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The relationship between behavioral inhibition and time perception in children.

PURPOSE: To test one component of Barkley's (1997) model of executive functions by examining the relationship between behavioral inhibition and time perception in children. METHOD: Correlation analysis was used to determine the relationships between measures of behavioral inhibition and time perception for the entire sample, and for boys (n = 34) and girls (n = 26) separately. FINDINGS: For both parent and child measures, behavioral inhibition and time perception scores were correlated for the total group and for girls. Child measure of behavioral inhibition and time perception were not correlated for boys. CONCLUSIONS: The findings of this study support Barkley's theory and indicate a relationship between poor behavioral inhibition and poor time perception in children.

Attention Deficit Disorder with Hyperactivity↗

PubMed1979

Perceptions of the school nurse's role.

This study identifies and compares perceptions of school personnel (principals, teachers, counselors and school nurses) about the nurse's role in secondary school settings. A two-art questionnaire was utilized. Part one elicited descriptive data, while part two consisted of 50 Likert-type items related to the school nurse's role. Mean perception scores on the 50 items were obtained by job category and compared using a one-way ANOVA. Chi-square analyses were performed on the frequencies of scale values to determine if their distributions, by item, were the same for all job categories. Correlation coefficients were utilized to determine relationships between training levels, experience, direct contact and perceptions. Analyses revealed: (1) Significant differences in perceptions of the school nurse's role between each group of educators and school nurses. (2) No significant relationship between training level, experience, number of contacts with the nurse and perceptions of the school nurse's role.

Administrative Personnel↗

PubMed1980

Dimensions of aggression: the perception of aggressive episodes.

The perception of real-life aggressive episodes was studied, in order to (a) represent the cognitive dimensions used by judges to differentiate between such episodes, (b) to evaluate the perceived differences between different categories of episodes, and (c) to assess the effects of the judges' age, sex and attitudes on their cognitive representation of aggressive episodes. Judgements of 22 aggressive episodes selected from a free-response pilot study were analysed by Carroll & Chang's (1970) INDSCAL procedure, and differences between categories of episodes and groups of judges were evaluated by multiple discriminant analyses. Results indicated that (a) four cognitive dimensions, probability of occurrence, justifiability, emotional provocation, and control, defined the psychological map for aggressive episodes; (b) domestic against public, drunken and non-drunken, criminal against non-criminal episodes were significantly differentiated in this perceptual space; (c) the judges' age, sex and Machiavellism scores were related to their perception of such episodes. The results are discussed in terms of the importance of implicit perceptions of aggression and crime in the criminal justice system. Specifically, it is suggested that similar techniques could be used to (a) gauge popular perceptions of crime as an input to the legislative process, and (b) for the study of perceptions of aggressive episodes by such crucial groups in the criminal justice system as policemen, judges, jury members, victims and offenders.

Aggression↗

PubMed1975

Experimenter bias and subliminal perception.

It has been suggested that subliminal perception phenomena may be in part due to experimenter bias effects. Two studies that obtained positive evidence of subliminal perception were therefore replicated with experimenters tested under blind and not blind conditions. There was only marginal support for the subliminal perception hypothesis and, although there were fairly clear indications of diffuse experimenter effects, the evidence for the experimenter bias explanation of subliminal perception was not strong. The need for more extensive replications of subliminal perception researches is noted. It is argued that the experimenter bias hypothesis lacks detail and generality; it is essential for it to be examined in the context of theoretically substantial issues.

Adult↗

PubMed2001

Coherence in children's speech perception.

Studies with adults have demonstrated that acoustic cues cohere in speech perception such that two stimuli cannot be discriminated if separate cues bias responses equally, but oppositely, in each. This study examined whether this kind of coherence exists for children's perception of speech signals, a test that first required that a contrast be found for which adults and children show similar cue weightings. Accordingly, experiment 1 demonstrated that adults, 7-, and 5-year-olds weight F2-onset frequency and gap duration similarly in "spa" versus "sa" decisions. In experiment 2, listeners of these same ages made "same" or "not-the-same" judgments for pairs of stimuli in an AX paradigm when only one cue differed, when the two cues were set within a stimulus to bias the phonetic percept towards the same category (relative to the other stimulus in the pair), and when the two cues were set within a stimulus to bias the phonetic percept towards different categories. Unexpectedly, adults' results contradicted earlier studies: They were able to discriminate stimuli when the two cues conflicted in how they biased phonetic percepts. Results for 7-year-olds replicated those of adults, but were not as strong. Only the results of 5-year-olds revealed the kind of perceptual coherence reported by earlier studies for adults. Thus, it is concluded that perceptual coherence for speech signals is present from an early age, and in fact listeners learn to overcome it under certain conditions.

Adult↗

PubMed2006

Subjective assessment of listening environments in university classrooms: perceptions of students.

A questionnaire is developed to evaluate perception of the listening environment by university students. The objectives were to develop a questionnaire-based measurement tool, derive a measure of perceived classroom-listening quality, use the questionnaire to investigate factors that enhance, impair, or do not affect perceived listening quality, and consider the implications for classroom design. The questionnaire was administered to over 5700 students in 30 classrooms at one university. Physical and acoustical measurements were also performed in each classroom. The questionnaire included items that recorded aspects of student perception, as well as individual, course-, and instructor-specific factors. Responses to 19 perception items generated a perception of listening ease (PLE) score for each student and a classroom-average score. Decreased PLE was associated with women, English-second-larguage students, those with hearing impairment, students not interested in the course material, and those who found the material difficult. Increased PLE was associated with higher speech transmission index, acceptable lighting, temperature and seating, better instructor voice, increased visual-aid use, and easier course material. Results indicate that PLE is a useful measure of student perception of the classroom-listening environment, and that optimal classroom acoustical design must take into consideration "in-use" conditions, as well as classroom physical characteristics.

Acoustic Stimulation↗

PubMed1982

Cross-language study of perception of the oral-nasal distinction.

To investigate the effect of linguistic experience on the perception of the oral-nasal distinction in vowels, Hindi and American English speakers were tested on identification and discrimination of four speechlike series generated by articulatory synthesis. In experiment I, no language-group differences were found in the discrimination of either a consonant series, [ba-ma] (a phonemic contrast in both languages), or a vowel series, [ba-bã] (phonemic only for the Hindi speakers). The vowel results were due to floor effects which obscured differences across language groups. Experiment II examined perception of two modified vowel series, one which increased the interval between members of discrimination pairs and one that extended the range of velar port opening. Cross-language differences in discrimination were found. Hindi perception of the oral-nasal distinction was categorical. English speakers' perception of the vowel series was more continuous. They accurately discriminated differences not only across categories, but also within the oral category. These findings indicate that linguistic experience can influence listeners' perception of vowels, but the effect is different from that shown for consonants.

Cross-Cultural Comparison↗

PubMed1990

Auditive and cognitive factors in speech perception by elderly listeners. II: Multivariate analyses.

In part I of this study [van Rooij et al., J. Acoust. Soc. Am. 86, 1294-1309 (1989)], the validity and manageability of a test battery comprising auditive (sensitivity, frequency resolution, and temporal resolution), cognitive (memory performance, processing speed, and intellectual abilities), and speech perception tests (at the phoneme, spondee, and sentence level) were investigated. In the present article, the results of a selection of these tests for 72 elderly subjects (aged 60-93 years) are analyzed by multivariate statistical techniques. The results show that the deterioration of speech perception in the elderly consists of two statistically independent components: (a) a large component mainly representing the progressive high-frequency hearing loss with age that accounts for approximately two-thirds of the systematic variance of the tests of speech perception and (b) a smaller component (accounting for one-third of the systematic variance of the speech perception tests) mainly representing a general performance decrement due to reduced mental efficiency, which is indicated by a general slowing of performance and a reduced memory capacity. Although both components are correlated with age, it was found that the balance between auditive and cognitive contributions to speech perception performance did not change with age.

Adolescent↗

PubMed1993

Electrode position, repetition rate, and speech perception by early- and late-deafened cochlear implant patients.

Psychophysical and speech perception studies were conducted on eight patients using the 22-electrode cochlear implant manufactured by Cochlear Pty. Ltd. Four early-deafened patients became deafened at 1-3 years of age and were implanted at 5-14 years of age. Four late-deafened (postlingual adult) patients became deafened at 38-47 years of age and were implanted at 42-68 years of age. Psychophysical studies measured the discrimination of trajectories with time-varying electrode positions and repetition rates. Speech perception studies measured performance using two speech coding strategies: a multi-electrode strategy which coded the first and second formant frequencies, the amplitudes of the two formants, and the fundamental frequency; and a single-electrode strategy which coded the amplitudes of the first and second formants, and the fundamental frequency. In general, the four late-deafened patients and one early-deafened patient were more successful than the other three early-deafened patients in the discrimination of electrode position trajectories and in speech perception using the multi-electrode strategy. Three of the four late-deafened patients were more successful than the early-deafened patients in the discrimination of repetition rate trajectories. Speech perception performance in the single-electrode strategy was closely related to performance in repetition rate discrimination. The improvement in speech perception performance from the single-electrode to multi-electrode strategy was consistent with successful performance in electrode discrimination.

Acoustic Stimulation↗

PubMed1993

Cue trading in the production and perception of vowel stress.

The distinction between stressed and unstressed vowels in noun/verb pairs differentiated by stress (e.g., as in the word "misprint") is known to be cued by the acoustic attributes fundamental frequency, intensity, and duration. The role of these cues and vowel centralization measures in perception is ordered differently from that in production. It is not known what variability there is between speakers, whether the acoustic factors vary with speech clarity that a speaker produces on different occasions, or what the relationship is between the various speech attributes. Importantly, no studies have been performed in which production and perception of materials is compared with respect to these questions. In the current study, noun/verb pairs differentiated by stress were produced by four speakers, and measures of produced and perceived clarity obtained for these subjects. The importance of the acoustic factors to the contrast was modeled in perception and production, and the results compared. Additionally, the variation with produced or perceived clarity was ascertained. Finally, comparison between cue trading in production and perception was made. The results are discussed in connection with models of speech perception and production.

Adult↗

PubMed1996

A developmental study of vowel perception from brief synthetic consonant-vowel syllables.

The purpose of this study was to assess the perceptual role of brief synthetic consonant-vowel syllables as cues for vowel perception in children and adults. Nine types of consonant-vowel syllables comprised of the stops [b d g] followed by the vowels [i a u] were synthesized. Stimuli were generated with durations of 10, 30, or 46 ms, and with or without formant transition motion. Eight children at each of five age levels (5, 6, 7, 9, and 11 years) and a control group of eight adults were trained to identify each vowel in a three-alternative forced-choice (3AFC) paradigm. The results showed that children and adults extracted vowel information at a generally high level from stimuli as brief as 10 ms. For many stimuli, there was little or no difference between the performance of children and adults. However, developmental effects were observed. First, the accuracy of vowel perception was more influenced by the consonant context for children than for adults. Whereas perception was similar across age levels for stimuli in the alveolar context, the youngest children perceived vowels in the labial and velar contexts at significantly lower levels than adults. Second, children were more affected by variations in stimulus duration than were adults. This finding was particularly prominent for the syllable [ga], where the dependency on duration decreased with age in a nearly linear fashion. These findings are discussed in relation to current hypotheses of vowel perception in adults, and hypotheses of speech perception development.

Adult↗

PubMed1997

A unitary model of pitch perception.

A model of the mechanism of residue pitch perception is revisited. It is evaluated in the context of some new empirical results, and it is proposed that the model is able to reconcile a number of differing approaches in the history of theories of pitch perception. The model consists of four sequential processing stages: peripheral frequency selectivity, within-channel half-wave rectification and low-pass filtering, within-channel periodicity extraction, and cross-channel aggregation of the output. The pitch percept is represented by the aggregated periodicity function. Using autocorrelation as the periodicity extraction method and the summary autocorrelation function (SACF) as the method for representing pitch information, it is shown that the model can simulate new experimental results that show how the quality of the pitch percept is influenced by the resolvability of the harmonic components of the stimulus complex. These include: (i) the pitch of harmonic stimuli whose components alternate in phase; (ii) the increased frequency difference limen of tones consisting of higher harmonics; and (iii) the influence of a mistuned harmonic on the pitch of the complex as a function of its harmonic number. To accommodate these paradigms, it was necessary to compare stimuli along the length of the SACF rather than relying upon the highest peak alone. These new results demonstrate that the model responds differently to complexes consisting of low and high harmonics. As a consequence, it is not necessary to postulate two separate mechanisms to explain different pitch percepts associated with resolved and unresolved harmonics.

Hair Cells, Auditory, Inner↗

PubMed1997

Stop-consonant and vowel perception in 3- and 4-year-old children.

Recent research on 5- to 11-year-old children's perception of stop consonants and vowels indicates that they can generally identify these sounds with relatively high accuracy from short duration stimulus onsets [Ohde et al., J. Acoust. Soc. Am. 97, 3800-3812 (1995); Ohde et al., J. Acoust. Soc. Am. 100, 3813-3824 (1996)]. The purpose of the current experiments was to determine if younger children, aged 3-4 years, can also recover consonant and vowel features from stimulus onsets. Ten adults, ten 3-year olds, and ten 4-year-olds listened to synthesized syllables composed of combinations of [b d g] and [i u a]. The synthesis parameters included manipulations of the following stimulus variables: formant transition (moving or straight), noise burst (present or absent), and voicing duration (10, 30, or 46 ms). Developmental effects were found for the perception of both stop consonants and vowels. In general, adults identified these sounds at a significantly higher level than children, and perception by 4-year-olds was significantly better than 3-year-olds. A developmental effect of dynamic formant motion was obtained, but it was limited to only the [g] stop consonant. Stimulus duration affected the children's perception of vowels indicating that they may utilize additional auditory information to a much greater extent than adults. The results support the importance of information in stimulus onsets for syllable identification, and developmental changes in sensitivity to these cues for consonant and vowel perception.

Adult↗

PubMed1999

Native Italian speakers' perception and production of English vowels.

This study examined the production and perception of English vowels by highly experienced native Italian speakers of English. The subjects were selected on the basis of the age at which they arrived in Canada and began to learn English, and how much they continued to use Italian. Vowel production accuracy was assessed through an intelligibility test in which native English-speaking listeners attempted to identify vowels spoken by the native Italian subjects. Vowel perception was assessed using a categorial discrimination test. The later in life the native Italian subjects began to learn English, the less accurately they produced and perceived English vowels. Neither of two groups of early Italian/English bilinguals differed significantly from native speakers of English either for production or perception. This finding is consistent with the hypothesis of the speech learning model [Flege, in Speech Perception and Linguistic Experience: Theoretical and Methodological Issues (York, Timonium, MD, 1995)] that early bilinguals establish new categories for vowels found in the second language (L2). The significant correlation observed to exist between the measures of L2 vowel production and perception is consistent with another hypothesis of the speech learning model, viz., that the accuracy with which L2 vowels are produced is limited by how accurately they are perceived.

Adolescent↗

PubMed1996

Categorical perception of sound frequency by crickets.

Partitioning continuously varying stimuli into categories is a fundamental problem of perception. One solution to this problem, categorical perception, is known primarily from human speech, but also occurs in other modalities and in some mammals and birds. Categorical perception was tested in crickets by using two paradigms of human psychophysics, labeling and habituation-dishabituation. The results show that crickets divide sound frequency categorically between attractive (<16 kilohertz) and repulsive (>16 kilohertz) sounds. There is sharp discrimination between these categories but no discrimination between different frequencies of ultrasound. This demonstration of categorical perception in an invertebrate suggests that categorical perception may be a basic and widespread feature of sensory systems, from humans to invertebrates.

Animals↗

PubMed2000

Influence of sumatriptan on gastric fundus tone and on the perception of gastric distension in man.

BACKGROUND: In animals, activation of 5-HT(1) like receptors causes a relaxation of the gastric fundus through the activation of intrinsic inhibitory neurones. AIMS: To investigate the effect of sumatriptan, an agonist at enteric neuronal 5-HT(1) receptors, on fasting fundus tone and sensitivity to gastric distension in man. METHODS: A gastric barostat was used to study the effect of placebo and sumatriptan, 6 mg subcutaneously, on basal fundic tone in healthy subjects. In addition, stepwise isobaric and isovolumetric gastric distensions were performed and perception was measured before and after the administration of placebo and sumatriptan. RESULTS: Placebo had no significant effects on gastric tone and on perception. Sumatriptan induced an immediate relaxation of the gastric fundus, reflected by an intragastric volume increase of 209 (39) ml (p<0.0005). After sumatriptan, intragastric pressures at the thresholds for perception or discomfort were not significantly altered. However, the intragastric volumes and the corresponding calculated wall tensions at perception and discomfort thresholds were significantly increased. CONCLUSIONS: Administration of the 5-HT(1) receptor agonist sumatriptan induces a relaxation of the gastric fundus in man, allowing larger intragastric volumes before thresholds for perception or discomfort are reached. The effects of sumatriptan on the gastric fundus may have therapeutic potential in the treatment of patients with functional dyspepsia.

Adult↗

PubMed2001

Perception of changes in wall tension of the proximal stomach in humans.

BACKGROUND: Hypersensitivity to distension of the stomach is a frequent finding in functional dyspepsia. During gastric distension studies both wall tension and elongation are increased. AIM: We wished to distinguish changes in wall tension from changes in elongation in the genesis of perception of mechanical stimuli originating from the proximal stomach in healthy subjects. SUBJECTS AND METHODS: Twenty six volunteers were studied using gastric barostat and antroduodenal manometry. In 14 subjects, stepwise isobaric and isovolumetric distensions were performed before and during erythromycin infusion. In all volunteers, on a separate occasion, phasic contractions of the proximal stomach were detected as intraballoon pressure increases during fixed volume inflation. These contractions were matched with perception changes during two 10 minute periods, before and during administration of erythromycin. RESULTS: Erythromycin significantly lowered the perception and discomfort thresholds during stepwise gastric distension. During fixed volume inflation, erythromycin increased the number and amplitude of fundic contractions and enhanced their perception from 51.1 (7.4)% to 64.0 (4.7)%. The proportion of perception score increases coinciding with fundic contractions increased from 47.3 (0.7)% to 81.5 (0.5)%. The amplitude of correctly identified isolated fundic pressure waves was higher compared with non-identified waves. CONCLUSIONS: These results support the hypothesis that changes in gastric wall tension may be involved in the genesis of symptoms originating from the stomach.

Adult↗

PubMed2002

Attitudes about sexual disclosure and perceptions of stigma and shame.

OBJECTIVES: To determine the association between stigma and shame about having a sexually transmitted disease and adolescents' past STD related care seeking; between stigma, shame, and perceptions about disclosure of sexual behaviours to a doctor or nurse; and whether the association of stigma, shame, and care seeking was moderated by perceptions about disclosure. METHODS: A household sample of 142 sexually active African-American youths, 13-19 years old, was questioned about STD related stigma (alpha = 0.89), STD related shame (alpha = 0.90), and perceptions about disclosure of sexual behaviours to a doctor or nurse (alpha = 0.81). RESULTS: Among females, stigma was associated with increased anticipation of negative reactions to disclosure of sexual behaviours to a doctor or nurse (odds ratio (OR) = 0.319; 95% confidence interval (CI) =0.12 to 0.85) while shame was not. Stigma was also independently associated with STD related care seeking in the past year (OR = 0.296; 95% CI = 0.09 to 0.94) while shame was not. There was no association between stigma and shame with perceptions about disclosure or past care seeking in males. Perceived outcomes of disclosing sexual behaviours did not moderate the association of stigma, shame, and past STD related care seeking. CONCLUSIONS: Stigma about STDs may influence how female adolescents perceive reactions to disclosure of their sexual behaviour to healthcare providers. It may also be an important factor in their decision seek to STD related care. Perceptions about disclosure of sexual behaviour to a doctor or nurse do not change the relation of stigma or shame to past STD related care seeking.

Adolescent↗