Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 6

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

The evoked cardiac response as a function of cognitive load in subjects differing on the individual difference variable of reaction time

100%
Kaiser J., Beauvale A., Bener J.
Acta Neurobiologiae Experimentalis
|
1996
|
vol. 56
|
issue 1
209-213
EN
We report research on different phasic evoked cardiac responses associated with differences in cogintive activity.These were examined in relation to a stable individual difference variable, mean simple reaction time (RT). Individual means on RT were found to be sufficiently stable over a 10 month period to consider them as individual functional characteristics. Subjects were divided into two subgroups on the basis of the first measure of their individual mean RT (above and below the group median). Each subject received 10 innocuous auditory stimuli with randomly varying interstimulus intervals. Stimuli were presented in one of two conditions defined by instructions allowing them to ignore (irrelevant condition), or requiring them to count the stimuli (relevant condition). A main effect of instruction was obtained in the evoked cardiac response. The initial heart rate deceleration was significantly larger in the relevant condition. Short-RT subjects had smaller heart rate changes to the irrelevant stimuli. The data are discussed in terms of the intensity of stimulus processing (both physical and cognitive) as a factor which may be related fundamentally to stable individual differences in RT.
2
Content available remote

Subjective mood estimation co-varies with spectral power EEG characteristics

100%
Wyczesany M., Kaiser J., Coenen A. M. L.
Acta Neurobiologiae Experimentalis
|
2008
|
vol. 68
|
issue 2
180-192
EN
Co-variation between subjectively estimated mood/activation and EEG characteristics, based on spectral power parameters, was investigated. Subjective estimation of mood was made by using Thayer's Activation-Deactivation Adjective Checklist, which yielded two dimensions: Energy-Tiredness (with Energy pole having positive valence connotation) and Tension-Calmness (negative connotation for Tension). A within-subject design with two sessions of EEG recording immediately followed by mood assessment was applied. These were separated by a cognitive task, introduced in order to modify the subjects' mood. The correlations between changes in mood estimation and changes in EEG spectral power parameters were calculated. Both ADACL dimensions co-varied with EEG in a specific way according to frequency and localization. Subjective estimation of Energy correlated negatively with alpha1 and, surprisingly, positively with delta, theta1 as well as theta2 relative power. Estimation of Tension correlated positively with theta1 and beta1, and negatively with alpha2 relative power. Presented results suggest that the adjective description of mood has objectively-measurable brain correlates in the EEG.
3
Content available remote

Evoked cardiac response components in cognitive processing: differential effects of amyotrophic lateral sclerosis

100%
Kaiser J., Wronka E., Barry R. J., Szczudlik A.
Acta Neurobiologiae Experimentalis
|
1999
|
vol. 59
|
issue 4
329-334
EN
We investigated the mechanism of two evoked cardiac response components associated with different aspects of information processing. Innocuous stimuli presented in an irrelevant condition elicit a simple cardiac deceleration termed ECR1. The same stimuli presented in a relevant condition (such as results from requesting subjects to silently count the stimuli) elicit a complex biphasic response with a large secondary acceleration in heart rate. This difference is attributed to the additional effect of cognitive task performance, resulting in an addition response component, ECR2. This may be realised by subtraction of the two responses. We investigated the mechanisms involved by comparing cardiac response profiles from a neurologically-impaired group with those from a control group. amyotrophic lateral sclerosis (ALS) has been associated with a loss of synaptic connections in the frontal lobe. Twelve ALS clinically non-demented patients were age-matched with twelve neurological patients without pathological changes in the brain. Cardiac response profiles for ECR1 and ECR2 were examined as a function of group. ECR1 did not differ between the groups, but ECR2 was significantly impaired in the ALS patients. The results are discussed in terms of different brain regions associated with these two cardiac response components. ECR1 may be associated with automatic preattentive stimulus registration involving, in the case of auditory stimuli, the auditory analyser and associated pathways, while ECR2 appears to be a correlate of controlled executive processing, involving the frontal cortex.
4
Content available remote

The auditory P3 from passive and active three-stimulus oddball paradigm

100%
Wronka E., Kaiser J., Coenen A. M. L.
|
|
issue 3
362-372
EN
The aim of this study was the comparison of basic characteristics of the P3 subcomponents elicited in passive and active versions of the auditory oddball paradigm. A 3-stimulus oddball paradigm was employed in which subjects were presented with random sequence of tones while they performed a discrimination task in visual modality with no response to the tone (passive task) or responded to an infrequently occurring target stimulus inserted into sequence of frequent standard and rare non-target stimuli (active task). Results show that the magnitude of the frontal P3 response is determined by the relative perceptual distinctiveness among stimuli. The amplitude of frontal component is larger for the stimuli more deviated from the standard in both passive and active tasks. In all cases however, a maximum over central or fronto-central scalp regions was demonstrated. Moreover, amplitude of this component was influenced by the strength of attentional focus ? a significantly larger response was obtained in the active session than in its passive counterpart. The apparent parietal P3 responses were obtained only in the active condition. The amplitude of this component is larger for the target than the non-target across all electrode sites, but both demonstrated a parietal maxima. This findings suggest that generation of early frontal P3 could be related to alerting activity of frontal cortex irrespective of stimulus context, while generation of later parietal P3 is related to temporo-parietal network activated when neuronal model of perceived stimulation and attentional trace are comparing.
5
Content available remote

The P3 produced by auditory stimuli presented in a passive and active condition: modulation by visual stimuli

100%
Wronka E., Kuniecki M., Kaiser J., Coenen A. M.
Acta Neurobiologiae Experimentalis
|
2007
|
vol. 67
|
issue 2
155-164
EN
The aim of this study was to investigate how the processing of auditory stimuli is affected by the simultaneous presentation of visual stimuli. This was approached in an active and passive condition, during which a P3 was elicited in the human EEG by single auditory stimuli. Subjects were presented tones, either alone or accompanied by the simultaneous exposition of pictures. There were two different sessions. In the first, the presented tones demanded no further cognitive activity from the subjects (passive or 'ignore' session), while in the second session subjects were instructed to count the tones (active or 'count' session). The central question was whether inter-modal influences of visual stimulation in the active condition would modulate the auditory P3 in the same way as in the passive condition. Brain responses in the ignore session revealed only a small P3-like component over the parietal and frontal cortex, however, when the auditory stimuli co-occurred with the visual stimuli, an increased frontal activity in the window of 300-500 ms was observed. This could be interpreted as the reflection of a more intensive involuntary attention shift, provoked by the preceding visual stimulation. Moreover, it was found that cognitive load caused by the count instruction, resulted in an evident P3, with maximal amplitude over parietal locations. This effect was smaller when auditory stimuli were presented on the visual background. These findings might support the thesis that available resources were assigned to the analysis of visual stimulus, and thus were not available to analyze the subsequent auditory stimuli. This reduction in allocation of resources for attention was restricted to the active condition only, when the matching of a template with incoming information results in a distinct P3 component. It is discussed whether the putative source of this effect is a change in the activity of the frontal cortex.
6
Content available remote

Correlation between long latency evoked potentials from amygdala and evoked cardiac response to fear conditioned stimulus in rats

100%
Kuniecki M., Coenen A. M. l., Kaiser J.
Acta Neurobiologiae Experimentalis
|
2002
|
vol. 62
|
issue 2
85-92
EN
We investigated relation between activity of central nucleus of amygdala (CE) and phasic heart rate deceleration during differential fear conditioning. We found that P2 component of long-lasting event potential (EP) to CS+ but not to CS- correlated strongly with HR deceleration in the 1st second after stimulus onset. Obtained results are discussed in the light of LeDoux?s and Kapp?s findings showing crucial role of amygdala in processing of emotionally relevant stimulation and it?s involvement in initiating autonomic responses.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.