Theories of long-term memory Flashcards
Episodic and semantic memory
Tulving (1972) - episodic memory refers to the storage (and retrieval) of specific events or episodes occurring in a particular place at a particular time;
Semantic memory contains information about our
stock of knowledge about the world.
More recent definition of episodic memory - Wheeler, Stuss, & Tulving (1997)
Its main distinguishing characteristic was “its dependence on a special kind of awareness that all healthy human adults can identify. It is the type of awareness experienced when one thinks back to a specific moment in one’s personal past and consciously recollects some prior episode or state as it was previously experienced.” They described this form of awareness as autonoetic or self-knowing.
Source amnesia
Being unable to remember where or how some piece of factual information was learned. Studied by Janowsky, Shimamura & Squire (1989) as a failure of episodic memory.
Damage to which part of the brain is hypothesized (Wheeler et al., 1997) to cause a failure of episodic memory?
Damage localised to the prefrontal cortex causes a selective loss in the episodic memory system.
Differences in blood flow to the prefrontal cortex for episodic/semantic encoding/retrieval tasks.
In 25 out of 26 studies, the right prefrontal cortex was more active during an episodic memory retrieval than during semantic memory retrieval.
In 18 out of the 20 studies, the left prefrontal cortex was more active during episodic encoding.
The repetition-priming effect
When the processing of a stimulus is faster and/or easier when it is presented on more than one occasion.
Differences in brain activity during implicit and explicit memory tasks.
Schachter et al. (1996) reported much activation in the hippocampus during an explicit memory task when compared to implicit memory tasks (which also showed reduced blood flow in the bilateral occipital cortex
The double dissociation between perceptual and conceptual implicit tests.
Alzheimer’s patients typically have impaired conceptual priming; patients with right occipital lesions have no perceptual priming.
Berry & Broadbent (1984)
Implicit learning experiment: managing a sugar production factory. People who were more consciously aware of the underlying principles being used were also a little worse at the task.
Howard & Howard (1992)
Implicit learning: which part of the screen will the asterisk appear in (moving in a complex pattern). Clear signs of learning, yet when asked about the next round, participants performed at chance level.
Differences in brain activity during implicit and explicit learning.
Grafton et al. (1995) “Explicit learning and awareness of the sequences required more activations in the right premotor cortex, the dorsolateral prefrontal cortex associated with working memory, the anterior cingulate, areas in the parietal cortex concerned with voluntary attention, and the lateral temporal cortical areas that store explicit memories”
Transfer appropriate processing approach to memory
Roediger (1990) distinguishes between two types of processing:
- Data-driven or perceptual processes - “the analysis of perceptual or surface level features (but may also include other representations required for stimulus identification)”
- Conceptually driven processes, which can be defined as “the analysis of meaning or semantic
information”
Common causes of amnesia
Closed head injury,
Bilateral stroke;
Korsakoff’s
anterograde amnesia
A marked impairment in the ability to remember new information which was learned after the onset of the amnesia.
retrograde amnesia
Difficulty in remembering events occurring prior to amnesia.
