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!