Memory Flashcards
Define memory
Process by which information is stored and retrieved, the ability to retain information over time
Memory is necessary for learning - Shettleworth 1998
How long does short term memory (STM) store information? Long term memory? (LTM)
STM seconds->hours
LTM years
How do studies of memory differ from studies of learning?
Learning- how relationships between events are learnt, which are learnt, how fast?
Memory- How information is encoded, stored and retrieved, what affects ease of this, how is information consolidated, mechanisms?
Who studied Western Scrub jays?
Tarbell 2004 - food storing animals, appear to remember which trees food is hidden in. May be a rule - eg. go to smallest tree first etc.
Neurally, what is short term memory doing?
Strengthening synaptic connections
How does consolidation from STM->LTM occur?
Gene expression and protein synthesis - growth of NEW synaptic connections
How may STM give behavioural outputs?
Behaviour alone or cued behaviour
How may LTM give behavioural outputs?
Spontaneous behaviour (recall memory) Cued behaviour (recognition memory)
Which factors affect encoding to STM?
Duratino of exposure to stimulus, no. of discriminable features a stimulus has, interference from other stimuli, salience of stimuli (surprise/distinctiveness/motivational relevance/value/stress/emotional state)
What must be considered when used delayed match to sample tasks to look at STM?
LTM is also used just to understand the task in the first place
Give a study looking at duration of exposure to stimulus and STM encoding
Grant 1976 - pigeons delayed match to sample, extending time between first and second stimuli
Give a study looking at no. discriminable features of a stimulus and encoding to STM
Zentall et al 1990 - pigeons adding colour to different shaped stimuli (delayed match to sample)
Give a study looking at interference from other stimuli and encoding to STM
Whitlow 1975- Habituation in rabbits to a tone demonstrated.
Then, light flashed between two tones same distance apart, habituation ruined and same initial response occurs upon second play of tone - information has been overwritten following encoding (RETROACTIVE INTERFERENCE)
Then, light and tone played first, again when tone played alone second time same initial response occurs - information has been interfered with during the encoding process (PROACTIVE INTERFERENCE)
What are primacy and recency effects?
Primacy - the first stimulus/picture/event is most memorable/ better recognition
Recency - the last stimulus/picture/event is most memorable/ better recognition
NB: Serial position curve of proactive and retroactive interference
What phenomenon is displayed in the serial probe recognition task? In what species?
Pigeons, monkeys and humans. Different retention intervals (RI) -> different prevalence of primacy/recency effects
- Short RI = Recency effects, last stimulus best memorised
- Medium RI = U shaped
- Long RI = Primacy effects, first stimulus best memorised
NB: Exact RI depends on species (Long RI = pigeons 10s, monkey 30s, human 100s)
Give two studies showing salience of stimulus affecting encoding to STM
Roberts 1980 - if matching to sample and all stimuli are circles, then one is a line, will be more easily matched
Laughlin and Mendl 2004 - pigs searching for food in 4 armed maze, when arms become costly to enter and search make fewer errors and remember better
What is the effect of stimulus saliency on STM encoding known as in humans?
Von Restorff effect
How does stress or emotional arousal impact encoding to STM?
Attention narrowing/focus - {task relevant }
Flashbulb memories - { stressors}
Attention shifts/lapses (task irrelevent stressors)
- Yerkes-Dodson Law
Why is the salience of a stimulus able to impact its encoding?
The value or importance of the information attempting to be memorised
What factors affect coding into LTM?
Cahill et al 1994 - Physiological responses to emotional stories increase memorisation. If given B blockers memory decreased
What did Sandi and Rose 1994 do?
Chicks - food aversion with corticosterone/control injection. Corticosterone (HPA response) chicks showed markedly more avoidance
Also shown with adrenaline
Which hormones are produced in response to an emotionally arousing or important stimulus? How do these act to affect memory?
Glucocorticoids and Catecholamines - GCs cross BBB -> Hippocampus directly, Catechols do not cross BBB but increase blood glucose enabling the brain to work more efficiently
What did Cahill et al 1996 show?
Increased amygdala glucose associated with remembering more of an emotional film
What are the two types of memory recall?
Recognition - cue similarity to stored information influences retrieval success. Context is important (external - location, odour, weather etc. Internal - affect, body clock etc.)
Recall - Apparently not cued, but possible that context and subconscious cues are registered
