PSYC*3410 Lecture #4 (Chapter 10)
Learning, Memory and Amnesia
Retrograde amnesia unable to remember past
Anterograde – unable to form new memories.
o Alcohol can effect
Infantile amnesia Barely, if at all remember anything from first 4 years
o Explicit (conscious) vs. implicit (unconscious) – implicit comes first?
Show some implicit recognition of classmates after summer break.
Medial temporal lobe amnesia – Henry Gustav Molaison ex.(treat epilepsy with
bilateral medial temporal lobe lesion, reduced seizures and longterm memory).
o Mild retrograde amnesia, severe anterograde.
o What’s in the medial temporal lobe?
o Assessing H.M’s amnesia
Digit span test – couldn’t get past 8 (715, 7154, 71540) normal =
Blocktaping memoryspan test – touch blocks in specific
• H.M was normal.
Mirror drawing – trace image looking in mirror.
• H.M showed experience (memory) from day to day.
o Implicit memory.
Rotary –pursuit test – use stylus to track rotating target.
• H.M had implicit but no explicit memory.
Incomplete pictures test – show more and more complete image
until person can identify correctly (test retest).
• H.M showed implicit but no explicit memory.
Eyeblink pavlovian conditioning
• H.M normal
o What does this tell us?
MTL important for memory.
Difference between long and short term memory.
MTL involved in explicit memory.
Types of Memory
Episodic – experiences, events.
Semantic –general info, language, reasoning, knowledge.
Procedural – skills, habits
Explicit conscious, declarative – event and facts (hippocampus, MTL, diencephalon) Implicit – unconscious, nondeclarative – skills, habits, priming, associative, non
Causes most ppl to be unable to form new explicit longterm memories.
Episodic memory effected (can learn new facts but don’t remember learning it),
semantic memory may not be affected.
Delayed Nonmatching to sample Test
Mishkin (1978) – money’s performing object recognition test.
o Four lesion groups: control, hippocampus, amygdala, and hippocampus +
Not much effect except for hippocampus + amygdala group.
o Aspiration Lesion techniques limited findings (damage adjectent cortex –
perirhinal cortex, entorhinal cortex, and parahippocampal cortex)
Proposed Hierarchical Organization of Object Representation in the Ventral Visual
Caudal – rostral = more integrated recognition (more intersecting streams of info).
Neurotoxic lesions will destroy cell bodies of specific regions without damaging
other areas of the brain.
o Zola – Morgan (1989) lesion to perirhinal and parahipocampal cortex
sparing the amygdala and hippocampus.
o Murray & Mishkin did this in 1998 to hippocampus and amygdala
sparring the adjacent cortex.
This failed to effect object recognition test.
Comparing rhinal cortex lesions and hippocampus + amygdala
lesion – rhinal cortex lesion group performed worse, other didn’t.
Spontaneous Object Recognition (Test object memory)
Rats made familiar with an object and then given choice between familiar and
o If rats investigate novel object more, then they remember the familiar
object. If they examine both objects the same, they don’t remember the
Hippocampus lesion didn’t affect memory, perirhinal cortex lesion
Radial Arm Memory (Test spatial memory)
Test working memory by measuring number of errors in each test.
o Hippocampus lesion affected working memory while perirhin