Learning and Memory Part one

Memory

Learning & Memory Lecture Overview

• Lecture 1 Title: Types of memory, classical conditioning and instrumental learning.

• Instructor: Dr. Simon Trent.

• Course Code: LSC-20076, School of Life Sciences.

Structure of the Lecture

• Part 1: Types of memory and models of short-term and long-term memories.

• Part 2: Classical conditioning.

• Part 3: Instrumental learning.

Characteristics of Memory

Short-term and Long-term Memory

• The two main types of memory characterized by several attributes:

  • Time of Storage After Acquisition:

    • Short-term: Immediate access to new information.

    • Long-term: Must be transferred from short-term memory through consolidation; this process is enhanced by practice or recycling information.

  • Duration:

    • Short-term: Lasts from seconds to hours.

    • Long-term: Can be retained for days, months, or even years.

  • Capacity:

    • Short-term: Limited capacity.

    • Long-term: Very large capacity.

  • Retrieval Time:

    • Short-term: Quick retrieval.

    • Long-term: Generally slower retrieval unless ingrained in memory.

  • Inability to Retrieve (Forgetting):

    • Short-term: Information fades quickly, often resulting in permanent loss.

    • Long-term: Usually transient inability to access, lasting until memory is consolidated into stable traces.

  • Mechanism of Storage:

    • Short-term: Transient changes in synapses.

    • Long-term: Permanent changes through structural alterations in neurons and formation of new synapses, often involving protein synthesis.

Attention Mechanism

• Intentional Spotlight: Refers to the idea that attention shifts so that items within its beam are processed preferentially, enhancing memory encoding.

The Atkinson-Shiffrin Model (1968)

• Memory Components:

  1. Sensory Input: Information received through senses.

  2. Short-term Memory: Also known as working memory, where information is actively processed.

  3. Long-term Memory: Information that is stored for an extended period.

• Retention: Some information is lost at each stage if not attended to or rehearsed.

Short-term Memory (STM) & Effortful Processing Strategies

• Effortful Processing: Strategies aimed at encoding information into memory to prevent decay and facilitate retrieval.

• Strategies Include:

  • Repeating information aloud.

  • Chunking: Grouping information to enhance memory retention.

  • Using Mnemonics: Associating images, maps, and peg-words to remember complex information.

  • Hierarchies/Categories: Organizing information into related groups.

  • Deep Processing: Making information personally meaningful to increase retention.

Memory Storage and the Brain

• Memory functions differently from conventional file storage; instead, memories are distributed across overlapping neural networks in the brain.

• Long-term memory storage does not fill up as it is highly adaptable and interconnected.

Model Complexity and Limitations

• Working Model of Short-term Memory:

  • Involves a central executive that directs attention and manages memory processes.

  • Key components: phonological loop, visuo-spatial sketchpad, and articulatory rehearsal (e.g., repeating a phone number).

• Problems with the Standard Model:

  • Over-simplifies the complexity of short-term memory; sensory inputs can bypass short-term memory and directly encode into long-term memory.

Types of Long-term Memory

• Memory systems divided into two main categories:

  • Declarative Memory (Explicit)

    • Episodic: Memory of personal events.

    • Semantic: Memory of facts and general knowledge.

  • Non-declarative Memory (Implicit)

    • Involves skills, habits, simple classical conditioning, and non-associative learning.

Important Questions About Memory

• Do the varying forms of memory share a common mechanism or location within the brain?

Revising Memory Models

• Updated models for the 21st century include specific pathways for various memory types and recognize that short-term memory is primarily associated with the frontal cortex, particularly the prefrontal cortex.

• Underlying Brain Regions:

  • Different types of memory are supported by distinct brain structures, including:

    • Hippocampus: Critical for forming new memories.

    • Amygdala: Involved in processing emotions related to memory.

    • Cerebellum & Motor Cortex: Important for procedural and non-declarative memories.

• Understanding the complexities of these systems aids in developing strategies for learning and memory retention.