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Biomedical subjects

W Tapp

Publications and source records attributed to W Tapp.

5 recordsLinked to original sources
PubMed1997

Vagal activity predicts eyeblink conditioning in human subjects.

A group of old (mean age 73 years) and young (mean age 19.8 years) human subjects received concomitant eyeblink and heart rate classical conditioning, in which a 1000 Hz tone was the conditioning stimulus and a corneal airpuff was the unconditioned stimulus. Fewer old than young subjects showed eyeblink conditioning and age greatly attenuated the magnitude of the brady-cardiac conditioned heart rate response. The heart rate conditioned response was also significantly smaller in the subjects who failed to show eyeblink conditioning regardless of age, suggesting a relationship between parasympathetic cardiac control and somatomotor learning. The power associated with the respiratory peak in the heart rate spectrum, which is vagal in origin, was also smaller in subjects that failed to show eyeblink conditioning, again suggesting a relationship between parasympathetic cardiac activity and motor learning.

Adolescent↗
PubMed1995

Vagal tone is reduced during paced breathing in patients with the chronic fatigue syndrome.

Patients with chronic fatigue syndrome (CFS) often complain of an inability to maintain activity levels and a variety of autonomic-like symptoms that make everyday activity intolerable at times. The purpose of the study was to determine if there were differences in vagal activity at fixed breathing rates in women with CFS. Twelve women with the diagnosis of CFS between the ages of 32 and 59 years volunteered for the study. Healthy women, who were between the ages of 30 and 49, served as controls. Full signal electrocardiograph and respiratory signals were collected during a paced breathing protocol of three fixed breathing rates (8, 12 and 18 breaths/min) performed in the sitting and standing postures. Vagal activity was analyzed by means of heart rate spectral analysis to determine the subject's response to specific breathing rates and postures. Heart rate variability was used as a non-invasive method of measuring the parasympathetic component of the autonomic nervous system. Using this method, although there was significantly less vagal power in the sitting versus the standing postures for both groups, the overall vagal power was significantly lower (p < 0.034) in the CFS group versus healthy controls. Vagal power was also significantly lower (p < 0.01 to p < 0.05) at all breathing rates in both postures except while standing and breathing at 18 breaths/min. Knowledge of the differences in vagal activity for CFS patients may allow stratification for the analysis of other research variables.

Adult↗
PubMed1988

Multiple sclerosis in the Shetland Islands: an update.

Annual incidence rates of multiple sclerosis (MS) in the Shetland Islands have been updated from 1938 to 1986. These reveal a significant decline in MS incidence beginning between 1951 and 1968. No significant change in prevalence, age-specific prevalence, duration of MS, or mean age of the MS population in Shetland has been found since the last survey in 1974, although a trend towards an older MS population was noted.

Adult↗
PubMed1985

Declining incidence of multiple sclerosis in the Orkney Islands.

The incidence of MS in the Orkney Islands has been updated from 1941 to September 21, 1983. Since 1965, MS incidence rates have fallen significantly when compared with those for 1941 to 1964. Alterations in age-specific prevalence, mean duration of illness, and mean age of the MS population are consistent with the decline in incidence of MS in recent years. Although the reason for the decreasing incidence is uncertain, it is consistent with the hypothesis that MS may be caused by canine distemper virus.

Adult↗