Long term memory
can be thought of as an archive of info about past events and knowledge learned . works closely with STM/ WM. storage stretches from a few moments ago to as far back as one can remember. more recent memories tend to be more detailed
Murdoch (1962) and Serial position curve
studied the distinction between short term and long term memories using the serial position curve.
participants read stimulus list and have to recall it.
showed that people tended to remember info better at the beginning or the end of a sequence. = showed a U shaped curve on the graph
primacy effect
memory better for stimuli presented at the beginning
One explanation is that it occurs because participants had more time to rehearse the earlier items , making them more likely to enter LTM.
recency effect
memory better for stimuli at the end of the list.
one explanation is that it occurs because the stimuli is still active in the STM at the point at which participants memory is tested. Introducing a delay can eliminate this effect.
coding
refers to the form in which stimuli are represented . the form a representation takes can have important implications. in both STM and LTM , visual, auditory, and semantic coding can be used. auditory coding tends to be the most common form in STM and semantic coding tends to be the most form in LTM
proactive interference
occurs when info learned previously interferes with learning new info.
retroactive interference
occurs when new learning interferes with remembering old learning
the Wickens experiment
had participants encode words from various categories . one condition involved presenting a series of items that all belonged to the same category.
-reduction in performance for successive items from the same category can be interpreted as proactive interference.
-Boost in performance for items presented after a category switch , which can be interpreted as release from proactive interference.
-demonstrated how changing the category of information can improve short-term memory recall
the neuropsychological approach
has contributed greatly to our understanding of the involvement of the hippocampus with encoding new long term memories
double dissociations
evident between STM and LTM :
someone who had surgery for epilepsy had impaired LTM but intact STM, and someone who had traumatic brain injury had impaired STM but intact LTM
Explicit memory
the conscious, intentional recall of facts and past events. includes episodic and semantic memory
implicit memory/ non-declarative
the unconscious, unintentional influence of past experiences on current behavior or skills. includes procedural memory, priming, conditioning
episodic memory
memory for personal events. Involves ‘mental time travel’. no guarantee if accuracy. multidimensional in nature (can include sensory details, emotional , contextual, etc)
semantic memory
memory of facts and knowledge. does not involve mental time travel . general knowledge
double dissociation and episodic and semantic memory
episodic and semantic show a double dissociation. ex. individual w damaged hippocampus had no episodic memory but semantic memory in tact. individual w impaired semantic memory , still had episodic memory preserved.
autobiographical memory
the recollection of personally experienced past events. memory of specific experiences . It is a type of explicit memory that combines both episodic (specific events) and semantic (facts) memory
distinctions in episodic and semantic memory
evidence from brain imaging experiments demonstrate that retrieving semantic and episodic memories activate somewhat different areas of the brain. There is still some overlap .
personal semantic memories
semantic memories that have personal significance
Petrican et al. (2010) remember/know procedure
used a remember/know procedure to measure familiarity and recollection.
-remember response: if a stimulus is familiar and the circumstances under which it was encountered can be remembered
-know response: if the stimulus is familiar but one doesn’t remember experiencing it earlier
-don’t know response: don’t remember the stimulus at all
results show the semanticization of remote memories. loss of episodic details for memories of long ago events. memories for more recent events more likely to include episodic content.
procedural (skill) memory
implicit memory. memory for actions. no memory of where or when learned. perform procedures without being consciously aware of how to do them. People who cannot form new LTMs can still learn new skills
priming
type of implicit . prior exposure to a stimuli changes a subsequent response to another stimulus.
conditioning
type of implicit. a response is learned through association between a stimulus and a behavior.
expert induced amnesia
expertise in a skill may result in it being carried out with such a degree of automaticity that the individual performing the action has little to no recollection of what actually happened
Graf et al. and repetition priming
examined how the presentation of a stimulus affects performance when it is presented again (i.e., repetition priming).
- participants had to rate how much they liked a series of words (facilitating incidental processing , i.e., participants were not attempting to memorize)
-participants tested in 2 ways : explicit memory test (assesses recall memory) and word stem completion (assesses implicit memory)
- 3 groups tested:
1. other inpatients (no signs of amnesia or alcoholism): INPT
2. patients being treated for alcoholism: ALC
3. amnesiac patients: AMN
- found impairment in explicit memory for amnesiac group. no deficit for implicit memory in that group.
