THE INFLUENCE OF AUDITORY STIMULUS INTENSITY ON APPARENT DURATION

B erglund , B., B erglund , U., E kman , G. & F rankenhaeuser , M. The influence of auditory stimulus intensity on apparent duration. Scand J. Psychol ., 1969, 10 21–26.— apparent duration of an auditory signal of 1000 C/S was measured by the method of magnitude estimation. Ten different stimulus intensities ranging from 57 to 104 dB were used in combination with three different durations: 50, 250, and 500 msec. The results showed that the apparent duration of the signal grew as a logarithmic function of stimulus intensity. These results are consistent with the hypothesis relating apparent duration to activation level as well as with results of similar experiments involving electrical and vibrotactile stimulation.     

PERCEIVED INTENSITY OF ODOR AS A FUNCTION OF TIME OF ADAPTATION

The perceived intensity of odor under conditions of constant stimulation with hydrogen sulphide was investigated in two experiments. A two-step scaling method, involving cross-modality matching and numerical scaling of the matching continuum, was used for measuring intensity of odor. Perceptual intensity was found to decrease exponentially with increase of time of stimulation. Preliminary data concerning the subsequent recovery phase were also obtained.     

OBJECTIVE AND SUBJECTIVE PERFORMANCE AS INFLUENCED BY DRUG-INDUCED VARIATIONS IN ACTIVATION LEVEL

Performance was measured by seven sensorimotor and perceptual tests given to 30 students in six successive trials, spread over five hours, before and after the intake of either 15 mg dexamphetamine, zoo mg Pentobarbitone, or a placebo. Subjective performance, level of aspiration, wakefulness, and mood were measured by a scaling method. A close agreement was found between the amount of objective and subjective improvement following dexamphetamine, whereas the objective impairment induced by Pentobarbitone was not reflected in the subjective measures. These results were examined in relation to the other indices of activation.     

LOUDNESS AS A FUNCTION OF THE DURATION OF AUDITORY STIMULATION

The perceived loudness of a 1000 c/s tone was measured by a direct scaling method under different conditions of intensity (19–35 db) and duration (50–500 msec) of stimulation. It was found that loudness grows as a logarithmic function of stimulus duration; the relation was verified for ten individual subjects and four levels of intensity. In addition, the relation between temporal threshold and level of intensity was tentatively described.     

A fast procedure for studying conditional accuracy functions

This paper describes a procedure for obtaining conditional accuracy functions(CAFs) from naive observers and a restricted number of trials. The method permits the experimenter to counter the subjects’ tendency to favor accuracy in tasks in which stimulus discrimination is easy. Each time a block of 12 trials contains less than three errors, observers are instructed, by means of a speed-up signal, to respond faster. The subject is continuously informed about her/his effective reaction time. The data show that the desired speed-accuracy tradeoff was obtained within each of the 7 observers. The mean percent error was around 25%.     

Using a multi‐feature paradigm to measure mismatch responses to minimal sound contrasts in children with cochlear implants and hearing aids

Our aim was to explore whether a multi‐feature paradigm (Optimum‐1) for eliciting mismatch negativity (MMN) would objectively capture difficulties in perceiving small sound contrasts in children with hearing impairment (HI) listening through their hearing aids (HAs) and/or cochlear implants (CIs). Children aged 5–7 years with HAs, CIs and children with normal hearing (NH) were tested in a free‐field setting using a multi‐feature paradigm with deviations in pitch, intensity, gap, duration, and location. There were significant mismatch responses across all subjects that were positive (p‐MMR) for the gap and pitch deviants (F(1,43) = 5.17, p = 0.028 and F(1,43) = 6.56, p = 0.014, respectively) and negative (MMN) for the duration deviant (F(1,43) = 4.74, p = 0.035). Only the intensity deviant showed a significant group interaction with MMN in the HA group and p‐MMR in the CI group (F(2,43) = 3.40, p = 0.043). The p‐MMR correlated negatively with age, with the strongest correlation in the NH subjects. In the CI group, the late discriminative negativity (LDN) was replaced by a late positivity with a significant group interaction for the location deviant. Children with severe HI can be assessed through their hearing device with a fast multi‐feature paradigm. For further studies a multi‐feature paradigm including more complex speech sounds may better capture variation in auditory processing in these children.     

A longitudinal model of executive function development from birth through adolescence in children born very or extremely preterm

Executive function deficits are often reported as a specific weakness in preterm children. Yet, executive function development is still not fully understood. In a prospective longitudinal study, 115 preterm born children, ≤31 weeks of gestation, were recruited at birth and subject to neuropsychological assessments at ages 5.5 and 18 years. By applying Miyake and colleagues’ integrative framework of executive function to our data, two core components of executive function, working memory and cognitive flexibility, were identified through confirmatory factor analysis. Developmental stability was investigated in a serial multiple mediator structural equation model. Biological, medical, and social factors as well as mental development at 10 months were entered as predictors. Both components of executive function were highly stable from 5.5 to 18 years. Gestational age, intrauterine growth, lack of perinatal medical complications, and female sex were positively related to mental development at 10 months, which together with parental education influenced both core executive functions at 5.5 years. Working memory at 5.5 years mediated outcome in working memory at 18 years. In addition to the mediation of cognitive flexibility at 5.5 years, perinatal medical complications and restricted intrauterine growth had a continued direct negative impact on cognitive flexibility at 18 years. The application of a theoretical framework added to our understanding of executive function development in preterm born children. The study supports early identification of executive deficits among children born preterm, as deficits are unlikely to diminish with maturation.     

A Swedish non-word repetition test for preschool children

A Swedish non-word repetition test for preschool children was constructed with the aim of measuring short-term phonological memory, which has been shown to correlate with language development and language proficiency. Normative data based on results for 200 children four to six years of age are presented. An item analysis of the original 30-item test resulted in a shortened 24 non-word version found suitable for four- to six-year old children. Results for this shortened version, which had a Cronbach's alpha of 0.73, showed longer non-words to be more difficult to repeat than shorter ones, and significant effects of age and compatibility of the tester's and the child's accent, but not of gender. The results are discussed within the framework of Baddeley's working memory model.     

Individual neuropsychological profiles at age 5½ years in children born preterm in relation to medical risk factors

Follow-up studies of preterm children have reported a range of cognitive deficits, particularly in executive functions, visuospatial abilities, and learning. However, few researchers have adopted a person-oriented approach, exploring individual neuropsychological profiles. The aim of this study was to identify typical neuropsychological profiles among preterm children and control children, respectively. A second aim was to investigate if neuropsychological profiles at age 5½ might be associated with perinatal medical risk factors. As part of the longitudinal Stockholm Neonatal Project, NEPSY for 4- to 7-year-old children (Korkman, 1990 Korkman, M. 1990. NEPSY, Neuropsychological Assesment 4–7 years: Swedish Version, Stockholm, , Sweden: Psykologiförlaget AB.  [Google Scholar]), WPPSI-R, and Movement ABC were administered at age 5½ years to 145 preterm (mean gestational age 28 weeks) and 117 control children born at term. For the present study, the NEPSY results of each child were transformed into summary z scores for each of 5 neuropsychological domains: attention, memory, sensory-motor, verbal, and visuospatial functions. Subsequently, Ward's cluster analysis was performed for the preterm and control groups separately, identifying 5 neuropsychological profiles in both groups explaining around 56% and 57% of the variance, respectively. Overall, preterm children had lower neuropsychological results but also more diverging profiles compared to controls. The variability in outcome could not be sufficiently explained by birth weight, gestational age, or medical risks. The results suggest that prematurity interacts dynamically with genetic, medical, and environmental factors in neuropsychological development.     

Diagnosis and treatment of respiratory tract infections in primary health care by the nurse versus the physician: Efficacy and patient attitudes

Abstract

Five district physicians and one registered nurse were compared regarding their effectiveness in diagnosing and treating acute upper respiratory tract infections in patients (n=186) at a Swedish community health centre. Attitudes and views of the patient, or of the accompanying adult when the patient was a child, regarding the consultation itself, as well as more general aspects of health care were investigated (n=99) using a questionnaire. The questionnaire included 42 propositions of a “fuzzy” type to be judged on a 100-point truth-value scale, 18 of them concerning the consultation and 24 the more general aspects. No differences between the physicians and the nurse were found in their efficacy of diagosis and treatment. Subjects' overall attitudes were found to be positive toward both the physicians and the nurse. Results of multivariate analyses of variance performed for the consultation and general aspects of health care items separately and concerning type of persons providing health care (physician/nurse), treatment (antibiotics/no antibiotics) and patient age (child/adult), revealed overall differences in questionnaire response as regards patient age in relation to the consultation items.