Lecture 25: Memory Expertise Flashcards
Cahill and colleagues (1995) examined the role of an emotional
story (with images) on memory. They argued that memory for a
narrative with emotional context:
Was similar to flashbulb memories in that the most emotional
events could be remembered, but less emotional details were
less accurate.
the most important details were remembered and these were the ones that were the most emotionally charged
Cahill and colleagues (1995)
Results: Those who had heard the emotional narrative had superior memory for the middle photos.
- Interestingly, the detail at the beginning and the end were not remembered as well.
- Cahill and colleagues suggested that the emotional nature of the events lead to deeper encoding of the narrative.
• This could be similar to the inaccuracies of flashbulb memories. We tend to forget
(make source monitoring errors) when the details are less important.
how do we confabulate?
take the schema
fill in the items we really remember (emotional)
then fill in the things you don’t remember with default values
Emotion interacts with episodic memory
• Autobiographical memories for emotionally-laden events
seem enhanced.
• Amnesiacs with no free recall of recently studied items will
show enhanced RECOGNITION memory performance for
emotional items.
=> suggests some memory for procedural items (context cues, of which emotion can be a part of)
• Items with emotional content (e.g. words such as death, kill,
joy, tickle) are more likely to be recalled in laboratory memory
studies, relative to neutral terms (Kensinger & Corkin, 2003).
Interestingly, the effect seems to be larger for negative words.
Emotion interacts with episodic memory
Why?
You may be more motivated to rehearse/retell emotional events (rehearsal).
You may also encode these items differently (because they have something different than regular items).
modulates the encoding
of emotional memories
The amygdala : group of different nuclei, bilateral
seems to have a strong role in fear conditioning (classical conditioning in associating a neutral stimulus with a negative stimulus)
fMRI studies
• show that emotional events
increase activity in the amygdala
(especially for fearful stimuli).
Patients with amygdala damage ?
do not get the memory boost for emotional events in a story.
suggests that the amygdala is strongly implicated
effect of blocking stress hormones (epinephrine)?
decreases emotional encoding of
memories (can break the classical conditioning).
This has important consequences for post-traumatic stress disorder (PTSD) and related conditions.
=>
Hyperthymesia,
also known as Highly Superior Autobiographical Memory
(HSAM)
is the ability to recall incredibly detailed accounts of personal events based on very poor memory cues (dates).
Some people seem to have a natural tendency to link episodic
information with strong emotional content.
Hyperthymesia Example
• Jill Price (patient A.J.) has near-perfect autobiographical memory of events since age 11.
• Her semantic memory is average.
=> clear distinction between semantic and episodic memory
- Given relatively simple temporal cues (e.g. a date), she can recall vivid memories of what they were doing or what she saw and how she felt about .
- It seems like flashbulb memory for everything, but with accuracy
The cause of hyperthymesia isn’t known;
however, it seems to be associated with changes in amygdala size and connectivity.
Patient HK
• Patient HK was the second diagnosed case. He is blind and has near perfect memory for
events after about age 10.
• Structural MRI show his right amygdala to be 20% larger than controls and connectivity to other areas is increased (Ally et al, 2013).
=> maybe emotionally label all the events
• When tested on false memory paradigms (like CogLab 33), people with hyperthymesia
make the same errors as controls. This suggests that their semantic associations are
the same as others’.
Savant Syndrome
A small subset of people affected by Autism Spectrum Disorder (ASD) demonstrate exceptional abilities in highly selective areas of cognition.
great semantic memory for confined regions
Though they may score below average on standardized intelligence tests, they may have
remarkable abilities in the areas of mathematics, declarative memorization, or music.
A very small subset of neurotypical people have
these abilities without developmental differences.
Additionally, some people have acquired savant abilities following head trauma involving the temporal lobe (Treffert, 2006).
Daniel Tammet
is a savant with synesthesia (for digits they have a color and a shape).
He has a memory span of 11.5 digits, compared to typical 6.5. He memorized pi to 22,514 digits.
Can neurologically typical subjects be induced to show savant-like skills?
Snyder et al. (2006)
- Numerosity is the ability to instantly estimate a large number of items.
- Snyder applied transcranial magnetic stimulation (TMS) to the left anterior temporal lobe (LATL) of participants. Other were presented with sham (fake) TMS.
- People were presented with 50 – 150 items on a monitor for 1.5 sec and asked to estimate the number.
- They were tested before and after TMS/sham administration.
