Schemas etc.

Discussion about how prior knowledge and expertise influences prototypes and categorization.
Introduction of the exemplar approach in contrast to the prototype approach.

Definition: The exemplar approach involves creating categories based on personal experiences or specific instances of a concept.
Process: When encountering a new object, one compares it against previously learned category examples to determine membership.
Example Exercise:
- Participants are asked to name the first example that comes to mind for different categories:
1. Amphibian
2. Burger
3. Fish
4. Insect
5. Mammal
6. Microorganism
7. [Unspecified]
- These categories were part of a study from the mid-nineties examining typicality rates based on examples provided by subjects.

Amphibian: Most common response was "frog".
- Participants tested their answers against the study data.
Insect: Common responses included "bee" and "fly". Many participants initially wrote "spider", although spiders are not classified as insects.
Mammals: Common responses varied, demonstrating differences in typicality ratings (e.g., responses included "whale", "human", and "dog").

Typicality: Refers to how representative an object is of a category. It influences how we perform comparisons and make categorization decisions based on previously learned examples.
Research Findings:
- The relationship between frequency and typicality can help predict category membership.
- Atypical members can enhance understanding of a category without necessarily matching every detail with more typical examples.
- The concept of exceptions helps define categories.

The exemplar approach allows comparison without strict reliance on feature lists to classify objects.
Interaction of past experience contributes to more flexible comprehension and categorization.
Limitations: More effective with categories that have fewer members; larger categories may overwhelm the exemplar method. Individual differences in knowledge can also affect outcomes.

Schemas:
- Definition: Abstract structures of knowledge based on prior experiences with specific instances.
- Function: They guide recognition, comprehension, and memory, influencing our top-down processing of new information.
Scripts:
- Definition: Specific types of schemas that represent sequences of actions for performing tasks.
- Influence of schemas on memory: We often encode and recall meaning rather than specific details, which can introduce errors if novel instances don't fit expectations from schemas.

Brewer and Trance Study (1980s):
- Experiment where participants remembered objects from an office waiting room based on schema expectations. They recalled items largely fitting the common office view (e.g., magazines, chairs) rather than what was actually present.
Boundary Extension Schema:
- Individuals often remember having viewed a larger scope of a scene than was actually presented.
- Experiments show consistent drawing of an expanded view from memory, implicating perceptual schemas in memory recall.

Acute stress can enhance retrieval of semantic (general knowledge) memories while inhibiting episodic memories.
Study Method: Participants underwent a Trier Social Stress Test, which induced stress, followed by general knowledge testing. Cortisol levels were measured pre and post-test.
Conclusions:
- Higher cortisol reactivity was associated with improved memory accuracy, suggesting a positive effect of stress on semantic memory retrieval.
- Implications suggest adaptation in emergencies or high-stress environments favors retrieval of facts over personal experiences.

Varying individual traits, such as anxiety levels or perfectionism, impact responses to stress during tasks.
Reaction to stress is not uniform; some may thrive in high-pressure environments while others may struggle.

Understanding these cognitive processes can aid in comprehension of diagnostic differences in dementia types and the broader implications for psychological and educational strategies.
Use of semantic memory frameworks may improve caregiving and education strategies for those experiencing cognitive decline.

Memory organization is structurally important for information retrieval.
Our experiences, schemas, and categorization strategies significantly impact memory, comprehension, and decision-making.
Acute stress could potentially enhance memory performance in controlled circumstances, reflecting varied influences on cognitive processes across different states and contexts.