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1

Synchronised oscillations of the human sensorimotor cortex

100%

Schnitzler A., Gross J., Timmermann L.

Acta Neurobiologiae Experimentalis

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2000

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vol. 60

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issue 2

271-287

EN

Oscillations are a prominent feature of macroscopic human sensorimotor cortical activity as recorded non-invasively with electroencephalography (EEG) and magnetoencephalography (MEG). The advent of whole-scalp MEG systems allowing rapid non-invasive recording from the entire cortex and accurate localisation of neural sources, and the development of refined signal analysis methods are important factors that led to an increasing interest in studies of sensorimotor oscillations during the last 10 years. Investigations on healthy subjects revealed frequency-specific localisation and modality-specific reactivity of 10 Hz and 20 Hz sensorimotor oscillations. Task-specific coherence between motor cortical and electromyographic oscillations, reflecting cortico-motoneuronal coupling, point towards a functional role of precentral oscillations in the cortical control of voluntary movements. Furthermore, abnormal cortico-motoneuronal coupling may underlie clinical symptoms of motor disorders, such as tremor. Thus, investigation of oscillatory sensorimotor activity proceeds from phenomenology to function and provides an interesting approach to address questions in human motor physiology and pathophysiology.

2

Novelty based feedback regulation in artificial neural networks

88%

Rychwalska A., Jablonski P., Zochowski M., Nowak A.

Acta Neurobiologiae Experimentalis

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2005

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vol. 65

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issue 3

453-463

EN

In this paper we present a theoretical framework for novelty based feedback regulation in artificial neural networks. Novelty is assessed on the basis of monitoring the coherence of network dynamics. The result of novelty detection is dynamically coupled to parameters that control the dynamics of the recognition process. The paper presents a new measure of novelty detection - the strength of the local field - and presents new simulation results concerning novelty detection. It also integrates previously published models and simulation results into a general dynamical model of feedback regulation.

3

The presence of coherence in sympathetic and phenic activities in a developing mammal

63%

Gootman P. M., Hundley B. W., Sica A. L.

Acta Neurobiologiae Experimentalis

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1996

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vol. 56

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issue 1

137-145

EN

To determine whether are devalopment changes in the baroreceptor and central respiratory modulation of sympathetic activity, we used ordinary and partial cohernce spectral analyses on cervical and splanchnic sympathetic activity in swine 1-36 days old. Removal of barareceptor influences from cervical sympathetic and splanchnic spectra using partialization shows that 3-6 Hz peaks are due to baroreceptors since coherence decreased in more then 19 days old while remaining unchanged in less then 2 weeks old piglets. The 8-12 Hz band (present in normal coherence after 21 days) was revealed in piglets less then 14 days old after removal of respiratory modulation by partialization; similarly increrased coherence was also observed in the 16-18 Hz band through 3 weeks. Thus, use of partial power and coherency is useful tool for unmasking the complex relationships found in developing SYMP outflows. These results suggest that there is a period of reorganization within the SYMP rhythm generating circuits, which may be essential for normal development.

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1 Rychwalska A.

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1 Sica A. L.

1 Timmermann L.

1 Zochowski M.

Synchronised oscillations of the human sensorimotor cortex

Novelty based feedback regulation in artificial neural networks

The presence of coherence in sympathetic and phenic activities in a developing mammal