Long Term Memory Encoding

Name: Long Term Memory Encoding
Uploaded: 2018-02-18T03:42:21.000Z
Duration: 1 h 38 min 15 s

Long-Term Memory Overview

Introduction to Long-Term Memory

The lecture focuses on long-term memory, a key aspect of memory often referenced in everyday discussions.

Long-term memory encompasses various types of information, including life events, knowledge, facts, and rules.

Atkinson and Shiffrin's Model

The Atkinson and Shiffrin model describes a three-part system: sensory register, short-term store, and long-term memory (LTM).

Sensory register captures incoming information briefly with high capacity but short duration.

Short-term store retains limited information for brief periods; working memory is an extension that allows more complex processing.

Processes Involved in Memory Transfer

LTM serves as the primary storage for most information processed by the brain.

Attention processes transfer data from the sensory register to the short-term store.

Rehearsal processes are crucial for moving information from short-term to long-term storage.

Characteristics of Long-Term Memory

Unlike short-term stores, LTM functions as a passive repository without active processing capabilities.

Information in LTM is organized systematically but requires retrieval processes to access it again.

Evidence for Long-Term Memory Existence

Serial Position Curve Experiment

The serial position curve experiment illustrates how recall accuracy varies based on item position in a list.

Items at both ends of the list (primacy effect and recency effect) are recalled better than those in the middle.

Implications of Findings

The results suggest two distinct systems or stores within memory due to differing recall rates based on item positioning.

Primacy effect items benefit from repeated exposure during learning phases, leading them to be stored in LTM effectively.

Understanding Memory: Short-term and Long-term Storage

The Process of Repetition in Memory

The number of repetitions for the first item in a list is calculated as n factorial, indicating that more items lead to increased processing demands.

Types of Memory Stores

There are two primary types of memory stores: short-term and long-term. The short-term store transitions into working memory, which includes components like the central executive, phonological loop, visual-spatial sketchpad, and episodic memory.

Subdivisions of Long-term Memory

Long-term memory is divided into two main categories: declarative and procedural. Declarative memory involves conscious retrieval (e.g., recalling personal events), while procedural memory consists of unconscious knowledge (e.g., riding a bicycle).

Characteristics of Declarative vs Procedural Knowledge

Declarative knowledge requires conscious awareness during retrieval; examples include memories from significant life events. In contrast, procedural knowledge operates unconsciously, making it difficult to articulate how certain tasks are performed. For instance, explaining how to ride a bicycle can be challenging despite knowing how to do it instinctively.

Types within Declarative Memory

Within declarative memory, there are semantic (world knowledge) and episodic (event-related) types. Semantic memory encompasses facts and rules, while episodic relates to specific experiences or episodes in one's life. Procedural memory also has subdivisions but will not be explored in detail here.

Understanding Priming in Procedural Memory

Priming is a phenomenon where prior exposure to information influences recognition or identification of an object later on; this can occur through semantic or perceptual priming techniques that enhance recall based on previous cues provided before perception occurs.

Conceptualizing Long-term Memory Capacity

Long-term memory is often described metaphorically as a "scrapbook" or "treasure chest," capable of storing vast amounts of information throughout one’s life—sometimes considered infinite due to the continuous accumulation of learned experiences until death. Evidence suggests that most information resides within long-term storage systems rather than being lost over time.

Investigating the Capacity Limits

Research by Thomas Landauer estimates that the cerebral cortex contains approximately 10^13 synapses, suggesting immense potential for storage capacity within long-term memory systems; however, exact limits remain debated among researchers studying cognitive functions related to memory retention and retrieval processes.

Understanding Neurons and Memory Formation

The Structure of Neurons

Neurons connect through synapses, which are the spaces between dendrites that facilitate communication via electrical and chemical messengers.

Chemical messengers, known as neurotransmitters, play a crucial role in transmitting information across synapses.

Memory Storage Mechanisms

Synapses are essential for memory formation; they allow the transfer of information from one neuron to another.

Biological theories suggest that memory storage involves phenomena like long-term potentiation and long-term depression.

Capacity of Memory

Research by Thomas Landauer estimates there are approximately 10^13 synapses in the cerebral cortex, equating to a vast amount of stored information.

Another estimate suggests around 10^20 bits of information transmitted over an average human lifetime based on neural connections.

Compression in Long-Term Memory

Long-term memory is theorized to have infinite capacity; it utilizes compression techniques similar to file archiving programs on computers.

Information selection and compression occur before storage, ensuring efficient use of memory space.

Short-Term vs. Long-Term Memory Encoding

Experiments by Alan Baddeley indicate that short-term memory encoding is often acoustic; confusion arises more with words that sound similar (e.g., "p" vs. "d").

In contrast, long-term memory tends to encode information semantically rather than phonetically.

Experimental Insights into Memory Encoding

Baddeley's experiments involved two groups: one received lists of similar-sounding words while the other received lists with dissimilar sounds or meanings.

Participants were tasked with recalling these words after engaging in an n-back counting task, which required them to count backward from a number (e.g., 1000).

This structured overview captures key concepts related to neurons and memory formation discussed in the transcript while providing timestamps for easy reference.

Memory Retrieval and Forgetting Theories

Experiment on Semantic Similarity

The task required participants to use all their attentional resources, preventing rehearsal during a 20-minute wait. This led to minimal effects on performance when retrieving words based on semantic similarity.

Participants showed no significant difference in recall between the words "map" and "man," but confusion increased with semantically similar words, indicating that meaning affects memory retrieval.

Ebbinghaus's Forgetting Curve

Ebbinghaus, a German psychologist, studied memory limits using consonant-vowel-consonant (CVC) trigrams to avoid biases from meaningful words.

His experiments revealed that after 31 days, participants could still recall about 20% of items from the list, suggesting long-term storage capabilities in memory.

Understanding Long-Term Memory

The persistence of recalling information over time supports the existence of long-term memory stores that retain information through rehearsal.

Forgetting is defined as the inability to retrieve information from memory; this can occur in both short-term and long-term contexts.

Theories of Forgetting

Several theories explain forgetting from long-term memory: poor encoding theory, decay theory, interference theory, and retrieval cue theory.

Poor encoding theory suggests that forgetting occurs because information was never properly encoded into long-term memory. For example, individuals may not remember where specific keys are on a keyboard if they have never used them.

Encoding Failure Theory

Encoding failure occurs when information does not transition from short-term to long-term memory due to lack of attention or usage. An example includes not knowing the location of rarely used keys like the tilde key on a keyboard.

Understanding Memory: Encoding and Retrieval Theories

The Nature of Memory and Forgetting

Discussion on older push-button phones highlights how people often do not remember the layout of numbers, indicating a shift in memory reliance due to technology.

Emphasizes that frequent use of certain functions (like pressing '0' on calculators) can lead to automaticity, making it difficult for individuals to consciously recall their locations.

Theories of Forgetting

Introduces two primary theories regarding forgetting from long-term memory (LTM): encoding failure and retrieval failure.

Clarifies that not all forgetting is due to poor encoding; some is attributed to difficulties in retrieving information stored in LTM.

Retrieval Failure Phenomena

Explains the "Tip of Tongue" (TOT) phenomenon where individuals struggle to retrieve known information, illustrating retrieval failure despite having encoded knowledge.

Provides an example of TOT where one knows details about a movie but cannot recall the actor's name, showcasing the complexities of memory retrieval.

Types of Retrieval Failure Theories

Outlines three theories related to retrieval failure: decay theory, interference theory, and retrieval cue theory.

Decay Theory

Describes decay theory as suggesting that memories fade over time if they are not used or retrieved regularly.

Discusses how modern reliance on technology (e.g., Google search engines) may contribute to this decay by reducing our need to actively recall information.

Biological Basis for Decay

Highlights the importance of using learned information; otherwise, it risks decaying over time due to lack of engagement with the material.

Notes that time between learning and retrieval significantly impacts memory retention; longer intervals without use increase chances of forgetting.

Neurobiological Explanation

Explains that when new memories form, they create connections in brain chemistry. If these connections are not utilized, they may erode over time.

Concludes with a biological perspective on why unused memories fade away—normal brain activities can diminish unutilized neural connections.

Understanding Memory and Forgetting Mechanisms

The Role of Neurons in Memory

Neurons communicate through neurotransmitters; if this communication ceases, it can lead to forgetting due to metabolic changes within the synapse.

Dopamine deficiencies in specific receptor types (D1, D3, D5) can result in behaviors similar to neuroticism when connections are not utilized over time.

Metaphors for Memory Decay

The analogy of railway warehouses illustrates how unused neural pathways decay over time, similar to forgotten train stations.

Just as abandoned railway lines fade from memory, so too does information in the brain that is not actively recalled or used.

Theories of Forgetting

Current theories suggest that forgetting is not merely a function of time but rather interference between memories.

Interference occurs when two similar items are presented close together, leading one memory to compete with another during retrieval.

Mechanisms of Interference

Research by Edison and Nele (1996) indicates that retrieval cues pointing to multiple targets can cause confusion and hinder memory recall.

Forgetting arises from competition among memories rather than just the passage of time; more similar memories increase the likelihood of interference.

Types of Interference

Two main types of interference exist: proactive interference (old memories disrupt new ones) and retroactive interference (new memories disrupt old ones).

An experimental paradigm demonstrates how learning lists A-B and then A-C leads to interference due to shared elements between the lists.

Pair Associate Learning Paradigm

In pair associate learning, participants learn associations like "goat-leaf," where "goat" serves as a cue for recalling "leaf."

Control groups show no interference when given unrelated tasks after learning; however, those who learned related lists experience significant recall difficulties.

Understanding Proactive and Retroactive Interference in Memory

Proactive Interference Explained

Proactive interference occurs when previously learned information interferes with the learning of new information. This is illustrated by the example where learning list A B creates interference with learning another list A B, as no prior list was established.

Retroactive Interference Defined

Retroactive interference happens when new information disrupts the recall of old information. An example provided is changing a phone number, where the new number makes it difficult to remember the old one.

Examples of Retroactive Interference

Learning a new language can interfere with recalling an older language. For instance, if someone learns Spanish after French, similar words (like "papier" vs "papel") may cause confusion and hinder performance on exams due to this interference.

Distinction Between Proactive and Retroactive Interference

In proactive interference, old memories interfere with new ones; for example, remembering where you parked your car based on past experiences can affect your ability to park today. This demonstrates how previous knowledge can complicate current tasks.

Retrieval Cue Theory of Forgetting

The retrieval cue theory posits that cues or hints are essential for memory retrieval; they act like keys that unlock stored memories in long-term storage. Using incorrect cues can lead to forgetting important information.

Importance of Multiple Cues in Memory Retrieval

Memories often have multiple retrieval cues associated with them, which can vary in potency based on emotional significance or context surrounding the memory event (e.g., feelings during a farewell party). The most emotionally charged cue tends to be the most effective for recall.

This structured approach provides clarity on key concepts related to memory interference and retrieval mechanisms while allowing easy navigation through timestamps for further exploration of each topic discussed in the transcript.

Understanding Retrieval Cues in Memory

The Role of Parties as Retrieval Cues

The context of a party, whether it's a farewell or home gathering, serves as a retrieval cue but has low weight compared to emotional experiences associated with that day.

Using improper cues for retrieval can lead to forgetting; effective retrieval relies on the right cues that align with how information was encoded.

Types of Retrieval: Recall vs. Recognition

There are two main types of retrieval from long-term memory: recall and recognition, which will be explored in detail later.

Recall tests require retrieving previously learned information without prompts (e.g., fill-in-the-blank questions), emphasizing the need for actual memory retrieval.

Mechanisms of Recognition

Recognition involves matching presented answers to what one remembers; it builds upon recall since you must first retrieve information before recognizing it.

Knowing something (recognition) is dependent on having remembered it (recall); multiple-choice tests exemplify this relationship.

Practical Examples and Implications

In a recognition scenario, such as identifying Helsinki as the capital of Finland among options, one engages in both recall and recognition processes.

Psychological exams often favor multiple-choice formats due to their reliance on recognition, making them prevalent in educational assessments today.