Anomalous anticipatory brain activation preceding exposure of emotional

Anomalous anticipatory brain. activation preceding exposure of emotional and neutral pictures An f. MRI Study Dick J. Bierman & Steven H. Scholte Universities of Amsterdam & Utrecht (NL) PA Convention, August 5 -8, Paris, France

What went on before? Presentiment experiment Presentiment is reported as the apparent psychophysiological effect of a future emotional ‘cause’.

Procedure • Subject sits relaxed with electrodes attached • Gets about 40 exposures of randomized neutral and calm stimuli • Skin conductance is averaged separately for emotional and neutral stimuli • Before, during and after stimulus • Baseline fixed at ~ -7. 5 seconds

Procedure Presentiment ‘trial’ Blank screen Or Calm baseline 0 5 Time Skin Conductance Subject Hits Button Random!!

For example the following sequence could arise c c e c We analyze this by averaging over the condition c e

Results First Subject (Radin-1) stimulus Before During After Emotional Presentiment? Calm

Results all Subjects (Radin-1) Emotional Presentiment! Calm

Replications

Replications • • • Amsterdam University Edinburgh University Lab. For Fundamental Research, Palo Alto Cornell University (in progress) Budapest POST HOC in already published data: – Antonio Damasio (Iowa university) – Alfons Hamm (Uni. Greifswald)

Results re-analysis Hamm’s data Erotic presentiment Calm

So What Next? • Can we differentiate between different emotions? • Can we locate the source of this phenomenon?

Event Related Design • • • 10 subjects 48 pictures (events) ~ 32 neutral, ~ 8 erotic, ~ 8 violent 4. 2 seconds exposure time 16. 8 seconds for one trial (= 8 volumescans) 1 vol: 22 slices, slice resolution: 64 * 64

Analysis procedure (1) • Dependent var: BOLD signal per voxel (Blood Oxygenation Level Dependent) • Pre-processing: – Slice time correction – Linear trend removal – 8 mm spatial smoothing – No further smoothing in time domain

Analysis Procedure • SPATIAL: – Fit data to a General Linear Model – Predictors : neutral, erotic, and violent stim. – Result: Regions of Interest with significant fit. • TEMPORAL (restricted to ROI): – Event related averaging of BOLD per condition – t-test of average BOLD signals in ROI

Contrast between emotional and neutral conditon. Brain regions which have a significant fit with emotional stims and neutral stim as predictor

Screen Dump of analysis software Output Input: Single individual’s brain signals

Event related averaging erotic Erotic Presentiment effect at time: -4 seconds. neutral Td = 2. 89 df= 39 p < 0. 01 Brain-map with ROI’s Plot for BOLDsignal for the whole experiment stimulus

violent ROI: -51, -78, 1 erotic

violent ROI: -1, -80, 37

Pooling of data • Mapping in Talairachspace • Loss of signal due to individual differences • So: separate male and female

All female: Erotic & Violent presentiment (t ~ 1. 75, df=158, p<0. 05 o. t. )

All male: Erotic presentiment (t ~ 2. 1, df=226, p<0. 01 o. t. )

Considered ‘Normal’ explanations • Artefacts Introduced by software – Hemodynamic curve – Smoothing • Chance fluke or over analysis • Incorrect Randomization • Subject Strategies

Subject Strategies A subject strategy reflects itself in the anticipation being a systematic function of the history of stimuli so far presented.

Subject anticipatory Strategies • • • Subject strategy: Ai = f(P 1…P i-1) Based upon Gamblers Fallacy In spite of the fallacy: produces normal effect Goes to 0 if N goes to infinity Simulation using ACTUAL random sequence – A increases after each neutral (sigmoid function) – A is reset after emotional stimulus

Results SS simulation Over-all Subjects the explained effectsize is 2% after N=48 trials

Reasons to reject SS explanation • Explained effect is too small • Does not explain spatial qualitative differences between emotions and gender • NO neutral anticipation observed!!!!!

Conclusion • This study should be seen as exploratory • And justifies further research – as usual • Theoretical speculation: – Could Consciousness be a Feynman-Wheeler’s multiparticle coherent absorber and therefore allow for advanced waves? – Replication study will focus on the coherence of brain states (meditative states)

Latest version of paper & presentation downloadable from: a 1162. fmg. uva. nl/~djb/publications/2002/ Or email: Bierman@psy. uva. nl