Presentation is loading. Please wait.

Presentation is loading. Please wait.

Introduction The rationale behind this experiment is that presentiment, the apparent response BEFORE a stimulus is presented, is supposed to be explained.

Similar presentations


Presentation on theme: "Introduction The rationale behind this experiment is that presentiment, the apparent response BEFORE a stimulus is presented, is supposed to be explained."— Presentation transcript:

1 Introduction The rationale behind this experiment is that presentiment, the apparent response BEFORE a stimulus is presented, is supposed to be explained as an example of time-symmetry in physics. Time symmetry has not been observed in physical systems, but theoretical considerations by Wheeler and Feynman (1945) suggest that this breaking of time- symmetry is due to the asymmetry in the availability of coherent multi particle transmitters, such as lasers, and coherent multi particle absorbers. Time symmetry might therefore occur when a multiple particle information absorbing system, like the brain, is extremely coherent. Meditation is thought to be a practice resulting in such coherent brain states. Therefore our main hypothesis is that meditators show larger presentiment effects than control subjects. Method Eight experienced meditators were trained to meditate in the hostile environment of a brain scanner. There they were presented with, in total, 64 random neutral, erotic and violent visual stimuli during meditation and during a non meditation session in the scanner (counterbalanced in order). 8 control subjects, matched on age and sex, participated in the study but did only a single session in the scanner. Presentiment effects are measured by comparing the brain activity, as represented by the BOLD signal, before emotional stimuli with the brain activity before neutral stimuli. Because these stimuli which are presented for 2 seconds with an interval of about 16 seconds are randomly selected, the subject, and in fact nobody, can know which type of stimulus will be presented, there should be no difference in brain activity preceding the stimuli. Brain Regions of Interest were obtained in two ways: First, by comparing the effects irrespective of stimulus type of meditation. And second by comparing the effect of all stimuli comparing meditators while not meditating with control subjects. The major hypothesis was then tested by comparing the effects of neutral and emotional stimuli before stimulus presentation in these regions. Acknowledgments The following persons did significantly contribute to this project: Jenneke van Ditzhuyzen Stephen Whitmarsh Eva Lobach Results * A total of 32 Regions of Interest were found by comparing the effect of meditation on processing of visual stimuli irrespective of the type of stimulus and by comparing meditors with controls processing visual stimuli (these results will be published in a separate paper). Conclusions Caveats The semi-qualitative approach that was used so far does not allow for sound statistical conclusions. Most notably, it is not allowed to treat the 36 Regions of Interest as totally independent. Therefore, statistics based upon the table should be considered with caution. Furthermore the unequal number of presentations of emotional and neutral stimuli could have an impact on the bump count method to construct that table. However, this latter aspect does not apply to the relative effects of erotic and violent stimuli because on the average an equal number of these were used. Preliminary conclusions Based upon the over-all averages of the time course showing a clear effect of stimulus type and most notably on the average violent time course preceding the stimulus and in combination with the table with bump counts we feel that we can conclude that the original fMRI-over-all presentiment results of non- meditators presented in Bierman & Scholte (2002) is replicated. More confidently it is concluded that meditation results in a decrease in violent presentiment and an increase in erotic presentiment. Next At present we are analyzing the data for a few a priori brain regions like the Amygdala and the Caudate. In exploratory analyses of the previous fMRI- presentiment experiment of Bierman & Scholte these areas showed some interesting effects which for the Caudate were expected on the basis of presentiment effects in skin conductance. Also we will develop a more quantitative approach to the bump count method taking into account dependencies and unequal number of observations. fMRI-Meditation study of presentiment: The role of ‘coherence’ in retrocausal processes (Bial 34-04) Dick Bierman University of Amsterdam and University for Humanistics, Utrecht The Netherlands For further information Please contact Dick Bierman d.j.bierman@uva.nld.j.bierman@uva.nl University of Amsterdam Phone: +31 (0)20 525 6727 Detailed information on this project, methods, materials, results etc. can be found in the Bial Final Report 34-04 Key References Bierman, D. J. & Radin, D. I. (1998). Conscious and anomalous non-conscious emotional processes: A reversal of the arrow of time? Toward a Science of Consciousness, Tucson III. MIT Press, 1999, 367-38 Bierman, D.J. & Scholte, H.S. (2002). A fMRI Brain Imaging study of presentiment. Journal of ISLIS, 20-2, 380-389. Wheeler J. A. and Feynman, R. P. (1945) Rev. Mod. Phys. 17, 157 Regions where meditation results in larger (upper left), or smaller BOLD responses (right). The lower figure gives a cortical display of these results. Presentiment-effects (over-all) For all of these regions combined, the average time course for neutral and emotional stimuli was calculated separately for all sessions. The resulting graph shows a clear bump in the time course preceding violent stimuli. Effect of Meditation on Presentiment For each of the Regions of Interest time courses preceding the three types of simuli were calculated for meditators while meditating and while not meditating and for controls. For each of these time courses the largest bump preceding any of the three stmuli was assessed. Table with number of largest bumps preceding a stimulus in the interval (-8,0 )seconds as a function of stimulus-type and condition. A simple binomial test assuming independence shows that the percentage ‘presponses’ before a neutral stimulus of 11.7% is significantly lower than the chance expectation value of 33.3%. (corresponding z-value: 5.6; but see caveats). Exploratory Results with respect to type of Emotion As can be seen from the table, a very interesting pattern that arises is that meditation seems to have a dramatic effect on the type of stimuli that show presentiment. For the non-meditating condition, as well for the control condition, there are more than twice as much violent ‘presponses’ as erotic ones. During meditation however, this pattern totally reverses and there are almost 6 as many erotic ‘presponses’. It seems that during meditation the ‘early warning’ for violence is switched off. Again quantitative assessment is difficult, due to the fact that the different clusters are not independent. A chi2 assuming independence yields a strongly significant result (chi2: 15.6, df=1, p<<0.000001; but see caveats)


Download ppt "Introduction The rationale behind this experiment is that presentiment, the apparent response BEFORE a stimulus is presented, is supposed to be explained."

Similar presentations


Ads by Google