The latest on biofeedback, consciousness, neuroscience & neurotechnology.
Sana Inoue and Tetsuro Matsuzawa of Kyoto University showed a computer screen grid of nine numbers to six chimpanzees. The chimps were previously trained to recognize the ascending nature of the numbers. They were also shown to nine college students. When subjects touched one of the numbers, all of the others vanished. They then had to touch the squares in the order of the numbers that used to be there.
When the numbers flashed for just four-tenths of a second or less, one of the chimps beat all of the college students.
Here's the press release from 'Current Biology', a publication of Cell Press:
Study on the impact of audio-visual stimulation (AVS) with the "Laxman" on cognitive performance, psycho-vegetative tension, general mental state and sleep
- Summary -
Dr. med. A. Gabriel specialist for psychiatry and psychotherapy Psychiatric University Hospital of the Charité at St. Hedwig Hospital Große Hamburger Str. 5-11, 10115 Berlin
1. Introduction
Principal purpose of the study is to find out by means of neuropsychological tests and psychopathological rating procedures, whether and into to what extent a daily application of the AVS with the Laxman of Neurotronics GmbH, over a period of three weeks, leads to an improvement of cognitive performance, a reduction of psycho-vegetative tension and anxiety, an improvement of general mental state and sleep.
The tests were carried out with 20 test persons before and after the three-week application phase and evaluated afterwards.
In a preceding first investigation a positive trend could already be pointed out concerning the improvement in the aforementioned items. The following items were evaluated with 11 test persons before and after an AVS application with the Laxman: general mood, vitality, relaxation, concentration ability, anxiety, nervousness, depression. The test persons indicated improvements in all items, the improvement in relaxation was significant.
Stress, fears, and sleep disturbances, as well as concentration and attention deficits, are wide-spread problems in our society. They often lead to psychotherapeutical and medicamentous treatments. It is to be examined whether and into what extent the AVS represents an alternative treatment method resp. can support a primary treatment.
In particular, it is to be found out whether the AVS resp. the Laxman can be an answer to the stresses that accompany the rising complexity of our society. This includes the treatment and/or prevention of burnout as well as an up-to-date stress management. At the same time it is to be examined whether the AVS can parallelly lead to an improvement in cognitive performance, i.e. attention, concentration, and memory, in order to be able to provide an alternative method for complexity management for high performers.
2. Methods
The audio-visual stimulation device Laxman of the company Neurotronics GmbH was used for the investigation. The Laxman is a device which sends audio-visual impulses by means of color Ganzfeld glasses and earphones, and for this purpose uses varied audio contents.
Before and after an application phase of several weeks, neuropsychological tests and psychopathological rating procedures were carried out, which measure memory, attention and concentration performance, the psychomotoric speed, as well as the psycho-vegetative tension, anxiety, quality of life and sleep.
During the application phase a 20-minute application with an alpha session was carried out daily on six days per week. The study was conducted over three weeks.
2.1 Study Participants
Altogether 20 healthy test persons participated in the study (10 women, 10 men). The average age was 51 years. All test persons were interviewed about their medical history. Only study participants were recruited who showed no indication of preceding transient consciousness disturbances, synkopes or other evidence of epileptic seizures. The anamnesis was carried out by a neurologically and psychiatrically experienced physician.
In order to form a group of test persons as naturalistic as possible and exclude possible factors of influence, e.g. persons were excluded who successfully use daily relaxation techniques such as autogenous training or progressive muscle relaxation, as well as persons who regularly get psychiatric medication. Likewise excluded were test persons with serious internal or neurological psychiatric illnesses.
The tests carried out can be divided into two main groups: psychometric rating procedures and neuropsychological tests. The individual tests are briefly described in the following.
2.2 Psychometric Rating Procedures
The State Trait Anxiety Inventory(STAI) is a psychometric procedure for measuring anxiety. The two scales of the STAI with 20 items each serve to measure anxiety as a state (State Anxiety) and anxiety as trait (Trait Anxiety).
The General Health Questionnaire (GHQ-14) is a procedure to measure the general psychological health. The procedure is based on a self evaluation of the condition in the past week.
The Perceived Stress Scale (PSS) is a common questionnaire to measure generally perceived stress. Statements concerning requirements, joy, concerns, and internal strain are evaluated on a four-stage frequency scale.
The Munich Quality of Life Dimensions List (MLDL) is a full standardized procedure for the self evaluation of adults concerning the cognitive assessment of elementary components of the quality of life. The questionnaire consists of 20 elementary components of life which have to be evaluated on a scale from 0-10 concerning their satisfaction, importance, desire to be changed, as well as the belief of being able to bring about the change in the respective field.
2.3 Neuropsychological Tests
The Concentration Endurance Test (d2 Test) is a universal test to measure the attention and concentration performance, which has been standardized and validated in psychological diagnostics for many years. On a test sheet there are 14 lines, each with 47 marks made up of combinations of the characters 'd', 'p', and 'q', and one, two, three, or four lines. Each 'd' that has two lines is to be crossed out from the random order After 20 seconds the test person is asked to switch to the next line.
The concentration performance value (KL value), which is used in the evaluation, measures the overall performance. It is formed by the amount of characters crossed out correctly (d with two lines) minus the mistakes (type F2). Thus, the evaluation takes into account the psychomotric speed as well as the quality of the performance. The KL value is falsification-resistant, normally distributed and highly reliable.
The Verbal Learning and Memory Test(VLMT) is a test for learning serial word lists in five test runs with subsequent distraction and renewed delayed call. The test material consists of two word lists (A and B) comprised of 15 semantically independent words each. There are two parallel test forms in order to exclude a recognition factor in the after test. By means of the VLMT different parameters of the declarative verbal memory such as the supraspan, the learning and encoding efficiency can be measured.
The Digit span backward is a subtest of the Wechsler Memory Scale, which measures the capacity of the working memory. It concerns the short term storage of information. For this test the test person is first given a row of digits consisting of two digits which have to be repeated backwards. After each successful test run the number of digits in the row is increased until the correct reproduction does not succeed any longer.
The Digit Symbol Test is part of the Wechsler Intelligence Scale and measures the general cognitive processing speed. In the test sheet, digits from 1 to 9 are to be connected with a certain symbol with the help of an allocation pattern.
The Trail Making Test (TMTA) is a specific test procedure to assess the general cognitive speed as well as the attention. In this procedure the numbers of 1 to 25 are randomly distributed on a sheet of paper. The task is to connect them as fast as possible with a pencil. The test value is the time needed for the correct connection of the numbers.
3. Results
3.1 Cognition
As shown in Table 1, there was an improvement in all examined fields. The improvement in concentration and attention was particularly obvious (D2, Digit Span).
Table 1
Test
Field
Pre Value
Post Value
Improvement
D2
concentration/
attention/speed
155,16
180,79
14,2 %
TMTA
cognitive speed (time in seconds)
33,21
24,37
26,6 %
Wordlist VLMT
memory
48,05
54,6
12,0 %
Digit Symbol
psychomotoric speed/
working memory
55,67
61,37
9,3 %
Digit Span
concentration/ working memory
5,2
6,05
14,1 %
3.2 Psychometric Rating Procedures
Compared to the neuropsychological tests the conclusions of the psychometric rating resulted from the subjective experience of the test persons. An improvement could be determined in all examined psychometric dimensions. Predominant was a reduction of the individual stress feeling (by 21.6 per cent) as well as an improvement in the relaxation ability (by 21.5 per cent). Altogether the test persons indicated an improvement of the general psychological health by 27 per cent.
The first three rating procedures (PSS, STAI, GHQ) use 'negative' questions, i.e. a smaller value represents an improvement. The MLDL, including its subtests, uses 'positive' questions, which means a higher value represents an improvement.
Table 2
Scale
Dimension
Wert prä
Wert post
Verbesserung
PSS
Stress
23,85
18,7
21,6 %
STAI (State)
anxiety
39,95
34,05
14,8 %
GHQ
psychological health
14,05
10,2
27,4 %
MLDL
personal well-being
5,9
7,1
16,9 %
relaxation ability
5,65
7,2
21,5 %
total (item 1-20)
131,65
143,45
8,2 %
4. Discussion
The study at hand is currently the most comprehensive investigation of the effect of audiovisual stimulation on cognitive and psychometric fields. Despite the effort towards a standardized execution, certain motivational, daily-temporal, and projektive factors of influence cannot be excluded, as with all studies on the psychological situation. Although the absence of a control group limits the statistical power, a high degree of objectivity is ensured by the use of tests and rating procedures that have been validated for many years.
The consistent results concerning the improvement of concentration and attention (D2 and Digit Span) allow a valid interpretation, whereas the increase in cognitive speed by 26.6 per cent in the TMTA can be partially explained by a possible exercise effect. The improvement of the memory functions might be a secondary effect of the increase in concentration ability.
The fact that there was an increase in the general psychological health by 27 per cent, whereas the general life situation improved only by 8 per cent, is an indication of the problem of social desirability when filling out psychometric questionnaires.
5. Forecast
The version at hand is a first short evaluation of a multiplicity of data. These will be further edited for a publication. In this context the further sub scales and their correlations will be evaluated, as well as the sleep questionnaires to find out about the possible influence of an improved sleep quality on the test results.
Despite certain limitations concerning the explanatory power of the findings, the study at hand shows a clear tendency to an increased stress tolerance and relaxation ability connected with an improvement of the concentration and attention performance. To what extent a larger number of test persons of matched age groups in relation to a control group will confirm these improvements, is subject to further investigations.
Concerning the medical use of the AVS we plan the publication of data from clinical post marketing surveillance studies. By request the complete data records of the test results can be made available as file.
Dr. med. A. Gabriel
Specialist for psychiatry and psychotherapy
Psychiatric University Hospital of the Charité at St. Hedwig Hospital
Researchers from Japan's ATR Computational Neuroscience Labs have created a new brain analysis technology that can recontruct images inside of a person's mind and then display them on a monitor. The researchers want to try to view the contents of dreams in the future.
Sounds like either the journalist or the scientist is exaggerating their findings, but I could be wrong. I just have a hard time believing this could be possible. Here's how they are claiming to do it:
'The scientists were able to reconstruct various images viewed by a person by analyzing changes in their cerebral blood flow. Using a functional magnetic resonance imaging (fMRI) machine, the researchers first mapped the blood flow changes that occurred in the cerebral visual cortex as subjects viewed various images held in front of their eyes. Subjects were shown 400 random 10 x 10 pixel black-and-white images for a period of 12 seconds each. While the fMRI machine monitored the changes in brain activity, a computer crunched the data and learned to associate the various changes in brain activity with the different image designs.
Then, when the test subjects were shown a completely new set of images, such as the letters N-E-U-R-O-N, the system was able to reconstruct and display what the test subjects were viewing based solely on their brain activity.'
The researchers also discuss applying the technology to reading feelings and complicated emotional states, but may have a difficult time displaying these things on a monitor.
The blog 'Pink Tentacle' says that this research is in the December 11 issue 'Neuron', but I haven't been able to find it.
lolwut? more later... Update - this is being reported about all over the place now. Scientific American also uses Pink Tentacle as a source, but claim that the scientists have 'reported it' to the journal 'Neuron', not that 'Neuron' has published anything about it. Big difference. We'll see where this goes.
Unfortunately I can't post them here in their entirety, but here's the abstracts:
Ganzfeld-induced hallucinatory experience, its phenomenology and cerebral electrophysiology
Abstract
Ganzfeld, i.e., exposure to an unstructured, uniform stimulation field, elicits in most observers pseudo-hallucinatory percepts, and may even induce global functional state changes (‘altered states of consciousness’). The present paper gives a comprehensive overview of the phenomenology of subjective experience in the ganzfeld and its electrophysiological correlates. Laboratory techniques for visual or multi-modal ganzfeld induction are explained. The spectrum of ganzfeld-induced phenomena, ranging from elementary percepts to complex, vivid, dream-like imagery is described, and the latter illustrated by transcripts of subjects' reports. Similarities and differences to related sensory/perceptual phenomena are also discussed. Earlier findings on electrophysiological correlates of the ganzfeld are reviewed. Our own studies of electroencephalographic (EEG) activity in the ganzfeld are presented in some detail, and a re-analysis of data on EEG correlates of hallucinatory percepts in statu nascendi is reported. The results do not support the hypothesis of the hypnagogic origin of the percepts; the ganzfeld-induced steady-state is an activated state, and the spectral EEG dynamics in the alpha frequency range reveals processes of attention shifts and percept formation. The final section is devoted to the controversial topic of allegedly anomalous communication between human subjects (‘ganzfeld telepathy’). It is shown that the use of ganzfeld in this research field relies partly on unsupported hypotheses concerning ganzfeld-induced states, partly on a weak conceptual background of the experimental procedure. The rôle of a particular belief system shared by the participants and experimenters is critically discussed.
Jiří Wackermann, Peter Pütz, Carsten Allefeld
Department of Empirical and Analytical Psychophysics, Institute for Frontier Areas of Psychology and Mental Health, Freiburg i. Br., Germany.
EEG correlates of multimodal ganzfeld induced hallucinatory imagery.
Abstract Multimodal ganzfeld (MMGF) frequently induces dreamlike, pseudo-hallucinatory imagery. The aim of the study was to explore EEG correlates of MMGF-induced imagery. In a screening phase, seven 'high-responders' were selected by frequency and quality of their reported hallucinatory experience in MMGF. Each of these subjects then participated in three MMGF sessions (45 min) with simultaneous 19 channel EEG recordings and indicated occurrences of imagery by pressing a button. Relative spectral power changes during percept formation (30 s preceding subjects' reports) with respect to intra-individual baselines (no-imagery EEG) were analysed. At the beginning of the 30-s 'image formation' period alpha was slightly reduced than in the 'no-imagery' periods. This was followed by increased power in the higher alpha frequency band (10-12 Hz) which then declined in a monotonic fashion. This decline in higher alpha power was accompanied by increased power in the beta frequency bands. Throughout the image formation period there was a steady decline in power of low frequency alpha (8-10 Hz). Correlations between descriptors of subjective experience and EEG power changes were evaluated in terms of their global average magnitude and variability in time. Results indicate that the acceleration of alpha activity is a nonspecific effect of MMGF. In contrast, the tri-phasic profile of faster alpha activity seems to be a specific correlate of the retrieval and transformation of memory content in ganzfeld imagery.
Peter Pütz, MatthiasBraeunig, Jiří Wackermann
Department of Empirical and Analytical Psychophysics, Institute for Frontier Areas of Psychology, Wilhemstrasse 3a, D-79098 Freiburg i. Br., Germany.
Two researchers from the Center for Brain and Cognition have found a rare new form of synaesthesia that they have labeled 'tactile-emotion synaesthesia'. They have found two individual cases of patients experiencing specific emotions whenever touching particular textures! The feeling of denim, in one of the cases, caused strong feelings of depression and disgust.
Abstract:
We discuss experiments on two individuals in whom specific textures (e.g., denim, wax, sandpaper, silk, etc.) evoked equally distinct emotions (e.g., depression, embarrassment, relief, and contentment, respectively). The test/retest consistency after 8 months was 100%. A video camera recorded subjects' facial expressions and skin conductance responses (SCR) were monitored as they palpated different textures. Evaluators' ratings significantly correlated with the valence of synesthetes' subjective reports, and SCR was significantly enhanced for negative synesthetic emotions. We suggest this effect arises from increased cross-activation between somatosensory cortex and insula for 'basic' emotions and fronto-limbic hyperactivation for more subtle emotions. It may represent an enhancement of pre-existing evolutionarily primitive interactions between touch and emotions.
Can Freud's Theory of Dreams Hold Up Against Modern Neuroscience?
This following is an excerpt from an article printed in 'The Believer' magazine written by Rachel Aviv. Oct 2007
It wasn’t until the 1950s, fifty years after the publication ofThe Interpretation of Dreams,that scientists began bringing people into their labs for sleepovers. They’d spray water on them, or rub their faces with cotton puffs, or ring a bell and then wake them up and see what happened. Volunteers were kept up for days and watched closely, to see whether or not they’d go insane. The early experiments were crude and often conducted by psychiatrists trained in Freudian theory. One prominent researcher studied sexual dream symbols by attempting to correlate erections (he wrapped a nooselike device around the sleeper’s penis) with aggressive dream content, like dog- and snakebites, knife fights, and scenes of choking. He was able to correctly predict tumescence seven times out of eight.
Other researchers took a sociological approach to dreams, meticulously cataloging their content: women dream of men more than men dream of women; black people are more likely to be physically damaged in their dreams than white people; 80 percent of adult dreams have a negative component—their hair looks bad or they can’t find their keys or their kid won’t stop crying—and after ninth grade, children’s dreams become significantly more aggressive.
The field of dream research deals with the worst kind of data: reported by groggy volunteers, grasping at half-formed memories. Once you wake someone up, you’ve already interfered with the evidence. Hobson’s Activation-Synthesis model was so well received, in part, because it was based on neuroscience, not subjective reports. Rosalind Cartwright, chair of psychology at Rush University Medical Center in Chicago, who is well known for her research on how dreams affect mood, recalls first hearing Hobson propose his model at a conference in the early ’70s. “A bunch of us were sitting next to each other and we said, ‘You got it the wrong way around! We won’t let your physiological tail wave our psychological dream-dog!’ I used to say about Allan, ‘Oh the trouble is, he’s looking at cell recordings, he’s not talking to people—if he were paying attention to his own dreams, he would be smarter at it.’ When he did start paying attention to these things, I felt he modified his ideas a good deal.”
Only in recent years has Hobson become willing to talk more about the part of dreams that most people are interested in—feelings, symbols, characters, themes. After waking up from a particularly vivid nightmare, few of us are wondering, What part of my brain was just functioning? With practice and the help of a Nightcap (a bandanna device that beeps every few hours, wakes you up, then records whatever you say about your interrupted dream), Hobson began focusing more on the softer side of his field. “I love to talk about my dreams,” he said at the consciousness conference last year. “I’m not sure any of it really makes any difference, or that I learn anything I didn’t know, but it’s a wonderful, wonderful thing to do.”
His enthusiasm for dreams became even more pronounced when, for a startling month in 2001, he lost the ability to have them. While vacationing in Monte Carlo, Hobson suffered a stroke that affected the precise part of the brain stem that he began his career studying. He knew how his body would respond because he had done countless experiments on how damage to this area affects lab cats. He became nauseous, lost balance, and felt he was drowning in his own saliva. For eight days, he lost the ability to fall asleep. For a month, he couldn’t dream. He felt himself becoming psychotic with exhaustion. Like Freud, inventor of the talking cure, dying of oral cancer, Hobson seemed to have the perfect affliction. “I was wide awake all night long,” he recalls. “I said to myself, I am a cat. I am an experimental animal. But this is no experiment.”
Sana Inoue and Tetsuro Matsuzawa of Kyoto University showed a computer screen grid of nine numbers to six chimpanzees. The chimps were previously trained to recognize the ascending nature of the numbers. They were also shown to nine college students. When subjects touched one of the numbers, all of the others vanished. They then had to touch the squares in the order of the numbers that used to be there.
When the numbers flashed for just four-tenths of a second or less, one of the chimps beat all of the college students.
Here's the press release from 'Current Biology', a publication of Cell Press:
The patient in the video had his corpus callosum removed in order to stop his seizures due to epilepsy. The procedure prevented the hemispheres from communicating with one another in any way and caused a sort of 'split consciousness'.
To reduce the severity of his seizures, Joe had the bridge between his left and right cerebral hemisphers (the corpus callosum) severed. As a result, his left and right brains no longer communicate through that pathway. Here's what happens as a result:
What are they and how do they work? Of
course everyone reading this already knows :) But it helps to have
a quick reminder to refresh our memory every once in a while.
Having a basic understanding about these special chemicals in our
brain and how they work helps us to understand memory, learning,
behavior, addiction, how drugs work, and emotions.
First we'll quickly go over some of the most important
neurotransmitters.
Acetylcholine: The first neurotransmitter to be
identified. It allows nerve cells to communicate with each other.
Noradrenalin (Norephinephrine): Acts as a stress hormone and
affects the parts of our brain where attention and responding
actions are controlled. It is what is behind the fight-or-flight
response.
Dopamine: Plays an important role in motivation and reward,
sleep, mood, attention, motor activity, cognition and learning.
Serotonin: Believed to help regulate anger, aggression,
mood, sleep, appetite, sexuality and body temperature.
GABA:
One of the most abundant neurotransmitters. It is an inhibitory
neurotransmitter - inhibiting all sorts of activating systems.
Glutamate: Heightens sensitivity to other neurotransmitters.
An excitatory neurotransmitter involved in cognitive functions like
learning and memory.
So... Neurons pass messages along themselves using electrical
impulses, but they use neurotransmitters to pass messages to other
neurons. Neurotransmitters are released from synaptic
vesicles, flow across gaps between neurons called
synapses and then bind with a receptor on the target
neuron.
Discussion on brain plasticity, or neuroplasticity, has increased during the past several years. What is it and why should we be concerned about it? Our brains can migrate activity associated with specific functions to a different location as a result of neuroplasticity. This is an extremely important ability to have after a brain injury or even after normal experience (such as aging). Neuroplasticity allows the brain to re-wire itself as a response to changes in the environment. It is also what is behind the learning process and memory formation.
Plasticity consists of laying out preferred pathways within the brain for circulating important information and is the brain's ability to adapt.
Biofeedback/neurofeedback may play an important role in the future if specific operant condition techniques can be designed to increase voluntary control of neuron responses that will increase neuroplasticity.
Here is a link to a great audio interview from CBC radio with Dr. Norman Doidge. He is the author of "The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science".
The DANA Foundation has decided to make
their book "The Dana Guide to Brain Health: A Practical Family
Reference from Medical Experts" section on brain disorders freely
available online.
With contributions from over one hundred of the most prominent
scientists and clinicians in the United States, The Dana Guide to
Brain Health is an extensive and wholly accessible manual on the
workings of the human brain. This richly illustrated volume
contains a wealth of facts and advice, on simple yet effective ways
to take care of our brains; the intimate connection between brain
health and body health; brain development from the prenatal period
through adulthood; and how we learn, remember, and imagine.
The brain is far too important to be
excluded any longer from our daily health concerns. The Dana Guide
to Brain Health remedies this oversight with a clearly written,
definitive map to our brains that reveals how we can take care of
them in order to sustain a long and rich life.
The browseable/searchable copy of the book can be found here.
Scientists from 'Wellcome Trust' claim
to have identified for the first time what happens in our brain in
the face of an approaching fear. They measured activity in the
brain using fMRI while a subject played a game similar to Pac-Man
and received an electric-shocks when they were caught by the video
game predator.
They found that activity in the ventromedial prefrontal cortex
(behind the eyebrows) increased when the enemy was in the distance
- this part of the brain is active when one is planning how to
respond to a threat. As the video game enemy approached,
predominant activity shifted to the periaqueductal grey - the part
of the brain responsible for flight or fight and preparing for
reaction to pain.
The title of their study is 'Free Will Takes Flight', as it shows
that we act more on impulse when a threat increases.
New experiments in light stimulation are
helping scientists learn more about neural systems. Optical
excitation using fiber optics can be used to stimulate specific
areas of the brain and is an alternative to electrode stimulation.
Electrode stimulation is unable to target single types of neurons
and instead activates the firing of all neurons in one neural area.
This new technology may allow us to uncover what roles specific
neurons play.
Light stimulation every 200 milliseconds generates electrical
activity in an area of the brain associated with depression.
Here is another article on using focused
beams of light to stimulate neurons from Howard Hughes Medical
Institute.
The illustration, which comes from a painting by
Duke University student Yifan Xu, conceptually illustrates a beam
of light shining into the olfactory bulb activating a mitral cell.
HHMI investigator Michael Ehlers and colleagues report they have
developed mice that express channelrhodopsin-2, a light-gated
cation channel from the green algae Chlamydomonas reinhardtii, in
neurons of the central nervous system. This enables researchers to
trigger neural activity with high spatial and temporal
precision—a powerful tool for those striving to map
functional circuits in the brain.
Researchers have devised a clever way to
activate neurons in a living mouse by shining light on the surface
of the animal's brain. The “light switch” that turns
neurons on is actually a light-sensitive protein that is produced
by algae. When this protein is genetically engineered into the
neurons of living mice, researchers can precisely trigger those
neurons with light, causing them to generate electrical impulses.
A new study (Aug 2007) published in the Archives of
General Psychiatry shows a direct correlation between ADHD and
low dopamine activity in the brain. This could shed light on what
seems to be large numbers of ADHD suffers among ex-methamphetamine
users. Article follows:
NEUROSCIENTISTS investigating a young woman with epilepsy believe
they have stumbled on an explanation why some people feel a ghostly
presence nearby or develop paranoia. The 22-year-old woman was
being assessed for brain surgery for epilepsy but was otherwise
psychologically healthy. Part of the evaluation pinpointed the area
for surgery, using thin electrodes implanted into a region of the
brain. Reporting the case in today's Nature, the weekly British
science journal, the doctors say that when they sent a small
current to the woman's left temporo-parietal junction, she said
she had the impression there was somebody behind her. The person
was a "shadow," young and of indeterminate sex and did not speak,
she said. The doctors slightly increased the current and changed
the woman's position from lying down to seated, and got her to hug
her knees. She then said she felt the creepy presence of man who
was also sitting and who was clasping her unpleasantly in his arms.
The temporo-parietal junction is used for social reasoning - to
assess oneself and distinguish oneself from others. - Sapa-AFP