OFC – LPFC—MPFC INTERACTION

advertisement
Orbitofrontal Cortex and
Its Contribution to
Decision-Making
Group 5
Alicia Iafonaro
Alyona Koneva
Barbara Kim
Isaac Del Rio
The Model of Decision Making Within
the PFC
• First, sensory, affective,
and motivational
information enter the OFC
• Next, the OFC encodes the
value of an outcome
• Then, the lateral PFC
constructs a way to obtain
the outcome
• At the same time, the
MPFC evaluates the effort
involved (likelihood of
success, cost v. benefit
analysis.
Model of PFC Decision Making
• PFC includes the OFC
• PFC holds sensory
info in working
memory and uses that
info to change activity
in other areas of
behavior
• LPFC encodes
sensory, behavior and
context of behavior
responses
Orbitofrontal
Cortex
OFC – LPFC—MPFC INTERACTION
• OFC takes in sensory,
affective and
motivational info and
calculates/encodes
value of an outcome –
but not how to get there
• LPFC makes a plan to
reach goal, prioritizes,
and predicts outcome
• MPFC evaluates value
of outcome and plan,
calculates – “Is this
worth doing?”
Example of a working OFC
MARIJUANA
OLFACTORY CORTEX
SMELL OF
MARIJUANA SMOKE
AMYGDALA
SMELLS GOOD
HYPOTHALAMUS
FEEL GOOD
OFC
INTEGRATES INFORMATION,
DERIVES VALUE OF POTENTIAL
REWARD OUTCOMES
DLPFC
CONSTRUCTS PLAN TO
OBTAIN REWARD
I WALK AWAY, DON’T SMOKE,
AND KEEP MY JOB AND STAY OUT OF JAIL
BEHAVIORAL RESPONSE
HE WALKS AWAY
MPFC
EVALUATES EFFORT
WALKING AWAY IS NOT THAT HARD
IF IT DOESN’T WORK,
I WILL TRY DIFFERENT PLAN
How does OFC interact with
other brain regions?
• Holding information about the
outcome in working memory can
be useful for performance.
• Working memory is used in solving
stimulus-reward reversal tasks.
• Lesions to the OFC affects learning
of reward-reversal learning and
cause perseveration.
• Monkeys with OFC lesions can’t
adopt the “win-stay, lose-shift”
strategy.
• The “win-stay, lose-shift” strategy
requires that monkeys hold info
about the outcome in working
memory .
Disorders associated with
OFC dysfunction
OFC that is not functioning properly can
results in compulsive disorders like:
•Drug use
•Pathological gambling
•Eating Disorders
•OCD
These disorders might result from lack of topdown control, not being able to plan for the
future and failing to bias behavior away from
immediate rewards towards better long-term
outcomes.
Does the model fit existing knowledge?
• It is a pretty good fit – as
far as it goes.
• However, the OFC is
composed of many
different sub-areas.
• As technology advances,
our understanding of the
brain becomes more
complex
• We expect that future
research will help to
delineate which sub-areas
of the OFC are responsible
for different types of
processing.
Download