9.00 Introduction to Psychology
Talia Konkle
21 Feb 07
Pop Quiz
The Plan for today :
:30
Review:
Neuroscience Methods
A little on TMS…
:40
Discussion:
Neuroscience of Lies
:15
:50
Timekeeper?
Logistics:
Paper Guidelines
Question:
How do we study the brain?
… why?
THE GOAL
Hey ___, you took brain
classes at MIT. How do
they get these brain areas
lighting up? What do you make of it?
Question:
How do we study the brain?
What methods can we use to
figure out what the role of a
certain brain area is?
Answers:
eeg
lesions
fmri
stimulation
single cell recording
fmri eeg lesion single-cell stimulation
Causality:
Direct
lesions
Indirect
fmri
single cell recording
eeg
stimulation
fmri eeg lesion single-cell stimulation
Precision
Good Spatial
fmri
Good Temporal
stimulation
lesions
single cell recording
eeg
stimulation
fmri eeg lesion single-cell stimulation
Invasive
Non Invasive
lesions
stimulation
single cell recording
eeg
stimulation
fmri
// Begin TMS //
Transcranial Magnetic Stimulation…
If you want to hear about
brain zapping, you’ve
come to the right place
and if you don’t… too bad
What is it and how does it work?
What is it and how does it work?
Electromagnetism
Coil Types
Spatial and Temporal Resolution
Neuron Stimulation… proof by
motor cortex
Will it hurt me?
Myths of TMS:
It will give me a seizure
It will damage my brain at high intensities
The effects are permanent
Animal studies show no cell death even
with high stimulation rates.
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Blind Braille readers
Repetitive
- Working memory
disruptions
- Sequence learning
Mythical Applications of TMS
Induce creativity (Australian report)
“I looked down at my work. The first felines were boxy and stiffly unconvincing. But after I had
been subjected to about 10 minutes of transcranial magnetic stimulation, their tails had grown
more vibrant, more nervous; their faces were personable and convincing. They were even
beginning to wear clever expressions. I could hardly recognize them as my own drawings,
though I had watched myself render each one, in all its loving detail. Somehow over the course
of a very few minutes, and with no additional instruction, I had gone from an incompetent
draftsman to a very impressive artist of the feline form.
As remarkable as the cat-drawing lesson was, it was just a hint of (Allan) Snyder's work and its
implications for the study of cognition. He has used TMS dozens of times on university students,
measuring its effect on their ability to draw, to proofread and to perform difficult mathematical
functions like identifying prime numbers by sight. Hooked up to the machine, 40 percent of test
subjects exhibited extraordinary, and newfound, mental skills. That Snyder was able to induce
these remarkable feats in a controlled, repeatable experiment is more than just a great
party trick; it's a breakthrough that may lead to a revolution in the way we understand the limits
of our own intelligence -- and the functioning of the human brain in general.”
From the New York Times: Savant for a Day, June 22, 2003, By LAWRENCE OSBORNE
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Hope that it might
be substitute for
electroconvulsive
therapy?
Single Pulse
- Motor System probe
- Virtual Scotoma
- Reading Braille
Repetitive
- Working memory
disruptions
- Sequence learning
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Reading Braille
Repetitive
- Working memory
disruptions
- Sequence learning
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Reading Braille
Repetitive
- Working memory
disruptions
- Sequence learning
Virtual Scotoma
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Reading Braille
Repetitive
- Working memory
disruptions
- Sequence learning
PET activation in blind individuals
when reading Braille.
PET activation in sighted individuals
when doing tactile discrimination
task.
Assessing functional relevance: TMS during tactile exploration
Blind individuals doing
identification task with
Braille
Sighted individuals doing
identification task with
embossed Roman letters
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Reading Braille
Repetitive
- Working memory
disruptions
- Sequence learning
How do you zap the right place?
How do you zap the right place?
Stereotaxic localization
How do you zap the right place?
for the economically minded: How much does this cost?
Neopulse
40K
Magstim
30 K
Polaris & Brainsight
60 K
EMG setup
10 K
// End TMS //
// Begin Ethics //
Question:
Should we use neuroimaging results in
court (e.g. lie detector technology)
read story…
Question:
Should we use neuroimaging to decide
about taking people off life-support?
LOGISTICS
Papers Due 1 week from today in section
- BRING 2 COPIES!!
Extras…
W. W. Norton
Synapse
W. W. Norton
Brodmann, K., Vergleichende Lokalisationslehre der Grosshirnrinde in ihren
Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig: J.A. Barth, 1909.
W. W. Norton
W. W. Norton
Broca’s Area:
Broca’s aphasia:
• language processing
• results from damage to Broca’s Area
(e.g., lesions)
• speech production and
comprehension
• unable to create grammaticallycomplex sentences
• speech described as telegraphic,
contains content words only
• comprehension is relatively normal
W. W. Norton
Stroop Effect
Word Set #1
Motor Systems Probe:
Brain-based poloygraph?
Simple (yes/no): Are you a man?
Complex:
How old are you?
Two effects:
Main effect (lie>truth,
pre and post)
Interaction
Pre-Question
Post-Question
Mythical Applications of TMS
Induce religious experience (Canadian
report)
Cook, CM and Persinger, MA Percept Mot Skills. 1997 85):683-93. Experimental induction
of the "sensed presence" in normal subjects and an exceptional subject.
9 of the 15 volunteers who were exposed to successive 3-min. durations of bursts of
different types of weak (1 microT) complex magnetic fields or sham-fields reported the
sense of a presence as indicated by a button press at the time of the experience… An
exceptional subject who had a history of experiencing within his upper left peripheral visual
field "flashing images" concerning the health and history of people [when handling their
photographs] was also exposed to the burst sequences. Numbers of button presses
associated with the experiences of a mystical presence, to whom the subject attributed his
capacity, increased when the complex magnetic fields were applied without the subject's
knowledge. The results support the hypothesis that the sense of a presence, which may be
the common phenomenological base from which experiences of gods, spirits, angels, and
other entities are derived, is a right hemispheric homologue of the left hemispheric sense of
self.
What’s it good for?
Applications of TMS
Clinical
Experimental
- Integrity of motor pathways
- Treatment of depression
Single Pulse
- Motor System probe
- Virtual Scotoma
- Blind Braille readers
Repetitive
- Working memory
disruptions
- Sequence learning
Motor Systems Probe:
Assessment of Motor Pathways in Multiple Sclerosis
TMS stimulation over ulnar nerve
TMS stimulation at C-7 level of spinal cord
TMS stimulation over motor cortex
TMS stimulation over ulnar nerve
TMS stimulation at C-7 level of spinal cord
TMS stimulation over motor cortex
Briefly, what’s a MEP? …
Brain-based
polygraph?
Motor Systems Probe:
Does action observation engage motor system? (Aziz-Zadeh et al., 2002)
Participant watches a movie of
person moving either the left or
right index finger.
High frequency (3 Hz) stimulation
Disruption of sequence production
SMA Stimulation
Motor Cortex
Stimulation
Range over which errors occurred after TMS
SMA: “I
forgot where
I was in the
sequence”
MC: “My
hand got
stuck.”
CONFORMITY & OBEDIENCE:
MILGRAM STUDY
Newspaper ad - study of memory - Yale
Two people
Researcher - here to help science improve learning and
memory through punishmnet
One “teacher” and one “learner” - a set of word pairs to
memorize
Teacher gives word, learner responds
Correct response - “good” or “that’s right”
Incorrect response - - press button that delivers shock
CONFORMITY & OBEDIENCE:
MILGRAM STUDY
Shock Generator
15 volts - 15 volts steps - 30 switches
150 volts - “STRONG SHOCK”
255 volts - “INTENSE SHOCK”
375 volts - “DANGER, SEVERE SHOCK”
435 volts - “XXX”
450 volts - “XXX”
CONFORMITY & OBEDIENCE:
MILGRAM STUDY
Initially,learner does well
Then errors
Learner complains that shocks are starting to hurt
Screams
Says that he or she does not want to continue
Hesitate, question researcher
Learner complains about heart condition
More errors - teacher pleads to concentrate
“You have no right to keep me here!”
“I refuse to answer any more! You can’t hold me here! My
hearts bothering me!”
At 300 volts, no more response
Experimenter says that after 5 sec, it is a wrong answer
CONFORMITY & OBEDIENCE:
MILGRAM STUDY
Shock Generator
15 volts - 15 volts steps - 30 switches
150 volts - “STRONG SHOCK”
255 volts - “INTENSE SCOCK”
375 volts - “DANGER, SEVERE SHOCK”
435 volts - “XXX”
450 volts - “XXX”
All the way to 450?
CONFORMITY & OBEDIENCE:
MILGRAM STUDY
Shock Generator
15 volts - 15 volts steps - 30 switches
150 volts - “STRONG SHOCK”
255 volts - “INTENSE SCOCK”
375 volts - “DANGER, SEVERE SHOCK”
435 volts - “XXX”
450 volts - “XXX”
All the way to 450? - 65%
Imagery-Specific
Activations
Patient and group of 12 healthy volunteers imagined playing
tennis or moving around a house
Owen et al., Science, 2006
E
J
6
7
If a card has a vowel on one side, then it
has an even number on the other side.
E
J
6
7
If a card has a vowel on one side, then it
has an even number on the other side.
Correct answer - E & 7 (10%)
Common answers - E, E & 6
Confirmation bias
We look for evidence that confirms what we
believe, and overlook evidence that could
disconfirm what we believe.
E - see an even number - confirm
6 - not even needed, but feels like it confirms
7 - would disconfirm - if there is a vowel on the
other side
A different, but related example…
24
18
If you have a beer, you must be 21 or older.
This is EXACTLY the same as the previous example!
6
E
24
7
J
18
If you have a beer (vowel) ---> you must be over 21 (even#)
P --> Q
Not Q --> notP
Check all p’s (all beers, all even numbers)
Check all NOT Q’s (underage, all odd numbers)
We’re Good At Finding Cheaters