PSY 322 Exam 3 Flashcards
Eye-witness testimony:
What is it, what are the problems with it:
Testimony by an eyewitness to a crime about what he or she saw during the crime
Like other memory, eyewitness testimony can be inaccurate: Mistaken identity, Constructive nature of memory
Eye-witness testimony:
Relevant studies
Wells and Bradfield (1998): Participants view security videotape with gunman in view for 8 seconds, Everyone identified someone as the gunman from photographs afterward, The actual gunman’s picture was not presented → Errors due to attention and arousal
Stanny and Johnson - weapons focus experiment: Presence of a weapon that was fired is associated with a decrease in memory about the perpetrator, the victim, and the weapon → Errors due to familiarity: Source monitoring AND Errors due to suggestion: Suggestive questioning - The misinformation effect, Confirming feedback - Post-identification feedback effect
Wells and Bradfield’s “Good, You Identified the Suspect” experiment: The type of feedback from the experimenter influenced subjects’ confidence in their identification, with confirming feedback resulting in the highest confidence. Confidence in one’s memories may be increased by postevent questioning/ May make memories easier to retrieve
Hyman and coworkers (1995): False Memories - Participants’ parents gave descriptions of childhood experiences. Participant had conversation about experiences with experimenter; experimenter added new events. When discussing it later, participant “remembered” the new events as actually happening
Eye-witness testimony:
How can we make it better?
Inform witness that perpetrator might not be in lineup, Use “fillers” in lineup similar to suspect, Use sequential presentation (not simultaneous), Improve interviewing techniques like cognitive interview
Conceptual knowledge:
Concept:
Categorization:
Categories Are Useful:
Conceptual knowledge: enables us to recognize objects and events and to make inferences about their properties
Concept: mental representation used for a variety of cognitive functions
Categorization: the process by which things are placed into groups called categories – Categories are all possible examples of a particular concept
Categories Are Useful: Help to understand individual cases not previously encountered - “Pointers to knowledge” → Categories provide a wealth of general information about an item, Allow us to identify the special characteristics of a particular item, Provides general info with no need to start from scratch
Definitional approach to categorization - What is it, what are its problems
Determine category membership based on whether the object meets the definition of the category, Not all members of everyday categories have the same defining features like different objects, all possible “chairs.”
Family resemblance
Definitional approach to categorization - Things in a category resemble one another in a number of ways, but do not have to share every feature - participation exercise
Prototype (Typical) approach to categorization
Example Birds: Three real birds—a sparrow, a robin, and a blue jay - “prototype” is
Results of Rosch’s (1975a) experiment:
Typicality effect:
High prototypicality:
Low prototypicality:
Low overlap:
Results of E.E. Smith et al.’s (1974):
Definitional approach to categorization - An abstract representation of the “typical” member of a category, characteristic features that describe what members of that concept are like, an average of category members encountered in the past, contains the most salient features, true of most instances of that category
Example Answer: bird that is the average representation of the category “birds.”
Results of Rosch’s (1975a) experiment: in which participants judged objects on a scale of 1 (good example of a category) to 7 (poor example): (a) ratings for birds; (b) ratings for furniture. Procedure for Rosch’s (1975b) priming experiment. Results for the conditions when the test colors were the same are shown on the right. (a) The person’s “green” prototype matches the good green, but (b) is a poor match for the light green. How Rosch explains the finding that priming resulted in faster “same” judgments for prototypical colors than for non prototypical colors. Typicality effect
Typicality effect(explained by the Exemplar Approach): prototypical objects are processed preferentially – Highly prototypical objects judged/named more rapidly - Sentence verification technique
High prototypicality: a category member closely resembles the category prototype - “Typical” member For category “bird” = robin
Low prototypicality: a category member does not closely resemble the category prototype - For category “bird” = penguin
Low overlap = low family resemblance and large amount of overlap with characteristics of other items in the category, the family resemblance of these items is high
Results of E.E. Smith et al.’s (1974): sentence verification experiment. Reaction times were faster for objects rated higher in prototypicality
Exemplar approach to categorization
Exemplars may work best for
Prototypes may work best for
Concept is represented by multiple examples (rather than a single prototype), Examples are actual category members (not abstract averages), To categorize, compare the new item to stored examples
Similar to prototype view (Representing a category is not defining it); Different (representation is not abstract - descriptions of specific examples)
The more similar a specific exemplar is to a known category member, the faster it will be categorized
Exemplars may work best for small categories
Prototypes may work best for larger categories
Levels of categories: global (superordinate), basic, specific (subordinate)
Global: Furniture or Vehicle
Basic: Table or Truck
Specific: Kitchen Table or Van
Why is the “basic” level special?
People almost exclusively use basic-level names in freenaming tasks
Quicker to identify basic-level category member as a member of a category
Children learn basic-level concepts sooner than other levels
Basic-level is much more common in adult discourse than names for superordinate categories
Different cultures tend to use the same basic-level categories, at least for living things
Hierarchical networks: Collins and Quillian (1969)’s model
Semantic Networks:
Node
Cognitive economy:
Exceptions:
Inheritance:
Semantic Networks: Concepts are arranged in networks that represent the way concepts are organized in the mind - Model for how concepts and properties are associated in the mind
Node = category/concept
Concepts are linked
Cognitive economy: shared properties are only stored at higher-level nodes
Exceptions: are stored at lower nodes
Inheritance: Lower-level items share properties of higher level items
Nonhierarchical (spreading activation) networks: Collins and Loftus (1975)’s model
Spreading Activation:
Lexical decision task:
Meyer and Schvaneveldt (1971):
Spreading Activation:
Activation is the arousal level of a node
When a node is activated, activity spreads out along all connected links
Concepts that receive activation are primed and more easily accessed from memory
Lexical decision task:
Participants read stimuli and are asked to say as quickly as possible whether the item is a word or not
Meyer and Schvaneveldt (1971):
“Yes” if both strings are words; “no” if not
Some pairs were closely associated
Reaction time was faster for those pairs
Spreading activation
Four proposals for how concepts are represented in the brain:
Sensory-Functional Hypothesis
Multiple-Factor Approach
Semantic Category Approach
Embodied Approach
Sensory-Functional Hypothesis:
Different brain areas may be specialized to process information about different categories
- Double dissociation for categories “living things” and “nonliving things” (artifacts)
- Category-specific memory impairment
Sensory-functional hypothesis:
living things → sensory properties
artifacts → functions
Performance on a naming task for patients K.C. and E.W., both of whom had category specific memory impairment. They were able to correctly name pictures of nonliving things (such as car and table) and fruits and vegetables (such as tomato and pear) but performed poorly when asked to name pictures of animals.
Multiple-Factor Approach:
Distributed representation: how concepts are divided within a category
Animals → motion and color
Artifacts → actions (using, interacting)
Crowding: when different concepts within a category share many properties
For example, “animals” all share “eyes,” “legs,” and “the ability to move”
Semantic Category Approach:
Specific neural circuits for specific categories
Figure 9.24 Results of the Huth et al. (2016) experiment in which participants listened to stories in a scanner. (a) Words that activate different places on the cortex. (b) Close-up of a smaller area of cortex. Note that a particular area usually responded to a number of different words, as indicated in Figure 9.25.
Embodied Approach:
Knowledge of concepts is based on reactivation of sensory and motor processes that occur when we interact with the object.
Mirror neurons: fire when we do a task or we observe another doing that same task
Semantic somatotopy: correspondence between words related to specific body parts and the location of brain activation
Figure 9.26 Hauk et al. (2004) results. Colored areas indicate the areas of the brain activated by (a) foot, finger, and tongue movements; (b) leg, arm, and face words.
Mental imagery/Visual imagery: what is it
Visual imagery: “seeing” in the absence of a visual stimulus
Provides a way of thinking that adds another dimension to purely verbal techniques
Mental imagery: experiencing a sensory impression in the absence of sensory input
Paivio’s conceptual peg hypothesis: concrete vs abstract words
Paired-associate learning:
Conceptual peg hypothesis:
Pegword technique:
Proposed that imagery is propositional:
Paired-associate learning: Developed ways to measure behavior that could be used to infer cognitive processes
Conceptual peg hypothesis: Memory for words that evoke mental images is better than for those that do not
Pegword technique: Associate items to be remembered with concrete words → Pair each of these things with a pegword - Create a vivid image of things to be remembered with the object represented by the word
Proposed that imagery is propositional: Can be represented by abstract symbols
Mental rotation experiments (i.e. Shepard and Metzler):
Mental chronometry:
Mental chronometry: Participants mentally rotate one object to see if it matched another object
