Abstract

The impetus for the present study was the findings of Spottiswoode (1997a, 1997b) showing that free response Anomalous Cognition (AC) effect size appears to be associated with Local Sidereal Time (LST) and that correlations between AC effect size and Global Geomagnetic Field (GMF) fluctuations appear to vary with LST. The need for replicating these findings in light of the lack of a sufficient amount of new AC data was highlighted. Using as an example a previous study on traffic accidents as related to GMF fluctuations and LST (Westerlund & Dalkvist, 1999), it was suggested that data from non-parapsychological databases could be used to test Spottiswoode's findings.

Memory data from 2859 subjects, collected in an ongoing prospective study on memory and health in Umea, a city in the northern part of Sweden, were examined for effects of GMF fluctuations and LST. Based on modern memory theory, three different types of memory were distinguished: episodic (personal), semantic (knowledge about the world) and implicit (unconscious) memory.

Using epoch analysis, for episodic and semantic memory, the correlation pattern between memory performance and the ap geomagnetic index (a measure of GMF fluctuations) was found to converge toward a negative correlation at the day of simultaneous measurement of the two variables and close to the hour of simultaneous measurement (one or two hours later). Although these results are not directly relevant for testing Spottiswoode's findings, and need to be confirmed, they do suggest that future research on GMF fluctuations as related to various types of data, ordinary psychological as well as purely parapsychological data, should be a fruitful approach within parapsychology.

The results of the analysis involving LST were less clear and less positive than those involving GMF fluctuations only. The attempt to replicate using memory data Spottiswoode's relationship between performance in AC experiments and LST failed. Except for semantic memory, overall significant effects of LST were obtained, reflecting increases in performance at 7-10h LST or so. But the relationship obtained did not resemble very closely that obtained by Spottiswoode. Most notably, our performance/LST curves were displaced backward in time by at least three hours as compared to Spottiswoode's curve. In the same vein, the attempt to replicate Spottiswoode's relationship between the correlation between GMF fluctuations and performance and LST also failed. Comparatively strong negative correlations were found around 10h LST, but the relationship deviated clearly from that obtained by Spottiswoode. Again, our curves were displaced backward in time, now by at least two hours as compared with that obtained by Spottiswoode.

Based on the present results, along with corresponding negative results from the previous traffic accident study, it was concluded that Spottiswoode's findings most likely were due to incidental correspondences between periodic events. It was pointed out that such incidental correspondences may occur when performance on a particular task is affected by an interaction of (ordinary) time of day and (ordinary) time of year.