Week 7: Learning And Memory Flashcards
Memory
Memories are not copies of the world
Memories are representations of the world
Memories are prone to error and bias
Memories vary in accuracy
Memory
Definition
Encoding
Storage
Retrieval
Definition: memory is the ability to retain information over time
Encoding: making mental representations of information which can be stored in memory
Storage: placing encoded information into storage for later recall
Retrieval: recalling information from memory storage
Types of memory
Sensory memory
Short-term memory
Long-term memory
Sensory memory
SM receives and holds information for very brief duration
If unattended, memories disappear without a trace
Short-term memory
STM holds limited amount of information (7) for short period of time (20-30 sec)
If unrehearsed, memories disappear
Long-term memory
LTM holds almost unlimited amounts of information for almost unlimited amounts of time
Types of long-term memory
Declarative (explicit)
Semantic (facts)
Episodic (events)
Non-declarative (implicit)
Procedural (skills & habits)
Conditioning (associative)
Memory: neural basis
Amnesia
Inability to form and/ or recall long term memories
Other cognitive faculties are relatively unimpaired (language, attention, short term memory)
Retrograde amnesia - cannot recall old memories
Anterograde amnesia - cannot form new memories (patient HM)
KC & clive wearing both?
Beyond the hippocampus
Patients who fail to produce any of the complex figure or who are deficient at producing either remote semantic memories or remote autobiographical events will prove to have damage beyond the hippocampus.
Extent of lesion in hippocampus and surrounding brain structures is directly related to the degree of impairment
Forms of memory organisation
George Mandler (1972, 2011) proposed three types of memory organisation:
-an associative structure in which multiple events are linked by direct and indirect associations within a network
(Rats with hippocampal lesions succeed in learning individual elements and associations but fail in linking indirectly related elements in an associative organisation).
-a sequential structure involving a temporal organisation of serial events
(Rats with hippocamal lesions succeed in remembering items in a list but fail in remembering the order of the items in the sequential organisation.
-a schematic structure involving a hierarchal or similarly complex organisation of items in memory
(Rats with hippocampal lesions succeed in learning trained choices of all pairings in a five-item hierarchy but fail in inferring relations between indirectly related elements in a hierarchal schematic organisation
Damage to the hippocampus leads to specific impairments in associative, sequential and schematic forms of memory organisation
These include a) inferring relations between indirectly related items and b) the order of multiple items
LTM STM interactions
These observations support the view that patients with medial temporal lobe lesions can succeed at remembering whatever they have encountered, so long as the material to be remembered can be supported by a limited-capacity, short-term memory system
Prefrontal hippocampal interactions
Prefrontal & hippocampal regions interact in the service of memory
The PFC receives direction projections from the vHPC (anterior HPC in humans) and projects indirectly (via the perirhinal & entorhinal cortices) to the dHPC (posterior HPC in humans).
In this model, when one is cued by context to recall memories, contextual cues are processed by the vHPC, which sends this information to the PFC, which then biases the retrieval of the context-appropriate memories in the dHPC.
PFC involved in establishing the organisation of relationships among memories and in monitoring retrieval
Memory impairment caused by prefrontal damage can be characterised as a deficit in the suppression of interfering memories
Patients with PFC damage do not have severe impairments in standard tests of event memory
Deficits resulting from PFC damage are apparent when memory for target information must be obtained under conditions of memory interference or distraction
PFC controls memory retrieval by selecting memories relevant to the current context and suppressing irrelevant memories and suppressing inappropriate memories
Prefrontal hippocampal interactions
Bidirectional hippocampal - PFC interactions support memory encoding and context-dependent memory retrieval
Cognitive control by the prefrontal cortex may also support the development and updating of memory organisations by guiding the integration of new memories into the organisation of preexisting knowledge
New memories are initially represented within the hippocampus and subsequently become interleaved into the semantic organisation of existing related memories in the neocortex. This integration of memories into knowledge organisations relies on the PFC
PFC plays an essential role in the acquisition of schematic organisations and in making inferences between indirectly related memories, memory retrieval from schematic organisations
Attributes of memory: remember / know
The remember / know paradigm was introduced by ended tulsi great (1985) to measure the different states of awareness thought to underlie memory retrieval. John gardiner (1988) refined the paradigm
Participants in a memory experiment were asked to indicate the basis on which they judged that an item had been previously studied. (Do you remember? Or do you simply know?)
Remembering: the ability to become consciously aware of some aspect or aspects of what occurred or was experienced at the time the test item was first presented
Knowing: recognition that the test item had been presented earlier but without the ability to recollect consciously anything about its actual occurrence or what had happened or what was experienced at that time.
Attributes of memory: remember / know
Dual process interpretations:
Two qualitatively different memory components, systems, or processes
Remember:
Autnoetic awareness , episodic memory
Distinctiveness of processing at study
Recollection process
Know:
Noetic awareness, semantic memory
Fluency of processing at test
Familiarity process
Attributes of memory: remember / know
Signal detection theory interpretations
Remember and know responses reflect different levels of confidence concerning the products memory retrieval
7 sins of memory
Omission
Transience= decreasing accessibility of memory over time
Absent-mindedness = lapses of attention that result in forgetting
Commission
Blocking = information that is present but temporarily inaccessible
Misattribution = memories are attributed to an incorrect source
Suggestibility = implanted memories about things that never occurred
Bias = current knowledge and belief distort our memories about the past
Persistence = unwanted recollections that we can never forget
It is often useful and even necessary to forget information that is no longer current, such as old phone numbers or where we parked the car yesterday
Information that is no longer needed will tend not to be retrieved and rehearsed, thereby losing out on the strengthening effects of post-event retrieval and becoming gradually less accessible over time
The seven sins can be usefully viewed as by-products of otherwise adaptive features of memory
JJ is talking to his sister about a hip hop artist he read about. With some annoyance, he realises that he cant remember the name of the artist anymore.
Assuming JJ’s memory has failed him, what sin of memory has his mind committed?
A. Blocking
B. Suggestibility
C. Misattribution
D. Transience
A. Blocking
