Chapter 11: Memory pt. 3 Flashcards
How are memories for events or places visited encoded?
Retrospective coding
Prospective coding
Retrospective coding
where you have been
thinking about past events
Prospective coding
where you need to go
imagining future events
strategy to reduce memory load
switch form retrospective to prospective coding when you are half way through!
retrospective memory load increases linearly as # of places visited increases, it decreases for prospective memory as # of places visited increases
Retro and prospective coding
Meomory load and errors
Kesner and Despain (1988)
Rats
- 16 arm radial maze
- allowed to enter diff # of arms on diff trials then removed for short time, then placed back in maze.
- enter 1 of 2 arms; one they HAD visited and one they HAD NOT visited.
Humans
- tested on analogous task using the computer
results:
- coding strategies varied according to ask demands
- results suggest they use a switching strategy to reduce memory load
- switch from retrospective coding to prospective coding after 8 arm entries
Retention and rehearsal
- after acquisition phase!
- evidence fr rehearsal processes in working memory, comes from studies on direct forgetting
Direct forgetting
forgetting that occurs bc a stimulus (a forget cue) indicates that working memory will not be tested on that trial
- important example of stimulus control in memory
- tested with variations of DMTS test
- remember cues and forget cues
Directed forgetting in pigeons
Roper, Kaiser, & Zentral (1995)
remember cue and a forget cue
R-cue = accurate matching
F-cue = disrupted memory (altered rehearsal)
Free Reward cue: anticipation of reward helps keep experiences in memory
Retrieval
once info is acquired and retained it needs to be retrieved for use
Retrieval research is the subject of
reference memory research
cues present during ___ can be used to aid in retrieval
acquisition
- at a given time, we only recall small portion of what we know
retrieval processes are triggered by…
reminders (aka retrieval cues)
Retrieval cues in infants
Borovsky & Rovee-Collier, 1990)
- Stimuli present during acquisition can be used as retrieval cues
- can cloth liner be used as a retrieval cue for instrumental response?
- instrumental response was leg kicking
- reinforcer was mobile movement
Memory priming
Suuss et al (2012)
retrieval cue presented at end of retention interval, but memory is not tested until the next day
Forgetting
failure to remember previously acquired info
memory failure may be a more accurate term
Why is forgetting important for an organism?
can help the organism adapt and allow for flexibility when situations change and require relearning
proactive interference
disruption of memory caused by exposure to stimuli BEFORE the event to be remembered
retroactive interference
disruption of memory caused by exposure to stimuli FOLLOWING the event to be remembered
Retrograde amnesia
amnesia greatest for events at the time of injury
- severe head injury causes memory loss
- animal models for retrograde amnesia
consolidation
transfer of info from ST to LT memory
Consolidation vs. retrieval failure?
Hypothermia as an amnesia agent in rats
Briggs and Riccio (2007)
- shuffle box w/ one black side, one white side
- rats fear conditioned to black side with shock
- extinction to black side
- retroactive hypothermia treatment either: 0, 30 or 60 min (after extinction training ended)
- next day tested with shuttle box for fear of black side
measure: how long to enter black compartment?
No ext: did not undergo extinction (lots of fear)
ext: no fear to black side
- hypothermia disrupted consolidation in the 0 min and 30 min groups, but not the 60 min groups -> suggests consolidation failure
Explanations of retrograde amnesia
consolidation window
consolidation failure explanation
retrieval failure hypothesis
consolidation window
limited period after activation of memory during which memory is subject to modification by new info
- cooling to 0 or 30 min after occurred in this window; memory not consolidated
- hypothermina disrupted consolidation process
Consolidation failure explanation
disruption in original acquisition of memory
info could never be recovered
retrieval failure hypothesis
disruption makes new memories more difficult to recover (retrieval phase)
amnesia can be reversed w/ proper procedure to reactivate memory
Briggs and Riccio (2007) Retrieval failure hypothesis?
memory for extinction may have been encoded in context of low body temp
- if so: memory of extinction can be reactivated if rats are cooled again!
Results:
- returning subjects to the state they experiences just after extinction = in activation of memory of extinction
- hypothermia cues incorporated into memory, extinction performance was only evident when cues available during test
- consolidation not disrupted
Retention and rehearsal!
after acquisition!
- potential issue is rehearsal
- animals keep info “active” in working memory through some form of “rehearsal”
rehearsal
animals keep info “active” in working memory through some form of “rehearsal”
Reconsolidation
contrary to previous views of memory, currently see memory as active vs. inactive (not ST vs. LT)
- when memory is in a “working state” it is labile
