Academic journal article The Journal of Parapsychology

Does Autonomic Nervous System Activity Correlate with Events Conventionally Considered as Unperceivable? Using a Guessing Task with Physiological Measurement

Academic journal article The Journal of Parapsychology

Does Autonomic Nervous System Activity Correlate with Events Conventionally Considered as Unperceivable? Using a Guessing Task with Physiological Measurement

Article excerpt

There are several reports on the anomalous effects of events conventionally considered as not perceivable on affect, cognition, and behavior. This means that these events occur in an unforeseeable manner in the future and/or spatially separated from the person. The use of psychophysiological methods to examine correlations between the unforeseeable future or spatially separated events and the autonomic nervous system activity of the participants began in the 1950s (for reviews, see Beloff, 1974; Palmer, 1978, 1982). In this vein, Sartori, Massaccesi, Matinelly, and Tressoldi (2004) and Tressoldi, Martinelli, Massaccesi, and Sartori (2005) used a forced-choice guessing task (FCGT) with physiological measurement. In each block, four pictures of objects were presented sequentially on a screen, each for a period of 10 s. After that, participants conducted a precognition task: They were asked to guess which one of the four objects would be randomly chosen by the computer as a target. Then, one object was chosen randomly and presented. It was hypothesized that the future event of presenting one object as the target at the end of each block would affect the heart rate in response to this object during the previous sequential presentation despite the fact that the selection of the target object is conventionally considered to be unpredictable. The results of these studies revealed that a significantly increased heart rate was associated with the presentation of objects later shown as targets compared with the presentation of nontargets. Lobach and Bierman (2010) confirmed this result. In their study, a significantly higher heart rate was observed during the 3 s of object presentation due to a continuous decrease of the interbeat intervals throughout the 3 s. All these studies showed a hit rate of target objects at chance expectation.

In psychophysiological research, physiological responses to the stimuli presented are explained by the concept of the orienting response. This is a response of an organism to all perceivable changes in the environment, and was first characterized by Pavlov in 1927 (Sokolov, 1963). The most important determinants of the orienting response are the novelty, significance, and intensity of a stimulus (e.g., Lynn, 1966). Stimuli that differ with respect to one or more of these determinants can be distinguished by means of the physiological responses they evoke during their sequential presentation (e.g., Barry, 1990; Ben-Shakhar, 1994; Turpin, 1999). This psychophysiological mechanism is used in the Guilty Knowledge Test (Lykken, 1959) for the detection of concealed information. In a common variant of the test, participants are confronted with objects belonging to different categories in a mock crime, with the aim to have these objects gain particular significance for the participants. In the subsequent test phase, pictures of these objects are presented sequentially in combination with pictures of unknown objects from the same categories. It is assumed that similar objects of one category evoke comparable physiological responses and that differences in the responses to the objects are mainly attributable to the particular significance the objects gained during the previous confrontation. By using such a categorical design, the statistical power of the test is enhanced. Each object presentation is combined with the question whether the object has been part of the mock task. The significance of the particular object, together with the instruction to deny one's knowledge, are known to evoke different electrodermal response amplitudes, heart rate changes, respiratory activity (assessed via the respiration line length), and pulse activity (assessed via the finger-pulse waveform length) than to objects that do not have a specific significance (Gamer, 2011). With respect to electrodermal activity, an increase in response amplitudes is directly associated with the modulation of the orienting response as a result of the significance of stimuli (Barry, 2004). …

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