Academic journal article The Journal of Parapsychology

Explorations with the Perceptual ESP Test

Academic journal article The Journal of Parapsychology

Explorations with the Perceptual ESP Test

Article excerpt

In the first of several previous experiments using a perceptually based ESP test (Palmer & Johnson, 1991), a slide with a quasi-random assortment of the lowercase letters a to d was flashed for 150 ms to Dutch college students, who were asked to respond with the letter that seemed most salient to them when the slide was flashed. This was probably, but not necessarily, the letter that was in the center of their visual field. The idea was that a paranormal process would guide their eye movements in such a way that the fixated or otherwise most salient letter would match a randomly selected target letter being viewed by an agent. The broader purpose of the procedure was to minimize the intellectual kind of mental activity often associated with more traditional ESP tests in which subjects are required to conjure up an image or impression. There are indications in the literature that such linear thought processes are psi-inhibiting, especially in forced-choice ESP tests (Stanford, 1975).

Immediately prior to the presentation of the letter slide in this earlier work, a subliminal picture was flashed to the subject. The picture was either the standard Defense Mechanism Test (DMT) slide, in which a threatening male figure is peering down at a boy seated at a desk (Kragh & Smith, 1970), or a control slide in which the countenance of the male figure in the background is pleasant and smiling. Palmer and Johnson expected more negative ESP scores when the face was threatening than when it was smiling. The hypothesis was not confirmed, but two post hoc findings suggested that there was some ESP in the data. First, there was a confirmation of Stanford's (1975) response-bias hypothesis. When a particular letter was called six times or less out of the 40 trials, the number of hits on these undercalled trials was significantly above chance (p [is less than] .01) and significantly greater than on the remaining trials (p [is less than] .01).

Because one purpose of the perceptual ESP test is to minimize linear thought processes, it was hoped that there would be less evidence of response biases with this procedure than with a traditional forced-choice ESP test. It seemed that such biases were indeed reduced, particularly the undercalling of XX doublets, but the biases were still present to some degree. This was good news in one sense because it suggested that the perceptual responses to the letter slide were not merely random: there was evidence of some kind of information in the responses, whether or not any of that information was psychic.

The second finding was overall tight variance (p [is less than] .005), which has been associated with a negative mood in the literature (Rogers, 1966, 1967). The puzzling aspect of this finding was that the tight variance was present with the smiling subliminal picture as well as the threatening one. Two possible explanations were offered. First, the smiling picture may not have been as benign as was originally thought; for example, in retrospect, it could be construed as lecherous, especially by females. Second, a possibly negative context of the experiment as a whole could have caused the fight variance. For instance, to fulfill the requirements of a visual field manipulation, subjects had to wear uncomfortable goggles and place their chins on a chin rest during the ESP task. A third possibility was that the presentation of subliminal stimuli might itself have had a negative effect.

A partial replication of this experiment that excluded the visual field manipulation and the DMT control slide was subsequently conducted at the Institute for Parapsychology (Palmer, 1992). The targets were changed from the letters a to d to typewriter carets (or [caret]s) pointed up, down, left, or right. The test procedure henceforth was dubbed the caret test. The carets were chosen over the letters because they were thought to be more uniform physically and thus might further reduce response biases. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.