Memory Processes and The Atkinson-Shifrin Model
General Definition of Memory
Memory is defined as the process of encoding, storing, and retrieving information.
Misconceptions About Amnesia
Clive Wearing is used as an example to clarify misconceptions about classic amnesia.
Question: Is Clive Wearing a classic amnesic?
Answer: No.
Definition of Classic Amnesic:
Characterized by localized brain damage.
Damage typically involves bilateral lesions to the hippocampus.
Introduction to Brain Anatomy
We begin discussing brain structure and memory to accommodate students from various backgrounds (psychology majors vs. those without neuro and bio courses).
The temporal lobe is a significant area of focus.
Location: Near the temples of the brain, present on both sides.
Function: Memory processing and more.
Hippocampus in Memory
The hippocampus is located deep within the temporal lobe.
Singular vs. Plural: Technically referred to as "hippocampi," but commonly as "the hippocampus."
Importance:
Critical structure for memory.
Damaged hippocampi lead to classic amnesia (bilateral lesioning).
Surrounding tissue and memory deficits are also discussed as related to amnesic conditions.
Multimodal Functions of the Brain
Brain areas are categorized by functions and localization in space.
The human brain is multimodal, with various areas dedicated to processing different types of sensory input (e.g., visual, auditory, olfactory, gustatory, tactile).
Example: Auditory experiences activate specific auditory cortex regions while visual tasks engage visual cortex areas simultaneously.
Combining sensory inputs creates a full experience through the activation of multiple brain regions.
Sensory Processing Regions
Different regions of the brain are specialized for various sensory inputs:
Sounds processed in the auditory cortex.
Visual inputs processed in the visual cortex, etc.
The brain's ability to process sensory information is distributed across different specialized areas.
Key Note: Processing is not uniformly distributed; specific areas handle specific inputs more proficiently.
The Atkinson-Shiffrin Model of Memory
Introduced the Atkinson-Shiffrin model, crucial in educational texts and commonly taught in psychology courses since 1968.
Researchers: Richard Atkinson (Stanford and UCSD chancellor) and Richard Shiffrin (graduate student).
Students encouraged to appreciate the institutional heritage and connections at UC San Diego regarding memory research.
Overview of Memory Stores in the Atkinson-Shiffrin Model
The model consists of three key components:
Sensory Memory:
Brief Duration: Retains sensory information for a very short time (milliseconds).
Holds incoming sensory data just long enough for processing.
Short-Term Memory (STM):
Acts as a temporary storage system for information (referred to interchangeably with working memory).
Has limits, often quoted as "7±2" items.
Long-Term Memory:
Has virtually unlimited capacity and duration.
Information stored long-term from STM.
Emphasis on how sensory information moves through these components to become stored.
Memory Processes and Rehearsal
Long-term storage involves the hippocampus, which aids in encoding, but is not the site of long-term memory storage.
The ability to recall distributed memory relies on the concurrent activation of sensory areas engaged during the initial experience.
The distinction between short-term memory and long-term memory as separate processes must be clarified.
Key inquiries into how information moves between memory types and the role of rehearsal.
Sensory Memory Research You Should Know
Research by George Sperling established foundational understandings of sensory memory.
Iconic Memory Experiment: 1964
Participants recall letters flashed for 50 ms.
Results showed pathways for assessing memory retention and processing leads to better conclusions about sensory memory capabilities.
Full Report Method: Participants recall all seen letters—typically remembering only about half.
Partial Report Method: Following the immediate tone, participants could correctly recall almost all letters in a designated row!
Delayed Recall in Research: With delayed tones causing loss of memory due to sensory memory's brief duration.
Rehearsal's Implications in Memory
The effectiveness of rehearsal in encoding information to long-term memory continues to be a focal point of studies.
Overt Rehearsal Tasks: Identifies the impact of rehearsal on memory while understanding how the position of words in a list impacts recall (primacy effect).
When instructions lead to graduated rehearsal tasks, an observable primacy effect denotes a long-term memory reliance.
Incidental Learning Tasks: Explore the boundaries of memory retention without explicit rehearsal strategies.
Outcomes demonstrate the shift’s significance in confirming rehearsal as a memory facilitator.
Conclusion on Primacy and Recency Effects
Primacy Effect: Words at the beginning of a list are better recalled than those in the middle.
Recency Effect: Words at the end of a list are similarly better remembered than those before.
Both phenomena reveal distinctions on how memory utilizes short-term and long-term encoding, with non-functional habituation of rehearsal.
Future discussions will delve deeper into these memory processes, comparative studies, and assessments.