Shorter articles and notes: A case of fluctuation of awareness with the pulse

The case is described of a man in whom certain percepts of central origin (after-images of hallucinations) fluctuated rhythmically with the arterial pulse. The phenomenon is explained in terms of contemporary theories of consciousness and the inhibitory effects of baroceptor impulses.

In a previous communication (Oswald, 1957) it was described how some persons may experience visual after-images not only after retinal stimulation but also after the prolonged contemplation of a voluntary vivid image (hallucination). One of those described, Subject Wi, is further discussed below. It is relevant to this case and to the interpretation suggested, to recall that Griffits and Gordon (1924) described the rhythmical increase and decrease of the size, intensity, or apparent distance of vivid images (hallucinations) with rhythmical fluctuations of vasomotor tone, of pulse rate and, by inference, of blood pressure.