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Personality correlates to electrophysiological measures of prestimulus response

ProQuest Dissertations and Theses, 2009
Dissertation
Author: Paula Kaur Singh
Abstract:
This study assessed personality correlates to electrophysiological measures of prestimulus response (PSR). PSR is the body's response to a future stimulus prior to experiencing the stimulus. PSR may be an approach to measuring an aspect of intuition. One-hundred candidates for the study completed the Myers-Briggs Type Indicator (MBTI). Data were scored to generate raw points and to categorize each participant by 4 of 8 MBTI personality factors. Forty-two participants consisting of 21 people with the highest respective scores on the MBTI Intuition and Sensation scales were selected for inclusion in the study. Electrophysiological data were acquired during a PSR experiment utilizing a roulette simulation. The participants were connected to a Biopac MP150® data acquisition system to continuously acquire electrocardiogram (ECG) for heart rate variability (HRV) and skin conductance levels (SCL). In each of 26 trials, the participants made a simulated investment and chose either red or black as the future target. Once the electrophysiological data were acquired, the target was determined by a random number generator. For each participant, HRV and SCL were analyzed separately for win and loss trials for 3 segments of each trial--prebet, postbet, and postresults. Random permutation analysis was used to determine statistical significance of the differences for HRV and SCL respectively for win and loss trials. Stouffer Z scores were calculated for participants categorized to the 8 personality factors in order to determine which personality factors, if any, correlated with electrophysiological evidence of PSR. Participants categorized as Sensation on the MBTI demonstrated a significant HRV response to prestimulus information in the prebet segment ( N = 19, Z = -1.83, p = .0333). SCL evidence of prestimulus response was not statistically significant. The results of this study may be applicable to areas of business, learning, overall well-being, creativity, medical diagnosis, healing, and spiritual growth.

v Table of Contents

Abstract

.......................................................................................................................................... iii List of Tables

............................................................................................................................... viii List of Figures

................................................................................................................................ ix Chapter 1: Introduction

................................................................................................................... 1 Research Question

.............................................................................................................. 1 Significance of Research

..................................................................................................... 2 Overview of Study Design and Analysis of Results

........................................................... 3 Overview of Dissertation

.................................................................................................... 4 Chapter 2: Literature Review

.......................................................................................................... 5 Overview of Literature on Prestimulus Response

.............................................................. 5 Prestimulus Response Studies

............................................................................................. 5 Prestimulus response studies using event related potentials.

.................................. 5 Prestimulus response studies using skin conductance levels.

............................... 12 Prestimulus response studies using functional magnetic resonance imaging.

...... 16 Prestimulus response studies using heart rate variability.

.................................... 17 Theoretical Literature Relevant to Prestimulus Response

................................................ 23 Overview of Measures of Paranormal Beliefs and Experiences

....................................... 25 Chapter 3: Research Methods

....................................................................................................... 27 General Design

.................................................................................................................. 27 Participants

........................................................................................................................ 28 Procedure

.......................................................................................................................... 30 Instruments

........................................................................................................................ 32 Treatment of Data

............................................................................................................. 34 Myers-Briggs type inventory

................................................................................ 34

vi Skin conductance levels

........................................................................................ 35 Heart rate variability

............................................................................................. 35 Statistics for skin conductance levels and heart rate variability

........................... 36 Correlation of MBTI category to evidence of prestimulus response

.................... 38 Internal Validity

................................................................................................................ 38 External Validity

............................................................................................................... 40 Chapter 4: Results

......................................................................................................................... 41 Overview

........................................................................................................................... 41 Participant Characteristics: Demographic Data

................................................................ 41 Gender.

.................................................................................................................. 41 Ethnicity.

............................................................................................................... 41 Relationships

......................................................................................................... 41 Vocation

................................................................................................................ 41 Overall Findings

................................................................................................................ 42 Correlation of MBTI Categories to Electrophysiological Evidence of PSR

.................... 42 Chapter 5: Discussion

................................................................................................................... 47 Summary and Integration of Results

................................................................................. 47 Sensation

............................................................................................................... 47 Judging

.................................................................................................................. 47 Females

................................................................................................................. 48 Roulette Simulation Scenario

........................................................................................... 48 Comparison of Findings to Past Literature

....................................................................... 48 Convergent findings with past literature.

.............................................................. 48 Divergent findings with past literature

................................................................. 49 Contribution to prestimulus response research

..................................................... 49

vii Limitations

........................................................................................................................ 49 Delimitations

..................................................................................................................... 50 Suggestions for Future Research

...................................................................................... 51 References

..................................................................................................................................... 52 Appendix A: Recruitment Flyer

.................................................................................................... 59 Appendix B: Consent Form

.......................................................................................................... 60 Appendix C: Screening Questionnaire

.......................................................................................... 63

viii List of Tables Table Page 1 Measures Used in Prestimulus Response Studies

....................................................6 2 Comparison of Participant Gender by Age

............................................................42 3 Comparison of Prebet HRV Analysis by MBTI Category

....................................43 4 Comparison of Prebet HRV Analysis by Gender, Age, and Personality Factor

....45

ix List of Figures Figure Page 1 Schematic representation of normal ECG trace (sinus rhythm) with waves and RR interval labeled ..........................................................................................36

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Chapter 1: Introduction Research Question The purpose of this study was to explore the question, “Do characteristics of personality correlate to electrophysiological measures of prestimulus response (PSR), and if so, which ones?” PSR is the body’s response to a future stimulus prior to experiencing the stimulus. The emotional significance of the future stimulus is often reflected in PSR; the greater the emotional significance of the future stimulus the larger the physiological response prior to experiencing the stimulus. PSR may be an approach to measuring an aspect of intuition. There is a plethora of research on intuition; however, there is not a consensus about a definition or theory of intuition (Agor, 1984; Assagioli, 1990; Bailey, 1978; Berne, 1949; Bradley, 2007; Govinda, 1969; Hogarth, 2001; Jung, 1933; Laughlin, 1997; Liester, 1996; McCraty, Atkinson, & Bradley, 2004a, 2004b, in press; McLean, 1978; Torff & Sternberg, 2001; Vaughan, 1973; Weil, 1972; Wild, 1938). McCraty et al. (2004b) regarded “nonlocal intuition” as a process by which information normally outside of the range of conscious awareness is immediately sensed and perceived by the body’s psychophysiological system. Experiences of intuition may occur in many forms. McCraty et al. explained that “the experience of intuition is not confined to cognitive-based perception, but involves the entire psychophysiologic system, often manifesting through a wide range of emotional feelings and physiologic changes experienced through the body” (p. 326). PSR may be a form of intuitive perception. Bradley (2007) described intuitive perceptions as “those perceptions that are not based on reason or logic or on memories or extrapolations from the past, but are based, instead, on accurate foreknowledge of the future” (p.

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61). In PSR studies, the body’s apparent foreknowledge of the future is detected and measured by electrophysiological instruments. There is a large body of research showing electrophysiological evidence of PSR (Bierman, 2000; Bierman & Radin, 1997, 1998; Bierman & Scholte, 2002; Bierman & van Ditzhuijzen, 2006; Don, McDonaough, & Warren, 1998; Gillin et al., 2007; Hinterberger, Studer, Jäger, Haverty-Stacke, & Walach, 2006; La Pira & Gillin, 2006; La Pira, Gillin, & Scicluna, 2006; Levin & Kennedy, 1975; McCraty et al., 2004a, 2004b, in press; McDonough, Don, & Warren, 2002; May, Paulinyi, & Vassy, 2005; May & Spottiswoode, 2003; Norfolk, 1999; Paige, Newton, Reese, & Dykman, 1987; Parkhomtchouk et al., 2002; Radin, 1997a, 1997b, 2004; Radin & Lobach, 2007; Spottiswoode & May, 2003; Warren, McDonough, & Don, 1992a, 1992b; Wildey, 2001). However, not all participants in PSR studies show individual electrophysiological evidence of PSR. If personality characteristics, for instance, Intuition on the Myers-Briggs Type Inventory, correlate with PSR electrophysiological data, then personality instruments may be used to inform the selection of participants in future PSR studies. Significance of Research Studying PSR is relevant to virtually every aspect of our lives. By studying electrophysiological responses to information about future events before these events actually take place, we may be able to use our body’s electrophysiological responses to inform choices and decisions in business, learning, overall well-being, creativity, medical diagnosis, healing, and spiritual growth. Studying the correlation of personality characteristics to electrophysiological measures of PSR may inform the selection of participants in future studies of PSR and the selection of people for roles that may benefit from having information about future events before these events actually take place.

3

Overview of Study Design and Analysis of Results The following procedure was used to assess the correlation of personality characteristics to electrophysiological measures of PSR. A personality measure, the Myers-Briggs Type Indicator (MBTI) Form M, was administered to a pool of 100 candidates for the study. The MBTI data were hand scored using the procedure described on the Form M scoring templates to generate raw points for the eight factors (namely, Extrovert, Introvert, Intuition, Sensation, Thinking, Feeling, Judging, and Perceiving) and to categorize each participant by 4 of the 8 personality factors. Forty-two participants consisting of 21 people with the highest respective scores on the MBTI Intuition and Sensation scales were selected for inclusion in the study. The dichotomous preferences, Intuition and Sensation, were selected because PSR may be a measure of an aspect of intuition. Electrophysiological data were acquired during the following PSR experiment utilizing a roulette simulation developed and tested by the Institute of Heart Math (Gillin et al., 2007; La Pira & Gillin, 2006; La Pira et al., 2006; McCraty et al., in press). The participants were connected to a Biopac MP150® data acquisition system (McMullen & Kremer, 2007) to continuously acquire electrocardiogram (ECG) for heart rate variability (HRV) and skin conductance levels (SCL). HRV is a measure of the beat-to-beat changes in heart rate. SCL is a measure of the electrical conductance of the skin. In each of 26 trials, the participants made a simulated investment and chose either red or black as the future target. After electrophysiological data were acquired, the target was determined by a random number generator. The result of each run was tallied on the bottom left-hand side of the screen so that the participant received feedback and knew whether she or he won or lost on each trial. A running total (win/loss) was also displayed on the screen.

4

For each participant, HRV and SCL were analyzed separately for win and loss trials for three segments of each trial—prebet, postbet, and postresults. Random permutation analysis was used to generate z-scores to determine statistical significance of the differences in HRV and SCL respectively in win and loss trials. Stouffer Z scores were calculated for participants categorized to the eight personality factors of the MBTI in order to determine which personality factors, if any, correlated with electrophysiological evidence of PSR. Further analysis was conducted based on gender and age of the participants (see Chapter 4). Overview of Dissertation This dissertation is divided into four subsequent chapters. Following this introductory chapter, Chapter 2 offers an overview of the PSR studies as delineated in the available literature. Following the literature review, Chapter 3 describes the details of the research methods used, including the rationale for the overall design, a description of the participants, the instruments used, the procedures for data acquired, and the analysis techniques. Chapter 4 presents the results of this study. Finally, Chapter 5 concludes this dissertation with a discussion that integrates data, describes limitations and delimitations, and provides suggestions for future research.

5

Chapter 2: Literature Review Overview of Literature on Prestimulus Response This chapter provides an overview of the history of PSR studies and an overview of measures of paranormal beliefs and experiences. The PSR studies in this review use several measures (see Table 1); however, for organization, they will be divided into four subsections: studies using event related potentials (ERP), skin conductance levels (SCL), functional magnetic resonance imaging (fMRI), and heart rate variability (HRV). The literature will be reviewed chronologically within each subsection. This will be followed by a review of theoretical literature relevant to PSR and an overview of measures of paranormal beliefs and experiences. Prestimulus Response Studies Prestimulus response studies using event related potentials. Levin and Kennedy (1975) were the first researchers to publish physiologic evidence of PSR in a peer reviewed journal. Levin and Kennedy acquired electroencephalogram (EEG) to measure event related potentials (ERP) in a pilot study to determine whether people use psi information in neural processing to prepare for voluntary motor responses. ERP are voltage fluctuations that are associated in time with some physical, mental, or emotional occurrences and can be recorded from the scalp. ERP have measurable components such as negative slow waves (NSW). On each trial, an amber warning light preceded either a red or green light by 1.25 seconds. Five participants were instructed to press a key as quickly as they could when they saw a green light. Levin and Kennedy observed significantly larger NSW brain potentials associated with PSR, after the amber warning light, but before the randomly determined green light (z = 1.96, p = .05, two tailed).

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Table 1 Measures Used in Prestimulus Response Studies Table 1: Measures Used in Prestimulus Response Studies PSR Study Author, Date BVP ERP fMRI HR HRV ns-SCR SCL Bierman, 2000

X

X

X

Bierman & Radin, 1997

X

X

X

Bierman & Radin, 1998

X

X

X

Bierman & Scholte, 2002

X

Bierman

& van Ditzhuijzen, 2006

X

Don, McDonaough, & Warren, 1998

X

Gillin, LaPira, McCraty, Bradley, Atkinson, Simpson, & Scicluna, 2007 X X X Hinterberger,

Studer, Jäger, Haverty - Stacke, & Walach, 2006

X La Pira & Gillin, 2006

X

X

X

La Pira, Gillin ,

& Scicluna, 2006

X

X

X

Levin & Kennedy, 1975

X

May, Paulinyi, & Vassy, 2005

X

May &

Spottiswoode, 2003

X

McCraty, Atkinson, & Bradley, 2004a

X

X

X

X

McCraty, Atkinson, & Bradley, 2004b

X

X

X

X

McCraty, Atkinson, & Bradley, in press

X

X

X

McDonough, Don, & Warren, 2002

X

Norfolk, 1999

X

Paige, Newton, Ree se, & Dykman, 1987

X

Parkhomtchouk, Kotake, Zhang, Chen, Kokubo, & Yamamoto, 2002

X X X Radin, 1997a

X

X

X

Radin, 1997b

X

X

X

Radin, 2004

X

X

X

Radin

& Lobach,

2007

X

Spottiswoode & May, 2003

X

Warren, McDonough ,

& Don 1992a

X

Warren, McDonough ,

& Don 1992b

X

Wildey, 2001

X

Note. BVP = blood volume pulse; ERP = event related potentials; fMRI = functional magnetic resonance imaging; HR = heart rate; HRV = heart rate variability; ns-SCR = nonspecific skin conductance response; SCL = skin conductance level.

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Levin and Kennedy’s (1975) findings were supported by an unrelated Pavlovian conditioning study. Paige, Newton, Reese, and Dykman (1987) reported significant PSR ERP in 10 male medical students (mean age = 26 years, range = 24 to 28 years) in the habituation phase of a conditioning experiment. The medical students showed a significantly larger P300 (an ERP component) prior to conditioned stimuli before they had any way of knowing which of two stimuli (conditioned or unconditioned) would be later presented. In two separate studies Warren et al. (1992a, 1992b) reported significant prestimulus ERP changes in Malcolm Besset during computerized PSR trials using targets selected by a random number generator. Besset is an exceptional participant who has shown above-chance performance in other published laboratory psi tasks (see Honorton, 1987). Besset was administered 200 self-paced trials (20 runs with 10 trials per run). On each trial, Besset was shown four card images on a computer monitor 2.5 seconds after being presented with the last four card images. Besset then selected one of the card images using a game paddle to move the cursor on the screen and registered his guess using the paddle enter key. Once he made the selection, the target image was randomly chosen by the computer among the four card images and displayed on the monitor. Besset was instructed to inhibit his eye-blinks and movements as well as his body movements during the stimulus presentation sequence for each trial and to attempt to blink during other less critical portions of the trial or between trials. Besset was permitted rest breaks and allowed to smoke at will. Besset showed larger PSR in two ERP components, P100 and the NSW, to targets than nontargets (Warren et al., 1992a). The significantly larger P100 and NSW were widely distributed across all 10 scalp sites examined by the investigators. The P100 and NSW accounted

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for two-thirds of the variance in a significant, successfully cross-validated, multiple regression model predicting target-nontarget status. However, in his conscious guesses Besset scored nonsignificantly below chance level in the 200 self-paced trials over a 1⅔ hour period. The investigators concluded that PSR is unconscious because information is not consciously available to improve guessing accuracy. Possible explanations for below chance performance not discussed by the investigators include habituation, decrease in motivation, and fatigue. Warren et al. (1992b) partially replicated their first study using exactly the same protocol. Consistent with the preliminary findings, prestimulus response NSW were significantly larger to targets than nontargets. However, the significantly larger prestimulus response NSW only occurred at the five left-hemisphere scalp sites examined in the study. Also consistent with the preliminary findings, Besset’s correct guesses were nonsignificantly below chance. The investigators suggested that Besset’s performance may have been due to increased demands associated with the need to control eye movements and with the distractive effect of having electrodes attached to his scalp. The significant P100 findings reported in the first study could not be replicated. The preceding prestimulus response NSW findings were extended in two subsequent gambling studies with participants who were not selected for self-reported psychic ability or experience (Don et al., 1998; McDonough et al., 2002). Each participant was selected for self- report of gambling activity at least once a week. In the first gambling study, 25 participants (17 male and 8 female, mean age = 27.4 years, range = 18 to 49 years) were given 80 trials similar to those in the preceding studies. The study utilized a crossover design; half of the 80 trials used in the study were “nonwager trials” (each participant played just for fun) and in the other half each participant wagered 50 cents per hand, with a $2 possible payoff per hand.

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Don et al. (1998) observed significantly larger PSR in NSW over the left hemisphere to targets than nontargets in nonwager trials (F = 7.33, p = .007, one-tailed), and a very early negativity peaking at about 59-67 ms in both “nonwager” and “wager” trials (F = 5.26, p = .03). NSW were found to be approximately similar in size and direction over both (left and right) hemispheres; at the same time, the right hemisphere data failed to reach statistical significance. The investigators mentioned that the nonsignificant tendencies observed over the right hemisphere preclude conclusions about the involvement or noninvolvement of the right hemisphere. Don et al. (1998) findings suggest that participants allocated more attentional resources to targets than they did to nontargets. Again, this possible allocation of attention did not appear to be a conscious process because it did not inform the participants. The participants’ performance in the gambling task during nonwager trials was nonsignificantly below chance. Guessing accuracy tended to be nonsignificantly above chance in the wager trials. Except for the very early negative peaking at about 59-67 ms, the NSW observed for targets in the nonwager trials did not occur in the wager trials. In fact, the ERP was slightly positive in the wage trials, suggesting that the act of wagering may affect prestimulus response ERP. Firm conclusions cannot be drawn from nonsignificant tendencies; however, it is possible that nonsignificantly positive prestimulus response ERP are associated with the nonsignificantly above chance correct guessing accuracy. This association may indicate that the participants in this study had a different motivational/attentional set in wager trials than in nonwager trials, which improved their ability to discriminate targets from nontargets (Don et al., 1998). In the second gambling study, the investigators (McDonough et al., 2002) studied PSR in 20 participants (16 males, 4 females, mean age = 27.4 years, range = 18 to 49 years) who self-

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reported gambling activity at least once a week. The protocol was similar to the first gambling study. Results were reported only for the nonwager trials. PSR was observed in significantly larger NSW for targets than for nontargets over the six sites examined in the right hemisphere (F = 4.29, p ≤ .05), but not over the left hemisphere sites examined in this study. The investigators mentioned that it is possible that more than one type of NSW was elicited by the PSR task. Participants’ guessing accuracy was nonsignificantly above chance. Bierman and van Ditzhuijzen (2006) studied PSR in 32 participants (22 female, 10 male, mean age = 23 years, range = 17 to 51 years). Participants were students and could earn course credit or money or a combination. The amount of money they could earn was determined by the outcome of the slot-machine task. At the beginning of the experiment the participants received a loan of seven pieces of 50 eurocents. Participants were informed that they had to pay 50 cents for each trial and that the outcomes were random. The slot-machine was implemented using video clips. Each video clip contained a movie of a slot-machine with three windows with moving fruits. The participants had to press any key to initiate a trial and run the clip. The video clip to be presented was copied randomly when the participant initiated the trial from a prepared pool of 128 slot-machine video clips. One second after the participant pressed any key to initiate the trial, the left-most window froze to display one of three possible fruits. After another second the middle window froze into one of three possible fruits, and after another 1-second the last rightmost window froze into one of the three possible fruits. There were three types of outcomes: three subsequent different fruits (XYZ), two equal fruits followed by a different one (XXY) and three equal fruits (XXX).The outcome where all three windows had equal fruits was a win and the experimenter paid the participants 14 pieces of 50 eurocents for each win. A priori probability for an XXX-event was 12.5% throughout the

11

experiment. Each participant completed 128 trials. The subjects kept the money they won and did not pay anything whenever they lost money. The investigators compared the mean voltage during the one second preceding the outcome pooled from three mediofrontal electrodes. As in other studies showing evidence of PSR, the investigators expected that the brain signals preceding a win would differ significantly from the brain signals before a loss. PSR was confirmed by comparison of two types of outcomes, XXX and XXY, for the period from 1 to 2 seconds (at XX and before the last fruit is known). During this time there were no visible differences for the participants, even though the brain signals differed by about 1.9 microvolt on average (t = 2.34, df = 31, p = 0.026). The effect size was larger for males (~ 2.6 microvolt) than for females (~1. 5 microvolt) but the difference was not significant. Radin and Lobach (2007) studied PSR in 20 participants (13 females, age = 18 to 65 years; 7 males, age = 48 to 65 years). The investigators recorded slow brain wave activity from the occipital region (associated with vision) at the back of their participants’ brains via EEG while the participants were visually stimulated at random times. The stimulation came in the form of a light that was quickly flashed toward the subject's eyes through a pair of opaque glasses fitted with light-emitting diodes (LEDs). To start each individual test trial, the participant clicked a computer mouse that they held in their hands. After 4 seconds (which constituted the prestimulus period) had passed, the computer sampled a random number generator to determine whether it should activate the LEDs in the participants’ glasses and produce a flash, or whether it should keep them dark until the end of the trial (indicated by a computer tone). The same process was then repeated for the next trial. One hundred trials were conducted per participant. The probability of the subject seeing the LEDs flash or not was exactly .50 for each trial.

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Female participants showed evidence of PSR with a slightly higher level of brain wave activity in the prestimulus period on the trials where the LEDs were flashed than on the trials where the LEDs did not flash (z = 2.72, p = 0.007, two-tailed). The investigators found that the peak level of brain wave activity for the female participants occurred approximately 1-second before the light flash. For males, the same analyses were weakly negative, in that their level of brain wave activity was slightly lower on flash trials than on no flash trials (z = -1.64, p = 0.10, two-tailed). This latter finding was not statistically significant. However, the gender differences between outcomes were significant (z = 3.08, p = .0002, two-tailed) and warrant further research. The strength of Radin and Lobach (2007) PSR study lies in its rigorous design and analysis, thereby providing results that are not caused by anticipatory strategies, equipment or environmental artifacts, or violation of statistical assumptions. A weakness in this study is the small sample size. The investigators mention that caution is warranted in generalizing the study findings. ERP will not be used in the current study due to the amount of time and expertise required to acquire and analyze EEG and ERP data. In the current study, physiologic measures will be limited to HRV and SCL. SCL has been chosen as the second physiologic measure because of its frequent use in PSR studies. The next section summarizes the findings of studies showing SCL evidence of PSR. Prestimulus response studies using skin conductance levels. Bierman and Radin (1997) observed significant prestimulus differential effects in skin conductance levels (SCL), heart rate (HR), and blood volume pulse (BVP) measures prior to presentation of emotional and neutral photographic stimuli.

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In a series of four experiments (Radin, 1997b), 31 participants were asked to read an informed consent form explaining that some disturbing pictures might be shown and to provide their verbal consent before the PSR experiment began. Electrodes and photoplethysmograph were placed for recording SCL, HR, and BVP. Participants sat in a reclining chair approximately two feet in front of a computer monitor. Participants pressed a mouse button that started each trial. After the button press, the computer screen remained blank for 5 seconds, and then the computer randomly selected a target photograph which was displayed for 3 seconds. The target photographs were digitized color photographs from a pool of 120 photographs. Some target photographs labeled “calm” included landscapes and cheerful people; other target photographs labeled “extreme” included violent (mutilated bodies) and erotic topics (explicit sexual activity). The 3-second presentation of the target photograph was followed by a blank screen for 5 seconds. This blank screen was then followed by a 5-second rest period. After the rest period, a message indicated that when the participant was ready to begin the next trial, the button could be pressed again. The participant viewed 41 pictures in a single session, one picture at a time. The experimenter observed the participant on the first trial to make sure that the procedure was followed correctly, while the remaining 40 trials were performed without any supervision. Only the last 40 trials were used in the analysis. SCL, HR, and BVP were continuously monitored throughout all of the trials. The analysis was designed to take into consideration the fact that people have different baseline (tonic) levels and that electrophysiological measurements vary over time within individuals (Andreassi, 1989). Higher tonic levels of electrodermal activity are associated with increased attention and better vigilance on perceptual tasks. “Labiles,” people with higher baseline tonic levels of electrodermal activity, manifest larger electrodermal responses to

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emotionally significant stimuli (Prokasy & Raskin, 1973). Different underlying baselines were taken into account by taking the differences between the mean values of a given epoch and all of the individual samples in that epoch. The baseline mean per epoch was based on the electrophysiological values of the first 5 seconds of the epoch, before the display of the photograph. Analysis, based on the mean of all prestimulus reactions, showed a clear PSR that peaked with a four standard error difference in electrophysiological measures between extreme and calm targets 1 second before the target photograph was displayed. This supported Radin’s (1997b) presentiment hypotheses that emotional shock caused by viewing an emotional picture in the future causes an unconscious physiologic “preaction.” Radin (1997b) informally interviewed each of the participants in his study. None of the participants reported any conscious awareness of the targets to be presented or any systematic electrophysiological differences before the presentation of the targets. Radin’s (1997b) study has been replicated by Bierman and Radin (1997, 1998), Bierman (2000), Parkhomtchouk et al. (2002), and Radin (2004). All of the replication studies showed results that support the presentiment hypothesis. As with Radin’s first presentiment study in 1997, these studies have found that the magnitude of the results depends on the sample and on different methods of grouping pictures in calming/emotional categories. The major strength of Radin’s (1997b) presentiment study is the design, quantification, and hypothesis-testing capability. The design fits the gold standard for scientific research as a straightforward, transparent laboratory demonstration of psi that can be replicated by any competent experimenter, including a skeptical one, using participants drawn from the general population. Radin discussed and refuted alternative hypotheses that the results were due to

15

chance, cueing artifact, analysis artifact, targets being presented in a nonrandom order, and anticipatory effects. A criticism of Radin’s (1997b) study is that photographic stimuli elicit idiosyncratic responses. A picture that has been rated as having a high average affectivity may have a low affectivity for some individuals and vice versa. For example, people who fear snakes may show higher SCL in response to a photograph of a snake than an individual who enjoys snakes as pets. Idiosyncratic responses would also affect controls, so presumably any idiosyncratic reactions may cancel each other. The idiosyncratic responses to photographic stimuli could be identified by measuring the real time electrophysiological reaction after the photograph is shown. Categorizing pictures and then selecting a few pictures from each category to test for the degree of emotion generated by each participant prior to a PSR study can remedy this limitation. Spottiswoode and May (2003) developed an experiment eliminating the possible confound that photographic stimuli elicit idiosyncratic responses. They replaced the emotional visual stimuli with acoustic startle stimuli of 97 decibels for 1 second, and they replaced the calm visual stimuli with silence for 1 second. Spottiswoode and May also simplified the analysis by declaring their dependent variable to be the difference of proportions of 3-second prestimulus intervals that contained fully formed nonspecific skin conductance responses (ns-SCR) prior to acoustic stimuli compared to prior silent controls. The null hypothesis was that the prestimuli proportions of intervals that contained fully formed ns-SCR should be equal for both the 1 second startle stimuli of 97 decibels and for the 1 second of silence. Spottiswoode and May (2003) studied prestimulus ns-SCR in 125 participants (65 females, 60 males, ages ranging from 20 to 74 years). Spottiswoode and May found mean proportions of 0.099 for ns-SCR before acoustic stimuli and 0.064 before silent controls. Instead

Full document contains 75 pages
Abstract: This study assessed personality correlates to electrophysiological measures of prestimulus response (PSR). PSR is the body's response to a future stimulus prior to experiencing the stimulus. PSR may be an approach to measuring an aspect of intuition. One-hundred candidates for the study completed the Myers-Briggs Type Indicator (MBTI). Data were scored to generate raw points and to categorize each participant by 4 of 8 MBTI personality factors. Forty-two participants consisting of 21 people with the highest respective scores on the MBTI Intuition and Sensation scales were selected for inclusion in the study. Electrophysiological data were acquired during a PSR experiment utilizing a roulette simulation. The participants were connected to a Biopac MP150® data acquisition system to continuously acquire electrocardiogram (ECG) for heart rate variability (HRV) and skin conductance levels (SCL). In each of 26 trials, the participants made a simulated investment and chose either red or black as the future target. Once the electrophysiological data were acquired, the target was determined by a random number generator. For each participant, HRV and SCL were analyzed separately for win and loss trials for 3 segments of each trial--prebet, postbet, and postresults. Random permutation analysis was used to determine statistical significance of the differences for HRV and SCL respectively for win and loss trials. Stouffer Z scores were calculated for participants categorized to the 8 personality factors in order to determine which personality factors, if any, correlated with electrophysiological evidence of PSR. Participants categorized as Sensation on the MBTI demonstrated a significant HRV response to prestimulus information in the prebet segment ( N = 19, Z = -1.83, p = .0333). SCL evidence of prestimulus response was not statistically significant. The results of this study may be applicable to areas of business, learning, overall well-being, creativity, medical diagnosis, healing, and spiritual growth.