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PubMed2005

Perception of the voicing distinction in speech produced during simultaneous communication.

UNLABELLED: This study investigated the perception of voice onset time (VOT) in speech produced during simultaneous communication (SC). Four normally hearing, experienced sign language users were recorded under SC and speech alone (SA) conditions speaking stimulus words with voiced and voiceless initial consonants embedded in a sentence. Twelve hearing-impaired listeners participated, with three of them randomly assigned to audit the speech sample provided by each one of the four speakers under the SC and SA conditions. In addition, 24 normal hearing listeners were randomly assigned to audit the speech samples produced by the four speakers under the SC and SA conditions, three listeners in noise and three listeners in filtered listening conditions for each of the four speakers. Although results indicated longer sentence durations for SC than SA, results showed no difference in the perception of the voicing distinction for speech produced during SC versus speech produced during SA under either the noise or filtered listening condition, or any difference in perception for the hearing-impaired listeners. This conclusion is consistent with previous research indicating that temporal alterations produced by SC do not produce degradation of temporal or spectral cues in speech or disruption of the perception of specific English phoneme segments. LEARNING OUTCOMES: As a result of this activity, the participant will be able to: (1) describe simultaneous communication; (2) explain the role of simultaneous communication in communication with persons who are hearing-impaired; (3) discuss methods of measuring perception of voice onset time with hearing-impaired listeners and with hearing listeners under filtered and noise conditions; and (4) specify the ability of listeners to perceive the voicing distinction in speech produced during simultaneous communication.

Adult↗

PubMed2004

Allophonic mode of speech perception in dyslexia.

Perceptual discrimination between speech sounds belonging to different phoneme categories is better than that between sounds falling within the same category. This property, known as "categorical perception," is weaker in children affected by dyslexia. Categorical perception develops from the predispositions of newborns for discriminating all potential phoneme categories in the world's languages. Predispositions that are not relevant for phoneme perception in the ambient language are usually deactivated during early childhood. However, the current study shows that dyslexic children maintain a higher sensitivity to phonemic distinctions irrelevant in their linguistic environment. This suggests that dyslexic children use an allophonic mode of speech perception that, although without straightforward consequences for oral communication, has obvious implications for the acquisition of alphabetic writing. Allophonic perception specifically affects the mapping between graphemes and phonemes, contrary to other manifestations of dyslexia, and may be a core deficit.

Case-Control Studies↗

PubMed2004

The interaction of formant frequency and pitch in the perception of voice category and jaw opening in female singers.

This study represents a first step toward understanding the contribution formant frequency makes to the perception of female voice categories. The effects of formant frequency and pitch on the perception of voice category were examined by constructing a perceptual study that used two sets of synthetic stimuli at various pitches throughout the female singing range. The first set was designed to test the effects of systematically varying formants 1 through 4. The second set was designed to test the relative effects of lower frequency formants (F1 and F2) versus higher frequency formants (F3 and F4) through construction of mixed stimuli. Generally, as the frequencies of all four formants decreased, perception of soprano voice category decreased at all but the highest pitch, A5. However, perception of soprano voice category also increased as a function of pitch. Listeners appeared to need agreement between all four formants to perceive voice categories. When upper and lower formants are inconsistent in frequency, listeners were unable to judge voice category, but they could use the inconsistent patterns to form perceptions about degree of jaw opening.

Acoustics↗

PubMed2005

Multidimensional scaling of breathy voice quality: individual differences in perception.

Experiments on disordered voice quality with multidimensional scaling (MDS) have resulted in solutions with low R-square and have failed to show consistent dimensions across different listeners. These findings have been suggested to indicate large individual differences in the perception of voice quality. However, these inconsistencies may originate from several factors, including random stimulus selection, instructions that encourage listeners to respond to global difference in pairs of voices, and noisy perceptual data. This experiment used MDS techniques to study individual differences in perception of breathiness. The voices in the experiment were selected to have a relatively wide variation in breathiness but only minimal variation in roughness, strain, and fundamental frequency. Additionally, listeners were instructed specifically to rate similarities in breathiness rather than judging global differences in voices, and several judgments from each listener were averaged to minimize noise in the data. It was hypothesized that these modifications would result in an MDS solution that accounted for greater variance in perceptual data than previously shown. Results show that averaging multiple responses from each listener increased the R-square from 45% to approximately 75%. The poor R-square and large individual differences in voice quality perception observed in past research may have partly resulted from the experimental procedures in previous studies. These findings suggest that individual differences in the perception of voice quality are not as large as previously thought, and a model of voice quality perception for an "average" listener may be a good representation for the general population.

Adult↗

PubMed2006

Distinct mechanisms of form-from-motion perception in human extrastriate cortex.

The exquisite sensitivity of the human visual system to form-from-motion (FfM) cues is well documented. However, identifying the neural correlates of this sensitivity has proven difficult, particularly determining the respective contributions of different motion areas in extrastriate visual cortex. Here we measured visual FfM perception and more elementary visual motion (VM) perception in a group of 32 patients suffering from acute posterior brain damage, and performed MRI-based lesion analysis. Our results suggest that severe FfM perception deficits without an associated deficit of VM perception are due to damage to ventral occipito-temporal cortex (VOT), whereas associated deficits of FfM and VM perception are due to damage either in proximity to area MT+/V5 or an area including lateral occipital complex (LOC) and VOT. These data suggest the existence of at least three functionally and anatomically distinct regions in human visual cortex that process FfM signals.

Adult↗

PubMed2005

The effect of silence on tinnitus perception.

OBJECTIVE: The effect of sustained silence was studied on the emergence of tinnitus perception in 120 normal hearing young adult Caucasians and African Americans. STUDY DESIGN AND SETTING: After sitting in a sound booth for a period of 20 minutes, participants were asked to complete a questionnaire documenting whether they perceived sounds in the silent setting and descriptions of the sounds they heard. RESULTS: Tinnitus-like sounds were perceived in 64% of listeners overall. No significant differences in tinnitus perception were observed between males and females. However, there was a significant difference in tinnitus perception between Caucasian and African American subjects, with tinnitus sounds emerging in sustained silence less frequently in African American listeners. Tinnitus emerged quickly in a majority of subjects (less than 4 minutes) and African American subjects who perceived tinnitus heard a greater number of individual tinnitus-like sounds than did Caucasian subjects. Ring (57%), buzz (21%), pulse (22%), heartbeat (21%), and hum (14%) were the most common sounds heard, with ring being the most common overall tinnitus perception. CONCLUSIONS AND SIGNIFICANCE: Few investigators have documented at the emergence of tinnitus in normal hearing subjects. Results of the current study found significant differences in tinnitus perception between Caucasian and African American subjects, but found no significant differences when comparing males and female subjects. EBM RATING: C.

Adolescent↗

PubMed2005

Effects of anti-asthma therapy on dyspnea perception in acute asthma patients.

Blunted perception of dyspnea may predispose patients to fatal asthma attacks. To examine whether this impaired perception of dyspnea in patients with acute asthma could be corrected by anti-asthma therapy, the medical records of 104 consecutive asthma patients who had been hospitalized as a result of asthma attacks were analyzed retrospectively. During the course of treatment with conventional asthma medications, the forced expiratory volume in 1s (FEV1) and the Borg scale-based dyspnea perception scores during breathing through an inspiratory muscle trainer were measured at least twice. The baseline Borg score measured just before discharge was significantly lower than from that measured initially, regardless of improvement in FEV1. In contrast, the Borg score at the highest resistance (HR; 3.12+/-0.26 vs. 5.03+/-0.53; P<0.01) and the HR-induced DeltaBorg score (1.68+/-0.20 vs. 4.47+/-0.54, P<0.001) were increased significantly in the Poor Perceivers (Borg score 5 at HR and HR-induced DeltaBorg score 3). Patient age (r=0.363, P<0.001), blood eosinophil counts (r=-0.285, P<0.01), and serum total IgE levels (r=-0.213, P<0.05), but not FEV1, were significantly related to the effect of the treatment on the HR-induced DeltaBorg scores. These findings suggest that anti-asthma treatments decrease dyspnea even without a concomitant improvement in lung function and correct the impaired perception of inspiratory resistive load in acute asthma, and that age and allergy influence the effect of treatment on impaired perception.

Acute Disease↗

PubMed2005

Sensorimotor gating, orienting and social perception in schizophrenia.

Basic neurocognition and social cognition appear to influence the social impairments of persons with schizophrenia. This study examined relationships between two very basic automatic processes (i.e., sensorimotor gating and orienting) and social perception in schizophrenic patients. Thirty outpatients with schizophrenia completed psychophysiological measures of sensorimotor gating (prepulse inhibition, PPI), orienting (prepulse facilitation, PPF), and social perception (the Half Profile of Nonverbal Sensitivity, Half PONS). A median split was used to divide patients into poor and good gaters and poor and good orienters. Analyses revealed that patients with good PPI scored significantly higher on the Half PONS than patients with poor PPI. PPI showed a significant correlation (r=-0.54) with Half PONS performance, indicating that schizophrenia patients who were better able to gate out competing stimuli (i.e., less startle) were also better at detecting relevant social cues. Orienting (PPF) and social perception were not related. This study is the first to our knowledge to demonstrate an association between sensorimotor gating and social perception. The findings are consistent with other studies that have demonstrated relationships between basic neurocognition and social cognition. By showing a link between sensorimotor gating and social perception, this study supports social cognition's potential role as a mediator of the relationship between neurocognition and social functioning in schizophrenia.

Adult↗

PubMed2001

Dietetics professionals have a positive perception of professional development.

This study summarizes the perceptions towards the Professional Development Portfolio method of recertification and attitude towards professional development of dietetic professionals as measured in the national pilot study of the Portfolio. Portfolio compared to control respondents had greater awareness, and better understanding and knowledge of the Portfolio process after using the Portfolio guide. The perception that the Portfolio process will aid in maintaining competence did not differ between groups. The perception that self-reflection aided in determining career goals and confidence to conduct a learning needs assessment differed slightly between groups. Both groups had a positive attitude towards professional development and that continuing professional education (CPE) improved competence. All perceptions and attitudes were positive. The focus of CPE in foods, business, management, education, and research did affect the ability of dietetics professionals to find appropriate CPE. Rural and unemployed respondents had more difficulty finding appropriate CPE. The findings indicate that the Portfolio guide aides the dietetics professional using the Portfolio process and that the perception towards the Portfolio process is positive. Some dietetics professionals with different CPE focus had difficulty finding appropriate CPE, and this did not differ by control and Portfolio group. More innovative methods of CPE delivery may need to be considered for these practitioners.

Adult↗

PubMed2000

"Danger is lurking everywhere". the relation between anxiety and threat perception abnormalities in normal children.

The present study examined the relation between anxiety and depression and threat perception abnormalities. Children were exposed to stories describing social situations. Some of the stories were ambiguous (i.e., these stories contained information that could be interpreted as threatening) whereas other stories were non-threatening (i.e., these stories contained no obvious trace of threat). From children's responses to the stories, several threat perception indices were derived. Children's level of anxiety and depression were assessed by means of self-report questionnaires. Results indicated that high levels of anxiety were accompanied by a high frequency of threat perception, high ratings of threat, a high frequency of threatening interpretations, high levels of negative feelings and cognitions, and an early detection of threat. Interestingly, significant associations between anxiety and threat perception abnormalities were not only observed in response to ambiguous stories but also in relation to non-threatening scenarios. Furthermore, depression was also connected with threat perception distortions. Even when controlling for anxiety levels, depression remained significantly related to threat frequency, threat ratings, and threat thresholds.

Adolescent↗

PubMed2001

Perception without awareness: perspectives from cognitive psychology.

Four basic approaches that have been used to demonstrate perception without awareness are described. Each approach reflects one of two types of experimental logic and one of two possible methods for controlling awareness. The experimental logic has been either to demonstrate a dissociation between a measure of perception with awareness and a measure that is sensitive to perception without awareness or to demonstrate a qualitative difference between the consequences of perception with and without awareness. Awareness has been controlled either by manipulating the stimulus conditions or by instructing observers on how to distribute their attention. The experimental findings based on all four approaches lead to the same conclusion; namely, stimuli are perceived even when observers are unaware of the stimuli. This conclusion is supported by results of studies in which awareness has been assessed with either objective measures of forced-choice discriminations or measures based on verbalizations of subjective conscious experiences. Given this solid empirical support for the concept of perception without awareness, a direction for future research studies is to assess the functions of information perceived without awareness in determining what is perceived with awareness. The available evidence suggests that information perceived without awareness both biases what stimuli are perceived with awareness and influences how stimuli perceived with awareness are consciously experienced.

Attention↗

PubMed1999

Synchronous change and perception of object unity: evidence from adults and infants.

Adults and infants display a robust ability to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion (e.g. Kellman, P.J., Spelke, E.S., 1983. Perception of partly occluded objects in infancy. Cognitive Psychology 15, 483-524). Ecologically oriented accounts of this ability focus on the primary of motion in the perception of segregated objects, but Gestalt theory suggests a broader possibility: observers may perceive object unity by detecting patterns of synchronous change, of which common motion is a special case. We investigated this possibility with observations of adults and 4-month-old infants. Participants viewed a center-occluded object whose visible surfaces were either misaligned or aligned, stationary or moving, and unchanging or synchronously changing in color or brightness in various temporal patterns (e.g. flashing). Both alignment and common motion contributed to adults' perception of object unity, but synchronous color changes did not. For infants, motion was an important determinant of object unity, but other synchronous changes and edge alignment were not. When a stationary object with aligned edges underwent synchronous changes in color or brightness, infants showed high levels of attention to the object, but their perception of its unity appeared to be indeterminate. An inherent preference for fast over slow flash rates, and a novelty preference elicited by a change in rate, both indicated that infants detected the synchronous changes, although they failed to use them as information for object unity. These findings favor ecologically oriented accounts of object perception in which surface motion plays a privileged role.

Adult↗

PubMed2002

The relationship between visual perception and visual mental imagery: a reappraisal of the neuropsychological evidence.

Visual perception and visual mental imagery, the faculty whereby we can revisualise a visual item from memory, have often been regarded as cognitive functions subserved by common mechanisms. Thus, the leading cognitive model of visual mental imagery holds that visual perception and visual imagery share a number of mental operations, and rely upon common neural structures, including early visual cortices. In particular, a single visual buffer would be used "bottom-up" to display visual percepts and "top-down" to display internally generated images. The proposed neural substrate for this buffer consists of some cortical visual areas organised retinotopically, that is, the striate and extrastriate occipital areas. Empirical support for this model came from the report of brain-damaged patients showing an imagery deficit which parallels a perceptual impairment in the same cognitive domain. However, recent reports of patients showing double dissociations between perception and imagery abilities challenged the perception-imagery equivalence hypothesis from the functional point of view. From the anatomical point of view, the available evidence suggests that occipital damage is neither necessary nor sufficient to produce imagery deficits. On the other hand, extensive left temporal damage often accompanies imagery deficits for object form or colour. Thus, visual mental imagery abilities might require the integrity of brain areas related to vision, but at an higher level of integration than previously proposed.

Brain Damage, Chronic↗

PubMedDate not supplied

[Psychometric characteristics of questionnaires designed to assess the knowledge, perceptions and practices of health care professionals with regards to alcoholic patients].

UNLABELLED: Failure of the French health care services to diagnose and manage problem drinkers has been established on many occasions. This results from a relative lack of knowledge of the basics of alcoholism and the low level of involvement of health care professionals in the management of these patients. In response to this inadequacy, the French Public Health Ministry promoted the development of managed care and coordination of care for these patients. Teams in charge of coordinating care for problem drinkers have been implanted in 96 French hospitals since 1996. These teams aim to provide support to health care providers caring for problem drinkers. For this purpose, they have delivered continuing medical education designed to prepare health care providers to identify and manage these patients in various settings. However, no formal assessment of the impact of these interventions on the knowledge, perceptions, and practices of health care professionals has been planned. The assessment of these interventions can rely on qualitative methods such as observation, focus groups, or individual interviews. However, qualitative methods require specific skills, are time-consuming, and cannot be implemented on a large scale. In contrast, quantitative methods using survey questionnaires or standardized instruments appear to be more appropriate for large scale or repeated evaluations. However, the accuracy of ratings provided by these instruments can be affected by many methodological factors, including the quality of the instrument in terms of validity, reliability, and sensitivity to changes. The aim of this paper is to describe the properties of French and English language questionnaires designed to assess the knowledge, perceptions, and practices of health care professionals with regards to alcoholic patients. METHODS: The instruments were retrieved by searching the Medline, Pascal, and Sudoc computerized bibliographic databases from January 1964 to December 2002. The following medical Subject Headings (MeSH) and text words were used: "*alcoholism/psychology/therapy", "questionnaire", "healthy care surveys", "attitude of health personnel", and "*knowledge/attitude/practice". In addition, the table of contents of the French journals devoted to alcoholism that were not indexed in electronic bibliographic databases were examined (Alcoologie et addictologie, Alcoologie). The bibliographies of relevant articles were also examined for additional citations. Finally, a phone survey of 34 professionals caring for alcoholic patients located in French university hospitals was carried out to retrieve unpublished questionnaires. Two authors independently extracted data from each study using a standard date abstract form. Disagreements were resolved through consensus. They extracted information on the development process and properties of validity, reliability, and sensitivity to changes. Validity is a concept concerned with the extent to which an instrument actually measures what it is supposed to measure. It is assessed through different facets (content, construct, criterion, discriminant, and predictive validity). Reliability reflects the amount of error inherent in any measurement. Sensitivity to change corresponds to the property of an instrument to identify small but clinically significant changes in attitude or practice. RESULTS: A total of 57 relevant publications involving 39 original instruments were identified. Eighty questionnaires were not available, despite the solicitation of their developers. Overall, the study included 21 instruments. Of these, 20 were English-language questionnaires and one was in French. The conceptual frameword was specified for only two questionnaires: "the Addiction Belief Scale" and "the Alcohol and Alcohol Problems Perception Questionnaire". The number of items ranged from 9 to 122. Items were derived from qualitative surveys in only two cases. In the other cases, they were derived from the literature, expert panels, or form unknown sources. The internal construct validity of eight questionnaires was assessed using principal component analysis, factor analysis, or cluster analysis. We considered that external construct validity was analyzed by testing empirical hypotheses derived from the literature for 15 of the instruments studied. Predictive validity cas evidenced for only one questionnaire. Internal consistency was documented for seven instruments, using Cronbach's coefficient. Test-retest or inter-rater reliability was assessed for none of the instruments. The sensitivity to change of two instruments was analyzed. The response rate to the instruments ranged from 46% to 93%. DISCUSSION: The main finding of this study is that properties of validity, reliability, and sensitivity of questionnaires designed to assess the knowledge, perceptions, and practices of health care professionals with regards to alcoholic patients are neglected. Moreover, these questionnaires generally lack a theoretical background. Hence, the interpretation of responses to these questionnaires may be misleading. The present study has several limitations. The search strategy could be criticized for searching only a small number of databases, and selecting French and English language questionnaires. However, given the large range of journals included, it was unlikely that the strategy has limited the generality of the results. In addition, we identified no additional relevant articles by contacting professionals working with alcoholic patients in French university hospitals. Articles reporting instruments designed to assess the knowledge, perceptions, and practices of health care professionals with regards to alcoholic patients are incomplete. Journals should require minimum evidence of validity, reliability, and sensitivity when reporting results of surveys, development of questionnaires or standardized instruments. CONCLUSION: The psychometric characteristics of French language questionnaires were given very little attention. In order to evaluate the effectiveness of their continuing medical education programs, the teams that train French medical staff caring for alcoholic patients should either develop a standardized survey questionnaire following a strict methodology or translate an English language instrument, which would also require a cross-cultural validation.

Alcoholism↗

PubMed1997

Maternal perception of sound-provoked fetal movement in the early intrapartum period.

OBJECTIVE: To determine the relationship between maternal perception of sound-provoked fetal movement in the early intrapartum period and perinatal outcome. METHOD: 739 singleton pregnant women of at least 32 weeks gestation who were admitted to the labor ward, underwent the maternal perception of sound-provoked fetal movement test. All were in the latent phase of labor with singleton cephalic presentation. The result of maternal perception of sound-provoked fetal movement was compared with the perinatal outcome using sensitivity, specificity, negative predictive value, positive predictive value and accuracy. RESULTS: When 739 pregnant women were compared to the perinatal outcome, maternal perception of sound-provoked fetal movement had sensitivity 100%, specificity 98.9%, positive predictive value 15.1%, negative predictive value 100%, and accuracy 90.1%. CONCLUSION: The finding suggested the usefulness of maternal perception of sound-provoked fetal movement as an effective screening test to identify fetuses at risk in the early intrapartum period because of its high sensitivity and specificity. This is a simple and inexpensive test for evaluating fetal well-being in a primary health care setting.

Acoustic Stimulation↗

PubMedDate not supplied

The effect of temporal manipulation on the perception of disfluencies as normal or stuttering.

UNLABELLED: The purpose of this investigation was to study the effect of temporal features within repetition of speech segments on the perception of stuttering. Past research has provided evidence that certain temporal aspects of repetitions produced by people who stutter tend to be shorter than those produced by normally fluent speakers. The effect of these temporal factors on the perception of the disfluency as "stuttering" or "normal" has not yet been studied. Conversational speech of five children who stutter was recorded. Two short utterances. one containing part-word repetition (PWR) and one containing whole-word repetition (WWR), were identified in the speech of each child and then manipulated by the CSL and CSpeech computer softwares. Two selected elements within repetitions, namely the vowel of the repeated unit and the interval between the repeated units (e.g., but-but), were lengthened to simulate normal disfluency. Results indicated that both factors (interval duration and vowel duration) moderately affected listeners' perception. In general, repetitions with short vowel and interval durations were judged as more representative of stuttering, whereas repetitions with longer vowel and interval duration were judged as more representative of normal speech. LEARNING OUTCOMES: As a result of this activity, the reader will learn about (1) various factors that influence the perception of disfluent segments as stuttering, (2) the special effect of duration of specific elements within repetitions on the perception of disfluency as stuttering, and (3) the possible implications of the new information for therapeutic considerations.

Child, Preschool↗

PubMed2002

Does visual perception of object afford action? Evidence from a neuroimaging study.

Positron emission tomography (PET) was used to explore the neural correlates of a potential involvement of motor representation during the perception of visually presented objects with different tasks. The main result of this study was that the perception of objects, irrespective of the task (judgement of the vertical orientation, motor imagery, and silent generation of the noun or of the corresponding action verb), versus perception of non-objects, was associated with rCBF increases in a common set of cortical regions. The occipito-temporal junction, the inferior parietal lobule, the SMA-proper, the pars triangularis in the inferior frontal gyrus, the dorsal and ventral precentral gyrus were engaged in the left hemisphere. The ipsilateral cerebellum was also involved. These activations are congruent with the idea of an involvement of motor representation already during the perception of object and thus provide neurophysiological evidence that the perception of objects automatically affords actions that can be made toward them. Besides this common set of cortical areas, each task engaged specific regions.

Adult↗

PubMed2002

Electrophysiological indexes of illusory contours perception in humans.

The present study investigated brain mechanisms underlying the perception of illusory contours, using recordings of event-related potentials of the brain (ERPs) in right-handed individuals. Forty different stimuli were presented randomly 1600 times in foveal vision; twenty of them produced the perception of illusory contours of a Kanizsa square, the remaining were obtained rotating outwards the inducers and they did not produce any illusory percept. Half of them had white inducers on a black background and vice versa; half of them were symmetrical and the other half asymmetrical. In lateral occipital areas illusory percepts produced larger evoked responses starting as early as 145 ms post-stimulus with the N1 peak. ERP data did not provide evidence of right-sided lateralisation of the processes underlying illusory contours formation at sensory level, as suggested by some neuroimaging and neuropsychological studies. The two cerebral hemispheres were differently activated while the subjective patterns formation progressed through neural processing stages. Indeed, brain response to illusory contours was more pronounced in the left occipital area at N2 component level (about 250 ms post-stimulus) and at right parietal sites at the latency of P300 component. Both background luminance and stimulus symmetry interacted with illusory boundaries formation. Present results confirm the hypothesis that the integration of contours arises at early stages of visual processing and highlight the primary role of edges continuity and boundary alignment in illusory contours perception.

Adult↗