Dick J' Bierman

1
(No Transcript)
2
.
Anticipatory brain activation preceding stimulus
presentation a true anomaly??

• Dick J. Bierman Steven H. Scholte
• Universities of Amsterdam Utrecht (NL)

IGGP Freiburg sep 25 2002
3
Overview

• The phenomenon of presentiment
• Experimental studies using Skin Conductance
• Re-analysis of main stream data
• Experimental study using fMRI
• Relation between SC and fMRI studies
• Possible Normal explanations
• Theoretical specualtions

4
PRECognition or Sentiment
Cognition concerns conscious knowledge Sentiment
may be non (less) conscious
5
What is Presentiment?
Consider the sep. 11 WTC attack. Was there
anybody in the general public having some uneasy
feeling before the attack?
6
There are a lot of stories.
7
Was this just coincidence?
Ed Cox (1960) Compared train ridership on days
with and without a train accident. He found that
on accident days there were significant less
people on trains. (Note Utts redid the analyses
and found a smaller effect after correction for
holidays)
8
What went on before? Presentiment experiment
Presentiment is defined as the apparent
psycho-physiological effect of a future emotional
cause.
9
Procedure of empirical approach

• 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

10
Procedure Presentiment trial
Skin Conductance
Time
11
For example the following sequence could arise
c
c
c
c
e
e
e
c
We analyze this by averaging over the condition
12
Results First Subject (Radin-1)
Before
During
After
13
Results all Subjects (Radin-1)
Emotional
Calm
14
Replications

• Amsterdam University 0
• Edinburgh University 0
• Lab. For Fundamental Research, Palo Alto
• Cornell University (conceptual)
• Budapest ?
• Durham (NC) 0?
• POST HOC in already published data
• Antonio Damasio (Iowa university)
• Alfons Hamm (Uni.Greifswald)

15
This should be everywhere!
Main stream emotion research
Measure baseline of dependent var Present an
emotional / calm event Measure response of
dependent var
baseline
event
response
time
16
Mainstream Research questions
R f ( emotional level of event) Find f R
Response - BaseLine Implicit assumption BaseLine
is independent of future emotional level
17
What did we do?
Search for main stream databases that Measure a
BaseLine for at least 4 seconds. Use strong
emotional events For which Data can be obtained
18
What did we find?
Hamm group on the speed with which fear arises
in animal phobic patients Damasio group on
implicit emotional learning during Gambling task
19
Procedure Animal fear study
Skin Conductance
time
20
Results re-analysis Hamms data
stimulus
21
Damasio gambling procedure

• Participant gets initially 2000
• Draws cards from one of 4 different decks
• Card is either winning or losing

Preparation
Skin Conductance
time
22
Damasio dataset analyses

• Damasio-analysis P f (type of deck) !!!
  Advantageous vs non-advantageous
• Our Re-analysis P f(type of Card)
  Winning vs Losing

23
Winning vs. Losing Cards

• Quote from Bechara, Damasio et al, Science,
  275, 28 February 97, 1293-1295
• .. the players have no way of predicting when
  a penalty will arise

24
Results re-analysis Gambling experiment

• t 1.634 df117 p 0.053
• Presentiment effect 20!!!!

25
So What Next?

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

26
Brain scanner, Amsterdam Summer 2001
27
fMRI 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

28
Pre-Processing of Data

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

29
Analysis Procedure

• SPATIAL
• Fit data to a General Linear Model
• Predictors neutral, erotic, and violent
  stimulus.
• 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

30
(No Transcript)
31
Screen Dump of BV analysis software Output Input
Single individuals brain signals
32
Erotic Presentiment effect at time -4
seconds. Td 2.89 df 39 p lt 0.01
33
(No Transcript)
34
(No Transcript)
35
What has this to do with Skin Conductance?
Premotor (pre) frontal cortex
Sensory limbic Cortex
Amygdala
Hippocampus
Caudatus
Septum
Pallidum
Hypothalamus
Formatio Reticularis
Skin Conductance
36
Do these brain regions involved in SC show an
effect?

• Hippocampus
• Pallidum
• Amygdala (left and or right?)
• Caudate nucleau

37
Hippocampus
38
Pallidum
39
Amygdala
40
Caudatus
41
Pooling of data

• Mapping in Talairachspace
• Loss of signal due to individual differences
• Soseparate male and female

42
all female
43
all male
44
Amygdala
Negative presentiment in neutrals???
45
Considered Normal explanations

• Artefacts Introduced by software
• Hemodynamic curve
• Smoothing
• Chance fluke or over analysis
• Incorrect Randomization
• Subject Strategies

46
Subject Strategies
A subject strategy reflects itself in the
anticipation being a systematic function of the
history of stimuli so far presented.
47
Subject anticipatory Strategies

• Subject strategy Ai f(P1P 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

48
Results SS simulation
Over-all Subjects the explained effectsize is 2
after N48 trials
49
Reasons to reject SS explanation

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

50
Conclusion

• This study should be seen as exploratory
• And theoretical speculation
• Time symmetry Could Consciousness be a
  Feynman-Wheelers multiparticle coherent absorber
  and therefore allow for advances waves?
• Are there quantum aspects to consciousness
  introducing non-local (space-time) aspects?
• Replication study will focus on the coherence of
  brain states (meditative states)