Midterm 2 _ chapter 6 Flashcards
Long-Term Memory
- Archive of info about past events in our lives and knowledge we have learned
- System responsible for storing info for long periods of time
- Stretches from just a few moments ago (30sec) to as far back as we can remember
Serial Position Curve
- Created by presenting a list of words to a participant, one after another
- After the last word, the participant writes down all the words they can rememeber in any order
[Murdoch 1962]
- found that participants are more likely to remember words presented at the beginning of a sequence (Primacy effect) or at the end of a sequence (Recency effect)
Primacy Effect
Better memory for items at the beginning of a sequence
[possible explanation]
- Participants had time to rehearse the words at the beginning of the sequence and transfer them to LTM
- Because no other words are presented, the first word receives 100% of participants attention
[Rundus 1971]
- added a twitst to the experiment by presenting another list and asking his participants to repeat the words out-loud during the 5-sec interval between words.
- Results suppoted the idea that the primacy effect is related to the longer rehearsal time
- The words presented early in the list were repeated more
Recency Effect
Better memory for items at the end of a sequence
[Possible explanation]
- The most recently presented words are still in STM, therfore are easy for participants to remember
[Glander & Cunitz 1966]
- Had participants recall the words after they had counted backwards for 30 sec right after hearing the last word of the list
- Prevented rehearsal and allowed time for info to be lost from STM
- The delay cause by counting eliminated the recency effect
- Concluded that recency effect is due to storage of recently presented items in STM
Coding
The form in which stimuli is presented
[ex.]
- physiological approach to coding_ detemining how stimuli is presented by the firing of neurons
- mental approach to coding_ determining how stimulus is represented in the mind by describing [visual coding][auditory coding][semantic coding]…
Visual coding in STM & LTM
[STM]
- ‘Recalling Visual Patterns’
- Remebering the patterns by representing them visually in your mind
[LTM]
- Visualizing a person or place from the past
Auditory Coding STM & LTM
[STM]
- Conrad’s demostration of the phonologycal similarity effect [confusing letters that sound the same rather than look the same]
[LTM]
- playing a song in your head
Predominatly in STM, repeating a phone # in your head
Semantic coding STM
The Wickens Eperiment
- On each trial, participants were presented with words related to either group 1 (fruits) or group 2 (professions)
- Participants in each group listened to 3 words, counted backwards for 15 sec, the attempted to recall the 3 words
- Proactive interference occured decreasing the memory due to previously presented words interfering with newly presented ‘categorically’ similar words
- Release from proactive interference when the next set of words were from a different category than the group’s designated one, memory increased back up
Semantic Coding LTM
The Sachs Experiment
Participants listened to a tape recording of a passage and then measured they recognition memory to determine whether they remembered the exact wording of sentences in the passage or just the general meaning
- Many correctly identified exact worded sentence
- A number of ppl remembered the sentece’s meaning but not its exact wording
- This description in terms of meaning is an example of semantic coding in LTM
predomenantly LTM, remebering meaning over details as time passes
Measuring Recognition Memory Method
The identification of a stimulus that was encounted earlier
-Procedure for measuring is to present a stimulus during a study period and later to represent the same stimulus along with others that were not presented
- similar to multiple choice testing
- Different from recall which would be fill-in-the-blanks
Patient HM
Henry Molaison 1953
- Underwent a procedure removing his hippocampus on both side to eliminate his epileptic seizures
- Eliminated his ability to form new long-term memory
- Short-term memory remained intact
- Led to understanding the role of the hippocampus in forming new long-term memories
- suggested a separation between STM & LTM
Double Dissociation with KF
Patient KF
- Suffered damage to his parietal lobe in a motorbike accident
- Resulted in poor STM with a digit span of 2
- Reduced recency effect in his serial position curve
- Long-term memory intact
Double dissociation with HM
Brain imaging
[Ranganath & D’Esposito 2001]
- asked whether the hippocampus might also play a part in in holding info for STM
- sample face was presented for 1sec followed by a 7sec delay
- novel face vs familiar face condition
- activity in the hippocampus increases as participants are holding novel faces in memory duringn 7 second delay
- only changes slightly with familiar face [LTM]
- concluded that the hippocampus is involved in maitining novel info in memory during short delay
shows that the hippocampus and other medial temporal lobe structures also play a role in STM
Episodic vs semantic memory
Explicit
Turving 1985
-first proposed that handle different types of information and can be distinguished by the type experience is associated with each
- Episodic –> rememering
- Semantic –> Knowing
[Evidence]
patient kc
- damaged hippocampus
- lost his episodic memory
- ability to relive events from his past
- sematic memory intact –> dates… facts
patient LP
- encephalitis attack
- damaged sematic memory –> recognizing familiar ppl… forgot meaning of words
- Episodic memory still intact –> recalling what she did during the day …
Double dissociation
Auto-Biography Memory
Memory for specific experiences from our life which can include both
- episodic components –> relived specific events
- semantic components –> facts related to these events
[Westmacoot et all 2003]
- ran memory experiment on ppl with brain damage who had lost their episodic memory
- There was no enhanced memory for autobiographically significants names
Thus, when episodic memory is present, semantic memory is enhanced
Remember/Know procedure
Method
Participants are presented with a stimulus they’ve encounted before and asked to respond with:
- [remember] if the stimilus is familiar and remember the circumstances under which they originally encounted it
- [Know] if the stimulus seems familar but they don’t remember experiencing it
- [don’t know] don’t remember stimulus at all
Petrican et al. 2010
- Determined how people’s memory for public events changes over time
- presented descrptions of events that happened over a 50-year period [age mean: 63]
- used remeber/know method
[results]
- complete forgetting increased over time
- remember responces decreased much more than* know* responces
- Illustrated the sematicization of remote memories_ loss of episodic detail for older memories
Imagining future events
patient KC who lost episodic memory was unable to use his imagination to describe personal events that might happen in the future
- affected his personal prediction not his prediction of others future
[Brain imaging]
- Addis et al. 2007
- FMRI results indicated that all brain regions that were active while thinking about the past were also active when thinking about the future
The constructive episodic simulation hypothesis
States that episodic memories are extracted and recombined to construct simulations of future events
- it was found that both past and future recollection was more likely to be done from a third-person perspective
- link to default mode network
Explicit vs Implicit memory
Explicit
- Declarative memory
- conscious, can be described to other ppl
- Episodic and semantic memory
Implicit
- non declarative
- unconscious
- [Procedural memory] –> Cognitive stage (declarative –> associative (practice) –> Autonomous stage (stays intact even with brain damage]
- [Priming] representation of 1 stim affects responces to a later one –> responce occurs even though participant may not remember the original presentation
Avoiding Explicit Remembering in a Priming experiement
Method
- Presenting the priming stimulus in a task that does not appear to be a memory task
- presenting a list of words and asking them to press a key every time they see a 4 letter word
- Requiring a rapid responce to decrease conscious recollection
Perceptual priming
Peceptual effect
-depends on the perceptual over lap between primes and targets
[Cave 1997]
- long lasting perceptual priming
- Two session 6-48 weeks appart
- recognition task (did you see this item in session 1)
- Demonstarted that priming can be detected long term
- Even seen in patients with impaired declarative memory
[Repetition Suppression]
- less neural activation for repeated presentation of the same stimulus
- Shows sharpening/ efficiency in future representation
Semantic Priming
Meaning being primed rather than perception
[Lexical decision task]
- Quickly determining if presented word is real or made-up
- Faster more accurate responses to targets that are sematically related to primes
