Biomedical subjects

R F Hoffmann

Publications and source records attributed to R F Hoffmann.

3 recordsLinked to original sources

PubMed1991

The electrophysiological correlates of dream recall and nonrecall from stage 2 sleep.

This research examined the relationship between cortical activation, defined by electroencephalographic (EEG) measures, and the ability to recall dreams following awakenings from Stage 2 sleep. Period-analyzed EEG data from 40 subjects were examined for the preawakening, postawakening, and preawakening-to-postawakening time intervals. Recall differed from nonrecall at the postawakening and preawakening-to-postawakening periods on measures of muscle activity and time spent in the sigma (12-16 Hz) frequency band. There were no distinctions in recall ability on EEG hemispheric asymmetry measures. Generally, the findings do not support the hypothesis linking increased recall ability to increases in cortical activation prior to awakening. However, the recall groups depicted a different pattern of arousal in their transition from sleep to wakefulness.

Adult↗

PubMed1979

Conceptual and methodological considerations towards the development of computer-controlled research on the electro-physiology of sleep.

A critical discussion of the visual scoring approach to the measurement of sleep electrophysiology details some theoretical shortcomings of that procedural model. An alternative approach employing high-speed, general purpose digital computers is then presented. It is argued that the measurement potential of computers is barely tapped by using computers to score sleep stages and the advantages of collecting data which are suitable for parametric and multivariate statistical analysis are described. Researchers are urged to include detailed reports on their procedural choices along with a discussion of the methodological implications of these procedures. Examples of computer collected data are presented along with a description of some simple data reduction strategies.

Computers↗

PubMed1978

Developmental changes in human infant visual-evoked potentials to patterned stimuli recorded at different scalp locations.

Visual-evoked potentials (VEPs) to patterned stimuli were recorded from 4 different scalp locations in 2 groups of infant subjects (ages 6 weeks and 10 weeks). Seven VEP components were identified that changed in amplitude as a function of changes in the amount of contour in the stimuli presented. Developmental shifts in these effects were interpreted to indicate a change in the physiological locus of control of infant visual preferences from a subcortical to a cortical locus over the age range examined.

Age Factors↗