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Complex Cognition (Subject) / Task 2 (Lesson)
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- How are Objects placed in Categories_ Definitional Approach g – decide whether something belongs to a category by determining whether an object fits the definition of the category g Categories are clearly defined, mutually exclusive & collectively exhaustive g Doesn’t work as not all members of a category have the same features
- Categories Prototype Based Approach P Membership in a category is determined by comparing the object to a prototype that represents the category P The typical prototype is based on an average of members of a category that are commonly experienced § Not an actual member, but an average representation (e.g. when you say bird you don’t have a particular bird in mind… at least I don’t… but you know what you’re talking about)
- Family resemblance – idea that thing in a category resemble one another in a number of ways (allows variation)
- Variations within categories P Variations within categories = differences in typicality § High typicality – member closely resembles prototype § Low typicality – obviously doesn’t § Rosch’s experiment (smaller number = higher typicality)
- Typicality effect P – ability to judge highly prototypical objects more rapidly
- Naming P prototypical members are named first
- Priming P prototypical members are named first
- Exemplar-Based Approach P Like prototype approach involves determining whether an object is similar to another object P Standard: many examples, each of which are called an exemplar § Exemplar – actual member of the category that an individual has encountered in the past P Store exemplars as separate, individuated memory traces, refer new items to these stored exemplars & include them in the category if they are similar enough g “slide carousel of instances” P People probs use both approaches AdvantagesP Can more easily take into account atypical cases like birds that can’t fly (don’t become lost in the average) P Can deal more easily with variable categories like “games”
- Theory-Based Categorisation P One decides whether something belongs to a category by determining whether the features of the test item are best explained by the “theory” that underlies the category
- Explanation-Based Categorisation P Explanatory information is critical in making categorisation decisions
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- Levels of Categories P Hierarchical organisation – large, more general categories are divided into smaller, more specific categories P Superordinate level – global/broad (e.g. furniture) P Basic level (e.g. table) § Basic level effect – the level people tend to focus on (careful: only when not specialised in a specific category!) P Subordinate level – specific (e.g. kitchen table) P Knowledge – the level that is special (= meaning that people tend to focus on it) depends on expertise and thus is not the same for everyone § More expertise & familiarity = focus on more specific information
- Working Memory Categorisation System g Rule-based categorisation g Decide whether a test item belongs to a particular category by determining whether it fits a rule that defines the category g Requires selective attention & temporary storage g Involved cognitive operations 1. Selectively attending to each critical attribute (= one mentioned in the rule) 2. Determining whether its value matches a value/ feature specified in the rule 3. Combine the outcomes of stage 2 in WM to determine final categorisation Supportg Activation in left hemisphere: inferior parietal cortex, parietal occipital cortex, anterior cingulate § Associated with selective attention & WM g Activation in right ventral prefrontal cortex g AD patients have difficulties with rule-based, CBD with similarity-based g double dissociation
- Explicit LTM Categorisation System g Two similarity-based categorisation processes § Decide whether a test item belongs in a category by determining its similarity to remembered exemplars of that category § Or by comparing it to the prototype of a category Supportg Builders vs. Diggers experiment g “positive match” (= applies to rule & similarity) more quickly processed & less mistakes than “negative match” that fits in two different categories depending on whether you go by rule or similarity g Activation in both hemispheres: temporal-parietal cortex § Associated with integration of multiple features
- Implicit LTM System g Decide whether an item belongs to a category by assessing the ease with which its perceptual features can be processed § Greater perceptual fluency = greater likelihood of category membership g Similarity-based categorisation can be based on either explicit or implicit memory (support comes from amnesics g performed normally during implicit categorisation while showing impairment in recognition) g Deactivation of occipital area
- The knowledge based view/ theory based categorisation The knowledge-based view/ theory-based categorization: a person does not compare features or physical aspects of the objects and events to aspects of stored representations but uses his or her own knowledge of how the concept is organized to justify the classification and to explain why certain instances happen to go together (children, photo albums, pets, cash… à things to save when the house burns down) - The approach offers an explanation for why things go together in the same category - People’s theories or mental explanations about the world are intertwined with their concepts and provide a basis for categorization
- Influence of Context during Development P Young children reason differently until about 10 years of age § Unlikely to learn about similarities between humans & other animals until well after 10 P Flexibility in development: overlap between humans and rest of nature depends on language, culture & amount of direct experience P Previous research has shown that qualitative changes in conceptual organisation must take place at the age of 10...ish § First more likely to think that animals possess a biological property after learning that humans do so than the other way around but after 10 they don’t think that anymore P There are multiple frameworks to reason about nature which can be primed P Study: are there different developmental trends for categorising humans as belonging with the rest of nature depending on whether personal (= think about personal experience with nature) or abstract frames of reference (= think about what they know about some aspect of nature) for reasoning about nature are primed? P Method: prime then categorisation task (“what belongs together?”) P Results: greater likelihood to categorise humans with other nature items in the personal frame of reference P SO: category-based induction and environmental attitudes vary across contexts
- Study: 5-8 years old More likely to categorise humans with other nature items in the personal frame of reference condition
- Study: 9-12 years old No significant difference in likelihood g stage of conceptual transition!
- Study: Adults Less likely to categorise humans with other nature in the personal frame of reference than the abstract frame of reference
- Essentialism P View that every entity has a set of attributes that are necessary to its identity & function g innately determined § Inductive potential – group membership is telling of the individual member’s characteristics § Inalterability – group membership is fixed for a relatively long duration P View that certain categories (e.g. women, racial groups, dinosaurs…) have an underlying reality/ true nature that one cannot observe directly § This reality is thought to give objects their identity and to be responsible for similarities across category members § E.g. someone might believe that there exist deep, non-obvious differences between males and females without having an idea about what those differences are P Helps structure our understanding of the social world by organising groups into meaningful categories with distinct attributes P Less creativity
- Essentialist theory P belief that race is a real entity that consists of underlying essence, determining a person’s dispositions and is characterised by clear, unalterable physical & psychological markers
- Principle of hypodescent One Drop Rule P assign multicultural individuals to the subordinate racial category (= child with parents from different racial groups assigned to subordinate group) One-drop rule – individuals with any non-white ancestry are classified as members of non-white race
- Ingroup overexclusion perspective P effects of racial essentialism are due to the motivation to maintain ingroup dominance and membership purity
- Lay theory perspective P effects of racial essentialism are due to the motivation to maintain ingroup dominance and membership purity
- Lay racial essentialism P conceptualise race as a fundamental & meaningful source of human division that has an inherent, inalterable biological basis § Domain specific: influences categorisation only in the racial domain § Categorise people along racial lines more readily § More sensitive to subtle variations in phenotypic racial traits & adopt more stringent phenotypic criteria in racial categorisation § No difference in effect between racial majorities & minorities g no ingroup exclusion bias
- Effects of Language on color discrimination P Speeded colour discrimination task P Russians make linguistic distinction between lighter and darker blues § Category advantage – faster in discriminating two colours when they fall into different categories (in English blue = blue so no category advantage in any condition) § Habitual/ obligatory categorical distinctions made in one’s language result in language specific categorical distortions in objective perceptual dual tasks P Category advantage was eliminated by a verbal but not spatial dual task g verbal interference (had to remember a series of digits) P Language specific representations seem to be brought online spontaneously during even rather simple perceptual discriminations