SHORT TERM MEMORY

Overview of Short Term Memory

• Short Term Memory Measurement

  • Examined different ways to measure and understand short term memory.

  • Noted that it is often auditory in nature, involving auditory loops for rehearsing information.

• Chunking in Short Term Memory

  • Example of Steve Falloon who remembered 82 random digits by chunking them using familiar knowledge (e.g., running times/distances).

  • This showcases that short term memory utilizes semantic information and is an active process, rather than passive storage.

Working Memory Model by Baddeley and Hitch

• Basic Structure

  • Proposed in the 1970s, highlighting distinct components in working memory.

  • Visual-Spatial Sketchpad: Holds visual and spatial information (e.g., remembering a map).

  • Phonological Loop: Holds audial information.

  • Central Executive: Oversees the workings of the memory system, akin to the operator in the Wizard of Oz.

• Evidence of Separate Systems

  • Baddeley and Hitch presented information suggesting selective interference between phonological loop and visual-spatial sketchpad, indicating they function independently.

Central Executive Function

• Role

  • Responsible for attentional control, task switching, and cognitive functioning.

  • Integrates and manages information from both phonological and visual spatial components.

• Episodic Buffer

  • Connects new information from short term memory with the temporal context it was experienced.

  • Tags information with time-related data to aid recall.

Research on the Phonological Loop

• Experiments by Salome and Baddeley

  • Participants recalled 9 digits with various background conditions: control (no sound), nonsense syllables, and real words.

  • Found that spoken language significantly impaired digit recall, suggesting phonological loop’s specialization in processing language.

• Charlie's Teacher Effect

  • Even non-verbal sounds mimicking natural language can disrupt memory, indicating auditory processing is highly sensitive to human speech patterns.

Impact of Music and Background Noise on Memory

• Experiment Findings

  • Comparing silence, spoken words, and music types on digit recall.

  • All forms of auditory stimulation interfered with memory retrieval, highlighting the phonological loop’s susceptibility to auditory distractions.

Articulatory Suppression

• Effect on Memory Performance

  • Participants verbally repeated a simple word while learning lists impaired their recall.

  • Results indicate memory performance was affected by phonological similarity of words, emphasizing the auditory nature of the phonological loop.

Visual Spatial Sketchpad

• Representation of Spatial Memories

  • Demonstrated through participants recalling a four by four grid layout and the spatial orientation of numbers.

  • Those who engaged visual imagery in memory retrieval fared better than those who processed verbally, illustrating the visual spatial sketchpad's significance.

• Secondary Task Impact

  • Conducting a rotor pursuit task while recalling spatial layouts increased error rates, substantiating the competition for cognitive resources between tasks.

Detailed Functions of the Central Executive

• Executive Functions Overview

  • Includes updating information, setting goals, planning, and response inhibition.

• Examples of Executive Tasks

  • Updating: Integrating new information into existing short term memory (e.g., remembering a party guest list).

  • Task Switching: Adapting to new rules in a sorting task; individuals with prefrontal cortex damage struggle with this.

  • Inhibition: Control over automatic responses in varying contexts, illustrated with traffic situations.

Long Term Memory Types

• Declarative (Explicit) vs. Nondeclarative (Implicit)

  • Declarative: Facts and events that can be consciously recalled (episodic vs. semantic).

  • Nondeclarative: Skills and tasks (e.g., riding a bike) that are performed rather than verbalized.

• Episodic vs. Semantic Memory

  • Episodic: Personal experiences and events (mental time travel).

  • Semantic: General knowledge and facts (improvement with repetition).

Mechanisms of Forgetting

• Decayed vs. Interference Model

  • Forgetting in both short term and long term memory is attributed primarily to interference rather than simply decay over time.

  • Proactive interference: Older information obstructing new learning (e.g., studying multiple languages).

  • Retroactive interference: New information hindering retrieval of older information.

• Two List Experiment

  • Demonstrated how additional similar word lists interfere with memory retrieval of both prior and new information based on interference paradigms.

Implications for Cognitive Functioning**

• Central to Executive Functions

  • Related to intelligence through various tasks assessing fluid and crystallized intelligence.

• Case Studies of Brain Damage

  • Discussed effects of damage to prefrontal cortex through patient examples, emphasizing the relevance of executive function in daily tasks and decision-making processes.

Conclusion

• Memory Systems Complex and Interdisciplinary

  • Emphasized continued exploration of short and long term memory dynamics and their implications for understanding cognitive function and behavior.