These results suggest the presence of an anomalous psychophysiological interaction effect. This effect was localised in the posterior temporal/occipital cortex, which is consistent with the effects of visual stimulation. The lack of such an effect in the group of "receivers" who were not paired with a "sender" further suggests that this effect is dependent on sensory stimulation of another participant, and cannot be attributed to a general methodological flaw, or to direct anomalous perception of the remote stimuli. The similar magnitude of the effect seen in related and unrelated pairs further suggests that an empathic relationship and prior interaction between participants is not necessary for the induction of the effect, as some previous studies have suggested (Grinberg-Zylberbaum, Delaflor et al. 1994), and is in agreement with the conclusions of other studies who also found a similar pattern of results (Wackermann, Seiter et al. 2003). As however the unrelated and no-sender groups in the first study were too small to allow statistical comparisons between groups to be made, a second study was conducted with equal numbers of participants in each group (thirteen pairs in each of the related and unrelated groups, and thirteen single participants in the no-sender group; total N=65). An additional feature of the second study is the adoption of an 'oddball' stimulation paradigm, where two types of stimuli are presented (green and red flashes) at a ratio of 3-to-1. The less common stimuli typically evoke a different pattern of cortical responses in the stimulated participants than the common stimuli, and we will examine if the same pattern can be observed in non-stimulated participants. The presence or absence of this similarity will help in clarifying the physiological characteristics of the anomalous effect. A further improvement in the second study involves recording EEG simultaneously from both the stimulated and non-stimulated participants.
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