Contralateral and heteromodal interaction effects in somatosensation: Do they exist?

In this paper we concern ourselves with the problem of whether or not conditioning stimuli of other modalities or stimuli applied to a distant locus of the body interact with a sensitive test of somesthetic temporal acuity we have called the gap test. The results of the experiment indicate that visual stimuli do not exert an observable influence on this temporal judgment, but that auditory stimuli and contralateral stimulation in the same modality do show a significant but relatively small effect. This is compared and contrasted with the very large and persistent effect reported when the conditioning stimulus is applied to the same electrodes as the gap test. By comparing our results with experiments of similar design carried out on lower animals by other investigators, some insights into the neural localization of the reported effects is obtained.     

Averaged occipital responses to stimulation of sites in the upper and lower halves of the retina

Averaged responses of the occipital lobes to flashes imposed along the midline of the upper part of the retina are larger and of shorter latency than responses to flashes imposed on the lower retina. Since reaction times also are shorter when the upper retina is stimulated, this study provides further evidence for the generalization that reaction time varies inversely with amplitude and directly with latency of the evoked response.     

Intermanual transfer of practice decrements with a haptic illusion

Sixteen subjects were given 8 pre-practice, 80 practice, and 8 post-practice trials with the inverted T illusion figure. Judgements were made haptically with one hand being used on pre- and post-practice trials and the other hand on practice trials. Mean illusion diminshed in magnitude over the practice trials. Inter-manual transfer of the practice decrement was found, but it was partial rather than complete. The illusion after practice was less than before practice, but it was greater than the error found on the last block of practice trials. The bearing of these results on the different theories of illusions is considered.