7. Memory

Process of memory storage model (Atkinson & Shiffrin)

Incoming information → sensory memory → STM/working memory → elaborative rehearsal → LTM

4 components of working memory

1. Central executive

2. Phonological loop

3. Episodic buffer

4. Visuo-spatial sketchpad

2 components of LTM

1. Explicit (declarative)

2. Implicit (non-declarative)

2 components of explicit memory

1. Episodic (experienced events)

2. Semantic (knowledge and concepts)

2 components of implicit memory

1. Procedural (skills and actions)

2. Emotional conditioning

Arguments that working memory is distinct from LTM come from

• Introspection

• Physiology

• Consideration of computational utility

• Experiments on “normal” subjects

• Effects of brain damage

Brown-Peterson distraction paradigm

Participants read a short list and try to retain it while counting backwards by threes until cued to recall. Retention rapidly declined over time, and then leveled off which indicated two memory components

Recency effect

Words at the end of a list are relatively well remembered in comparison to other words in the list

Primacy effect

Words at the start of the list are relatively well remembered in comparison to other words in the list

Chunking

Grouping pieces of information for deeper processing for better recall

Single-trace theory

Memory trace decays rapidly to start with, then more slowly

Dual-trace theory

Retrieval after short interval mediated by temporary rapidly-decaying memory trace; retrieval after longer interval mediated by a more permanent memory trace

Factors selectively imparing free recall

• List length = longer the list the fewer items are recalled BUT recency effect is unchanged

• Faster presentation of words

• Older age

• Alcohol

Single dissociation

Occurs when a brain injury impairs one cognitive function while leaving another intact indicating they might be separate

Double dissociation

Requires two patients with reciprocal impairments (e.g., Patient A: good short-term/poor long-term; Patient B: poor short-term/good long-term), conclusively proving that two functions are independent and rely on distinct brain areas

Amnesic syndrome

Normal working memory, but little or no ability to convert new facts/events to permanent memory

Stress and working memory

Working memory capacity is limited so worrying can act as a secondary task which competes for resources

Types of recall tests

• Recall of events, story recall (hard to score)

• Free recall of lists of nameable items (% recalled)

• Cued recall e.g. paired associates (% recalled)

• Serial recall (% in correct position)

Recognition test

Ability to discriminate “old” from “new” items (% correct)

Reasons for forgetting

Interference and retriveval failure

Proactive interference

Previous (old) information interferes with the recall of newer information

Retroactive interference

Recent (new) information interferes with the recall of older information

Retention interval

The time elapsed between the initial encoding of information (learning or experiencing an event) and the attempt to retrieve it

Factors that influence retrieval

• Processing at encoding/aquisition

• Consolidation after encoding

• Interference from other memory traces at retrieval

• Similarity of encoding and retrieval contexts

Organisation at acquisition

Organising the material is what produces effective acquisition, not effort to learn (by itself)

Depth of processing at acquisition

Processing the meaning is better than processing surface form

Why do mnemonics work

They bind idea to a pre-established framework, which organises them, and the imagery encourages formation of rich nexus of association between the frame and the concept attached to the hook

Retrograde memory loss after concussion

After traumatic brain injury, there is often retrograde memory loss spanning many minutes, even hours → disruption of porcess of consolidation of memory trace in hipoocampal/medial temporal cortex system

Fan effect

Recognizing or retrieving a specific piece of information takes longer and is more prone to error as more associations (a "fan") are learned about that information

False memories

Memories that are fabricated, distorted, or mistaken recollections of events that never occurred or happened differently, often feeling entirely real to the individual

Context-content paradox

The way emotions affect false memories depends on

• Whether the emotion is part of the to-be-remember event

• Or whether (negative) mood is the context in which something is remembered

Motivation and learning

Learning is easy when in the state of motivation and curiosity → feeling of leanring something interesting (rewarding)