Memory and Cognitive Processes

Memory Overview

  • Memory Types:
    • Sensory Memory
    • Short-Term/Working Memory
    • Long-Term Memory

Three-stage Modal Model of Memory (Atkinson-Shiffrin Model)

  • Sensory Memory: Captures sensory information for brief periods (0.5 to 4 seconds).
  • Short-Term/Working Memory: Holds information actively being thought about; limited to (7 \pm 2) items.
  • Long-Term Memory: Unlimited capacity and duration.

Memory Processing Stages

  1. Encoding: Acquisition of information.
  2. Storage: Retention of information over time.
  3. Retrieval: Accessing stored information.

Sensory Memory

  • Briefly holds sensory information.
  • Types:
    • Iconic memory: Visual sensory memory.
    • Echoic memory: Auditory sensory memory.

Short-Term Memory (STM) or Working Memory

  • Active processing and manipulation of information.
  • Limited duration (5 to 30 seconds) and capacity.
  • Components:
    • Phonological Loop: Stores sounds.
    • Visuospatial Sketchpad: Stores visual/spatial information.
    • Episodic Buffer: Integrates information.
    • Central Executive: Directs attention resources.

Long-Term Memory (LTM)

  • Divided into:
    • Explicit Memory (Declarative): Memory that can be consciously recalled.
    • Implicit Memory (Non-declarative): Memory of skills and tasks without conscious recall.
Types of Explicit Memory:
  • Episodic Memory: Personal experiences.
  • Semantic Memory: General factual information.
Mechanisms of Long-Term Memory Storage
  • Hippocampus: Critical for forming new explicit memories.
  • Frontal Lobes: Involvement in recalling and working memory tasks.
  • Long-Term Potentiation (LTP): Biological basis for learning enhancing synapse strength after repeated stimulation.

Memory Disorders

  • Amnesia Types:
    • Organic Amnesia: Causes like brain injury or disease (e.g., Alzheimer’s).
    • Psychogenic Amnesia: Psychological causes (e.g., dissociative disorders).

Alzheimer’s Disease

  • Causes:
    • Genetic components, strokes, and risk factors like obesity and low vitamin D levels.
    • Characterized by neuron loss and formation of amyloid plaques.
Memory Reconstruction
  • Memory can be altered and is not wholly accurate; reconsolidation can modify memories when recalled.

Effects of Sleep on Memory

  • Sleep deprivation negatively impacts memory and cognitive performance, increasing risks for various health issues and hampering learning processes.
    • Recommendations: Regular sleep routines, cognitive behavioral therapy for insomnia, and sleep-promoting practices.

Savant Syndrome & Hyperthymesia

  • Savant Syndrome: Exceptional cognitive performance in certain areas, often linked with autism.
  • Hyperthymesia: Rare condition with almost perfect autobiographical memory.

Déjà Vu

  • Experience of feeling that a current situation has been previously experienced; influenced by factors like stress and fatigue.

Conclusion

Understanding these components illustrates the complexities of memory, its function, and the impact of various factors on retention and retrieval processes, contributing to a comprehensive study of cognitive psychology and neurobiology.