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PubMed1988

Perception and production of the final /s-ts/ contrast in Dutch by misarticulating children.

This study investigates the specific relationship between speech perception and speech production by comparing 6- and 7-year-old children who misarticulated the final consonant cluster /-ts/ with three control groups. One control group of children misarticulated other phonemes than the specific /-ts/ cluster, another group of children had no articulation problems at all, and a third control group consisted of normally articulating adults. Perception was studied by assessing identification functions on a /moes/-to-/moets/ speech continuum in which the silence period had been manipulated. Production was analyzed by measuring the silence periods in productions of the Dutch word muts. The results show a clear hierarchical trend: The poorer the articulation proficiency of a group, the more variability there is in both production and perception. In perception, this variability is not restricted to the problematic /-ts/ cluster but includes the whole /-s/-to-/-ts/ contrast. Furthermore, it appears that a general as well as a specific relationship exists between perception and production and that the character of this relationship does not support the motor theory of speech perception.

Adult↗

PubMed1986

Speech cue enhancement for the hearing impaired: I. Altered vowel durations for perception of final fricative voicing.

Hearing-impaired persons with reduced voicing perception for final fricatives were studied for improvement in perception via training or enhancement of the vowel duration cue. Ten utterances each of the syllables /baef, baes, baev, baez/ composed three stimulus sets that were graded for the magnitude of the vowel duration cue. These sets were used differentially among 25 hearing-impaired listeners to train and test voicing perception. When enhanced, the vowels of the utterances were lengthened before voiced fricatives and shortened before voiceless fricatives. Training for the utterances with unmodified vowels yielded a small performance improvement for a subgroup of 14 listeners. In comparison, this subgroup showed considerably more improvement for the utterances with vowel duration enhancements. Another subgroup of 5 listeners displayed good fricative voicing perception independent of training or the vowel duration enhancements. A remaining subgroup of 6 listeners manifested poor use of the maximum unmodified vowel duration cues, even subsequent to training. This group showed a significant improvement in perception only for the voiced fricatives when extra duration enhancement and further training were used. This subgroup also demonstrated the poorest performance for a measure of vowel duration discrimination. Among the auditory variables examined, the listeners' tone thresholds at 250 Hz showed the highest relation to perception of fricative voicing.

Auditory Threshold↗

PubMed2000

The interplay between social and cultural context and perceptions of cardiovascular disease.

This paper seeks to explore the impact of social and cultural factors upon perceptions of the patients' cardiovascular risk and intended lifestyle changes. Qualitative and quantitative research approaches were used. The sample was purposeful; matched groups of 10 first time post myocardial infarction (MI) patients, 10 informal (spouse, blood relative or partner) and 10 formal carers (nursing staff) were selected on a convenience basis. Personal interviews were conducted with participants, during which a semistructured questionnaire was completed. A combination of descriptive statistics and qualitative analysis of these data revealed that social and cultural factors formed the basis of patients' and informal carers' perceptions of cardiovascular risks and social information networks provided the main source of information about cardiovascular risk. For the staff, known risk factors based on epidemiological evidence (lack of exercise and diet) formed the basis of their perceptions of the patients' cardiovascular risk factors. However, for all the participant groups (i.e. patients, informal carers and staff) the risk factors - diet and exercise were indicated as being the patients' intended lifestyle changes., The results illustrate potential interplay between 'social' and 'cultural' context and perceptions of cardiovascular risk and incongruency between perceptions of risk and perceptions of the patients' intended lifestyle change. These results may assist nurses in giving effective advice to patients and relatives about lifestyle change following myocardial infarction and inform future policy for cardiac rehabilitation.

Adult↗

PubMed2001

Pitch perception shift: a rare side-effect of carbamazepine.

Carbamazepine-induced pitch perception shifts have rarely been described. Two cases of shifted pitch perception developing during medication with carbamazepine are described. Case 1 possessed absolute pitch. Her pitch perception shift disappeared with the discontinuance of carbamazepine. Case 2 did not have absolute pitch. Even though he experienced a pitch perception shift, he developed a tolerance to the shift. We concluded that carbamazepine was the cause of the pitch perception shift in the first case, while the second case probably became attuned to the change in pitch perception because he did not possess absolute pitch.

Adolescent↗

PubMed2002

Relationship between the perception of dyspnoea and airway inflammatory markers.

Poor dyspnoea perception in asthmatic patients seems to be associated with increased risk of asthma exacerbation. We have studied the relationship between basel ne dyspnoea perception and inflammatory markers in sputum in eight patients with mild asthma and in 13 patients with moderate to severe asthma. The perception of dyspnoea was scored on the Borg scale. Eosinophilic cationic protein (ECP) was measured by fluoroimmunoassay and by an interleukin (IL)-5 sandwich ELISA. The baseline Borg score was significantly higher in patients with severe asthma than in patients with mild to moderate asthma (4.1 +/- 0.29 vs. 2.28 +/- 0.28, P<0.05). The proportion of eosinophil and ECP levels in the sputum were significantly higher in patients with moderate to severe asthma. IL-5 in sputum was significantly increased in moderate to severe asthmatic patients compared to mild asthmatic patients. A significant relationship was found between the baseline perception score and FEV1/FVC (r = -0.53, P<0.01), sputum eosinophils (r = 0.70, P<0.01) and sputum ECP (r = 0.62, P<0.01). These findings suggest that the baseline perception score is related to inflammatory markers in sputum, and that the perception of dyspnoea as well as airway inflammatory markers may be considered to evaluate asthma severity.

Acute Disease↗

PubMed1997

Consciousness of perception after brain damage.

Disturbances of visual perception after brain damage provide clues to understanding consciousness and the brain. In this article we review six visual disorders in which perception and consciousness are dissociated as a result of brain damage: blindsight, implicit shape perception in apperceptive visual agnosia, covert recognition of faces in prosopagnosia, unconscious perception in neglect and extinction, implicit reading in pure alexia, and implicit object recognition in associative visual agnosia. We consider these six disorders from the standpoint of three main schools of thought concerning consciousness and the brain, namely a localized system for consciousness, consciousness as a state of integration, and consciousness as a property of graded representation. The findings suggest that these syndromes do not share a single mechanism and that it is conceivable that more than one explanation will be necessary both within and across syndromes. We conclude on the basis of the current evidence that it is unlikely that any single brain system is necessary for conscious awareness of perception that does not play a role in perception as well.

Agnosia↗

PubMed1993

Barber-pole illusions and plaids: the influence of aperture shape on motion perception.

The barber-pole illusion and its influence on plaid perception were investigated in two experiments to test the following expectations: (i) apertures which bias the perception of grating motion in directions consistent with plaid direction will facilitate plaid perception, and (ii) apertures which bias the perception of grating motion in directions inconsistent with plaid direction will disrupt plaid perception. In experiment 1 the barber-pole illusion was measured as a function of grating orientation (20 degrees, 45 degrees, and 70 degrees, clockwise and counterclockwise from horizontal), and aperture shape (vertical, horizontal; at each of three elongations). Barber-pole illusions reported with 45 degrees gratings increased with increased aperture elongation. However, this was not found with 20 degrees and 70 degrees gratings; these were almost always reported as moving in a direction parallel to the side of the aperture with which the gratings formed angles approaching 90 degrees. In experiment 2 this dependence of barber-pole illusions on the relative orientation between gratings and apertures was also evident with 45 degrees gratings in oblique apertures; only oblique directions of grating motion were reported. The influence of the same apertures on the separate contrast thresholds required for initial plaid coherence and initial plaid decomposition was measured. In experiments 1 and 2, coherence thresholds were unaffected by apertures, contrary to expectation (i). However, in both experiments expectation (ii) was confirmed; decomposition thresholds decreased in apertures which biased perceived direction of gratings towards vertical (plaid direction), and increased in apertures which biased grating motion away from vertical. Adaptation of plaid mechanisms during measurement of decomposition thresholds was proposed to explain the discrepancy between coherence and decomposition data. Taken together, the results were interpreted as reflecting interactions between mechanisms mediating the barber-pole illusion and mechanisms mediating plaid perception.

Humans↗

PubMed1998

Attentional modulation in perception of visual motion events.

Identical visual targets moving across each other with equal and constant speed can be perceived either to bounce off or to stream through each other. This bistable motion perception has been studied mostly in the context of motion integration. Since the perception of most ambiguous motion is affected by attention, there is the possibility of attentional modulation occurring in this case as well. We investigated whether distraction of attention from the moving targets would alter the relative frequency of each percept. During the observation of the streaming/bouncing motion event in the peripheral visual field, visual attention was disrupted by an abrupt presentation of a visual distractor at various timings and locations (experiment 1; exogenous distraction of attention) or by the demand of an additional discrimination task (experiments 2 and 3; endogenous distraction of attention). Both types of distractions of attention increased the frequency of the bouncing percept and decreased that of the streaming percept. These results suggest that attention may facilitate the perception of object motion as continuing in the same direction as in the past.

Attention↗

PubMed2002

Understanding Dali's Slave market with the disappearing bust of Voltaire: a case study in the scale information driving perception.

A generic problem in vision is to know which information drives the perception of a stimulus. We address this problem in a case study that involves the perceptual reversal of an ambiguous image (here, Dali's painting the Slave Market with the Disappearing Bust of Voltaire 1940). In experiment 1, we use 'bubbles' (Gosselin and Schyns, 2001 Vision Research 41 2261-2271) to disambiguate the image and to determine the specific visual information that drives each possible perception (here, the nuns versus the bust of Voltaire). Experiment 2 validates that this information does determine the selective perception of the ambiguous image. We adapted the spatial-frequency channels of observers selectively to the information that mediates one of the two perceptions, to induce the opposite perception of the ambiguous image in a transfer phase. Together, the results suggest a method of revealing the visual information that drives perception.

Art↗

PubMed2006

Perceiving causality after the fact: postdiction in the temporal dynamics of causal perception.

In simple dynamic events we can easily perceive not only motion, but also higher-level properties such as causality, as when we see one object collide with another. Several researchers have suggested that such causal perception is an automatic and stimulus-driven process, sensitive only to particular sorts of visual information, and a major research project has been to uncover the nature of these visual cues. Here, rather than investigating what information affects causal perception, we instead explore the temporal dynamics of when certain types of information are used. Surprisingly, we find that certain visual events can determine whether we perceive a collision in an ambiguous situation even when those events occur after the moment of potential 'impact' in the putative collision has already passed. This illustrates a type of postdictive perception: our conscious perception of the world is not an instantaneous moment-by-moment construction, but rather is formed by integrating information presented within short temporal windows, so that new information which is obtained can influence the immediate past in our conscious awareness. Such effects have been previously demonstrated for low-level motion phenomena, but the present results demonstrate that postdictive processes can influence higher-level event perception. These findings help to characterize not only the 'rules' of causal perception, but also the temporal dynamics of how and when those rules operate.

Causality↗

PubMed2000

Cortical networks subserving the perception of tinnitus--a PET study.

Subjective tinnitus is an auditory phantom perception that may arise from any aberrant signal within the auditory system. Further processing of this signal and the conscious perception of tinnitus takes place in the cerebral cortex. A few functional brain-imaging studies have been performed to elucidate the underlying cerebral mechanisms of this perception. These studies mostly concern rare types of tinnitus (e.g. tinnitus changeable by oral-facial movements), or compared tinnitus patients with healthy volunteers. These studies attributed variable activation of the primary auditory cortices, associative auditory cortices and the left hippocampus to the perception of tinnitus. Based on these heterogeneous results, no consensus on the underlying mechanisms has been reached. The aim of the present study was to obtain further details of the central perception and processing of the tinnitus signal. Positron emission tomography (PET) was used to map the tinnitus-specific central activity. By contrasting PET-images of suppressed tinnitus with PET-images of the habitual tinnitus sensation, we were able to identify a right prefrontal-temporal network associated with the perception of tinnitus. Besides the evidence of activation of associative auditory sensory regions, the results indicated that activation of cortical centres subserving attention and emotion may underlie the continuous irritability associated with severe tinnitus.

Adult↗

PubMed2004

Effects of limiting the number of active electrodes on Mandarin tone perception in young children using cochlear implants.

OBJECTIVE: To evaluate the short-term effects of varying the number and location of programmed electrodes on Mandarin tone perception in young children using Nucleus CI 24 implants. MATERIAL AND METHODS: Six children using CI 24 implants participated in the study. The Mandarin tone recognition of each subject was assessed using a self-designed word list containing 80 words under 5 different map conditions. The map conditions were: (i) the subject's current map with all functional electrodes; (ii) removing (i.e. not programming) the even-numbered active electrodes; (iii) removing the five most apical electrodes; (iv) removing the six most basal electrodes; and (v) removing all electrodes except the six most apical. RESULTS: Reducing the number of active electrodes caused a small but significant decrease in performance of Mandarin tone perception. However, a relatively high tone perception score (58.1%) could be maintained even when subjects used only six apical electrodes. The location of the electrodes, i.e. apical or basal, did not appear to be important in tone perception. For each individual tone, the scores for tones 1 and 4 were significantly higher than those for tones 2 and 3 for all map conditions. Comparing tone perception with word recognition, reducing the number of active electrodes had a much more negative effect on word recognition. CONCLUSIONS: A small but significant decrease in Mandarin tone perception was observed when the number of active electrodes was reduced in children using CI 24 implants. The location of the electrode is not important in tone recognition. Moreover, tone recognition is far more resistant than word recognition to the negative effects of reducing the number of active programmable electrodes, possibly because it relies mostly on temporal envelopes while word recognition requires more spectral details.

Child↗

PubMed2000

Perceptions of dual identity and separate groups among secular and religious Israeli Jews.

The authors examined the effects of perceptions of dual identity and separate groups on tendencies to handle intergroup conflict through problem solving and contention. Among secular Israeli Jews, regression analyses revealed a significant interaction between perceptions of dual identity and perceptions of separate groups: Only under high perception of dual identity was the perception of separate groups associated with contention. Among religious Israeli Jews, problem solving and contention were unrelated to either dual identity or to perceptions of separate groups. The results are discussed in terms of the common ingroup identity model (S. L. Gaertner, M. C. Rust, J. F. Dovidio, B. A. Bachman, & P. A. Anastasio, 1994) and in the context of the conflict between religious and secular Jews in Israel.

Adult↗

PubMed1988

Perception of self and parents by second-generation Holocaust survivors.

This study's objectives were to test the emotional stability and self-perceptions of Holocaust survivors' offspring (HSO) and to investigate how HSO perceive their parents. It was assumed that the investigation of these two issues would broaden our understanding of the mediating processes through which the psychological burdens of the survivors might be transmitted to their descendants. Forty-seven subjects, all second-generation Holocaust survivors, were compared with 46 control subjects on measures of emotional stability (anxiety and depressive moods) and measures of self-perception and perception of parents. The groups did not differ on the emotional stability and self-perception measures. However, it was found that the children of Holocaust survivors, compared with the control subjects, perceived their parents as more tense, but also as more attractive. The correlations between self-perception and perception of parents were lower in the HSO group than in the control group. These findings suggest that HSO seem to have developed unique coping mechanisms that enable them to deal with their parent's psychological burdens.

Adult↗

PubMed2006

Absolute and comparative risk perceptions as predictors of cancer worry: moderating effects of gender and psychological distress.

Risk perceptions for cancer measured on absolute scales (e.g., "What is the likelihood that you will get cancer?") and on comparative scales (e.g., "How does your risk compare with that of someone similar to you?") are independently associated with worry about cancer. We examined this finding in a large sample across several types of cancer, and explored whether these relationships are moderated by three clinically relevant variables-gender, levels of psychological distress, and cancer experience. Participants were respondents in a national survey who reported risk perceptions and worry regarding colon cancer (923 men, 1,532 women), breast cancer (2,154 women), and prostate cancer (860 men), and completed a validated measure of psychological distress. Analyses showed that absolute and comparative risk perceptions were independent predictors of worry across all cancer sites, but that absolute risk perceptions were significantly more predictive than comparative risk perceptions of worry for women (but not men). Among people who were more highly distressed, comparative risk perceptions were the only significant predictor of worry. Absolute risk and comparative risk were equally predictive of cancer worry among people who previously had been diagnosed with cancer. These findings imply that interventions highlighting the communication of comparative risk information may be differentially effective depending on the audience.

Adult↗

PubMed2004

Influence of age, sex, and education on the Visual Object and Space Perception Battery (VOSP) in a healthy normal elderly population.

The assessment of visual perception and cognition forms an important part of any general cognitive evaluation. We have studied the possible influence of age, sex, and education on a normal elderly Spanish population (90 healthy subjects) in performance in visual perception tasks. To evaluate visual perception and cognition, we have used the subjects performance with The Visual Object and Space Perception Battery (VOSP). The test consists of 8 subtests: 4 measure visual object perception (Incomplete Letters, Silhouettes, Object Decision, and Progressive Silhouettes) while the other 4 measure visual space perception (Dot Counting, Position Discrimination, Number Location, and Cube Analysis). The statistical procedures employed were either simple or multiple linear regression analyses (subtests with normal distribution) and Mann-Whitney tests, followed by ANOVA with Scheffe correction (subtests without normal distribution). Age and sex were found to be significant modifying factors in the Silhouettes, Object Decision, Progressive Silhouettes, Position Discrimination, and Cube Analysis subtests. Educational level was found to be a significant predictor of function for the Silhouettes and Object Decision subtests. The results of the sample were adjusted in line with the differences observed. Our study also offers preliminary normative data for the administration of the VOSP to an elderly Spanish population. The results are discussed and compared with similar studies performed in different cultural backgrounds.

Age Factors↗

PubMed2002

Variables influencing food perception reviewed for consumer-oriented product development.

Consumer wishes have to be translated into product characteristics to implement consumer-oriented product development. Before this step can be made, insight in food-related behavior and perception of consumers is necessary to make the right, useful, and successful translation. Food choice behavior and consumers' perception are studied in many disciplines. Models of food behavior and preferences therefore were studied from a multidisciplinary perspective. Nearly all models structure the determinants related to the person, the food, and the environment. Consequently, the overview of models was used as a basis to structure the variables influencing food perception into a model for consumer-oriented product development. To this new model, referred to as food perception model, other variables like time and place as part of consumption moment were added. These are important variables influencing consumers' perception, and therefore of increasing importance to consumer-oriented product development nowadays. In further research, the presented food perception model is used as a tool to implement successful consumer-oriented product development.

Choice Behavior↗

PubMed2004

Evaluation of SET--a new device for the measurement of pain perception in comparison to standard measures of diabetic neuropathy.

BACKGROUND: Early detection of sensory impairment and loss of protective pain sensation is of major importance for the prevention of neuropathic foot ulceration. The aim of our study was to evaluate a new handheld device (SET, a prototype developed by Dr. W. Henniges, Zülpich, Germany) for measurement of pain perception, in comparison with established methods for diagnosis of diabetic neuropathy. METHODS: Sixty-one patients with diabetes mellitus (13 type 1, 48 type 2; 42 men, 19 women; mean +/- SD age 61.6 +/- 11.6 years) received measurement of pain perception threshold using the new SET device and a measurement of light touch sensation, temperature sensation, and vibration sensation by the use of standard clinical devices. In addition, warm, cold, heat pain and vibration perception thresholds were determined by the use of a computer-based peltier thermode and a vibration stimulator (TSA 2001, Medoc, Ramat Yishai, Israel). RESULTS: Using the new SET device, patients with sensory impairment showed significantly elevated pain perception thresholds at the dorsum of the foot (P < 0.001), while only a trend towards higher measurements could be observed at the plantar aspect of the foot. A significant correlation could be observed between plantar and dorsal measuring sites (r = 0.78, P < 0.0001) and between both feet (r = 0.85, P < 0.0001). Compared with other qualities of sensory dysfunction, pain perception measurement with the SET device provided the highest sensitivity (pain = 0.82; vibration = 0.61; temperature = 0.42; light touch = 0.11). CONCLUSIONS: Measurement of pain perception threshold using the SET device is an easy and reliable method for identifying patients with impaired small nerve fiber function.

Cold Temperature↗