We used the stimulus-driven 40-Hz auditory steady-state response (ASSR) that localizes tonotopically to the region of primary auditory cortex (A1) to study modulation of this region by top-down attention. Experiment 1 presented amplitude modulated (AM) auditory and visual stimuli simultaneously (AM at 40 Hz and 16 Hz, respectively) while participants responded to targets in one modality or the ...

The cross-tolerance technique was used to analyze the receptor mechanisms of analgesia induced by electroacupuncture (EA) of 2 Hz, 100 Hz, or 2-15 Hz. (1) Rats were given EA stimulation of 2 Hz, 100 Hz and 2-15 Hz for 30 min with 30 min intervals successively. The percentage increase in tail-flick latency (TFL) was taken to indicate the intensity of EA analgesia. Rats made tolerant to repeated ...

BACKGROUND Survival of post-myocardial infarction patients is related inversely to their levels of very-low-frequency (0.003 to 0.03 Hz) RR-interval variability. The physiological basis for such oscillations is unclear. In our study, we used blocking drugs to evaluate potential contributions of sympathetic and vagal mechanisms and the renin-angiotensin-aldosterone system to very-low-frequency R...

Abstraet-Neurophysiological studies in cats have established a functional relationship between waking 12-15 Hz sensorimotor cortex rhythmic EEG activity (the sensorimotor rhythm or SMR) and a similar pattern during sleep, the sleep spindle. Both result from oscillatory thalamocortical discharge involving ventrobasal thalamus and sensorimotor cortex, and both are associated with a state of suppr...

Cell phones emitting pulsed high-frequency electromagnetic fields (EMF) may affect the human brain, but there are inconsistent results concerning their effects on electroencephalogram (EEG). We used a 16-channel telemetric electroencephalograph (ExpertTM), to record EEG changes during exposure of human skull to EMF emitted by a mobile phone. Spatial distribution of EMF was especially concentrat...

The prefrontal cortex plays an important role in planning complex cognitive behavior, personality expression, and decision making. This study aims to assess the phase synchronization of signals of the oxyhemoglobin concentration changes (Δ[HbO2]) in the left and right prefrontal tissues through near-infrared spectroscopy (NIRS) with wavelet phase coherence (WPCO) method. The NIRS signals were c...

The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0...

BACKGROUND Morbid obesity is directly related to deterioration in cardiorespiratory capacity, including changes in cardiovascular autonomic modulation. OBJECTIVE This study aimed to assess the cardiovascular autonomic function in morbidly obese individuals. METHODS Cross-sectional study, including two groups of participants: Group I, composed by 50 morbidly obese subjects, and Group II, com...

Background The prognostic implications of alterations in heart rate variability have not been studied in a large community-based population. Methods and Results The first 2 hours of ambulatory ECG recordings obtained on original subjects of the Framingham Heart Study attending the 18th biennial examination were reprocessed to assess heart rate variability. Subjects with transient or persistent ...