is not overly prone to practice effects and is reliable for repeat administrations. Performance on TASIT is affected by information processing speed, working memory, new learning and executive functioning, but the uniquely social material that comprises the stimuli for TASIT will provide useful insights into the particular difficulties people with clinical conditions experience when interpreting complex social phenomena.

Adult↗

PubMedDate not supplied

A preliminary account of phonological and morphophonological perception in young children with and without otitis media.

This investigation examined the effects of otitis media with effusion (OME) and its associated fluctuating conductive hearing loss on the perception of phonological and morphophonological /s/ and /z/ in young children. We predicted that children free of OME (OME-) would perform better than children with histories of OME (OME+). We also predicted that for the OME+ group morphological perception would be harder than phonological perception, because the former category carries an additional linguistic load (i.e., plurality). Sixteen children, ages 26 to 28 months (M = 26.5, SD = 0.6) were divided into two groups, the OME- (n = 8) and OME+ (n = 8) based on OME history during the first year of life. Subjects in the OME- group were free of the disease for 4/5 visits and pure tone average (PTA) was 12.6 dB HL (SD = 4.8). Subjects in the OME+ group had the disease on 3/5 visits and PTA was 23 dB HL (SD = 2.7). Experimental stimuli were six monosyllabic novel word-pairs. Members of each word-pair differed only in the presence of final voiced or voiceless fricative, marking the targets phonologically (e.g., [g [symbol: see text]]/[g [symbol: see text] s] as in 'law', 'loss') or morphophonologically (e.g., [daep]/[daeps] as in 'map' 'maps'). Subjects were taught the unfamiliar word pairs using a fast mapping procedure. Perception was tested with the bimodal preferential looking paradigm. Children in the OME- group performed significantly better than their OME+ counterparts. Individual word-pair analyses showed that OME+ group performed more poorly than the OME- group on one phonological and on two morphological targets, all ending with [s]. For the OME+ group, targets with final [s] posed greater difficulty than those with final [z], especially on morphophonological plural-(s) targets. The results suggested that the fluctuating hearing loss associated with OME might have a negative impact on speech perception.

Child, Preschool↗

PubMed2005

Face emotion perception and executive functioning deficits in depression.

Frontal, limbic and temporal regions of the brain important in emotion perception and executive functioning also have been implicated in the etiology and maintenance of depression; yet, the relationships among these topics remain poorly understood. The present study evaluated emotion perception and executive functioning among 21 depressed women and 20 nondepressed women controls. Depressed women performed significantly worse than controls in emotion perception accuracy and in inhibitory control, an aspect of executive functioning, whereas the groups did not differ in other cognitive tests assessing memory, visual-spatial, motor, and attention skills. The findings suggest that emotion perception and executive functioning are disproportionately negatively affected relative to other cognitive functions, even in a high-functioning group of mildly depressed women. Measures of emotion perception and executive functioning may be of assistance in objectively measuring functional capability of the ventral and dorsal neural systems, respectively, as well as in the diagnosis of depression.

Adolescent↗

PubMed1979

Influence of sonic noise on human stereoscopic depth perception.

Scientific establishment of the no-effect response to finite levels of exposure to a physical or chemical agent is indeed a rigorous exercise and is frequently controversial. In earlier research by Slutsky under direction of the senior author, a statistically significant increase in stereoscopic depth perception error was noted among 24 test subjects exposed to high intensity noise. Additional extensive research reported in this paper indicates that error in stereoscopic depth perception is not significantly altered by exposure to continuous white noise of short duration at levels ranging from 70 to 115 dBA. Furthernore, exposure of humans for periods of a few minutes to white noise in octave bands centered on 250 Hz, 1000 Hz, 4 kHz and 16 kHz at 115 dB does not affect their depth perception measured by the Howard-Dolman test. A comprehensive analysis of depth perception errors measured under noise exposure conditions (n = 4040) in comparison with those obtained under control conditions (n = 1430) produced a mean change in error of -0.38 mm, a statistically insignificant difference (p = 0.17). Even if such an error were attributable to high level noise, it should be noted that minus sign designates an improvement of depth perception in noise and that it is difficult to imagine visual tasks in which change in error of +/-0.38 mm at a distance of 6.0 meters is meaningful.

Depth Perception↗

PubMedDate not supplied

Occupant perception of indoor air and comfort in four hospitality environments.

This article reports on a survey of customer and staff perceptions of indoor air quality at two restaurants, a billiard hall, and a casino. The survey was conducted at each environment for 8 days: 2 weekend days on 2 consecutive weekends and 4 weekdays. Before and during the survey, each hospitality environment satisfied ventilation requirements set in ASHRAE Standard 62-1999, Ventilation for Acceptable Indoor Air. An objective of this study was to test the hypothesis: If a hospitality environment satisfies ASHRAE ventilation requirements, then the indoor air is acceptable, that is, fewer than 20% of the exposed occupants perceive the environment as unacceptable. A second objective was to develop a multiple regression model that predicts the dependent variable, the environment is acceptable, as a function of a number of independent perception variables. Occupant perception of environmental, comfort, and physical variables was measured using a questionnaire. This instrument was designed to be efficient and unobtrusive; subjects could complete it within 3 min. Significant differences of occupant environment perception were identified among customers and staff. The dependent variable, the environment is acceptable, is affected by temperature, occupant density, and occupant smoking status, odor perception, health conditions, sensitivity to chemicals, and enjoyment of activities. Depending on the hospitality environment, variation of independent variables explains as much as 77% of the variation of the dependent variable.

Air Pollution, Indoor↗

PubMed1999

Interhemispheric asymmetries in the perception of unimanual and bimanual cutaneous stimuli. A study using transcranial magnetic stimulation.

Previous studies have shown that transcranial magnetic stimulation (TMS) of the sensorimotor cortex can induce a suppression of cutaneous perception from the fingers of the contralateral hand. In this work, 17 normal subjects were submitted to focal TMS of frontal and parietal scalp sites of each hemisphere. TMS was delivered at two interstimulus intervals (20 and 40 ms) following a cutaneous electrical stimulation of the first, third and fifth digits of either hand or both hands near the subjective threshold of perception. The aim of our study was to investigate whether TMS could detect an asymmetrical hemispheric specialization in the sensory perception of unimanual and bimanual, ipsilateral and contralateral sensory stimuli. At each interpulse interval, the right parietal cortex was significantly more sensitive to TMS interference with stimulus detection for both contralateral and ipsilateral stimuli compared with the left parietal cortex. These effects were mainly evident during bimanual discrimination tasks. Our results are indicative of an interhemispheric difference in the detection of cutaneous sensation, showing right hemispheric prevalence in the perception of contralateral as well as of ipsilateral stimuli. They provide neurophysiological support in normal humans to the clinical evidence which indicates that right hemisphere lesions can indeed produce deficits in the perception of ipsilateral sensory stimuli.

Adult↗

PubMed2003

A neural basis for the perception of voices in external auditory space.

We used functional imaging of normal subjects to identify the neural substrate for the perception of voices in external auditory space. This fundamental process can be abnormal in psychosis, when voices that are not true external auditory objects (auditory verbal hallucinations) may appear to originate in external space. The perception of voices as objects in external space depends on filtering by the outer ear. Psychoses that distort this process involve the cerebral cortex. Functional magnetic resonance imaging was carried out on 12 normal subjects using an inside-the-scanner simulation of 'inside head' and 'outside head' voices in the form of typical auditory verbal hallucinations. Comparison between the brain activity associated with the two conditions allowed us to test the hypothesis that the perception of voices in external space ('outside head') is subserved by a temperoparietal network comprising association auditory cortex posterior to Heschl's gyrus [planum temporale (PT)] and inferior parietal lobule. Group analyses of response to 'outside head' versus 'inside head' voices showed significant activation solely in the left PT. This was demonstrated in three experiments in which the predominant lateralization of the stimulus was to the right, to the left or balanced. These findings suggest a critical involvement of the left PT in the perception of voices in external space that is not dependent on precise spatial location. Based on this, we suggest a model for the false perception of externally located auditory verbal hallucinations.

Acoustics↗

PubMed2004

Characterization of deficits in pitch perception underlying 'tone deafness'.

Congenital amusia is a disorder characterized by life-long, selective deficits in the perception of music. This study examined pitch-perception abilities in a group of 10 adults with this disorder. Tests were administered that assessed fine-grained pitch perception by determining thresholds both for the detection of continuous and segmented pitch changes, and for the recognition of pitch direction. Tests were also administered that assessed the perception of more complex pitch patterns, using pitch-sequence comparison tasks. In addition, the perceptual organization of pitch was also examined, using stream segregation tasks that assess the assignment of sounds differing in pitch to one or two distinct perceptual sources. In comparison with 10 control subjects, it was found that the participants with congenital amusia exhibited deficits both at the level of detecting fine-grained differences in pitch, and at the level of perceiving patterns in pitch. In contrast, no abnormalities were identified in the perceptual organization of pitch. The pitch deficits identified are able to account for the music perception difficulties in this disorder, and implicate deficient cortical processing.

Acoustic Stimulation↗

PubMed2005

The sniff is part of the olfactory percept.

In this review, we use data obtained primarily from humans to argue that sniffs are not merely a stimulus carrier but are rather a central component of the olfactory percept. We argue that sniffs 1) are necessary for the olfactory percept, 2) affect odorant intensity perception and identity perception, 3) drive activity in olfactory cortex, 4) are rapidly modulated in an odorant-dependent fashion by a dedicated olfactomotor system, and 5) are sufficient to generate an olfactory percept of some sort even in the absence of odor.

Humans↗

PubMed2004

Inner city African-American elderly patients' perceptions and preferences for the care of chronic knee and hip pain: findings from focus groups.

BACKGROUND: African Americans undergo joint replacement less often than do white persons. The authors studied African-American perceptions and preferences for the care of knee and hip pain. METHODS: 10 focus groups were conducted in an inner city community. Participants, older persons with chronic knee or hip pain, were asked to discuss their perceptions and preferences for the care of knee and hip pain. Transcripts were coded for thematic structure using NUD*ST software. RESULTS: Cultural preferences and perceptions for care emerged as a major theme. Important subcategories of this theme included respect for the patient's faith and religiosity and perceptions of physician ethnicity, race, and sex. CONCLUSIONS: This sample of older inner city African Americans expressed unique cultural perceptions and preferences for the care of their knee and hip pain. Respect for patients' faith was important, whereas physicians' race, ethnicity, and religious background were not.

Black or African American↗

PubMed2000

Frontal processing and auditory perception.

Disordered processing of the pattern in sound over time has been observed in a number of clinical disorders, including developmental dyslexia. This study addresses the brain mechanisms required for the perception of such a pattern. We report the systematic evaluation of temporal perception in a patient with a single intact right auditory cortex and a large right frontal lobe lesion. A striking dissociated deficit was demonstrated in the perception of temporal pattern at the level of tens or hundreds of milliseconds. This proves that, contrary to common belief, mechanisms in the pathway up to and including the primary auditory cortex are not sufficient for the normal perception of temporal pattern. This work suggests a need for frontal processing for the normal perception of auditory pattern.

Adult↗

PubMed2000

Changes in horizontal oculomotor behaviour coincide with a shift in visual motion perception.

During full-field rotation of the visual field, subjects commonly experience an initial perception of object-motion which 'switches' to a perception of self-motion. We studied the characteristics of the horizontal optokinetic nystagmus responses evoked by a moving visual stimulus in these two perceptual states over a range of stimulus velocities. During self-motion perception mean eye position was found to shift more in the direction of the newly appearing stimulus elements with a slight reduction in slow phase gain in comparison to the nystagmus evoked during object-motion perception. The results may reflect a modified strategy of spatial attention with increased emphasis on anticipatory eye movements during visually induced self-motion perception.

Adult↗

PubMed1986

Students' perceptions of values emphasized in three medical schools.

The purpose of the study presented here was to assess medical students' perceptions of the weight given to scientific and humanistic values in their learning environment and to determine whether students' perceptions in a given school vary according to their level of medical training and personal characteristics. The study was conducted in 1979 via a mail questionnaire sent to a sample of 713 freshmen, juniors, and graduates from three U.S. medical schools; 82.2 percent responded. The results indicated that the students' perceptions of school values varied little according to the students' personal characteristics, such as sociodemographic and educational background, interests before medical training, and expected specialty choice. However, important differences were observed in students' perceptions of values emphasized to them at different schools. Preclinical and clinical students' perceptions of the importance given to scientific values were similar. As for humanistic values, significantly lower ratings were given by clinical students than preclinical students in two of the schools.

Humanism↗

PubMed1996

Knowledge, attitudes and perception of AIDS in rural Senegal: relationship to sexual behaviour and behaviour change.

OBJECTIVES: To describe the determinants of 'at risk' sexual behaviour and perception of AIDS-related prevention messages in rural Africa. SETTING: A rural area in Southern Senegal. DESIGN: Cross-sectional study using a standardized questionnaire administered by local interviewers to 240 men and 242 women aged 15-59 years, randomly selected among the general population. RESULTS: Twenty-eight per cent of the sexually active men and 27% of the sexually active women declared at least one casual sexual partner in the 12 months preceding the interview. Among these, 27% of men and 30% of women declared having used a condom in most acts of casual intercourse. Seasonal migrants and divorced or widowed women were more likely to declare casual sex. Causal sex was motivated by material needs for 66% of the women who experienced it, and those of the women who reported casual sexual intercourse were less likely to feel at risk of AIDS [odds ratio (OR), 3.9; P = 0.01] and were more optimistic about their future (OR, 3.6; P = 0.03). For men, the motivations explaining a change in sexual behaviour in order to avoid HIV infection included the perception of AIDS as a health problem (OR, 11; P = 0.004), the perception of the disease as serious (OR, 5.4; P = 0.001) and the feeling of personal risk of becoming HIV-infected (OR, 3.2; P = 0.02). Perceived skill in changing one's behaviour was strongly associated with declaration of past behaviour change for both men and women (men: OR, 3.4; P = 0.02; women: OR, 6.3; P = 0.0001). CONCLUSION: Men and women exhibit two different patterns regarding their behaviour and perception towards AIDS. Material needs appear to be of importance for women, whereas perception of a real threat lead men to adopt protective behaviours. In the very area of this study, widowed and divorced women as well as male seasonal migrants are particularly exposed to HIV infection. They are characterized by a higher risk behaviour, a low rate of condom use and seldom declared any protective measures to avoid HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMed1997

The contour test of loudness perception.

OBJECTIVE: This article presents the underlying rationale, normative data, and reliability data for a test of loudness perception (the Contour Test) that was devised for use in clinical hearing aid fitting. The Contour Test yields data describing the sound level required for each of seven categories of loudness ranging from very soft to uncomfortably loud. DESIGN: Two experiments are described. Experiment 1 yielded norms for the test. The subjects were 23 male and 22 female normal-hearing listeners. Test stimuli included warble tones at six frequencies and broad band speech. Experiment 2 assessed the reliability of the test results. Ten hearing-impaired listeners responded to the test at two frequencies on two occasions separated by several days. Both experiments also evaluated the effect of using different stimulus increment sizes on the measured levels of loudness categories. RESULTS: Based on the data from experiment 1, norms for each category of each stimulus are reported in terms of mean level and typical between-subject variation in responses. Data are provided in HA-12 cm3 coupler levels as well as in hearing levels (dB HL). The shape of the loudness growth function for warble tones was somewhat different from that for speech. When data were expressed in HL, there were no differences in mean loudness category levels across warble tone test frequencies. Thus, test frequencies were combined and equations were generated to describe the upper and lower limits of typical normal performance for warble tone stimuli. These equations can be used to construct a template for clinical comparison of normative values to patient loudness growth curves. Experiment 2 provided information about the test-retest variability of data yielded by the Contour Test. Reliability appears to be similar to that of the few other category scaling tests described in the literature. Most test-retest differences were 6 dB or less. Although a moderate variation in test increment size did not significantly affect the loudness category levels for young normal-hearing listeners, levels corresponding to loudness categories were significantly higher when larger increments were used with elderly hearing-impaired listeners. CONCLUSIONS: Evidence from this and other research indicates that standardized measurement of loudness perception is an achievable goal for clinical practice. The Contour Test appears to offer a viable approach to clinical measurement of loudness perception: It has good patient acceptance and combines fairly rapid administration with acceptable reliability. Details of test procedures and scoring sheets for manual administration can be downloaded from the Internet at www.ausp.memphis.edu/harl. However, it is important to keep in mind that the application of loudness perception data for narrowband stimuli (such as warble tones) to hearing aid prescription is complicated by the need to account for the effects of loudness summation across bandwidth. There is a need for additional research to establish an empirical link between clinically measured loudness perception and optimal amplification characteristics.

Adolescent↗

PubMed1999

Cochlear implants in young children: the relationship between speech perception and speech intelligibility.

OBJECTIVE: To determine the relationship between measures of speech perception and speech production after cochlear implantation of young children with profound congenital and prelingual deafness. DESIGN: A prospective study was undertaken on a consecutive group of children with profound deafness. There were 126 children at the preimplantation interval and 71, 50, 26, and 20 children, respectively, at the 2, 3, 4, and 5 yr follow-up after implantation. Speech perception and speech intelligibility were assessed using hierarchical rating scales. Spearman rank correlation coefficients were used to determine the statistical correlations. All patients were either congenitally deaf or deafened before the age of 3 yr and were implanted before age 7 yr. The patients all received the Nucleus multichannel cochlear implant system with the most appropriate speech encoding strategy. RESULTS: Speech intelligibility at 5 yr was strongly correlated with speech perception at the 2, 3, 4, and 5 yr intervals after implantation (Spearman coefficients 0.77, 0.81, 0.58, 0.58; p < or = 0.01). Speech intelligibility at the 2, 3, and 4 yr intervals also correlated in a similar manner with earlier speech perception abilities (p < or = 0.01). CONCLUSIONS: The results suggest that speech intelligibility between 2 and 5 yr after implantation in young children with congenital and prelingual profound deafness can be predicted by measures of earlier speech perception.

Age Factors↗

PubMed1997

Risk ranking by perception.

The study of people's perception and acceptability of risk is important in understanding the public reaction to technology and its environmental and health impact. The perception of risk depends on several factors, including early experiences, education, controllability of the risk, the type of consequence, and the type of person(s) who makes the judgment. This paper reviews some of the main factors influencing people's perception and acceptability of risk. Knowledge about which factors influence the perception of risk may enhance the understanding of different points of view brought into risk controversies, improve risk communication, and facilitate policy making. Results from a risk ranking by perception survey conducted in Ghana are also presented.

Environmental Health↗

PubMed1998

Depth perception in random dot stereograms is not affected by changes in either vergence or accommodation.

PURPOSE: To test the hypothesis that extraretinal cues related to vergence angle and lens accommodation are used to scale horizontal disparities for fixation distance. METHODS: Depth perception of random dot stereograms was studied in 10 healthy adult subjects with normal visual acuity by modifying retinal disparity, fixation distance, vergence angle, and accommodation. Statistical analysis was used to compare the data. RESULTS: Depth perception increased with fixation distance. The increment of depth perception persisted even when horizontal retinal disparity was kept constant. The magnitude of depth perception was independent of vergence angle. Depth perception did not vary with changes in accommodation. CONCLUSIONS: Extraretinal cues related to vergence angle and accommodation seem to be not necessary to scale horizontal disparities for viewing distance.

Accommodation, Ocular↗