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 361 records · Page 20Linked to original sources

PubMed1999

Current perspectives on symptom perception in asthma: a biomedical and psychological review.

Symptom perception in patients with asthma is often inadequate. Patients may fail to perceive serious airway obstruction or suffer from breathlessness without objective cause. These extremes are associated with fatal asthma and excessive use of medicines, respectively. This article covers symptom perception in a multidisciplinary perspective. A presentation of current definitions and methods for studying symptom perception in asthma is followed by a summary of theories on the origin of breathlessness. Next, biomedical and psychological factors influencing symptom perception are examined. Preliminary biomedical research emphasizes neural pathway impairment, but causal factors remain inconclusive, particularly regarding the overperception of symptoms. Psychological studies suggest that the accuracy of symptom perception is influenced by (a) competition between asthmatic and nonasthmatic sensory information, (b) negative emotions, and (c) acquired response tendencies (e.g. habituation to symptoms, repression of symptoms, selective perception, and false interpretation of symptoms). These factors may favor either blunted perception or overperception. Empirical data in support of psychological factors are still insufficient. Methodological problems and procedures to improve symptom perception are discussed.

Journal Article↗

PubMed1999

Children's perceptions of parental drinking: the eye of the beholder.

OBJECTIVE: Children learn about alcohol and about how to drink through modeling experience, in part. Modeling is typically studied by asking parents to describe their drinking behavior. However, children's perception of parents' drinking may differ from the way parents describe it. This study examined the degree to which children's perceptions and parents' reports agreed. METHOD: A sample of 177 grade-school children and their parents was drawn from a public school in Kentucky. Children completed questionnaires inquiring about their perceptions of the quantity, frequency and the positive and negative consequences of their parents' drinking. Their parents completed similar questionnaires describing their own drinking and its consequences. RESULTS: As hypothesized, first and second grade children's perceptions of parents' drinking were unrelated to parents' self-reports: Most of these children perceived their parents as nondrinkers even though parents reported drinking. Also as hypothesized, children's perceptions and parents' reports were significantly correlated for third through sixth grade students. However, there was a great deal of reliable, but unshared variance between these older children's perceptions and parents' reports. Children's perceptions and parents' reports were consistently quite different, even when both child and parent described the parent as a drinker. CONCLUSIONS: Studies of modeling influences on children regarding drinking should assess children's perceptions of their parents' behavior rather than parents' self-reports.

Age Factors↗

PubMed2004

Intergroup conflict management strategies as related to perceptions of dual identity and separate groups.

The authors examined the relations between (a) the perceptions of dual identity and separate groups and (b) intergroup conflict management strategies, in two contexts: the conflict between the secular and religious sectors in Israel and the allocation of resources among organizational subunits. In both contexts, contention (i.e., forcing one's will on the other party) was associated with the perception of separate groups. Only in the organizational context, avoidance (i.e., doing nothing or discontinuing participation in the conflict) was associated with the perception of dual identity. Problem solving (i.e., finding a solution that is acceptable to both parties) was related to the perception of dual identity in the secular-religious context. In the organizational context, this relation appeared only under a low perception of separate groups. Yielding (i.e., satisfying the other party's needs at the expense of one's own) was related to the perception of dual identity in the organizational context. In the secular-religious context, this relation appeared only under a high perception of separate groups. The authors discussed the varying pattern of the associations between (a) the perceptions of dual identity and separate groups and (b) the conflict management strategies in the two contexts in terms of the Dual Concern Model and the perceived feasibility of the strategies.

Adult↗

PubMed2002

Affective percept and voluntary action: a hypothesis.

I present a hypothesis concerning the neuronal, mental and behavioral effects of all kinds of affective (emotional) stimuli, i.e., of unpleasant and pleasant stimuli. I use the term stimulus in its broad sense. Affective stimuli evoke two associated percepts: "cognitive" and "affective". A food in the mouth, for example, evokes the gustatory percept and the percept of pleasure. However, affective percepts are unstable parts of cognitive-affective compounds. Five types of affective percepts are pain, fear, pleasure, "desire" and appetite in the broad sense of these words. Desire is evoked by inadequate pleasant stimuli. Affective percepts are "lower" or "higher". The latter are not directly associated with bodily needs. Esthetic and social percepts are higher, for example. Although pain and pleasure are essentially innate, they can be modified by sensory experience. Alimentary and esthetic preferences and social values are modifiable, for example. The neurons of pain and fear and of the unpleasant components of desire and appetite motivate four types of voluntary actions. These are, respectively, escape, avoidance, "optimization" and approach actions. All these actions eliminate the motivating displeasure. In addition, avoidance actions protect from the signaled pain, optimization actions increase the existing pleasure and approach actions provide the signaled pleasure. Thus, voluntary actions associated with different percepts occur according to one universal principle. Voluntary actions are "internal" and behavioral. During internal actions a goal and then an action plan are decided. These actions often provide the images of the goal stimuli and of particular movements.

Affect↗

PubMed1992

Strengthening physical self-perceptions through exercise.

Two studies examined the effects of physical activity/exercise on physical self-perceptions, self-efficacy, body satisfaction, fitness and relationships among these variables. In study 1, 34 female undergraduates participated in a 10-week exercise/activity program. Participants were selected from existing classes forming a weight training, aerobic exercise and activity control group. Results revealed changes in physical self-perceptions, strength, and body composition over the 10-weeks. Improvements in physical self-perceptions and fitness occurred independent of exercise/activity group. Groups differed in the perceived importance attached to physical self-perceptions. Correlations among the measures revealed relationships among physical self-perceptions, body satisfaction, global self-esteem, and fitness. In study 2, we hypothesized that weight training would have a greater effect on physical self-perceptions and body image perceptions than physical education activity classes. Thirty-seven males and 28 females were selected from existing classes forming a weight training and activity group. Results revealed no significant changes in physical self-perceptions, body image, or global self-esteem over the 10-week program, while strength and physical self-efficacy improved. Correlations among measures from both studies offer preliminary support for Sonstroem and Morgan's model for the examination of self-esteem in exercise settings.

Adolescent↗

PubMedDate not supplied

Predicting change in physical activity, dietary restraint, and physique anxiety in adolescent girls: examining covariance in physical self-perceptions.

OBJECTIVES: To examine: i) the mean changes in adolescent females' body mass index (BMI), global self-esteem, physical self-perceptions, social physique anxiety, physical activity, and dietary restraint; ii) the stability of measuring self-perceptions, BMI, self-esteem, physique anxiety, activity, and dietary restraint; and iii) the relationships among changes in these variables over 12 months. METHODS: 631 female adolescents (15-16 years old) involved in a two-year study of self-report measures completed validated questionnaires in high school classroom settings. RESULTS: There were small but significant group increases in BMI and social physique anxiety and significant decreases in sport, conditioning, and strength physical self-perceptions and physical activity. Stability analysis indicates moderate to strong stability for all variables. Change analyses indicated that BMI, due to its high stability, is a poor predictor of change in all variables. Stronger significant correlations were noted between change in body appearance self-perceptions and change in social physique anxiety (r=-0.54) and dietary restraint (r=-0.27). There was also a significant relationship between change in physical activity and the physical self-perceptions, although conditioning was the only significant (p<0.05) predictor of change in physical activity (beta=0.340). INTERPRETATION: Physical self-perceptions are a stronger predictor of change in physical activity, dietary restraint, and social physique anxiety compared to BMI. This demonstrates the importance of physical self-perceptions when investigating health-related behaviours associated with dieting and physical activity. The decline in physical activity and increase in BMI is an ongoing concern, as is the link between body appearance self-perceptions and dietary restraint and social physique anxiety.

Adolescent↗

PubMedDate not supplied

Pain perception and fibromyalgia.

INTRODUCTION: Although psychological factors and self-regulation processes rarely cause pain they have enough importance to exacerbate pain and contribute to its maintenance. Nevertheless, pain perception and associated beliefs can influence its confrontation and the sensation of intensity. Pain perception in fibromyalgia acquires special relevance due to an abnormal sensitivity to digital pressure on the so-called "tender points". This constitutes the main factor for its differential diagnosis. METHOD: The aim of the present study is to determine differences in pain perception and associated beliefs that appear between a group of patients with fibromyalgia (n = 36), a control group with chronic pain with objectified non-inflammatory locomotion apparatus pathology (n = 44) and a control group with healthy subjects (n = 31). Pain perception and beliefs concerning pain were assessed using Spanish versions of the following self-reports: West Haven Yale Multidimensional Questionnaire (WHYWP) and Pain Perceptions and Beliefs Inventory (PBAPI). RESULTS: Results show that the difference between patients with chronic pain is not related to pain global perception, but rather to greater perception of pain as more incapacitating when carrying out every day activities in fibromyalgic patients. In this sense, these people use escape-avoidance strategies in their every day lives believing that pain incapacitates them and therefore that physical activity should be avoided. CONCLUSIONS: Measurement of pain perceptions and beliefs could be considered relevant for assessment and for intervention programs on pathologies associated with chronic pain.

Adult↗

PubMed1996

Variation in nutrient intake with dental status, age and odour perception.

OBJECTIVES: Since the proportion of elderly people with an insufficient intake of nutrients is high and many of the elderly have poor odour perception or poor dental state, in this study, the relation between age, odour perception, dental state and nutrient intake is explored. DESIGN: Single centre cross sectional study. SETTING: Independently living elderly were tested at their homes in 4 locations in Belgium, ranging in ages 60-90 y. SUBJECTS: 200 elderly participated in a 7 d food record study, resulting in 119 complete records. INTERVENTIONS: Food quantities were converted to nutrient intake levels. For all people, odour detection threshold was determined of isoamylacetate and dental status was noted. Path analysis was used and the separate effects of age, dental state, odour perception and gender were tested on macronutrient intake and micronutrient intake respectively. MAIN OUTCOME MEASURES: For all nutrients, no significant correlation was observed between nutrient intake and odour perception, except for energy, water, Fe and niacin (P < 0.05). A significant separate effect of odour perception was observed for water intake (CR = 2.09). Significant separate effects of dental state were observed for animal protein (CR = 2.29), niacine (CR = 2.04) and mono-unsaturated fats (CR = 2.32). CONCLUSIONS: Although odour perception and dental state can not fully explain variability in nutrient intake, our results show that people with poor odour perception have lower nutrient intake levels than people with good odour perception. Dental state may not be a direct cause of poor nutrition but a contribution factor in those elderly who have other risk factors.

Aged↗

PubMed1995

Assessment of heat pain perception in relation to vibration exposure.

The effect of vibration on thin unmyelinated sensory fibers was studied by perception threshold measurement of heat pain. The investigation was a cross-sectional study of 98 vibration-exposed and 53 non-vibration-exposed workers. Pain perception was determined by using the "Marstock" method. The perception threshold of contact heat induced pain was assessed by the method of limits. Quantified personal energy-equivalent vibration exposure was assessed for all subjects on a group basis. The cumulated lifetime equivalent frequency-weighted vibration exposure was estimated based on measurements according to ISO 5349. The mean heat perception threshold was 46.2 degrees C (SD 2.6 degrees C) for the right hand and 46.0 degrees C (SD 2.7 degrees C) for the left. The results showed no mean difference (left = 0.1 degree C, right = 0.6 degree C) in heat pain perception between vibration-exposed and non-exposed subjects. There was a high correlation between the right and left hand measurements (r = 0.81). The risk (rate ratio) for impairment was 1.02 (95% CI 0.81-1.30) for the right hand and 1.00 (95% CI 0.79-1.26) for the left. The results of the study did not indicate any impairment as assessed by an increased perception threshold for heat pain. The lack of an increased heat pain threshold among the vibration-exposed workers in our study cannot exclude a possible lesional somatosensory influence from the exposure, as the lesional effect may also be a lowering of the threshold. The multiple and unrelated percepts of thermal sensations imply that it is not legitimate to draw conclusions about the total status of the small calibre afferents when testing only the heat pain perception.

Adult↗

PubMed1996

Visual hallucinosis: the major clinical determinant of distorted chromatic contour perception in Parkinson's disease.

Recently distorted chromatic contour perception has been demonstrated in Parkinson's disease (PD). The aim of our study is to determine the clinical factors which influence chromatic contour perception in PD. Chromatic and achromatic contour perception, colour discrimination and clinical data were evaluated in 73 patients with PD. We used a computer-aided method to determine the chromatic fusion time (CFT) which indicates the acuity of monochromatic contour perception. Chromatic CFT was generally shortened in patients as compared to controls (p < 0.01), whereas achromatic CFT was not significantly different. Variance analysis revealed the ability of colour discrimination and the risk of visual hallucinations as statistically significant (p < 0.05) variables influencing contour perception of certain stimuli. In contrast, disease stage, disease duration and disease severity have no relevant effect on chromatic contour perception in Parkinson's disease. On the basis of those properties one may suggest that distorted chromatic contour perception is due to an impairment at a central stage of visual processing in PD and an imbalance of the serotonergic system. Whether CFT is a reliable method to predict the individual risk of hallucinosis in PD has to be evaluated.

Aged↗

PubMed2003

Experience-dependent visual cue recalibration based on discrepancies between visual and haptic percepts.

We studied the hypothesis that observers can recalibrate their visual percepts when visual and haptic (touch) cues are discordant and the haptic information is judged to be reliable. Using a novel visuo-haptic virtual reality environment, we conducted a set of experiments in which subjects interacted with scenes consisting of two fronto-parallel surfaces. Subjects judged the distance between the two surfaces based on two perceptual cues: a visual stereo cue obtained when viewing the scene binocularly and a haptic cue obtained when subjects grasped the two surfaces between their thumb and index fingers. Visual and haptic cues regarding the scene were manipulated independently so that they could either be consistent or inconsistent. Experiment 1 explored the effect of visuo-haptic inconsistencies on depth-from-stereo estimates. Our findings suggest that when stereo and haptic cues are inconsistent, subjects recalibrate their interpretations of the visual stereo cue so that depth-from-stereo percepts are in greater agreement with depth-from-haptic percepts. In Experiment 2 the visuo-haptic discrepancy took a different form when the two surfaces were near the subject than when they were far from the subject. The results indicate that subjects recalibrated their interpretations of the stereo cue in a context-sensitive manner that depended on viewing distance, thereby making them more consistent with depth-from-haptic estimates at all viewing distances. Together these findings suggest that observers' visual and haptic percepts are tightly coupled in the sense that haptic percepts provide a standard to which visual percepts can be recalibrated when the visual percepts are deemed to be erroneous.

Adolescent↗

PubMed1998

Perception of emotion and neurocognitive functioning in schizophrenia: what's the link?

In schizophrenia, relatively little is known about the association between deficits in emotion perception and basic neurocognitive functioning. The present study examined perception of emotion and a discrete set of neurocognitive functions in 28 treatment-resistant schizophrenic patients. Measures of emotion perception included a facial emotion identification test (still photographs presented on videotape), a voice emotion identification test (audiotape), and an affect perception test (brief interpersonal vignettes presented on videotape). Measures of neurocognitive functioning were selected based on hypothesized relationships to perception of emotion. These measures included: (a) Span of Apprehension task, a measure of early visual processing, visual scanning, and iconic read-out; (b) Degraded-Stimulus Continuous Performance Test, a measure of visual vigilance; and (c) Digit Span Distractibility Test, a measure of immediate or working memory. Among these measures, performance on the Span of Apprehension strongly correlated with performance on all three emotion perception tasks. The associations between perception of emotion and the other two measures were in the same direction, but were significantly smaller than those of the Span of Apprehension. These findings implicate the importance of early perceptual processing (i.e. visual scanning) in the ability of schizophrenic individuals to perceive emotion.

Adult↗

PubMed2005

Imaging implicit perception: promise and pitfalls.

The study of implicit perception - perception in the absence of awareness - has a long history. Decades of behavioural work have identified crucial theoretical and methodological issues that must be considered when evaluating claims of implicit perception. Neuroimaging methods provide an important new avenue for illuminating our understanding of perception both with and without awareness, but most imaging experiments have not met the rigorous conditions that the behavioural work has shown are necessary for inferring implicit perception. Here, we review the literature of both behavioural and neuroimaging studies, and note the pitfalls of studying implicit perception as well as the promise that neuroimaging studies have for providing insights about implicit perception when combined with appropriately rigorous behavioural measures of awareness.

Animals↗

PubMed2007

Hearing lips and seeing voices: how cortical areas supporting speech production mediate audiovisual speech perception.

Observing a speaker's mouth profoundly influences speech perception. For example, listeners perceive an "illusory" "ta" when the video of a face producing /ka/ is dubbed onto an audio /pa/. Here, we show how cortical areas supporting speech production mediate this illusory percept and audiovisual (AV) speech perception more generally. Specifically, cortical activity during AV speech perception occurs in many of the same areas that are active during speech production. We find that different perceptions of the same syllable and the perception of different syllables are associated with different distributions of activity in frontal motor areas involved in speech production. Activity patterns in these frontal motor areas resulting from the illusory "ta" percept are more similar to the activity patterns evoked by AV(/ta/) than they are to patterns evoked by AV(/pa/) or AV(/ka/). In contrast to the activity in frontal motor areas, stimulus-evoked activity for the illusory "ta" in auditory and somatosensory areas and visual areas initially resembles activity evoked by AV(/pa/) and AV(/ka/), respectively. Ultimately, though, activity in these regions comes to resemble activity evoked by AV(/ta/). Together, these results suggest that AV speech elicits in the listener a motor plan for the production of the phoneme that the speaker might have been attempting to produce, and that feedback in the form of efference copy from the motor system ultimately influences the phonetic interpretation.

Auditory Perception↗

PubMed1998

Modulation of gut perception in humans by spatial summation phenomena.

1. We have recently shown that perception of intestinal stimuli increases by spatial summation phenomena. Our aim was to determine in humans whether intestinal perception depends on (a) the length of gut stimulated, and (b) the distance between stimuli. 2. In a first series of studies, we compared perception of isobaric intestinal distensions applied over a 3 cm segment and a 36 cm segment by means of two separate barostats (n = 8). In a second series of studies we compared perception of intestinal distensions applied simultaneously by two balloons sited 3, 12 or 48 cm apart (n = 6). 3. Distension of the 36 cm segment induced significantly greater perception than distension of the 3 cm intestinal segment (discomfort perceived at 20 +/- 2 mmHg and 31 +/- 2 mmHg, respectively; P < 0.05). Perception of intestinal balloon distension increased when a second stimulus was simultaneously applied, independently of the distance between the two balloons (the discomfort thresholds were 30 +/- 11, 20 +/- 6 and 28 +/- 7% lower with simultaneous distensions 3, 12 and 48 cm apart, respectively). 4. We conclude that perception of intestinal distension is determined by the extension of the field of stimulation, and the summation effect is similar whether adjacent or distant fields are stimulated.

Adult↗

PubMed1990

A new version of duplex perception: evidence for phonetic and nonphonetic fusion.

In a series of experiments, a variant of duplex perception was investigated. In its original form, duplex perception is created by presenting an isolated transition to one ear and the remainder of the syllable, the standard base, to the other ear. Listeners hear a chirp at the ear receiving the isolated transition, and a full syllable at the ear receiving the base. The new version of duplex perception was created by presenting a third-formant transition in isolation to one ear and the same transition electronically mixed with the base to the other ear; the modified base now has all the information necessary for syllabic perception. With the new procedure, listeners reported hearing a chirp centered in the middle of their head and a syllable in the ear presented the modified base that was clearer than that produced by the isolated transition and standard base. They could also reliably choose the patterns that contained the additional transition in the base when attending to either the phonetic or nonphonetic sides of the duplex percept. In addition, when the fundamental frequency, onset time, and intensity of the isolated third-formant transition were varied relative to the base, the phonetic and nonphonetic (lateralization) percepts were differentially affected, although not always reliably. In general, nonphonetic fusion was more affected by large differences in these variables than was phonetic fusion. However, when two isolated third-formant transitions were presented dichotically, fusion and the resulting central location of the chirp failed markedly with relatively small differences in each variable. The results were discussed in terms of the role of fusion in the new version of duplex perception and the nature of the information that undergoes both phonetic and nonphonetic fusion.

Adult↗

PubMed1993

The interaction of luminance, velocity, and shape information in the perception of motion transparency, coherence, and non-rigid motion.

The perception of luminance transparency for superimposed patterns depends on how luminance, figural, and topological conditions are simultaneously satisfied. Motion transparency or coherence for two superimposed patterns, which correspond to the perception of both patterns moving across one another or to the perception of compound motion of the regions of pattern intersection, depends on the relation between the local velocity, luminance, and shape information. This study analyzes how luminance, shape, and local velocity interact in the perception of motion transparency and coherence. Psychophysical experiments done with sinusoidally modulated bar patterns are presented which show that the perception of motion transparency or coherence can be described as the result of the interaction of two integration modules: the velocity-luminance and the velocity-shape processes. The velocity-luminance process describes the integration of the local velocity with luminance information. When the luminance transparency rules are satisfied this process always generates the perception of motion transparency independently of the shape or contour information. On the other hand, when the luminance transparency rules are violated one can either perceive motion coherence or non-rigid motion; one perceives motion coherence when the patterns have small or zero amplitude, and non-rigid motion when the patterns have large amplitude. The velocity-shape process describes the integration of local velocity with shape information, and this depends on the relation between the error in the extraction of the local velocity and the magnitude of the contour amplitude. As a result of these experiments it is conjectured that the velocity-luminance and the velocity-shape processes do interact constructively or destructively. The constructive interaction occurs when the luminance transparency rules are satisfied. The destructive interaction occurs when the luminance transparency rules are violated, and such that, although the patterns contain sufficient shape information to solve the aperture problem and therefore generate the perception of motion transparency, one perceives non-rigid motion. This shows that global information describing the stratification of superimposed patterns can affect the integration of local velocity information with, for example, shape information, and this is not described by current motion theories.

Form Perception↗

PubMedDate not supplied

[Neural codes for perception].

OBJECTIVE: This article describes experiments designed to show the neural codes associated with the perception and processing of tactile information. DEVELOPMENT: The results of these experiments have shown the neural activity correlated with tactile perception. The neurones of the primary somatosensory cortex (S1) represent the physical attributes of tactile perception. We found that these representations correlated with tactile perception. By means of intracortical microstimulation we demonstrated the causal relationship between S1 activity and tactile perception. In the motor areas of the frontal lobe is to be found the connection between sensorial and motor representation whilst decisions are being taken. CONCLUSIONS: S1 generates neural representations of the somatosensory stimuli which seen to be sufficient for tactile perception. These neural representations are subsequently processed by central areas to S1 and seem useful in perception, memory and decision making.

Brain↗