Memory

Memory and Information Processing

• Memory is the process of observing, converting, storing, retrieving, and utilizing information.
• Mental representations are formed when sensory inputs are encoded by neuron activity, enabling recall without original stimuli.
• Representational modes can include images, sounds, and words, allowing multiple forms of processing information simultaneously.
• Motor representations store information about actions, while sensory representations hold info such as sounds and images.
• Visual representations provide detailed mental pictures, while olfactory memories are less reliable yet evoke strong past memories.
• Verbal representation is prevalent, often constituting the primary format for thinking and problem-solving.

Standard Model of Memory

• The mind is compared to a computer, categorizing memory into different stores: primary (short-term) and secondary (long-term).
• Information starts in sensory registers, moves to short-term memory (STM), and can be transferred to long-term memory (LTM).
• Sensory registers maintain information for about half a second post-stimulus, ensuring brief mental representations.
• STM holds limited information (about seven items), accessible for 20-30 seconds before it fades or is replaced.
• Rehearsal techniques (maintenance and elaborative) help in retaining information, with elaborative rehearsal being more effective for LTM storage.

Information Loss and Retrieval

• Information can be lost at any stage if unimportant or disrupted by traumatic events.
• Serial position effect indicates better recall for items at the beginning and end of a list.
• Evolving models have shifted from strict and sequential processing to understanding memory as involving multiple simultaneous pathways.

Working Memory

• Working memory refers to short-term storage and processing, necessary for problem-solving and goal achievement.
• It comprises three main components: a visual memory store (visuospatial sketchpad), a verbal memory store (phonological loop), and a central executive for control and manipulation.
• The episodic buffer integrates various information forms and interacts with LTM.

Varieties of Long-Term Memory

• Declarative memory encompasses facts (semantic) and personal events (episodic), linked with the hippocampus.
• Procedural memory includes skills and tasks learned over time without conscious effort.
• Explicit memory involves conscious recall, while implicit memory refers to knowledge shown through behavior without introspection.
• Prospective memory focuses on future intentions, requiring both cognitive and temporal elements.

Encoding and Organization of Memory

• Encoding transforms information into memory traces for future retrieval; the quality of encoding directly influences accessibility.
• Level of processing varies from shallow (structural) to deep (semantic), affecting how well information is retained.
• Contextual and state-dependent memory illustrates the influence of environmental factors and emotional states on recall.
• Mnemonic devices leverage vivid retrieval cues to enhance memory, while techniques like the method of loci and SQ4R provide structured ways to retain information.
• Networks of association organize knowledge in memory, allowing activation spreading across related nodes, facilitating recall through interconnected information.### Memory Overview
• Schemas help organize experiences, enabling efficient memory storage and retrieval.
• Initial understanding of events influences how information is encoded in long-term memory (LTM).

Schemas and Encoding

• Schemas guide memory encoding by shaping the interpretation of events.
• Default values in schemas can fill gaps in memory, leading to misclassification and inaccuracies.
• Cultural models dictate the relevance of information retained and influence memory organization.

Forgetting and Memory Availability

• Forgetting is characterized by the inability to retrieve information.
• The availability of information refers to whether it remains stored in memory, while accessibility involves the ease of retrieval.
• Long-term memories can endure for a lifetime if consolidated through spaced learning.

Memory Errors

• Memory errors arise from cognitive and emotional factors, including:
  • Transience: Fading of memories.
  • Absentmindedness: Inattentiveness leading to forgetfulness.
  • Misattribution: Incorrectly identifying the source of a memory.
  • Suggestibility: Misinformation leading to erroneous memories.
  • Bias: Distorted recall influenced by personal beliefs or feelings.
  • Persistence: Unwanted memories that resurface.

Flashbulb Memories

• Flashbulb memories are vivid recollections of significant events but often contain inaccuracies.
• Emotional arousal may enhance memory but does not guarantee accuracy.

Eyewitness Testimony

• Eyewitness memory is influenced by questioning techniques, with stress potentially affecting attention to detail.

Memory Across the Lifespan

• Infantile amnesia describes the loss of early childhood episodic memories, influenced by neurogenesis in early development.
• As individuals age, episodic memory tends to decline, whereas semantic and procedural memories may remain stable or improve.

Theories of Forgetting

• Decay theory posits that memories fade over time due to lack of use.
• Interference theory describes how memories overlap and hinder retrieval (proactive and retroactive interference).
• Motivated forgetting involves actively suppressing unwanted memories.

Amnesia Types

• Anterograde amnesia: Inability to form new memories after brain damage.
• Retrograde amnesia: Loss of memories formed before brain damage, often covering short spans.

Neurological Basis of Memory

• Memory systems are neuroanatomically distinct, with the hippocampus vital for explicit memory consolidation.
• Implicit memory operates independently of the hippocampus but relies on other brain regions for skills and conditioning.

Long-Term Memory Types

• Declarative memory includes:
  • Semantic memory: General knowledge and facts.
  • Episodic memory: Personal events and experiences.
• Procedural memory involves skills and procedures, expressed behaviorally, without conscious recall.

Information Encoding and Organization

• Effective memory encoding requires elaboration, reflection, and meaningful processing.
• Retrieval cues can enhance memory access; organizing information into networks facilitates this.
• Schema theory suggests memory is reconstructive, integrating specific memories with general knowledge.

Key Memory Terminology

• Anterograde amnesia: Inability to learn new information.
• Chunking: Organizing information into meaningful units.
• Decay theory: Memories fade due to disuse.
• Explicit memory: Conscious recollection of information.
• Implicit memory: Non-conscious memory expression.
• Prospective memory: Upcoming tasks or events to remember.### Memory and Retrieval Concepts
• Retrieval: The process of bringing information from long-term memory into short-term or working memory.
• Retrieval Cues: Stimuli or thoughts that assist in retrieving information from memory.
• Retroactive Interference: New information interferes with the ability to recall previously learned information.
• Retrograde Amnesia: Loss of memory for events that occurred before a brain injury, affecting recall from a specific time frame.
• Retrospective Memory: Involves recalling events that have already occurred.

Types of Memory

• Semantic Memory: A type of long-term memory that involves general world knowledge and facts, often referred to as generic memory.
• Sensory Registers: Memory systems that hold information for a very brief duration, capturing immediate sensory impressions.
• Sensory Representations: Information captured and stored in the brain through one of the sensory modalities.

Memory Effects and Strategies

• Serial Position Effect: The tendency for individuals to recall information presented at the beginning and end of a list better than the information in the middle.
• Short-term Memory (STM): Also known as working memory, it retains information accessible to consciousness for around 20-30 seconds.
• Spacing: The practice of distributing learning sessions over time, enhancing retention.
• Spacing Effect: Improved long-term retention of information when rehearsal sessions are spread out across longer time intervals.
• Spreading Activation Theory: A concept suggesting that presenting a stimulus activates related nodes in memory, facilitating recall.

Memory Techniques and Phenomena

• SQ4R Method: A mnemonic device for studying textbooks that includes steps: survey, question, read, recite, review, and write.
• Synapses: Locations where neurons transmit information to each other, essential for memory formation and recall.
• Tip-of-the-Tongue Phenomenon: The frustrating experience where a person knows they have information memorized but cannot retrieve it at that moment.
• Verbal Representations: Information encoded and stored in the brain as words, crucial for language-based memory.
• Visuospatial Sketchpad: A component of working memory that temporarily holds and manipulates visual information.
• Working Memory: A conscious workspace for operations involving retrieving and manipulating information, heavily reliant on maintenance rehearsal.