PSYCH 10.15

The Role of the Brain in Memory

• General Overview

  • The entire brain is involved with memory.

  • Emphasis on understanding specific areas of the brain related to memory rather than reproducing diagrams for exams.

Key Brain Structures Involved in Memory

Amygdala and Hippocampus

• Emotional Memories

  • The amygdala works in tandem with the hippocampus.

  • Functions to tag memories as emotional, facilitating easier recall.

Hippocampus

• Functionality

  • Involved in declarative memories, both episodic and semantic.

  • Utilized for recognition memory—important in exams with choices.

  • Aids in memory consolidation, which is the process of taking encoded memories throughout the day and training the neocortex to incorporate them into existing neural networks.

  • Memory consolidation primarily occurs during sleep.

Cerebellum

• Implicit Memories

  • Manages procedural types of memories, such as:

  • Riding a bike

  • Walking and running

  • Playing the piano and other automatic processes like typing.

Prefrontal Cortex

• Short-Term Memory

  • Involved in aspects of short-term memory and working memory.

  • Associated with attention tasks.

• Examples of Semantic Tasks

  • Categorizing objects as living or nonliving.

  • Generating synonyms for given words or inserting correct words into sentences.

Structure and Appearance of the Hippocampus

• Coronal Slice of the Hippocampus

  • The hippocampus appears like a seahorse, referred to as the head, body, and tail.

Neurotransmitters and Memory

• Complexity of Neurotransmitter Role

  • Multiple neurotransmitters involved in learning and memory, not just one.

  • Memory consolidation occurs through repeated neuronal activity.

• Long-Term Potentiation (LTP)

  • Refers to the phenomenon where repeated activation causes the threshold for excitation to lower.

  • Example:

    • Threshold might change from 10 millivolts to -5 millivolts due to continuous firing.

  • Hebbian Learning (conceptualized by Donald Hebb)

  • Neurons that fire together, wire together.

  • Observed through experimental means where neurons need less stimulation after repeated firing.

Arousal Theory

• Concept

  • Strong emotions lead to strong memories; weak emotions lead to weak memories.

  • The theory posits that stress during strong emotional experiences releases glutamate, aiding in memory retention.

Flashbulb Memories

• Definition

  • Autobiographical memory associated with unexpected events that carry strong emotional weight.

  • Characteristics include vivid recall, though they may not necessarily be accurate.

• Examples

  • Specific events like the onset of isolation due to COVID-19 serve as contemporary examples of flashbulb memories.

Memory Failures and Amnesia

Types of Amnesia

• Anterograde Amnesia

  • Characterized by an inability to form new long-term declarative memories following an injury.

  • Example: Characters from media (e.g., '50 First Dates', 'Ten-Second Tom').

• Retrograde Amnesia

  • Loss of memories for events prior to the injury.

  • While old memories might be forgotten, the ability to form new memories remains intact.

• Graded Amnesia

  • Occurs for events leading up to the injury, often lasting weeks to months.

• Case Study: Clive Wearing

  • Suffers from severe anterograde amnesia, unable to form new memories post-injury but can create procedural memories.

Understanding Memory Reconstruction

• Memory as a Reconstructive Process

  • Memory does not function like a video recording; it is constructed from fragments and cues.

  • Memory retrieval can modify existing memories, leading to inaccuracies over time.

• Examples of Variability in Recollection

  • Different individuals recalling the same event may remember different details due to varying attentional focuses.

Eyewitness Testimony and Memory Fragility

• Loftus's Research on Misinformation Effect

  • Exposure to incorrect information can lead individuals to misremember original events.

  • Experiment involved varying descriptive terms when asking participants about the speed of cars in an accident, demonstrating that adjectives influenced speed estimates.

  • Eyewitness misidentification is a significant concern for wrongful convictions in the legal system.

Memory and Suggestibility

• Concept

  • Memory suggestibility arises from misinformation, potentially leading to false memories.

• False Memory Syndrome

  • Individuals may recall events that did not occur, influenced by therapy or suggestion.

Ebbinghaus's Forgetting Curve

• Decaying of Memory Over Time

  • Ebbinghaus's findings indicated rapid memory decay, losing significant portions of memorized information shortly after learning.

• Forgetting Reasons

  • Encoding Failure: Inadequate attention during the learning phase can lead to forgetfulness.

  • Transience: Memory decay that occurs with time without reinforcement.

  • Absent-Mindedness: Failures due to a lack of attention to detail in everyday tasks.

  • Blocking: Retrieval failures leading to the tip-of-the-tongue phenomenon.

  • Misattribution: Correct memories that are incorrectly sourced.

  • Bias: Personal beliefs influencing memory recall.

  • Persistence: Inability to forget distressing memories, often pertaining to trauma.

Conclusion

• Memory Study Takeaways

  • Understanding memory's reconstructive nature and the potential inaccuracies should inform how we approach eyewitness testimonies and recollections of past events.

Final Notes

• Reiterate that cramming information is less effective than distributed learning, as demonstrated by Ebbinghaus's research on memory decay.