Biomedical subjects

K Reinikainen

Publications and source records attributed to K Reinikainen.

76 records · Page 5Linked to original sources

PubMedDate not supplied

Event-related brain potential of human newborns to pitch change of an acoustic stimulus.

We report here event-related potentials (ERPs) of human newborns to occasional pitch changes in a repetitive sequence of tone pips. These pitch changes elicited a large slow negative ERP component which resembles the mismatch negativity (MMN) generated by the adult brain under similar conditions. This MMN-type of negativity in newborns suggests that already at this early ontogenetic stage the brain monitors the acoustic environment for a possible change in any of its repetitive aspects. Apart from its theoretical interest, this finding might provide a new way to test the development of the central nervous system and to diagnose cerebral dysfunction at a very early stage.

Acoustic Stimulation↗

PubMedDate not supplied

Comparison of the effects of carbamazepine and oxcarbazepine on peripheral nerve conduction.

Twenty-five epileptic outpatients were studied to assess possible effects of the first 6 months of treatment with carbamazepine or oxcarbazepine using serial peripheral nerve conduction measurements. Carbamazepine caused a small slowing effect on the motor conduction of the median nerve after 4 weeks of treatment, and the effect was correlated with the fasting serum concentration of the drug. Slowed motor conduction value of the median nerve was also observed after 6 months of treatment with carbamazepine. Oxcarbazepine did not cause any statistically significant slowing of nerve conduction.

Adolescent↗

PubMedDate not supplied

Aging effects on auditory processing: an event-related potential study.

Deviant tones randomly embedded in a sequence of standard tones elicit an event-related potential (ERP) called the mismatch negativity (MMN), which reflects automatic stimulus-change detection in the human auditory system. When the tones are attended, deviant tones elicit also an N2b component that partly overlaps the MMN. Sequences of standard and deviant (probability 0.15) tones were presented to 13 healthy younger and 13 older subjects. Deviant stimuli were, in separate blocks, either occasional shorter duration or higher frequency tones. The interstimulus interval (ISI) was, in separate blocks, either 0.5 s or 1.5 s, and in the frequency-change condition also 4.5 s. Aging affected neither frequency nor duration of MMN with the 0.5 s ISI. This finding indicates that automatic stimulus discrimination per se is not impaired with normal aging. However, with a 4.5-s ISI the MMN/N2b-complex attenuated significantly more in the older than younger subjects. This suggests that the stimulus trace decays faster or that involuntary attention switching is less sensitive with aging.

Acoustic Stimulation↗

PubMedDate not supplied

[Physical basis of the generation of neuromagnetic fields].

Electrical processes at the neuronal level are considered, which cause the neuromagnetic fields. Those fields presently measured are due to the synchronous activity of about 10(5) neurons. Short magnetic signals can be caused by afferent and efferent strains of action potentials, the longer ones being due to the synaptic activity at the ends of apical dendrites in the fissural cortex.

Axons↗