Psychobiology of altered states of consciousness

The article reviews the current knowledge regarding altered states of consciousness (ASC) (a) occurring spontaneously, (b) evoked by physical and physiological stimulation, (c) induced by psychological means, and (d) caused by diseases. The emphasis is laid on psychological and neurobiological approaches. The phenomenological analysis of the multiple ASC resulted in 4 dimensions by which they can be characterized: activation, awareness span, self-awareness, and sensory dynamics. The neurophysiological approach revealed that the different states of consciousness are mainly brought about by a compromised brain structure, transient changes in brain dynamics (disconnectivity), and neurochemical and metabolic processes. Besides these severe alterations, environmental stimuli, mental practices, and techniques of self-control can also temporarily alter brain functioning and conscious experience.     

Selected pragmatic features in Spanish-speaking preschool children

We assessed Spanish-speaking preschool children for the development of seven language functions and three discourse features. Analyses consisted of spontaneous language samples averaging 136 utterances per child, for 18 subjects between 3:0 and 4:5 (years: months). Data for the frequency of occurrence and the percentage of appropriate usage showed that the preschoolers had established communicative competence for the functions and discourse features. Implications include establishing preliminary guidelines for the development of normal pragmatics in Hispanic preschoolers. We also discuss the 10-item taxonomy as a reliable and clinically useful tool with either English-speaking or Spanish-speaking children.     

A special flicker fusion frequency method for detection of the effects of gerontopharmaceuticals exemplified by the L-eburnamonine study

A clear difference between active drug and placebo is not always found when using the ascending and descending thresholds of the critical flicker fusion test (CFF). We selected a test requiring attention and concentration and performed again the CFF after this 6-minute concentration-test (reactive CFF). This reactive CFF was then used in a double-blind study in 30 ambulant patients with cerebro-vascular arteriosclerosis treated for 8 weeks with 80 mg/day cervoxan or placebo. After the treatment period the reaction of the CFF after the 6-minute concentration-test demonstrated a significantly more frequent improvement of the vigilance in the Cervoxan group compared to the placebo group.     

Current status of intrathecal antifibrinolytic therapy with p-aminomethylbenzoic acid (PAMBA) in subarachnoid hemorrhages

The blood-brain barrier is barely affected by slight or moderate subarachnoidal bleeding so that the p-aminomethylbenzoic acid (PAMBA) administered systemically for antifibrinolytic therapy does not attain the continuous level necessary in the cerebrospinal fluid. Thus the antifibrinolytic agent should be applied intrathecally because this would totally inhibit fibrinolytic activity in cerebrospinal fluid containing blood and during the wound healing of ruptured aneurysmas. The improvement in wound healing reduces the occurrence of rebleeding, especially during the first 10 days, and improves conditions for successful surgical intervention.     

Irreversible cerebral function loss (so-called brain death). Further experiences in diagnostic procedures

Analyzing international 15 years experiences the authors characterize the present situation of knowledges and practical possibilities concerning brain death diagnostics. It must be differentiated between generally accepted obliging criterions and the remaining space of responcibility of the neurologist, who is acting as a member of a brain death commission. In this frame procedures have to be chosen, which allow to diagnosticate without any doubt and as early as possible. Further developmental possibilities are shown.     

EEG source imaging during two Qigong meditations

Experienced Qigong meditators who regularly perform the exercises "Thinking of Nothing" and "Qigong" were studied with multichannel EEG source imaging during their meditations. The intracerebral localization of brain electric activity during the two meditation conditions was compared using sLORETA functional EEG tomography. Differences between conditions were assessed using t statistics (corrected for multiple testing) on the normalized and log-transformed current density values of the sLORETA images. In the EEG alpha-2 frequency, 125 voxels differed significantly; all were more active during "Qigong" than "Thinking of Nothing," forming a single cluster in parietal Brodmann areas 5, 7, 31, and 40, all in the right hemisphere. In the EEG beta-1 frequency, 37 voxels differed significantly; all were more active during "Thinking of Nothing" than "Qigong," forming a single cluster in prefrontal Brodmann areas 6, 8, and 9, all in the left hemisphere. Compared to combined initial-final no-task resting, "Qigong" showed activation in posterior areas whereas "Thinking of Nothing" showed activation in anterior areas. The stronger activity of posterior (right) parietal areas during "Qigong" and anterior (left) prefrontal areas during "Thinking of Nothing" may reflect a predominance of self-reference, attention and input-centered processing in the "Qigong" meditation, and of control-centered processing in the "Thinking of Nothing" meditation.