Memory Lecture Review

Structure of Memory

• Information Processing Model
• Sensory & Short-Term Memory
• Working memory

Experimental Psychology (Pre-1950s) - Behaviorism

• B.F. Skinner and John Watson were key figures.
• Classical Conditioning:
  • Associating an involuntary response with a stimulus.
• Operant Conditioning:
  • Associating a voluntary behavior with a consequence.

Experimental Psychology (1920s) - Behaviorism

• Focused on observable inputs and outputs, treating the mind as a "black box."
• The internal cognitive processes were largely ignored.

Experimental Psychology (1950s+) - Information Processing

• Shifted focus to internal mental processes, referred to as "Cognition."
• Emphasized how information is processed between input and output.

Information Processing Approach

• Views the mind as a system that processes information.
• Key components:
  • Input
  • Process (perception, thinking, decision-making)
  • Storage (memory)
  • Output

Multi-Store Model - Atkinson & Shiffrin

• A model of memory with three separate components:
  • Sensory Memory: Initial stage that holds sensory information briefly.
  • Short-Term Memory (STM): Limited capacity storage that holds information temporarily.
  • Long-Term Memory (LTM): High-capacity storage that holds information for extended periods.
• Process:
  • Environmental Input
  • Sensory Memory
    • Attention transfers info to STM
    • Forgotten through decay or displacement
  • Short Term Memory
    • Maintenance Rehearsal - maintains information
    • Elaborative Rehearsal - leads to storage in LTM
    • Forgotten through decay or displacement
  • Long Term Memory
    • Retrieval brings information back to STM
    • Forgotten through interference or retrieval failure

Memory's Role

• Memory is not just about the past; it shapes our perception of the present and influences our experiences in the moment.

Persistence of Motion

• Example provided of something rotating at 560 rpm

Memory's Influence

• Memory influences how we perceive and think about the world.

Atkinson & Shiffrin (1968) Multi-Store Model

• Evidence for 3 types of memory stores?
• Characteristics of each type of memory?

Sensory Memory

• What is retained in sensory memory? (Capacity)
• How long does this information last? (Duration)

Sensory Memory Demonstration

• The visual system processes a massive amount of information and we perceive all of it.
• If told what to remember beforehand, we are good at remembering some information.
• If not warned beforehand, we do not remember most of that information.
• How much information is saved in memory?

Testing Sensory Memory - Whole Report Procedure

• Participants are asked to recall all of the letters in a briefly presented display; a 3x3 grid of letters.

Testing Sensory Memory - Partial Report Procedure (Sperling)

• Participants are asked to recall only the letters indicated by a cue (e.g., a tone indicating a specific row).
• Example: Middle Row

Sperling (1960) Findings

• Whole Report: Recall about 33% of a 9-letter display.
• Partial Report: Recall more than 75% of a 3-letter row.

Sperling (1960) - Cue Delay

• Graphical representation showing the percentage correct recall as cue delay increases from 0 to 1 second.
• Partial report performance decreases as the cue delay increases, eventually converging with whole report performance.

Sperling (1960) Conclusion

• Sensory memory has a large capacity but information decays rapidly.
• After ~1 second, information fades but can be rehearsed (kept in short-term memory).
• whole report à partial report

Sensory Memory - Capacity & Duration

• Capacity = very large
• Duration = less than 1 second
• Attention transfers to Short Term Memory; otherwise information is forgotten.

Short-Term Memory

• What is retained in short-term memory? (Capacity)
• How long does this information last? (Duration)

Short-Term Memory - Capacity

• Holds about 7 "things" (Miller, 1956).
• Useful for everyday tasks such as mental arithmetic, holding a conversation, and remembering several names.
• Capacity measured with memory span test.

Memory Span

• For example: XXXX - 4

Short-Term Memory - Chunking

• A "thing" is a chunk of information.
• Example:
  • 3 – 5 – 7 – 1 – 3 – 2 (6 chunks)
  • D – A – I – Z – R – L (6 chunks)
  • L – I – Z – A – R – D (1 chunk - chunked as the word "Lizard")

Short-Term Memory - Visual Chunking

• Combine several words into a visual “chunk”:
  • white, cat, barrel, four, blind (5 chunks)
  • (Picture of Charlie Chaplin) (1 chunk)

Memory Span - Cultural Differences

• Memory span differs among cultures.
• Example memory spans for English, Spanish, Hebrew, and Arabic speakers.

Memory Span & Pronunciation Rate

• Chunks have “size” – bigger chunks take up more space
• Size related to pronunciation rate - when digits have more syllables, fewer can be held in STM (Naveh-Benjamin & Ayres, 1986).
• Pronunciation rate (in items/second) varies across languages.

Short-Term Memory - Word Length Effect

• Similarly, you can hold more short words than long words in STM:
  • Greece, China, Spain
  • Switzerland, Venezuela, Madagascar

Short-Term Memory - Peterson & Peterson (1959)

• Hear letter sequence, count backwards (time interval), recall sequence.
• CMJ ..143 143..140.. 137..134.. recall the letters CMJ ?
• Intervening task (count backwards) means no maintenance rehearsal.
• Memory decays as time interval increases.

Short-Term Memory - Duration

• Graph showing letter recall percentage decreases as retention interval (in seconds) increases.
• Duration STM < 30 seconds

Short-Term Memory - Interference

• Decay over time is not the only reason for forgetting.
• Forgetting can occur through interference from other things in memory.
  • Interference = displacement by other memories
  • Proactive Interference (from earlier memories)
  • Retroactive Interference (by later memories)

Brown / Peterson & Peterson Task - Wickens et al. (1976)

• Learning items from the same category yields increasingly worse memory. Evidence of Proactive Interference.
• Trial 1: Banana, Peach, Apple
• Trial 2: Pear, Grape, Cherry
• Trial 3: Lemon, Plum, Apricot

Brown / Peterson & Peterson Task - Release from Proactive Interference

• Change to a new category results in release from proactive interference.

Short-Term Memory - Capacity & Duration - Factors

• What factors limit how much we can hold in STM? Does the capacity of STM depend on the characteristics of the items?

Working Memory vs Short-term Memory

• Why use the term Working Memory rather than Short-term Memory?
• Baddeley & Hitch (1974): Working memory is not simply a passive storage area.
• A place where information for current goals and activities is held and actively processed.

Baddeley's Model of Working Memory

• Central Executive: Integrates information from other components (in episodic buffer).
• Phonological Loop: Stores auditory information.
• Visuospatial Sketchpad: Stores visual and spatial information.
• Episodic Buffer:
• Long-term Memory

Baddeley's Model of Working Memory

• Multi-component system distributed throughout the brain
• Prefrontal Cortex: Central Executive (Chai et al. 2018)
• ACC: Attention Controller
• Parietal Lobe: Episodic Buffer (perceptual processing)
• Broca's & Wernicke's: Phonological Loop
• Occipital Lobe: Visuo-spatial Sketch-pad

Working Memory - Task Complexity

• Visuospatial Sketchpad Task involves:
  • Visual Objects
  • Spatial Location

Working Memory - Distinction

• Evidence for distinction between Visuospatial Sketchpad and Phonological Loop:
  • Phonological information does not interfere with Visuospatial information.

Baddeley & Hitch (1974) - Working Memory Experiment

• Remember sequences of 0-8 digits while performing a spatial reasoning task.
• A à B true
• B à A false
• Size of digit load had no effect on spatial reasoning errors:
  • phonological loop does not interfere with visuospatial sketchpad
  • Does A precede B (True/False)?

Luck & Vogel (1997) - Visual Working Memory

• Test of visual working memory capacity: Ability to detect change in sets of 1-12 objects.
• Load condition: memorize and recall two digits
• Is this the same grid you saw earlier?
• remember: “47“

Luck & Vogel (1997) - Visual Working Memory

• Evidence for limited capacity: more errors as set size increases
• No effect of load à independence of visual, verbal WM capacity

Visuospatial WM Task

• Animal Mashup
• Cat + Pinguin

Working Memory - Verbal Encoding

• People commonly use verbal/acoustic encoding to remember visual objects.
• Subvocal rehearsal: "cup", "spoon", "basket”

Brandimonte, Hitch, Bishop (1992)

• Memorized six objects. Later, told to visualize object and subtract part of it.
• Original picture

Brandimonte, Hitch, Bishop (1992)

• Memorized six objects. Later, told to visualize object and subtract part of it.
• Specified part to be
  subtracted from the
  mental image

Brandimonte, Hitch, Bishop (1992)

• Memorized six objects. Later, told to visualize object and subtract part of it.
• Image that
  should result
  after subtraction
• D

Working Memory - Articulatory Suppression

• Articulatory Suppression (AS) Group: say “la-la-la” while memorizing objects.
• Prediction: AS will prevent turning pictures into words, preserving their image form
• AS Group will be more successful at this imagery task

Working Memory - Articulatory Suppression Results

• Articulatory Suppression (AS) Group: say “la-la-la” while memorizing objects.
• Control Group: 45 % -- accuracy
• AS Group: 63 % -- accuracy
• Further evidence for distinction between phonological and visuospatial information in WM

Baddeley's Model of Working Memory

• Central Executive
• Visuospatial Sketchpad
• Episodic Buffer
• Phonological Loop
• Long-term Memory

Baddeley's Model of Working Memory - Conclusion

• What is Baddeley’s model of Working Memory?
• Can you explain how we conclude that the phonological loop and the visuospatial sketchpad are separate storage areas?

Lecture Summary

• Information Processing Model (Atkinson-Shiffrin Multi-Store Model)
• Sensory Memory: Capacity & Duration
• Short-Term Memory: Capacity & Duration
• Working Memory (Baddeley’s Model of “Short-Term Memory”)