Biomedical subjects

Elzbieta Szelag

Publications and source records attributed to Elzbieta Szelag.

8 recordsLinked to original sources

PubMed2004

Temporal processing deficits in high-functioning children with autism.

It is well known that complex functions (e.g. perception, attention, memory, emotions, social interactions and language) are usually disturbed in autism. As these functions are characterized by specific temporal patterns, the present study examined whether children with autism show typical temporal processing in the time domain of a few seconds. Using a temporal-reproduction paradigm, we found that they were unable to link their responses to stimulus duration. Independently of stimulus duration, they reproduced auditory or visual stimuli with the same response duration of, on average, 3 s. These results demonstrate important deficits in duration judgment in individuals with autism. As other experiments provide evidence for a temporal processing platform of approximately 2-3 s in normal individuals, this platform may be preserved in a residual form in autism.

Adolescent↗

PubMed2004

Individual differences in temporal information processing in humans.

This article reviews some of our investigations concerning individual differences in temporal information processing. Two different levels of temporal information processing are discussed, namely the low-frequency (i.e., a few seconds time range) and the high-frequency processing level (i.e., some tens of milliseconds range) of temporal information with respect to various experimental paradigms. Evidence has been obtained indicating that the processing of temporal information on these two levels can be influenced by various subject-related factors, out of which age, gender, developmental disorders, auditory experience and localisation of damage in the brain seem to be the most significant.

Autistic Disorder↗

PubMed2004

Reproduction of auditory and visual standards in monochannel cochlear implant users.

The temporal reproduction of standard durations ranging from 1 to 9 seconds was investigated in monochannel cochlear implant (CI) users and in normally hearing subjects for the auditory and visual modality. The results showed that the pattern of performance in patients depended on their level of auditory comprehension. Results for CI users, who displayed relatively good auditory comprehension, did not differ from that of normally hearing subjects for both modalities. Patients with poor auditory comprehension significantly overestimated shorter auditory standards (1, 1.5 and 2.5 s), compared to both patients with good comprehension and controls. For the visual modality the between-group comparisons were not significant. These deficits in the reproduction of auditory standards were explained in accordance with both the attentional-gate model and the role of working memory in prospective time judgment. The impairments described above can influence the functioning of the temporal integration mechanism that is crucial for auditory speech comprehension on the level of words and phrases. We postulate that the deficits in time reproduction of short standards may be one of the possible reasons for poor speech understanding in monochannel CI users.

Acoustic Stimulation↗

PubMed2003

Sex differences in perception of temporal order.

On duration judgments lasting seconds to minutes, which are thought to be cognitively mediated, women typically perceive time intervals as longer than men do. On a perceptual level in the milliseconds range, few reports indicate higher acuity of temporal processing in men than in women. In this study, sex differences in the perception of temporal order of two acoustic stimuli were identified in neurologically healthy subjects, as well as in brain-injured patients with lesions in either the left or the right hemisphere. Women needed longer interstimulus intervals than men before they were able to indicate the correct temporal order of two clicks. Neurobiological evidence and findings on cognitive strategies are discussed to explain the apparent psychophysical sex differences.

Acoustic Stimulation↗

PubMed2002

Duration processing in children as determined by time reproduction: implications for a few seconds temporal window.

From research carried out over recent years using different experimental paradigms, it has become apparent that central information processing is temporally segmented into sequential units of a few seconds. This segmentation presumably reflects a neuronal process of temporal integration (TI) which automatically binds successive events into temporal units. Support for such TI comes, for example, from studies on temporal reproduction where standards up to approximately 2-3 s are reproduced veridically. Using this paradigm of temporal reproduction, we investigated the effect of normal cognitive development of sensory modality and of the range of presented standards on TI. Sixty children aged 6-7, 9-10 and 13-14 years reproduced visual or auditory standard durations ranged from 1 to 5.5 s or from 1 to 3 s. The results showed that durations of approximately 2 s were reproduced correctly, whereas those longer than 2.5 s were under-reproduced in the three age groups. For standards shorter than 2 s substantial age-related differences were revealed: the youngest group displayed significant over-reproduction comparing to older subjects. These observations indicate that the upper limit for TI is a stable feature across the different age groups. Furthermore an age-related modulation within the temporal window of the operating TI seems to be linked to cognitive development.

Adolescent↗

PubMed2002

Cortical involvement in temporal reproduction: evidence for differential roles of the hemispheres.

Only few studies have addressed temporal processing for durations longer than 1 s, and even fewer studies have investigated cortical involvement in time perception, in particular temporal production and reproduction. The present study investigated temporal reproduction in healthy control subjects and patients with anterior or posterior cortical lesions in the left or right hemisphere, or with subcortical left-hemispheric lesions. The paradigm involved presentation of either auditory or visual stimuli of 10 different standard intervals ranging from 1 to 5.5 seconds duration. Participants were required to reproduce the duration of a stimulus. Our results show that: (1) temporal reproduction across this temporal range can be better described with two separate linear regressions (bilinear approach) than with one single linear regression, thus contrasting the scalar timing concept; (2) that patients can, regardless of the hemisphere lesioned, perform reproductions of durations smaller than 2-3 s with reasonable accuracy; and (3) that patients with right-hemispheric lesions appear to be impaired in reproductions of stimuli longer than 2-3 s. Since attention appeared not to be impaired in the patients tested, the findings suggest that the integrity of the right hemisphere seems to be critical for temporal reproduction of intervals longer than 2-3 s.

Adult↗

PubMed2002

Temporal order judgement for auditory and visual stimuli.

The ability to perceive temporal order for pairs of auditory and visual stimuli was investigated in 12 volunteers. They were asked to make judgements about the order of presented stimuli by pressing two response buttons in a certain order. The performance on auditory and visual tests was studied in relation to the Inter-Stimulus-Interval (ISI), which varied from 5 to 500 ms. In general, the level of performance was similar for the two modalities and the criterion of 75% of correct responses was reached at ISI longer than 40 ms, independently of the modality. These findings are consistent with previous research. However, at ISI of 5 ms, a significantly higher level of correctness was observed for the auditory than visual task. Such a tendency was also observed for ISIs of 10, 20 and 40 ms. Better processing in the auditory compared to the visual task at shorter ISIs may result from a different kind of transduction mechanism at the level of receptive cells in each modality. Alternatively, subjects may use two different kinds of response strategies in the auditory modality, only one being comparable to the response strategy in the visual modality.

Acoustic Stimulation↗

PubMed1999

Temporal constraints of perceiving, generating, and integrating information: Clinical indications.

Neuropsychological research on temporal constraints of perception and motor performance can add important information to research on human behavior. Without considering temporal mechanisms of perceiving, generating, and updating information, brain mechanisms can never be fully understood. In this study temporal aspects of performance in psychophysical experiments on three different temporal levels (around 30 ms, 300 ms, and 3000 ms) were investigated in patients with acquired brain lesions and a control group without neurological deficits. The patients had acquired focal brain lesions in: anterior (pre-central) regions of the left hemisphere (with non-fluent aphasia), posterior (post-central) regions of the left hemisphere (with fluent aphasia), the left hemipshere in predominantly subcortical regions (without aphasia), or anterior (pre-central) or posterior (post-central) regions of the right hemipshere. Perception of temporal order (20 to 60 ms) was impaired in patients with left-hemispheric post-central lesions; repetitive voluntary action (300 to 500 ms) was affected mostly in patients with left hemi-spheric lesions, both pre-central and post-central; and a deficit in integrating (2000 ms to 3000 ms) information was most pronounced in patients with left and right pre-central lesions. These findings provide insight into the associations between different levels of temporal organisation and circumscribed regions of the neocortex.

Journal Article↗