Long Term Memory

LONG TERM MEMORY (LTM)  Variety of information stored in LTM:  The capital of Turkey  How to drive a car or use a computer Five major memory stores:  1. Working memory  2. Semantic memory  3. Episodic memory  4. Perceptual represenation system  5. Procedural memory

Explicit and Implicit Memory  Explicit memory  Performance on a task requires conscious recollection of previous experiences  E.g., can you remember your phone number – a recall event  Implicit memory  Performance on a task is facilitated in the absence of conscious recollection  E.g., dial a phone number person’s memory for the procedural activity of diallıng a phone number is tested and they are not aware of this

Episodic and Semantic Memory  Episodic memory  Storage and retrieval of specific events or episodes occuring in a particular place at a particular time  Semantic memory  Contains information and knowledge about the world

Semantic Memory Category-specific deficits (brain damaged patients) Category-specific activation (healthy individuals) Different parts of the brain activated for living and non livivng objects Left posterior middle temporal gyrus activated more for man-made items (non living objects) Left antero-medial temporal lobe activated for living things

Semantic Memory  Theoretical Explanation  Sensoy Function Theory (Farah & McClelland, 1991)  1. Living things distinguished from each other mainly on the basis of their visual or perceptual properties  2. Non-living things are distinguished from each other on the basis of their functional properties

Procedural Memory  Procedural memory:  Learning of motor and cognitive skills  E.g., learning to ride a bike  Repetition priming system:  Stimulus processing occurs faster and more easily on the second and successive presentations of a stimulus.

Skill Learning  Skill learning  Gradual improvment of performance with practice that generalises to a range of stimuli within a domain of processing.  Tasks which require extensive prefrontal and/or premotor areas of the brain shift to more automated pathways with practice  Transition dependent on the task itself

Organization of LTM Organization  Grouping discrete individual items into larger units based on a specific relationship among the items  Important encoding process Example  The words dog, cat, camel, and tiger are organised under the category of animal Organisation facilitates LTM  Schema’s – Loftus study Activation of nodes  Spreading activation theory  Accident example

What makes a cue effective?  Associative Strength Theory  A cue is effective if it has occurred frequently with the to be remembered event in the past  Strongly associated cues produce good memory than weakly associated cues  Study: whistle-train and green-train  At the time of the memory test the cue whistle or green was provided  participant asked to produce the other name (Train)  Better memory for whistle  Triın is more strongly associated with whistle than green

Associative Strength Theory  The more times the two events are paired the more strongly they are associated.  One word brings the other to mind automatically.

ENCODING SPECIFICITY PRINCIPLE  An item is encoded with respect to the context in which it is studied  A unique trace which incorporates information from both the target and context  For that encoded item to be retrieved, the cue information must match the trace of the item in context  Thus, memory performance depends directly on the similarity between the information in memory and the information available at retrieval.

ENCODING SPECIFICITY PRINCIPLE  Cues either weakly associated with the list words (Train-BLACK) or strongly associated (White-BLACK).  Results:  Recall performance was best when the cues provided at retrieval where the same as that at encoding.  Any changes in cues lowered recall, even when the shift was from weak to strong cues at recall.  Context (is also a cue), hence, change in context also affect affects recall.