Week 5 Slides Flashcards
Define Memory
- The Process - Encoding, Retaining, Retrieving and Using information after the original stimulus is no longer present
- Is Recalling - images, events and ideas
Active any time past experience impacts thinking and behaviour in the present
What is Long-term Memory
- Can be divided into STM & LTM
- memory constructs often overlap in functions
- We need to be careful how we divide memory
- Behavioural experiments and Neurophysiological studies can infer how we use memory
What is Long-term Memory
- Responsible for storing information for long periods of time
- Extends from just a few minutes in the past to earliest memories
Long-term Memory Interacts
- Retains information from past
- Interacts with STM and Working Memory to create current experience
Serial Position Curve
- Murdock 1962
- Asked subjects to listen to a list of words and then write them down as they remember
- Participants are more likely to remember the beginning of a list and the end of the list
- Primacy Effect
- Recency Effect
- Serial Position Curve
- Murdock 1962
- Primacy Effect
- Recency Effect
Primacy Effect
- People have more time to rehearse words at the beginning of a task
- These words are more likely to be transferred to LTM
Serial Position Curve - Rundus 1971
- 20 word list at 1 word/5 sec
- Found the SPC that Murdock found
- Also found the early words were repeated most often
Recency Effect
- Mudock 1962
- Most recently shown words are still in STM
- They are more easily recalled
Serial Position Curve - Glanzer & Cunitz 1966
- Asked participants to count backwards for 30s after hearing last word
- Mostly remembered words from beginning
- Recency Effect was eliminated as words no longer in STM
Semantic Coding in Memory
- How is meaning stored in STM/LTM
- Wickens et al
- SUbjects in two groups to recall three words across 4 trials
- One group fruits, other group three proffesions and one fruit
Wickens et al Findings
- Performance in the Fruit only group worsened
- This was due to proactive interference
- Performance in the Professions group worsened across three trials
- Professions group improved on final fruit trials
- Evidence that meanings of words are encoded in STM
Sachs 1967
- Many people identified the correct sentence as changed
- Still many people also identified the wrong sentence even though the wording was different
- Evidence that people don’t remember specific words
- Actually they remember the general meaning of the passage
Henry Molaison
- Underwent surgery to eliminate seizures
- Successful in eliminating seizures but also left him unable to form new memories
- STM remained intact but not able to transfer any STM to long term memory
- Evidence that STM & LTM served by separate brain regions
Double Dissociation
- Patient KF had parietal lobe damage from a motorcycle accident
- KF exhibited normal LTM but poor STM
- Reduced digit span to 2 and reduced Recency effect
- Evidence that LTM & STM are different parts of the brain and independent mechanisms
Ranganath & D’Esposito 2001
Presented a sequence of stimuli to participants under fMRI.
• Sample face for 1 s
• Delay for 7 s
• Show a face
• “Does this face match the sample?”
- Hippocampal activity increases if the “same face” is new
- Hippocampus is involved in maintaining new information during short delays
LTM Summary
LTM is responsible for storing information for long periods
Interacts with STM and Working Memory to create our ongoing experiences
Evidence that STM & LTM are used for tasks
- Serial Position Curve
- Primacy Effect
- Recency Effect
Double Dissociation HM & KF
Indicate that different structures in the brain are responsible for STM & LTM
Brain imaging shows us which areas of the brain are activated when we use memory
Tulving - Episodic and Semantic Memory
- Episodic - Memory for experience that have happened in the past
- Semantic - Memory for Facts
- Each handles memory in different ways
- Can be distinguished by the type of experience associated with the memory
Episodic Memory
Involves “time travel”
Reliving experiences from the past requires
Tulving says episodic memory is self knowing
Semantic Memory
- Involves accessing knowledge that is not a personal experience
- Facts, vocab, numbers & concepts
- We do not relive the past when we experience semantic memory
Patient KC - Kent Cochrane
- Severe damage to Hippocampus and Surrounds due to Motorbike Accident
- Lost ability to relive the past and imagine future
- Semantic Memory still intact
- Double Dissociation of Semantic and Episodic Memory
Levine et al. 2004
- Subjects kept audio diaries each day
- Described personal events and facts semantically
- Replaying tapes returned vivid episodic memory
- Semantic facts did not
- Evidence semantic and episodic memories activate in different areas of the brain
Semantic Memory can Influence Episodic Memory
Your knowledge of something can influence the way you experience it.
Autobiographical Memory
- Contains both Semantic and Episodic memories
- Semantic Memory is intertwined in story telling personal experiences
- People with no episodic memory don’t get enhanced memory for significant names
Autobiographical Memory - Westmacott & Moscovitch 2003
- Found knowledge of celebrities can be both Semantic and Episodic
- Participants were asked to label famous people as “know”
or “remember” - Memory was better and faster for famous people labelled
as “remember” - Autobiographical significant semantic memory
Episodic & Semantic Memory Over Time
- Recalled information is often distorted from original information
- Not simply forgetting
- Petrican et al. 2009
- Measured memories of public events over 50 years
- Asked subjects if they remember, know or
Petrican et al 2010
- Complete Forgetting was stronger after 40-50 years
- Remember responses decreased more than Know
- Episodic memory loses character over time more than semantic
- Semanticization of remote memories also occurs with recent memories
Using Memory to Think about Future
Remembering past is important for creating possible future scenarios
KS could not describe personal events that were going to happen
Addis et al 2007 - Constructive Episodic Simulation Hypothesis
- Subjects given a noun and asked to construct a past OR future event
- Once chosen, they pressed a button and elaborated for 20 seconds
- Strong overlap between areas activated during future & past events
- KC was not able to describe personal events due in the future
McDermott et al 2006 - Memory and the future
- Subjects asked to remember an event from the past or imagine a similar event in the future
- Asked to describe what they see as they went
- Were they describing in first person or third person
- Real and Imagined stories both likely to be imagined from both perspectives
- Eye levels and distance were similar across both styles
- Suggests: Episodic memory is for constructing possible future scenarios
Summary Episodic Memory
- Episodic - experiences that have occurred in the past
- Episodic memory can lose episodic nature over time
- Episodic memory can be adaptation the allows us to simulate future events
Procedural Memory
Explicit/Conscious Memory
- Episodic Memory
- Semantic Memory
Implicit/Not Conscious
- Procedural Memory
- Priming
- Conditioning
Skill Memory
- Also Procedural Memory
- Appears to be implicit - like typing or driving
- Does not require episodic/semantic memory.
- Amnesiac patients can acquire new skills though they cannot
remember learning it. - HM became quite good at the mirror drawing task
- Another patient LSJ improved at violin, though she could not
remember practising.
Procedural Memory and Attention
- Often procedural memory begins by paying close attention e.g. playing instrument
- Once mastered attending can hold back progress and performance
Expert Induced Amnesia
Often experts like musicians and sports stars cannot describe how they perform a task