lecture 5: memory 2 Flashcards
how did working memory come about?
The modal model made a distinction between STM and LTM (said ltm needed stm to come about) but was rejected in part because it could not handle
data from patients such as KF showing impaired STM and intact LTM (stm and ltm are distinct)
The working memory approach used dual task
methodology to fractionate WM into central executive, phonological loop, and visuo-spatial sketchpad, and solved a key problem that plagued the modal model.
*Neuropsychological and neuroimaging studies
have provided some insights into neural underpinnings of each WM component.
*Baddeley’s updated working memory model adds an
‘episodic buffer’ and posits specific connections between components of WM and LTM.
working memory approach
used dual task
methodology to fractionate WM into central executive,
phonological loop, and visuo-spatial sketchpad, and
solved a key problem that plagued the modal model
Neuropsychological and neuroimaging studies have provided some insights into neural underpinnings
of each WM component.
*Baddeley’s updated working memory model adds an
‘episodic buffer’ and posits specific connections between components of WM and LTM
Encoding
How we perceive/interpret our experiences; has a large influence on retention
semantic encoding
Retention benefits from semantic encoding: when we meaningfully associate new information to what we already know.
Neuroimaging of Encoding and Retrieval
*Prior to the widespread use of neuroimaging during the 1990s, there was little progress in understanding the brain basis of encoding vs. retrieval processes
*Neuroimaging techniques allowed a simple but important advance: the ability to measure separately brain activity during encoding and retrieval
*Early studies used levels of processing methodologies to study encoding, and simple cued recall or recognition paradigms to study retrieval
Blocked design fMRI encoding study
Make semantic judgments (abstract/concrete) during one block
Make nonsemantic judgments (upper case/lower case) during separate block
Compared average activity during the two blocks
Assess memory performance after scanning
Henry Molaison
IQ (=118)remained above average;
perception, attention, language comprehension/production, reading ability all intact
STM normal; severely impaired LTM
Generally characteristic of amnesic syndrome:
impaired LTM, normal or near-normal IQ and other cognitive abilities.
viral encephalitis
an inflammation of the brain caused by a virus
clive wearing
On 27 March 1985, Wearing, then an acknowledged expert in early music at the height of his career with BBC Radio 3, contracted herpesviral encephalitis, a herpes simplex virus that attacked his central nervous system. Since then, he has been unable to store new memories.
Anterograde amnesia
impaired memory for experiences that occur after incident/lesion that caused amnesia
Retrograde amnesia
impaired memory for experiences that
occurred prior to incident/lesion that caused amnesia
Damage to hippocampus and nearby structures in the MTL can cause both AA and RA, thereby linking these structures to
explicit/declarative memory
Confabulation
Confabulation is a type of memory error in which gaps in a person’s memory are unconsciously filled with fabricated, misinterpreted, or distorted information. When someone confabulates, they are confusing things they have imagined with real memories.
Evidence from patient HM
-Removed all of entorhinal cortex and perirhinal cortex (plus amygdala)
Removed 2/3rds of hippocampal formation; posterior hippocampus and parts of
parahippocampal cortex spared – contrary to Scoville’s original report.
case rb
Selective damage to the hippocampus (CA1 region)
after cardiac arrest and consequent anoxia
Episodic memory:
Episodic memory refers to the capacity for recollecting an autobiographical memory of events that occurred in a particular spatial and temporal context
Semantic memory:
Semantic memory is conscious long-term memory for meaning, understanding, and conceptual facts about the world. Semantic memory is one of the two main varieties of explicit, conscious, long-term memory, which is memory that can be retrieved into conscious awareness after a long delay (from several seconds to years).
mtl
medio temporal lobe (where hippocampus is)
Anterograde Memory Deficits in Patients with MTL Damage
Episodic memory:
Impaired on both recall and recognition tests for words, objects, faces, spatial information, as well as ongoing events in everyday life.
Impairments tend to be more severe with more MTL damage, e.g., H.M./Clive Wearing much more impaired than patient R.B.
Semantic knowledge acquired before amnesia generally OK.
Can patients with MTL damage acquire new semantic memories?
H.M. acquired some new vocabulary and knowledge of public figures who became famous after his operation; but very limited.
Patient KC
Suffered head trauma as a result of motorcycle accident in 1980; severe memory impairment
K.C. suffered from severe anterograde amnesia, in both verbal and non-verbal domains. This was accompanied by a selective retrograde amnesia for personal events experienced prior to the time of his injury (episodic memory), with relative preservation of memory for personal and world facts (semantic memory)
KC has no episodic memories of any events from before or after
his head injury. He has intact semantic knowledge for information
acquired before his head injury. Can he acquire any new semantic
Yes – can learn some new vocabulary and definitions – but like
H.M., his ability to learn new semantic knowledge is limited.
coronal
shows innermost brain
saggital
side view
fmri
Axial (a.k.a. transverse) plane refers to a horizontally-oriented plane which, when passes through the body in its anatomical position, divides it into upper and lower parts.
3 planes used to view brain scans
The different planes that Radiologists use are axial (divides the body into top and bottom halves), coronal (perpendicular), and sagittal (midline of the body). Radiologists call images that are axial or coronal view differently as they reverse left and right.
