types of long term memory explicitmemory consciously recalled semantic memory episodic memory vs. general knowledge autobiographical events 9/11 ABCs
types of long term memory implicit memory not consciously recalled priming previous experience influences behavior procedural memory motor skills
memory short term • limited capacity long term • “unlimited capacity” • “relatively permanent”
memory storage hippocampus vs. cortex
biology of memory Hebb theorized that enduring changes in the efficiency of synaptic transmission were the basis of long term memory. “Neurons that fire together, wire together.” A weak synapse & strong synapse converge on one neuron. If “simultaneously” stimulated, the weak synapse becomes strengthened.
LTP increase in # of receptors
LTP increase in # of synapses & spines
LTP GLUTAMATE AMPA: ordinary receptor (after glutamate binds, it opens sodium channels) NMDA: special receptor (depolarization required to unblock Mg for sodium & calcium entry) Calcium begins chain of events resulting in LTP.
anterograde amnesia • “stuck in time” • when attention shifts/distracted, info is lost forever • mild vs. severe no new memories TIME brain injury
retrograde amnesia • can’t recall previously formed memories • diff between mild vs severe memories lost TIME brain injury
dementia • memory impairment • (anterograde or retrograde) • 1+ cognitive deficits: - language • - motor activity • - recognition of objects • - executive functions
alzheimer’s disease Alzheimer’s disease is only ONE type of dementia
neuropsych testing confabulation to explain lapses
normal aging forgetfulness vs. AD compare & contrast for: • memory retrieval speed • severity • insight • progression of severity • impairment of function
Alzheimer’s disease • Types • Early onset: ≤ 65 yrs old • (runs in families) • Late onset: >65 yrs old • (most common)
Alzheimer’s disease For both early & late onset, abnormal accumulation of operational proteins: beta amyloid (plaques) between cells tau (tangles) inside cells
brain differences normal Alzheimer’s
Alzheimer’s disease mild • Repeating same questions/statements • Can’t follow conversation (confusion) • Can’t complete ordinary tasks (recipes) • Concrete thinking (can’t abstract/jokes) • Uses fewer words to communicate • Misplacing objects • Disorientation of time & place • Sudden mood or behavior change • Indifferent to normal courtesies or personal appearance moderate • Inappropriate behavior in public • Compulsions (sex, eating, etc) • Sleep disorders • Hallucinations, delusions, paranoia • Doesn’t make sense speaking • Forget to turn off appliances or take meds • Can’t do tasks re planning or calculating (e.g. checkbook balancing, grocery shop) • Withdrawal or outbursts of aggressiveness • Weakness & frequent infections • Hard time chewing, swallowing • Loss of speech • Withdrawn & unresponsive • Immune system - pneumonia • Blood vessel tau - brain hemorhage & allows aluminum severe • Little or no memory • Can’t recognize others or self • Needs assistance for self-care • Frequent incontinence • Sleep disorders
Alzheimer’s disease • runs 2 - 20 yrs (avg= 8 yrs) • 5% in 65 - 74 yr olds • 50% in 80+ yr olds
Alzheimer’s disease • Treatment • acetylcholine (for mild AD) • memantine (for severe AD) • risk vs. protective factors?