Electroencephalography and clinical neurophysiology. Supplement
-
Electroencephalogr Clin Neurophysiol Suppl · Jan 1996
ReviewMagnetic resonance imaging studies of functional brain activation: analysis and interpretation.
We have demonstrated that a time series of echoplanar images can contain low frequency noise components which confound analysis of functional MRI data. In simulated tasks of long duration, the false positive rate from t-test analyses greatly exceeded the statistical probability level. As task durations were shortened, the false positive rate declined. ⋯ Many of the advantages of the procedures described here are due to the alternation of short duration tasks rather than the application of frequency domain techniques per se. However, the success of these techniques in isolating periodic task-related signal changes suggest that a more complex design with concurrent stimulation presented at different frequencies might be feasible. Such designs may have advantages in that categories of stimuli would not be presented in isolation but against a changing ba
-
Electroencephalogr Clin Neurophysiol Suppl · Jan 1987
ReviewElectrophysiological monitoring in the intensive care unit.
Spontaneous electrical activity (EEG) and event-related computer averaged brain electrical potentials (EPs) are becoming an integral part of CNS function monitoring in neurological intensive care patients. EEG monitoring using the compressed spectral array (CSA) computer analysis offers continuous information about cerebral electrical activity, permitting an accurate definition of the severity of brain injury, forecasting patient's course, and early detection of secondary intracranial changes. It offers more precise indications for treatment and prognosis. ⋯ Changes is electrophysiological patterns are often related to changes in other physiological parameters or events affecting the patient. Consequently, it appears advantageous to monitor simultaneously other CNS and body functions and record, process and display the data obtained in the patient care area. To make this comprehensive monitoring system reliable and useful, a wise application of advanced computer technology and a high degree of understanding of intracranial dynamics are required.
-
Electroencephalogr Clin Neurophysiol Suppl · Jan 1987
ReviewSleep/wake disturbances in working life.
This paper reviews the effects of shift work on sleep, alertness and well-being. It is seen that shift work causes disturbed sleep and increased fatigue. ⋯ Similarly, wakefulness is displaced to the circadian trough where the sleep-promoting properties of the circadian rhythm are at their maximum. The review concludes with a discussion of possible countermeasures.