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Alzheimer’s Disease Problems: memory, thinking, behavior Brain: toxic amyloid plaques,
neurofibrillary tangles Frontal lobe: personality changes Temporal lobe: memory
Hippocampus and amygdala
Copyright © 2009 Allyn & Bacon
Parkinson’s Disease
Substantia nigra shows 60-80% damage signs show
Difficulty in controlled movt
Tremors Poor balance
Deep Brain Stimulation Electrode
placed in thalamus, or globus pallidus
Copyright © 2009 Allyn & Bacon
Protection from Brain Damage Exercise
Improve efficiency of dopamine Improves brain regulation of inflammation
prior to injury Larger brain volume of both grey and white
matter Bigger hippocampus
More sirtuin, and mitchondrial stimulation that produces neurogenesis
Copyright © 2009 Allyn & Bacon
How Your Brain Stores Information
Chapter 11Learning, Memory, and Amnesia
Copyright © 2009 Allyn & Bacon
Brain Mechanisms in Memory Engram: physical representation of
memory in brain Karl Lashley (1929)- earliest
psychologists to study Believed memory stored in association
cortex Performed series of lesion Deficit related to size of lesion, not location His conclusion: equipotentiality
http://www.youtube.com/watch?v=c62C_yTUyVg
Temporal lobe and Memory Patients w/ anterograde amnesia (deficit
in ability to form NEW memories) Case Study: HM
Accident led to seizures bilaterial removal of temp lobes (hippo, amygdala, & some assoc cortex)
Seizures improved; IQ, personality, skills unchanged, earlier memories intact
Suffered anterograde amnesia
Copyright © 2009 Allyn & Bacon
Amnesia Retrograde (backward-acting) – unable
to remember the past Anterograde (forward-acting) – unable
to form new memories While H.M. is unable to form most types
of new long-term memories (LTM), his short-term memory (STM) is intact
Copyright © 2009 Allyn & Bacon
Amnesic Effects of Bilateral Medial Temporal Lobectomy H.M. – an epileptic who had his
temporal lobes removed in 1953 His seizures were dramatically reduced
– but so was his long-term memory Mild retrograde amnesia and severe
anterograde amnesia
Copyright © 2009 Allyn & Bacon
Conclusions from HM studies Aspects of memory managed by diff
parts of brain Damage to medial temp lobesaffects
explicit NOT implicit memories Not affect LTM, but does affect transfer
of STM to LTM
Copyright © 2009 Allyn & Bacon
Where Are Memories Stored?Each memory is stored diffusely throughout
the brain structures that were involved in its formation
Hippocampus – spatial location Perirhinal cortex – object recognition Mediodorsal nucleus – Korsakoff’s Basal forebrain – Alzheimer’s disease
Copyright © 2009 Allyn & Bacon
Where Are Memories Stored? (continued)
Damage to a variety of structures results in memory deficits
Inferotemporal cortex – visual perception of objects – changes in activity seen with visual recall
Amygdala – processes emotional memories
Copyright © 2009 Allyn & Bacon
Where Are Memories Stored? (continued)
Damage to a variety of structures results in memory deficits (continued)
Prefrontal cortex Temporal order of events and working
memory Different part of prefrontal cortex may mediate
different types of working memory – some evidence from functional brain imaging studies
Copyright © 2009 Allyn & Bacon
Synaptic Mechanisms of Learning and Memory
What is happening within the brain structures involved in memory? Hebb – changes in synaptic efficiency are the
basis of LTM Repeated stimulation of neural circuits
Long-term potentiation (LTP) – synapses are effectively made stronger by repeated stimulation
Copyright © 2009 Allyn & Bacon
Bliss & Lomo (1973) Rapid series of electrical shocks to
hippo pathway increases PSPs in target cells.
Experience makes these synapses more efficient
Change in responsiveness in target cells called LTP
Copyright © 2009 Allyn & Bacon
Long-Term Potentiation (LTP) LTP is consistent with the synaptic
changes hypothesized by Hebb LTP can last for many weeks LTP only occurs if presynaptic firing is
followed by postsynaptic firing Hebb’s postulate for learning
Co-occurrence of firings in pre- and postsynaptic neurons necessary for learning and memory
Copyright © 2009 Allyn & Bacon
LTP as a Neural Mechanism of Learning and Memory
Elicited by high frequency electrical stimulation of presynaptic neuron; mimics normal neural activity
LTP effects are greatest in brain areas involved in learning and memory