- Pre-Frontal Cortex
- Phineas Gage
- First indication can survive major brain trauma
- Lost 1+ frontal lobe
- Working on a railroad in 1848
- Tapered rod thru back of left eye
- Out the top of his head
- Rod landed 80 feet away
- Retained
- Normal memory
- Speech & motor skills
- Changed?
- Mood, irritability, impatient
- Personality
- Impact exaggerated after his death
- “American Crowbar Case”
- Localization of functions
- His case was used pro and con
- Damage to frontal lobe
- Can describe best course of action
- But seek immediate gratification
- Phineas Gage
- Frontal lobes
- 1. Primary Motor cortex
- 2. Pre-motor cortex
- 3. Pre-frontal cortex
- Most anterior
- Not short term storage
- But if damaged, poor executive processes
- 3. Prefrontal cortex
- 10+ microscopically different cells
- working memory for objects
- working memory for spatial locations
- 3 regions
- a. dorsolateral
- b. orbitofrontal
- c. ventralmedial
- A. Dorsolateral
- last part of brain for myelination
- still developing at 30 years old
- interacts with other parts of brain
- Connected to
- Orbitofrontal prefrontal cortex
- Thalamus & Basal Ganglia
- Hippocampus
- Plus more
- Functions
- Location of stimuli
- Spatial info for sequence learning
- High-level planning & regulation
- Organizes movements
- Regulates thoughts & actions
- Integrates sensory & mnemonic info
- Executive Processes
- Not sole responsible
- Collaborative effort
- Damage causes problems with
- Social judgment
- Executive memory
- Abstract thinking
- Intentionality
- Tumors produce symptoms similar to schizophrenia
- Sleep deprivation inhibits activity here
- Truth Telling
- Involved in lying?
- Inhibit of normal process
- People usually tell the truth
- Lucid dream states?
- Hallucinations?
- B. Orbitofrontal
- Orbit – immediately above eye sockets
- Least explored
- Least understood
- Sometimes considered part of limbic system
- Controls
- social adjustment
- responsibility
- mood
- drive
- Function
- Cognitive processing
- Decision making
- Sensory integration
- Affective value of reinforcers
- Expectation of rewards-punish
- Compare expected with actual
- intuitive judgments
- Connections
- Extensive connections
- Reciprocal connections
- Ventral & dorsal visual streams
- Auditory-spatial processing
- Phonetic processing
- All sense modalities
- Damage
- Alzheimer’s disease
- neurofibrer tangles in this area
- Lesions
- feel no regret
- Causes problems with
- decision-making
- emotion regulation
- reward expectation
- Alzheimer’s disease
- ADHD
- dysfunction of reward circuitry
- controlling motivation
- reward
- impulsivity
- Obsessive-Compulsive
- Executive functioning
- Impulse control
- Addictions
- Dopaminergic activation of reward circuits
- Compulsive behavior
- Increased motivation take drug
- Decision making
- Reward system
- During cocaine withdrawal
- Increased metabolism in OFC
- Proportional to drug craving
- During protracted withdrawal
- (up to 3-4 months) cocaine
- reduced activity compared to healthy
- Alcoholics
- Less benzodiazepine receptors
- During withdrawal
- Decreased activity (compared to normals)
- Visual discrimination test
- Reversal learning
- Presented pictures A and B
- Learn rewarded for picking A
- When rule set, switch
- Damage to OFC, stay with A
- Extinction
- Rules don’t reversing
- Punished for either A or B
- DON’T PRESS BUTTON
- OFC damage: gotta press!
- Reversal learning
- Iowa Gambling Task
- 4 virtual decks of cards
- Each time choose a card win $$
- Every so often, will lose $$
- Win as much money as possible
- Choose by gut reaction
- Two decks are “bad decks”
- net loss in long run
- Two decks are “good decks”
- net gain over time
- Healthy Ss
- Sample each deck
- Stick to good after 40-50 cards
- OFC damage
- Stick with bad deck
- Even if know it’s a bad deck
- Galvanic Skin R of stress react
- Hover over bad deck
- Only 10 trials
- OFC dysfunction
- Never develop GSR reaction
- Faux pas Test
- Series of vignettes
- Social occasion
- Said but should not have said
- Awkward occurrence
- Identify what was said
- Why it was awkward
- How people would have felt
- OFC dysfunction
- Understand the story
- Can’t judge social awkward
- Disinhibited behavior
- Excessive swearing
- Hypersexuality
- Poor social interaction
- Compulsive gambling
- Drug, alcohol & tobacco use
- Little empathy
- Orbit – immediately above eye sockets
- C. Ventralmedial
- Includes
- Anterior cingulate cortex
- Hippocampus
- Includes
- 1. Anterior Cingulate Cortex
- Collar around corpus collosum
- Autonomic functions
- Heart rate & blood pressure
- Reward anticipation
- Decision making
- Empathy
- Dorsal part connects with
- Prefrontal cortex
- Parietal cortex
- M1
- Dorsal part as Central Station
- Processing top-down $
- Processing bottom-up $
- Assigning control to other areas
- Ventral part connects with
- Nucleus accumbens
- Hypothalamus
- Amygdala
- Ventral part involved in
- Assessing salience of emotion
- Assessing motivational info
- Problem solving
- When effort needed for task
- Activated by conflict
- Potential of an error
- Eriksen Flanker Task
- Arrow pointing to left or right
- Flanked by two distractor arrows
- compatible (<<<<<)
- incompatible (<<<>>)
- Stroop Task
- Don’t read word, name color
- Top-Down Processing
- Say the color you see:
- RED
- ORANGE
- GREEN
- BLUE
- Counting-Stroop
- Count neutral stimuli
- ‘dog’ presented four times
- Count interfering stimuli
- ‘three’ presented four times
- Count neutral stimuli
- Eriksen Flanker Task
- Functions
- Error detection
- Anticipation of tasks
- Attention, motivation
- Regulation of emotional R
- Error detection
- Respond to letter X after an A
- Ignore all other letter combos
- Monitoring conflict
- Incompatible trials produce the most conflict
- Conflict control system
- Reinforcement learning ERN
- Error-related negativity (ERN)
- Electrophysiological marker
- Making errors may cause changes in dopamine?
- More avoid errors, larger ERNs
- More learn from errors, less ERNs
- Receives conflicting input
- Assigns it to another area
- Reward-based learning theory
- detects and monitors errors
- evaluates degree of error
- suggests appropriate action
- Largest activation in loss
- Conscious experience corr
- more emotionally-aware
- recognition of emotional cues
- Active even when Ss not aware of their error
- Role in registering pain
- Physical pain activates ACC
- More intense pain, more active
- Damage causes
- Unclear what actually can’t do
- Appears to impact:
- Inability to detect errors
- Severe difficulty in Stroop task
- Emotional instability
- Inattention
- Maybe be seen in schizophrenia
- Social anxiety
- ADHD
- OCD
- Right Hemisphere
- Better at spatial relationships
- Better at perceiving patterns
- Better at perceiving emotions
- in gestures
- In tone of voice
- Damage
- Speak with less inflection
- Less expression in voice
- Left Hemisphere
- Better at details than patterns
- Lateralization of Function
- Best Practice
- Use same hemisphere for repeat measurements
- More accurate if smell two substances with same nostril
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