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 577 records · Page 32Linked to original sources

PubMed1996

Cue availability and affect perception in schizophrenia.

This study examined affect perception in schizophrenia. Subjects were 35 patients with schizophrenia or schizoaffective disorder, 11 with bipolar disorder, and 19 matched nonpatient controls. All patients were in the latter stages of an acute hospitalization. Measures included a videotaped test of affect perception administered with and without sound, two tests of facial affect perception based on photographs, and two measures of nonaffect perception. The patient groups did not differ from one another on any of the affect perception measures, and few differences occurred between schizophrenia patients and nonpatient controls. Affect perception in schizophrenia patients was not correlated with symptomatology or history of illness, and there were no gender differences. Deficits reported in prior studies may reflect limitations in the assessment methodology commonly employed.

Adult↗

PubMed2001

Variation in speech perception scores among children with cochlear implants.

OBJECTIVE: The objective of this study was to identify common factors affecting speech perception scores in children with cochlear implants. DESIGN: Speech perception data for 167 implanted children were collected at two cochlear implant centres in Melbourne and Sydney. The data comprised audition-alone scores on open-set word and sentence tests. Children were selected on the basis that they had a Nucleus 22-electrode cochlear implant. The average age of the children was 5 yr. Information was also collected about 12 factors that may have influenced speech perception scores for each child. Analysis of covariance was used to identify factors that significantly affected speech perception scores. Pearson pairwise correlation coefficients were also calculated for all factors analyzed. RESULTS: The analyses in this study identified factors that accounted for 51%, 34%, and 45% of the variance in phoneme, word and sentence perception scores. Scores decreased by 1.4 to 2.4% per year of profound deafness prior to implantation. Children who normally use oral communication scored significantly higher than children normally using sign or simultaneous oral and sign communication. Children implanted in Sydney scored higher on average than children implanted in Melbourne. CONCLUSIONS: The results show that a significant part of the variation in speech perception scores is systematically related to audiological and environmental factors for each child. The reasons for significant differences between children using different communication modes or from different clinics were not identified.

Adolescent↗

PubMed2002

Neurophysiology of cochlear implant users II: comparison among speech perception, dynamic range, and physiological measures.

OBJECTIVE: The overall objective of this study was to relate electrically evoked potentials recorded from different levels of the auditory pathway with behavioral measures obtained from adult cochlear implant subjects. The hypothesis was that adult recipients of cochlear implants who have open-set speech perception and those recipients with no open-set speech perception would differ in their neurophysiologic responses recorded at one or more levels of the auditory pathway. DESIGN: The subjects were 11 adults implanted with the Clarion cochlear implant. The electrical auditory brainstem response (EABR, Wave V), electrical auditory middle latency response (EAMLR, Na-Pa complex), and the electrical late auditory response (ELAR, N1-P2 complex), were recorded from three intra-cochlear electrodes. The stimuli used to record the evoked potentials varied in rate and amplitude. Behavioral measures (between threshold and upper limit of comfortable loudness) were used to define the subject's dynamic range at the different stimulus rates. Word and sentence recognition tests evaluated subjects' speech perception in quiet and noise. Evoked potential and behavioral measures were examined for statistical significance using analysis of variance for repeated measures and correlational analyses. RESULTS: Subjects without open-set speech recognition demonstrated 1) poorly formed or absent evoked potential responses, 2) reduced behavioral dynamic ranges, 3) lack of change in the size of the dynamic range with a change in stimulus rate, and 4) longer periods of auditory deprivation. The variables that differentiated the best performers included 1) presence of responses at all three levels of the auditory pathway, with large normalized amplitudes for the EAMLR, 2) lower evoked potential thresholds for the Na-Pa complex, 3) relatively large dynamic ranges, and 4) changes in the size of the dynamic range with changes in stimulus rate. CONCLUSIONS: In this study, the inability to follow changes in the temporal characteristics of the stimulus was associated with poor speech perception performance. Results also illustrate that variability in speech perception scores of cochlear implant recipients relates to neurophysiologic responses at higher cortical levels of the auditory pathway. Presumably, limited neural synchrony for elicitation of electrophysiologic responses underlies limited speech perception. Results confirm that neural encoding with electrical stimulation must provide sufficient physiologic responses of the central nervous system to perceive speech through a cochlear implant.

Adult↗

PubMed2005

Improved speech perception in adult congenitally deafened cochlear implant recipients.

OBJECTIVE: To determine whether congenitally deafened adults achieve improved speech perception when auditory and visual speech information is available after cochlear implantation. STUDY DESIGN: Repeated-measures single subject analysis of speech perception in visual-alone, auditory-alone, and audiovisual conditions. SETTING: Neurotologic private practice and research institute. SUBJECTS: Eight subjects with profound congenital bilateral hearing loss who underwent cochlear implantation as adults (aged 18-55 years) between 1995 and 2002 and had at least 1 year of experience with the implant. MAIN OUTCOME MEASURES: Auditory, visual, and audiovisual speech perception. RESULTS: The median for speech perception scores were as follows: visual-alone, 25.9% (range, 12.7-58.1%); auditory-alone, 5.2% (range, 0-49.4%); and audiovisual, 50.7% (range, 16.5-90.8%). Seven of eight subjects did as well or better in the audiovisual condition than in either auditory-alone or visual-alone conditions alone. Three subjects had audiovisual scores greater than what would be expected from a simple additive effect of the information from the auditory-alone and visual-alone conditions alone, suggesting a superadditive effect of the combination of auditory-alone and visual-alone information. Three subjects had a simple additive effect of speech perception in the audiovisual condition. CONCLUSION: Some congenitally deafened subjects who undergo implantation as adults have significant gains in speech perception when auditory information from a cochlear implant and visual information by lipreading is available. This study shows that some congenitally deafened adults are able to integrate auditory information provided by the cochlear implant (despite the lack of auditory speech experience before implantation) with visual speech information.

Adult↗

PubMed2005

Randot stereoacuity does not accurately predict ability to perform two practical tests of depth perception at a near distance.

PURPOSE: It is common practice to administer stereopsis tests such as the Randot Stereotest to prospective employees for occupations requiring depth perception. However, there is no evidence that stereoacuity measured with tests such as the Randot Stereotest will predict an individual's ability to perform a depth perception task at near. METHODS: Forty-eight people with normal binocular vision were tested on 2 practical depth perception tests, and their stereoacuity was measured with the Randot Stereotest. RESULTS: There was little correlation between stereoacuity and either of the practical tasks (r<+/-0.1). CONCLUSIONS: These results show that Randot stereoacuity does not reliably predict depth perception ability for people who enjoy normal binocular vision. A better method for determining depth perception ability might be to issue a practical depth perception task.

Adult↗

PubMed2006

The fusiform face area: a cortical region specialized for the perception of faces.

Faces are among the most important visual stimuli we perceive, informing us not only about a person's identity, but also about their mood, sex, age and direction of gaze. The ability to extract this information within a fraction of a second of viewing a face is important for normal social interactions and has probably played a critical role in the survival of our primate ancestors. Considerable evidence from behavioural, neuropsychological and neurophysiological investigations supports the hypothesis that humans have specialized cognitive and neural mechanisms dedicated to the perception of faces (the face-specificity hypothesis). Here, we review the literature on a region of the human brain that appears to play a key role in face perception, known as the fusiform face area (FFA). Section 1 outlines the theoretical background for much of this work. The face-specificity hypothesis falls squarely on one side of a longstanding debate in the fields of cognitive science and cognitive neuroscience concerning the extent to which the mind/brain is composed of: (i) special-purpose ('domain-specific') mechanisms, each dedicated to processing a specific kind of information (e.g. faces, according to the face-specificity hypothesis), versus (ii) general-purpose ('domain-general') mechanisms, each capable of operating on any kind of information. Face perception has long served both as one of the prime candidates of a domain-specific process and as a key target for attack by proponents of domain-general theories of brain and mind. Section 2 briefly reviews the prior literature on face perception from behaviour and neurophysiology. This work supports the face-specificity hypothesis and argues against its domain-general alternatives (the individuation hypothesis, the expertise hypothesis and others). Section 3 outlines the more recent evidence on this debate from brain imaging, focusing particularly on the FFA. We review the evidence that the FFA is selectively engaged in face perception, by addressing (and rebutting) five of the most widely discussed alternatives to this hypothesis. In section 4, we consider recent findings that are beginning to provide clues into the computations conducted in the FFA and the nature of the representations the FFA extracts from faces. We argue that the FFA is engaged both in detecting faces and in extracting the necessary perceptual information to recognize them, and that the properties of the FFA mirror previously identified behavioural signatures of face-specific processing (e.g. the face-inversion effect). Section 5 asks how the computations and representations in the FFA differ from those occurring in other nearby regions of cortex that respond strongly to faces and objects. The evidence indicates clear functional dissociations between these regions, demonstrating that the FFA shows not only functional specificity but also area specificity. We end by speculating in section 6 on some of the broader questions raised by current research on the FFA, including the developmental origins of this region and the question of whether faces are unique versus whether similarly specialized mechanisms also exist for other domains of high-level perception and cognition.

Animals↗

PubMed2004

Perception of facial expressions of emotion in bipolar disorder.

OBJECTIVES: Some studies have reported deficits in the perception of facial expressions among depressed individuals compared with healthy controls, while others have reported negative biases in expression perception. We examined whether altered perception of emotion reflects an underlying trait-like effect in affective disorder by examining facial expression perception in euthymic bipolar patients. METHODS: Sensitivity to six different facial expressions, as well as accuracy of emotion recognition, was examined among 17 euthymic bipolar patients and 17 healthy controls using an interactive computer program. RESULTS: No differences were found between euthymic bipolar patients and controls in terms of sensitivity to any particular emotion. Although initial analysis of the data suggested impairment in the recognition of fear among the patients, identification of this emotion was not relatively impaired compared with that of the other emotions. CONCLUSIONS: The study did not find any conclusive evidence for trait-like deficits in the perception of facially conveyed emotions in bipolar disorder. Altered perception of facial expressions that has been found to accompany depressed mood may instead reflect mood-congruent biases.

Adolescent↗

PubMed2004

Self-concept and perception of early mother and father behavior in normal and antisocial adolescents.

This study examines the self-concept and perceptions of early parental behavior in a group of 277 normal adolescents with respect to differences in age (12-18 years) and gender. A group of 30 antisocial adolescents of similar age (13-19 years) were included as a comparison group. The study was a cross-sectional questionnaire study and the Swedish translation of the Structural Analysis of Social Behavior (SASB) introject and mother/father questionnaires were used as measures of self- and parental concepts. Multivariate analyses of variance show that the normal adolescent self-concept and perception of early parental behavior are positive and that there are no age or gender differences. The early behavior of the mother is perceived more positively than that of the father. A positive self-concept is related to a positive perception of the parent's early behavior. The antisocial group of adolescents shows a more autonomous and negative self-concept and more negative perception of early parental behaviors. This was true especially in the group of antisocial girls. The conclusion from the study is that there is no evidence of a chaotic self-concept or tumultuous changes in the perceptions of early parental behavior during normal adolescence, but that an antisocial way of life might be reflected in a more negative and autonomous self-concept and in more negative perceptions of early parental behavior during adolescence.

Adolescent↗

PubMed2004

Racial and ethnic differences in patient perceptions of bias and cultural competence in health care.

OBJECTIVES: To determine: 1) whether racial and ethnic differences exist in patients' perceptions of primary care provider (PCP) and general health care system-related bias and cultural competence; and 2) whether these differences are explained by patient demographics, source of care, or patient-provider communication variables. DESIGN: Cross-sectional telephone survey. SETTING: The Commonwealth Fund 2001 Health Care Quality Survey. SUBJECTS: A total of 6,299 white, African-American, Hispanic, and Asian adults. MEASUREMENTS AND MAIN RESULTS: Interviews were conducted using random-digit dialing; oversampling respondents from communities with high racial/ethnic minority concentrations; and yielding a 54.3% response rate. Main outcomes address respondents' perceptions of their PCPs' and health care system-related bias and cultural competence; adjusted probabilities (Pr) are reported for each ethnic group. Most racial/ethnic differences in perceptions of PCP bias and cultural competence were explained by demographics, source of care, and patient-physician communication variables. In contrast, racial/ethnic differences in patient perceptions of health care system-wide bias and cultural competence persisted even after controlling for confounders: African Americans, Hispanics, and Asians remained more likely than whites (P <.001) to perceive that: 1) they would have received better medical care if they belonged to a different race/ethnic group (Pr 0.13, Pr 0.08, Pr 0.08, and Pr 0.01, respectively); and 2) medical staff judged them unfairly or treated them with disrespect based on race/ethnicity (Pr 0.06, Pr 0.04, Pr 0.06, and Pr 0.01, respectively) and how well they speak English (Pr 0.09, Pr 0.06, Pr 0.06, and Pr 0.03, respectively). CONCLUSION: While demographics, source of care, and patient-physician communication explain most racial and ethnic differences in patient perceptions of PCP cultural competence, differences in perceptions of health care system-wide bias and cultural competence are not fully explained by such factors. Future research should include closer examination of the sources of cultural bias in the US medical system.

Adult↗

PubMed1997

Speech perception in older adults: the importance of speech-specific cognitive abilities.

OBJECTIVE: To provide a critical evaluation of studies examining the contribution of changes in language-specific cognitive abilities to the speech perception difficulties of older adults. DESIGN: A review of the literature on aging and speech perception. CONCLUSIONS: The research considered in the present review suggests that age-related changes in absolute sensitivity is the principal factor affecting older listeners' speech perception in quiet. However, under less favorable listening conditions, changes in a number of speech-specific cognitive abilities can also affect spoken language processing in older people. Clinically, these findings suggest that hearing aids, which have been the traditional treatment for improving speech perception in older adults, are likely to offer considerable benefit in quiet listening situations because the amplification they provide can serve to compensate for age-related hearing losses. However, such devices may be less beneficial in more natural environments, (e.g., noisy backgrounds, multiple talkers, reverberant rooms) because they are less effective for improving speech perception difficulties that result from age-related cognitive declines. It is suggested that an integrative approach to designing test batteries that can assess both sensory and cognitive abilities needed for processing spoken language offers the most promising approach for developing therapeutic interventions to improve speech perception in older adults.

Aged↗

PubMed1998

Risk perceptions of offshore workers on UK oil and gas platforms.

Knowledge of the workforce's risk perceptions and attitudes to safety is necessary for the development of a safety culture, where each person accepts responsibility for working safely. The ACSNI Human Factors report stresses the importance of assessing workforce perceptions of risk to achieve a proper safety culture. Risk perception research has been criticized for insufficient analysis of the causal relationships between risk factors and perceived risk. The present study reports some of the factors which predicted risk perception in a sample of 622 employees from six UKCS offshore oil installations who completed a 15-section questionnaire. This paper focuses on the accuracy of workers' risk perceptions and what underlying factors predict the perception of personal risk from both major and minor hazards.

Accidents, Occupational↗

PubMed2006

Persistent allergic rhinitis and indoor air quality perception--an experimental approach.

In order to compare patterns of indoor air perception, including perceptions of temperature, air movement, indoor air quality (IAQ), mental concentration, and comfort, 33 subjects either with persistent allergic rhinitis or controls were exposed to different temperatures and constant relative humidity in an experimental office environment. Results were obtained by means of a self-administered visual analogue scale, analyzed using mean score comparisons and principal component analysis. At 14 degrees C, the rhinitis group reported higher scores for sensations of air dryness than controls. At 18 degrees C, in the rhinitis group, there was a correlation between dry, stagnant air, and difficult mental concentration. This group also correlated heat, dry air, and poor IAQ, in contrast to the control group, which correlated comfort, easy mental concentration, and freshness. At 22 degrees C, the rhinitis group correlated heat, dryness, stagnant air, and overall discomfort. This group also correlated non-dry air, freshness, and comfort, whereas the control group correlated heat, humidity, good indoor air, freshness, and comfort. This study suggests that the rhinitis group perceives indoor temperatures of 14 degrees C as dryer than controls do, and that at 18 and 22 degrees C this group positively correlates different adverse perceptions of IAQ. By means of a self-administered questionnaire in an experimental condition, the present study compares subjective patterns of indoor air perception from individuals with respiratory allergy (allergic rhinitis) to control individuals. It reports different patterns of perception of indoor air quality (IAQ) between the two groups, suggesting that allergic individuals could have different IAQ perception.

Adult↗

PubMed1984

Perception and eye movements in simulated traffic situations.

In an experiment to simulate the perception task of a driver, subjects were shown uninterrupted series of colour slides of different kinds of highway scenes. The dependent variables were eye fixations, fixation times and conscious perceptions for the part of the traffic signs and roadside advertisements. Perceptions were achieved mostly as a result of fixation, but partly also by using peripheral vision. On the other hand fixation did not always cause perception. The lengthening of fixation time increased the number of correct perceptions. When the traffic sign and the roadside advertisement were in the same slide, the advertisement disturbed the perception of the sign, but in the daylight conditions this effect was not noticed as an alteration of the fixation of the sign, but as prevention of further information processing. The disturbing influence of the advertisement was increased by its bad information ergonomics which caused a long fixation time.

Adult↗

PubMed1987

Pitch perception by cochlear implant subjects.

Direct electrical stimulation of the auditory nerve can be used to restore some degree of hearing to the profoundly deaf. Percepts due to electrical stimulation have characteristics corresponding approximately to the acoustic percepts of loudness, pitch, and timbre. To encode speech as a pattern of electrical stimulation, it is necessary to determine the effects of the stimulus parameters on these percepts. The effects of the three basic stimulus parameters of level, repetition rate, and stimulation location on subjects' percepts were examined. Pitch difference limens arising from changes in rate of stimulation increase as the stimulating rate increases, up to a saturation point of between 200 and 1000 pulses per second. Changes in pitch due to electrode selection depend upon the subject, but generally agree with a tonotopic organization of the human cochlea. Further, the discriminability of such place-pitch percepts seems to be dependent on the degree of current spread in the cochlea. The effect of stimulus level on perceived pitch is significant but is highly dependent on the individual tested. The results of these experiments are discussed in terms of their impact on speech-processing strategies and their relevance to acoustic pitch perception.

Acoustic Stimulation↗

PubMed1996

Critique: auditory form and gestural topology in the perception of speech.

Some influential accounts of speech perception have asserted that the goal of perception is to recover the articulatory gestures that create the acoustic signal, while others have proposed that speech perception proceeds by a method of acoustic categorization of signal elements. These accounts have been frustrated by difficulties in identifying a set of primitive articulatory constituents underlying speech production, and a set of primitive acoustic-auditory elements underlying speech perception. An argument by Lindblom favors an account of production and perception based on the auditory form of speech and its cognitive elaboration, rejecting the aim of defining a set of articulatory primitives by appealing to theoretical principle, while recognizing the empirical difficulty of identifying a set of acoustic or auditory primitives. An examination of this thesis found opportunities to defend some of its conclusions with independent evidence, but favors a characterization of the constituents of speech perception as linguistic rather than as articulatory or acoustic.

Cognition↗

PubMed2003

Perception of exercise induced asthma by children and their parents.

BACKGROUND: Exercise induced asthma (EIA) plays an important role in clinical evaluation. There has been little previous work validating EIA as reported directly by children and indirectly by their parents. AIMS: (1) To determine the strength of the association between children's symptoms of EIA and their physiological response to exercise in a laboratory setting. (2) To compare parents' perception of EIA with that of their children. (3) To seek factors influencing the perception of EIA. METHODS: Forty three asthmatic children and their parents answered a questionnaire, which included measures of symptom perception in EIA using visual analogue (VAS) and Likert scales. The children underwent a standardised treadmill exercise challenge, using spirometry to measure the physiological outcome, after which they and their parents independently completed the symptom scores. Twenty four subjects agreed to return for a second visit, in order to assess repeatability. RESULTS: The VAS and Likert scales were highly correlated. Children's symptom perception as measured by change in VAS scores related weakly to change in FEV(1) after exercise, and was unaffected by confounding factors such as age, gender, medication, and habitual exercise. Parents' perception of symptoms was unrelated to any physiological measure. There was no significant relation between parent and child VAS scores after exercise, and there was poor agreement between the Likert scale scores after exercise. The repeatability of the perception of change in FEV(1) after exercise was poor for both parents and children. CONCLUSION: Physicians should obtain reports of EIA from children rather than parents, but be aware of their limited accuracy and repeatability.

Adolescent↗

PubMed2006

Changing drinking pattern does not influence health perception: a longitudinal study of the atherosclerosis risk in communities study.

OBJECTIVE: To investigate if dynamic changes in the pattern of alcoholic beverages consumption are associated with modifications in health perception. DESIGN, SETTING, AND PARTICIPANTS: This study investigated 12 332 middle aged men and women from the atherosclerosis risk in communities study who reported drinking status and perceived health triennially from 1987 to 1995. Crude and adjusted risks for change in health perception between visits two and three by change in drinking status between visits one and two were computed. In the multivariate analysis the sample was restricted to participants with stable drinking status between visit two and three and stable health perception between visits one and two, to assure that exposure and outcome were not temporary. Covariates included age, sex, race, income, smoking status, educational level, and obesity. RESULTS: Health for persons who stopped or started drinking, or continued to abstain was more likely to decline than was health for persons who continued to drink even after adjustment and restrictions (drinking cessation: OR = 1.6, 95% CI = 1.1, 2.3; started drinking; OR = 1.4, 95% CI = 0.9, 2.2; continued abstaining from alcohol: OR = 1.5, 95% CI = 1.3, 1.9). Among participants with poor perceived health, starting, stopping, or continuing to abstain from alcohol did not improve health in relation to participants that continued to drink. CONCLUSION: Increasing and decreasing drinking patterns and continuous abstinence were associated with declining health perception in comparison with continuous drinking, while starting or stopping drinking did not improve health perception of persons with poor perceived health. These findings suggest that change in health perception was not biologically related to alcohol consumption.

Alcohol Drinking↗

PubMed2004

Emotional memory and perception in temporal lobectomy patients with amygdala damage.

BACKGROUND: The human amygdala is implicated in the formation of emotional memories and the perception of emotional stimuli--particularly fear--across various modalities. OBJECTIVES: To discern the extent to which these functions are related. METHODS: 28 patients who had anterior temporal lobectomy (13 left and 15 right) for intractable epilepsy were recruited. Structural magnetic resonance imaging showed that three of them had atrophy of their remaining amygdala. All participants were given tests of affect perception from facial and vocal expressions and of emotional memory, using a standard narrative test and a novel test of word recognition. The results were standardised against matched healthy controls. RESULTS: Performance on all emotion tasks in patients with unilateral lobectomy ranged from unimpaired to moderately impaired. Perception of emotions in faces and voices was (with exceptions) significantly positively correlated, indicating multimodal emotional processing. However, there was no correlation between the subjects' performance on tests of emotional memory and perception. Several subjects showed strong emotional memory enhancement but poor fear perception. Patients with bilateral amygdala damage had greater impairment, particularly on the narrative test of emotional memory, one showing superior fear recognition but absent memory enhancement. CONCLUSIONS: Bilateral amygdala damage is particularly disruptive of emotional memory processes in comparison with unilateral temporal lobectomy. On a cognitive level, the pattern of results implies that perception of emotional expressions and emotional memory are supported by separate processing systems or streams.

Adult↗