Download Orbitofrontal Cortex and Its Contribution to Decision

Orbitofrontal Cortex and Its Contribution to
Decision-Making
Part 1
Group 1
Amanda Ayoub, Alyssa Nolde, Cor Baerveldt,
Baoyu Wang
•Structural Anatomy
of the OFC


Part of the PFC and occupies the ventral
region of the frontal lobe
The OFC integrates sensory and other
sources of information to calculate a
reward.

It controls a persons decision making

Has 5 architectonic sub-regions




47/12, 10, 11, 13, and 14
The 47/12 region receives highly
processed visual and auditory
information.
The 13 region acts as a bridge
between the lateral and medial layers
of the brain. Primary olfactory and
gustatory cortex project to this region.
The 11 region is involved in planning,
reasoning, and decision making.
Connections in the OFC
OFC connections are compatible with a structure that
integrates sensory and reward information.
Three prominent features:
1. Frontal cortex receives information from all sensory modalities
- Area 47/12 processes visual information (from inferior temporal cortex), audio
information, somatosensory input (from secondary somatosensory cortex,) and
inputs from polysensory areas (like superior temporal cortex)
2. OFC has only weak motor connections, some exist between
-
47/12 and supplementary eye fields
Area 13 and ventral premotor cortex
PFC connects with cingulate motor area
Dorsal and later PFC connect with premotor cortex
3. OFC extensively connects with areas of the limbic system
- Including the amygdala, cingulate gyrus, and the hippocampus
- Influences the autonomic nervous system through the hypothalamus and other
brainstem structures
Damage to the OFC
Story of Elliot
Elliot was diagnosed with a brain tumor and had it successfully removed. The surgery
left him with bilateral damage to his OFC. Neuropsychologist ran test on Elliot but
found no evidence of brain damage.
- Tested intelligence, memory, reading and writing comprehension, verbal fluency,
visuospatial abilities, and facial recognition; also ran test designed specifically for
frontal lobe processes, such as working memory, rule switching, and cognitive
estimation did NOT show any deficits
Although Elliot did not show any brain damage in the areas listed above, he was
affected by the damage in his OFC:
Life Before the surgery
-Excelled in college
-Rose through the ranks of his career
-Happily married
-Seen as a role model and natural leader
Life After the surgery
-Devoiced his wife
- Quit his job and trouble holding a job
-Lost his money to a scam artist
-Lost contact with friends and family
-Remarried a prostitute and divorced
Damage to the OFC leaves our cognitive abilities intact, but demolishes our
ability to make decision in everyday life.
Two underlying theories:
Stimulus-Reward Learning and Flexible Behavior
• Monkey and Man:
•
Research paradigm: Reverse contingencies
• It’s all logical inference:
•
•
Inability to reverse stimulus-reward associations
unable to modify his/her behavior in response to negative feedback
• My understanding:
•
•
All behaviors shaped was kept as a temporal nerve tract in the brain
OFC is the eraser
Two underlying theories:
Somatic Marker Hypothesis
• Core idea:
•
•
Bodily states (somatic markers) corresponding to the emotions produced
while evaluating different courses of action help to facilitate normal decisionmaking.
Somatic markers are associations between reinforcing stimuli that induce an
associated physiological affective state. These somatic-marker associations can
reoccur during decision-making and bias our cognitive processing (e.g., a burnt
child dreads the fire).
• Underlying assumption:
• James-Lange theory of emotions: Behaviors first, then the emotion
• Explanations for Deficits of Decision-making
•
•
•
Iowa gambling task
“Shuffled” version of the gambling task
Stimulus-reward reversals stud