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T F Münte

Publications and source records attributed to T F Münte.

98 records · Page 6Linked to original sources
PubMed1989

Event-related potentials and visual spatial attention: influence of a cholinergic drug.

The effects of two dosages (200 mg, 600 mg, placebo) of a cholinergic nootropic (WEB 1881 FU) were investigated in a visual spatial attention task. Event-related brain potentials (ERPs) were used as a physiological measure of attention as they have previously been shown to be sensitive to allocation of attention to points in space. The typical enhancement of several peaks of the visual ERP due to attention was found in the present experiment. No systematic effect of the medication was revealed, suggesting that the effects of WEB 1881 FU do not extend to early perceptual processes.

Adult↗
PubMed1989

[Event related brain potentials and signal detection: decision confidence and signal probability].

This paper is concerned with the relation of two components of the late positive complex, P300 and slow wave, to parameters of signal detection theory. In the first experiment, basically a replication of Squires et al., signal probability was 50% and a six point rating scale was used for subjects' answers. Whereas for the P300 the well known relation to subjective confidence (and thus to response criteria) was confirmed, a similar relation could not be found for the slow wave. In the second experiment the local signal probability was varied from 25% to 75% on a trial to trial basis. Under these conditions neither the P300 nor the slow wave exhibited a relation to signal-probability, whilst the relation to decision-confidence was preserved.

Adult↗
PubMed1988

Effects of a cholinergic nootropic (WEB 1881 FU) on event-related potentials recorded in incidental and intentional memory tasks.

In a double-blind placebo-controlled randomized study the influence of a cholinergic nootropic (WEB 1881 FU) on event-related brain potentials (ERPs) related to memory performance was investigated. Two different encoding modes were imposed on the subjects, who had to memorize word lists. No significant drug effects were obtained on memory performance and the ERP-concomitant of encoding, the Dm, while ERP effects related to memory were clearly present. However, the two dosages of the drug significantly influenced the overall amplitude of the late cognitive ERP components, suggesting its effect on cognitive processes.

Adult↗
PubMed1987

Human event-related potentials and circadian variations in arousal level.

Contingent negative variation (CNV) potentials were recorded from ten male subjects during a single session in divided- and focussed-attention conditions. Beside a strong dependency of CNV and N1 amplitudes and reaction time on task difficulty, the results of the present study show an effect of the subject types, classified by their peak performance times. The slight increase of CNV amplitude form morning to afternoon recording in evening-type subjects contrasted with a substantial decline in the morning-type subjects. Unexpectedly, both task conditions showed remarkably similar time courses of amplitudes. The attempt to model the individual amplitude curves from arousal levels led to inconclusive results. No final conclusions about the relationship of CNV and arousal levels over the course of a day can be drawn.

Adult↗
PubMed1986

Use of endogenous event-related potentials (ERP) in the evaluation of psychotropic substances: towards an ERP profile of drug effects.

Although endogenous event-related potentials (ERPs) have been successfully used in psychology, they have largely been neglected in the study of psychotropic substances. In the present paper an overview is given of the diversified concepts of ERP research and useful adaptations of these approaches to psychopharmacological questions are shown. In particular, the influence of drugs on the various stages of information processing and the description of individual differences in drug reactions seem suitable for the use of endogenous ERPs. Other possible uses of ERPs in psychopharmacological research are briefly discussed and the problems of the technique are pointed out. It is concluded that future research should aim at the recording of 'ERP profiles' of a drug, monitoring pharmacological effects on the different levels of cognitive functions by a set of selected paradigms.

Brain↗
PubMed1985

[Methodological aspects of the analysis of the effects of drugs (diazepam and caffeine) on contingent negative variation].

The paper discusses the importance and implications of the event-related-potentials in the analysis of effects of centrally acting drugs. This is illustrated using a study on the influence of diazepam and caffeine on the contingent-negative-variation (CNV) as an example. Special emphasis is placed on methodological problems and their possible solutions. A linear robust fitting technique was used for quantification of the slow-rising, ramp-like CNV potentials as an alternative to conventional baseline-to-peak measures. Results obtained by this method were validated by a second analysis taking slow superimposed DC-shifts into account. This was achieved by defining a reference line from the data for CNV-development and -resolution. The possibilities of single-trial potential evaluation were explored by using a pattern recognition algorithm. The average CNV-waveform was used as a reference-signal to which the single-trial potentials were correlated. Since pattern recognition techniques are sensitive to morphological changes of the potentials they are adding a new aspect to event-related-potential analysis.

Adult↗
PubMed1984

Personality traits influence the effects of diazepam and caffeine on CNV magnitude.

The time course of the effects of caffeine (200 mg), diazepam (8 mg) and placebo on CNV magnitude, reaction time and state of mood was investigated in normal volunteers using a double-foreperiod paradigm. CNV changes were quantified by means of a linear robust fitting technique. In general, a reduction of amplitude was found for diazepam and an enhancement followed by a suppression in the caffeine condition. Emotional lability of the subjects, as measured by the Freiburg Personality Inventory was shown to strongly influence the nature and time course of these drug effects. Differential drug responses are discussed in terms of the attention arousal model.

Adult↗