The Corticohippocampal circuit: Disorder Flashcards
(59 cards)
(disorder of HF)
STUDY: israeli soldiers
remember study, consider how adverse PTSD affects were a result of hippocampal disorder
what happened to HM?
he suffered from an accident as a kid and developed epilepsy. Pennfield conducted a ground-breaking procedure (lobotomy, removed temporal lobe and hippocampi)
what was the impact of the lobotomy on HM?
- full anterograde amnesia: couldn’t form new memories in the future
- retrograde amnesia: couldn’t remember past events, but not complete temporally graded, the further back the memories go the more likely he was to remember them
why would HM experience full anterograde amnesia?
may occur because of distributed damage in sensory-associated areas but little in the HF
why would HM experience retrograde amnesia?
may occur because localized damage to specific pathways in HF (could also be because prolonged oxygen deprivation)
what did they find in the MRI of HM?
removed medial and temporal lobe bue some of HF intact in one hemisphere
what does recent tech about HF give insight into about HF?
can unfold HF to see what creates what, possible that targeted certain areas
STUDY: mirror-drawing task
tests motor functions for HM
RESULTS: didn’t recognize tasks but performed it progressively better
- learning occurs in the basal ganglia
who experiences loss of hippocampal tissue?
technically everyone, could be from aging of conditions, but natural slow loss
what is Alzheimer’s disease?
loss of exective control and memory loss
- fMIR finds atrophy in HF
- usually starts out as mild-cognitive-impairment (MCI)
what does the progression from healthy –> AD look like
healthy
MCI (greater HF activation, compensatory response
AD (hardly any hippocampal tissue left)
what is dementia?
deterioration of cognitive and emotional functioning
what is the greatest risk factor for AD?
family history
- sporadic Alzheimer’s disease associated with genetic marker (apoE) (E4 allele) – risk factor
- early onset family disease (known genetic mutations) – guaranteed
what is delusional misidentification syndrome?
*super obscure, think invasion of the body snatchers
- capgras syndrome = someone in family you believe to be a stranger
- pygdi syndrome = someone unknown you misidentify as someone known
why does delusional misidentification syndrome occur?
- false theory: that trauma to brain disconnected amygdala from other parts of brain
- correct theory: disorders of memory and damage to HF, failure to assign and remember prior emotional experiences (sometimes because oxygen deprivation)
disorders of dlPFC
disorders of executive functioning
(disorder of dlPFC)
STUDY: *recall, MDD to negative facial expressions
found hypoactivity of dlPFC
- dlPFC controls emotions, explicit control
what occurs in disorder of cognitive reappraisal?
(ex. “the shop is closed but at least I got to get out of the house in this beautiful weather”)
- greater activity in the dlPFC when reappraise (concurrent with amygdala activity)
- capacity to regulate and decrease amgydala response associated with greater dlPFC reaction and lower MDD
how is reappraisal in GAD?
when people with MDD can downregulate amygdala activity, they report lower and less severe symptoms
- dlPFC activity increases with lower symptom severity in GAD and PD
is dlPFC just associated with regulating negative emotion?
No. also impaired with dysfunction in making good things happen
STUDY: cognitive reappraisal and making good things happen
(look at positive scenes and try to increase your positive experience)
- dlPFC connectivity allows greater exertion of control
STUDY: relative threat response in Duke students
(did executive control impact better response to threat/ reward)?
- used threat response for amygdala, money for VS activation and memory test for dlPFC
RESULTS:
- high amygdala + low VS = high anxiety
- low dlPFC + high amygdala = high anxiety
what is the impact of CBT?
increases dlPFC activity
(task, put numbers in order)
TMS targeting of dlPFC
standard protocol, 30% remission, symptom improvement
