Joe Kamiya

Altered autonomic function in patients with arthritis or with chronic myofascial pain.

&NA; Dynamic autonomic function tests (pupillary light reflex, Valsalva maneuver, and mental arithmetic) were used to evaluate autonomic function (pupil size, heart rate, and skin conductance) in patients with inflammatory arthritis or with chronic myofascial pain. Physiological responses in both groups of patients suggest concurrent increases in tonic pupillary autonomic activity (sympathetic and parasympathetic), with a relative sympathetic dominance, and a decrease in tonic parasympathetic cardiovascular activity. Furthermore, in the arthritis group, the data suggest decreased cardiovascular parasympathetic reaction and enhanced sudomotor reaction.

Conflicting results in EEG alpha feedback studies: why amplitude integration should replace percent time.

Success or failure of EEG feedback training for alpha enhancement can depend on how alpha activity is quantified and fed back. Alpha-enhancement failures usually employ a percent time(%) technique; successes typically use amplitude integration(ε). To dramatize the differences between percent and integration techniques, we derived both measures simultaneously from left occipital(O1) and left central(C3) sites for 16 male subjects who were given 5.6 hours of integrated alpha feedback from the midline occipital(Oz) site. At both the O1 and C3 sites the integrated and percent measures were not equivalent and not linearly related. Statistically significant differences in the(integrated, percent) correlation coefficients(z-transformed) were observed under the different recording conditions: alpha enhancement, alpha enhancement, alpha suppression, and baselines. Theoretical discussion of integration and percent techniques is given and the adoption of amplitude integration measures and feedback stimuli is strongly advocated.

Abdominal-thoracic respiratory movements and levels of arousal

Respiratory movements of the abdomen and chest of human Ss were found to undergo progressive changes with loss of wakefulness. Abdominal-dominant breathing was associated with relaxed wakefulness, abdominal-thoracic equality with drowsiness, and thoracic-dominant breathing with sleep onset. During drowsiness, variations in amplitude of abdominal movements were closely related to vacillations between alpha and theta activity in the EEG.

Observation of very slow potential oscillations in human scalp recordings

Abstract Very slow oscillations (5–8 c/min) were observed in the scalp potential of ten normal awake humans, ages 21–40, who were sitting quietly with eyes open. The oscillations were sometimes nearly in phase with slow, spontaneous breathing but continued during breath holding. The wave form was nearly sinusoidal but waxed and waned in amplitude, having a 50–75 μV peak-to-peak amplitude for continuous wave trains. They were observed in left-to-right occiput, left occiput-to-neck, and vertex-to-right mastoid potentials. The occurrence of the very slow oscillations was unpredictable. Sometimes a subject who did not show any slow waves during one recording session would exhibit them almost continuously in another recording. On the average the wave trains were present about 15% of the time. No stimuli or mental activity were found to affect the onset or termination of these waves. Possible sources of the very slow oscillations are discussed.

A very stable electrode system for recording human scalp potentials with direct-coupled amplifiers☆

Abstract Electrochemical factors involved in DC recordings are presented. Described is an electrode system which uses long flexible tubes to separate the metal-electrolyte interface of an electrode from the electrolyte-skin interface. Using commercially available Ag/AgCl skin potential electrodes, the system gave less than 0.5 μV/h drift occurring at each metal-electrolyte interface. The stability of the electrode bias potential is unaffected by connecting the bridge tubes to the subject or by other disturbances that occur during recording. In 1 h recordings from four subjects, the total measured potential changed at an average rate of 9 μV/min—a five fold improvement over previously described electrodes.