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Biomedical subjects

A R Moffitt

Publications and source records attributed to A R Moffitt.

6 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↗
PubMed1981

A multivariate comparison between two EEG analysis techniques: period analysis and fast Fourier transform.

The present study investigated the statistical correspondence between two frequently used methods of analysing tonic EEG activity: (1) period analysis and (2) Fast Fourier Transforms (FFTs). For replication purposes, independent statistical analyses were carried out on the EEG of sleeping subjects and of awake subjects performing a cognitive task. From the results of two canonical correlations, the first two canonical variates were sufficient to account for 97% (awake group) and 99% (sleeping group) of the variance between the separate linear composites of all FFT and period analysis variables. Linear regressions of the 3 dependent measures generated by period analysis onto each respective FFT measure gave high and significant multiple correlations for all frequencies. Zero-order correlations were also gathered and discussed. It is concluded that period analytic and FFT analysed EEG share similar types of information and that period analysis can be used more often in EEG research.

Arousal↗
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↗
PubMed1975

Frequency discrimination by young infants.

The nonnutritive sucking of groups of 1-month-old infants was conjugately reinforced with either a 200-H or a 500-H pure tone. Following response acquisition and satiation, the sucking of the experimental groups was reinforced with a new pure tone (either 500 or 200 H) to a criterion of response decrement, after which sucking was reinforced with the original tone. Control groups were reinforced with a single tone (200 or 500 H) throughout the experiment. Frequency of nonnutritive sucking increased significantly in the experimental groups following a shift in frequency of the reinforcing tone but remained unchanged in the control groups, indicating discrimination between 200- and 500-H tones.

Acoustic Stimulation↗