Semantic Memory and Statistical Learning

Semantic Memory

• Lacks 'when and where', can be personal or general, strengthened by repetition of similar events
• Definition: Memory for facts and general information about the world that has been acquired over multiple learning episodes
• Does not include information about a specific context/event in which the knowledge was originally acquired

Theories of Categorization

• Classical view: A category is a combination of defining features, rule-based and hierarchical, with necessity and sufficiency
  • Challenges: Hard to come up with features that are both necessary and sufficient for category membership
• Probabilistic view: Concepts aren't defined by rules, but are built up over experience, with fuzzy boundaries
  • Exemplar model: Stores every example of a category and compares a probe to all, assessing aggregate similarity
  • Prototype model: Common features repeat across category members and are averaged into a prototype

Posner & Keele (1968) Study

• Tested categorization using the Posner random dot pattern task
• Results: Support for both prototype and exemplar theories
  • Prototype theory: Classification of the prototype is better than classification of studied exemplars
  • Exemplar theory: Studied exemplars are classified better than unstudied exemplars

Role of Consolidation

• The hippocampus rapidly binds together information from neocortex to form a conjunctive representation of an episode
• The hippocampus guides reinstatement of that material during episodic retrieval

Parallel Distributed Processing

• A model that simulates the slow learning process of the cortex acquiring semantic knowledge over multiple learning episodes
• Results in storage of probabilistic relations between concepts and their properties

Semantic Dementia

• A degenerative neuropathological condition resulting in progressive loss of semantic knowledge
• Characteristics: Gradual, selective deterioration of semantic memory, with preservation of non-verbal delay recall
• Temporal structure of semantic loss: Loss of unique information first, then general information

Statistical Learning

• We extract information about statistical regularities in our environment, even if not consciously aware
• Infants use statistical learning to identify patterns and regularities in speech to acquire language naturally and rapidly
• Adults use statistical learning within the constraints of their already established language frameworks

Skills and Habits

• Procedural memory/skill learning: Improved performance on perceptual-motor or cognitive tasks with practice
• Open loop vs closed loop skills: Open loop requires adjustments based on input; closed loop involves performing pre-defined sequences of actions
• Deliberate Practice: Failure is important; desirable difficulty allows getting past a plateau; practice should be challenging
• Transfer: Generalization of skills from one context to another, with transfer specificity and the "identical elements theory"

Neural Bases

• Basal Ganglia: Receives input from a wide range of cortical areas, regulates the direction, speed, and strength of movements, and plays a key role in reinforcement learning
• Cerebral Cortex: Cortical plasticity – learning skill-relevant perceptual, conceptual, and motor representations### Parkinson's Disease and Memory
• Parkinson's disease is a movement disorder that impairs procedural learning.
• Amnesia is a condition that impairs declarative memory.

Emotion and Memory

• Emotion is an episode of synchronized responses, including physiological, overt behavioral, and conscious feeling responses.
• Emotion helps us communicate and adapt to situations by coordinating our physiology and behavior.
• The role of emotion in memory:
  • Emotion enhances memory consolidation, especially for emotionally charged events.
  • Emotion can impair memory recall, especially under stress.

Emotion Processing in the Brain

• The amygdala is a critical structure for emotion processing, modulating perception, action, and memory.
• The amygdala receives multimodal sensory input and outputs to various regions, including the prefrontal cortex, medial temporal lobe, and basal ganglia.

Conditioning

• Classical conditioning: a process of learning associations between stimuli and responses.
• Elements of conditioning: unconditioned stimulus (US), unconditioned response (UR), conditioned stimulus (CS), and conditioned response (CR).
• Stages of classical conditioning: acquisition, extinction, and spontaneous recovery.

Fear Conditioning

• Fear conditioning is a type of classical conditioning that involves learning to associate a stimulus with a fearful response.
• Fear conditioning can lead to phobias, which can be treated with exposure therapy.
• The amygdala plays a critical role in fear conditioning.

Emotion and Learning

• Stress can both enhance and impair memory, depending on the context and timing of the stress.
• Emotion can enhance episodic memory, especially for emotionally charged events.
• The amygdala is involved in enhancing episodic memory for emotional events.

Emotion and Attention

• Emotional stimuli can capture attention and bias attention towards them.
• The dot probe task and attentional blink task demonstrate the attention-grabbing effect of emotional stimuli.
• The amygdala is involved in attentional modulation.

Forgetting

• Forgetting can be defined as the loss of a memory trace or the inability to retrieve a memory.
• Mechanisms of forgetting:
  • Decay: the weakening of memory traces over time.
  • Cue availability: the lack of effective retrieval cues.
  • Interference: the presence of competing memory traces.
  • Retrieval-induced forgetting: the forgetting of a memory due to retrieval of a competing memory.

Types of Forgetting

• Proactive interference: the negative effect of old memories on new memories.
• Retroactive interference: the negative effect of new memories on old memories.
• Cue overload: the negative effect of multiple cues on memory retrieval.

Retrieval-Induced Forgetting

• Retrieval-induced forgetting is a phenomenon where retrieving a memory can lead to the forgetting of a competing memory.
• The debate surrounding the mechanism of retrieval-induced forgetting: blocking vs. inhibition.

Motivated Forgetting

• Motivated forgetting is the volitional effort to prevent a memory from reaching awareness.
• The think/no-think paradigm demonstrates the effect of motivated forgetting on memory retrieval.

Benefits of Forgetting

• Forgetting can be beneficial by reducing cognitive load and increasing the likelihood of remembering recent experiences.
• Forgetting may also be protective and confer wellness benefits.

False Memory

• False memories can be implanted through suggestion and manipulation.
• Lab-based studies demonstrate the ease of false memory implantation.
• The Deese-Roediger/McDermott paradigm demonstrates the false recall of semantic associates.
• Confabulation and spreading activation are mechanisms of false memory.

Confabulation

• Confabulation is the filling of gaps in memory with fictional information.
• Confabulation can lead to false memories and is a common phenomenon in human memory.

Spreading Activation

• Spreading activation is the collateral activation of related concepts and words due to previous memory traces.
• The Deese-Roediger/McDermott paradigm demonstrates the effect of spreading activation on false memory.Here are the study notes for the provided text:
• Bias and the Suggestion Effect*
• Memory is reconstructive
• Misinformation effect: new information from a trustworthy source influences original memory, leading to source memory confusion and the sleeper effect
• Source memory confusion: difficulty in figuring out where information was learned
• Sleeper effect: delayed increase in belief in a persuasive message despite initial skepticism
• Mandela Effect*
• A type of false memory where many people incorrectly remember the same thing
• Explanations for the Mandela effect:
  • Confabulation: brain fills in gaps with statistically likely information
  • Post-event interference: edited stimuli makes it harder to remember the truth
  • Priming: misleading representations or cues that falsely construct stimuli
• Imagination and Memory*
• Imagination inflation: behavioral and EEG studies on imagination inflation
• Source memory confusion and imagination inflation
• Source memory failures
• Wrongful Convictions*
• Memory confidence and memory accuracy
• Signal detection theory explains why memory confidence and accuracy should be correlated
• Erroneous memory in the courtroom is often expressed with high confidence
• Witness is not remembering the original event, but rather the intervening acts of remembering and exposure to facts about the event
• False Memories*
• Situations that lead to false memories:
  • Source confusion
  • Memory for "gist" (similarity-based false recognition)
• "Gist error": false remembrance due to similarity between current stimulus and previous experiences
• Koutstaal et al. (1999) study: tested old/new recognition of a given "prototype" on three conditions
• Seven Sins of Memory*
• Define each of the "seven sins" of memory
• Provide a real-world or experimental example for each "sin"
• Rebound Effect*
• Instructing people not to think about a particular item or object can produce a rebound effect
• Studies by Wegner and associates (e.g., Wegner & Erber, 1992)
• Expatation*
• The idea that current functions of memory systems were not originally selected for their current functions
• Sherry and Schacter (1987) emphasized the possible role of expatations in human memory
• Aging and Memory*
• How the brain changes across the lifespan:
  • Anterior to posterior gradient in cognitive decline
  • Brain volume decreases slowly but steadily
  • Cognitive processing speed slows
  • Fluid intelligence declines
• Impacts to:
  • Episodic memory
  • Working memory
  • Semantic memory (preserved in healthy aging)
• Age-related stereotype threat:
  • Evidence for multiple system changes in memory with healthy aging
  • MTL dysfunction
  • Age-related decline in associative binding (Chalfonte & Johnson, 1996; Mitchell et al., 2000)
• Recollection vs. Familiarity-based Memory*
• Recollection: retrieval of qualitative information about a specific study episode
• Familiarity: global measure of memory strength/stimulus recency
• Consequences of diminished item context binding:
  • Jacoby (1999) source memory paradigm

Let me know if you'd like me to clarify or expand on any of these points!

Quiz about semantic memory, its definition, features, and characteristics. Learn about the difference between semantic memory and other types of memory.