Experimental Production of Illusory (False) Memories in Reconstructions of Narratives: Effect Size and Potential Mediation by Right Hemispheric Stimulation from Complex, Weak Magnetic Fields

Abstract

This experiment was designed to discern the proportion of false, inferential and verbatim memories that would be included in the reconstruction, on e week later, of a 5min narrative containing ambiguous but emotional content about a little boy. After 48 subjects were administered Spiegel's Hypnosis Induction Profile, they listened to the narrative, were exposed to on e of four applications of transcerebral weak, complex magnetic fields for 30min and then given either an accurate or inaccurate short summary of the story. One week later the group who received the erroneous summary reported more false memories about the original story than did the reference group; this treatment accommodated about 40% of the variance in numbers of false memories. Only an indicator of electrical lability within the temporal lobes (but not hypnotizability) was strongly associated with the numbers of inferential memories but not the numbers of false memories. The group that received transcerebral stimulation over the right hemisphere by a complex magnetic field and the erroneous summary reported three times the numbers of false memories compared to the other groups. Whereas verbatim memories showed a strong primacy effect inferential memories exhibited a strong recency effect (η2 =. 66).