PSYCH 240 - Exam 3

Knowledge, Visual Imagery, Problem-Solving, Judgement & Decisions, Special Topic III

What is conceptual knowledge?

knowledge that lets us recognize objects and events

• Can make inferences abt properties of objects & events

What is a concept?

mental representation of a class or individual (varies in generality)

What is categorization?

• the process by which things are placed into (categorical) groups

• include all possible examples of a particular concept

Why are categories so important?

1. Helps us understand unique cases not previously seen before

2. Give pointers to knowledge by providing general information → once categorized we can focus on unique characteristics

What are all of the approaches to categorization?

• Definitional approach

• Prototype approach

• Exemplar approach

What is the definitional approach?

Determine category membership based on whether the object meets the category definition

What is a major issue with the definitional approach?

Not all (commonly agreed) category members actually meet the definition

What is the prototype approach?

A prototype acts as a “typical”member of a category

The category members all vary in typicality

• Highly typical members strongly resemble prototype, eg.

What is the typicality effect?

Prototypical objects (most alike the prototype) are processed preferentially

• Processed faster (RT)

• Named first/earlier, during recall

• Stronger priming effects (RT)

What led to the rise of the prototype approach?

Wittgenstein (1953) theorized a “family resemblance idea,” where category members resemble each other in various ways but aren’t identical

What is the exemplar approach?

A concept is represented by multiple actual examples, not a single prototype

• No abstract averages like the prototype theory

• Categorize through comparing a new item to stored examples

What are the advantages of the exemplar approach over the prototype approach?

The exemplar approach is better at handling atypical cases, or unusual categories

What are the advantages of the prototype approach over the exemplar approach?

Prototypes may be better for large categories

How are the categories of the Exemplar approach typically organized?

hierarchically— from more specific to more general

What is the Rosch model of category organization?

subordinate/basic/superordinate

What is the ‘synonymous hierarchies’ model of category organization?

specific/basic/global

What evidence exists to show that the basic level of category organization is special?

• Going above the basic level → large loss of information

• Going below the basic level → little gain of information

*What’s basic may be relative; depends on the level of someone’s expertise

How are concepts arranged in the mind?

In (semantic) networks that represent how they are organized in the brain

Describe Collins & Quillian’s (1969) Hierarchical semantic network model

• A node represents a category or concept → semantically related nodes are linked

• Cognitive Economy

• Shared properties are stored at high-level nodes

• The propoerties at higher levels are inherited by related lower levels, exceptions are noted at lower level (and more specific) nodes

What is a “cognitive economy”?

Shared properties of concepts are stored at higher-level nodes, which means properties are inherited by the lower levels

What testable predictions does Collins and Quillian’s semantic network model make?

• Verifying should take longer the more “nodes” must be crossed, therefore indicating a longer distance

• The reaction time of “canary” and “sing” should be less than “canary” and “fly” and less than “canary” and “skin” though technically all of these words are somehow related.

What is ‘spreading activation’?

• When a concept is presented, the relevant node is activated

• When the node is activated, the activity spreads among all the connected links, which are semantically related concepts, properties, etc.

• The semantic network predicts that concepts that receive activation from spreading are now primed and are more easily accessed from memory

What is the lexical decision priming task? (Meyer and Schvaneveldt, 1971)

• Testing reaction time with various targets (pairs of words or nonwords)

• When both of the targets were words, some of the word pairs were related, and some weren’t

• Reaction time was much faster with RELATED words

• Showed the presence of spreading activation

• *another version of this task includes single words, but with the related word as a “primer” rather than a pair

What are some criticisms of Collins and Quillian’s semantic network model?

• Cannot explain some typicality effects

  • Ex. canary and bird verified faster than ostrich and bird, which by C&Q should be equal because the distance is the same for both sentences

• Little evidence for cognitive economy/inheritance

  • Ex. Some results suggest “wings” (also) stored at “canary” node

• Some sentence-verification results problematic

  • Ex. “pig is animal” verified faster than “pig is mammal” but the ‘animal’ distance is longer

What is connectionism?

• approach to creating computer models for representing cognitive processes

• propose concepts are represented in the distributed activity of many linked units → also called “parallel distributed processing” models

What is the most key element of the Connectionist view of the mind?

Linked “units”(neuron-like nodes)

• input units → hidden units → output units

• Connection weights determine how strongly signals from one unit increase or decrease activity of next unit

Describe the function of the input units of the Connectionist model

Activated by stimulation from environment and send input to hidden units

Describe the function of the hidden units of the Connectionist model

Receive input from input units and send input to output units

Describe the function of the output units of the Connectionist model

Receive input from hidden units

How do connectionist networks learn?

Rather than knowledge programmed in, begins with equal or random response parameters that train a network over many trials, like AI training data

How does the connectionist network modify itself?

1. After comparing actual response and correct response (note this is provided!), error signal is generated

2. Back-propagation

   1. Repeats until error signal is zero

3. Overall process fine-tunes connection weights

What is back-propogation?

Process where the error signal is transmitted back through the circuit

• This indicates how the connection weights should be changed to allow the output signal to match the correct signal

Describe the ‘pros’ of the connectionist approach

• Success in simulating many cognitive processes

  • Ex. can explain learning generalization —> similar concepts have similar connectionist patterns

• Seems analogous to real brains/neurons

  • Ex. Graceful degradation

What are the five main theories of how concepts are represented in the brain?

1. Sensory-functional hypothesis

2. Semantic Category approach

3. Property Cluster (Multiple Factors) Approach

4. Embodiment Approach

5. Hub and Spoke Model

What is the sensory function hypothesis?

Brain regions dedicated to categorizing by sensory information and other regions dedicated to categorizing by function

How was the sensory-functional hypothesis derived?

Derived from finding that some brain-damaged individuals have trouble categorizing animals, but not artifacts (or reverse)

• Brain damage patients who cannot categorize animals but can categorize artifacts (tools); also, the reverse pattern of impairment

• Suggests categorizing animals depends on sensory information while categorizing artifacts depends on function

What evidence exists against the sensory functional hypothesis?

Sometimes there was impairment to artifact categorization but no impairment to functional knowledge (and impairment to sensory categorization)

What is the Semantic category approach?

There are specific neural circuits in the brain for specific categories

• Emphasis isn’t on just particular areas in the brain like the FFA but about circuits in the brain, linking faces, emotions, etc.

What is the multiple factors (property cluster) approach?

Concepts are differentiated from each other as conjunctions of various kinds of properties (e.g., color, motion, performed action), not identifying specific brain areas/networks for existing concept

• Hoffman et al.

• “Crowding” may differentiate some concepts, where some categories (e.g., animals) share many features (crowded); others don’t

What is the embodied/embodiment approach?

Concepts are represented by reactivation of sensory and motor circuits that are active when we interact with the object → patterns of reactivations represent concepts in the brain

Give an example of perception/action connection as part of the embodied approach

• Mirror neurons:

  • fire when we do a task or when we observe another doing that same task

• Semantic somatotopy (Hauk et al.)

  • Both words and the related movements activate similar brain ideas (ex body parts and moving with the same body parts

Give one counterexample to the embodied approach

• It predicts that impairment w/making functional movements should predict trouble recognizing objects, but this isn’t always true → ex. Garcea, 2013, stroke patient

What is the Hub & Spoke model?

Anterior Temporal Lobe (ATL) is a hub that integrates information from specialized category areas (spokes) in the brain

Give evidence in support of the Hub & Spoke model?

• Some patients with anterior temporal lobe damage have semantic dementia

• Porbric et al. (2010): used TMS to stimulate ATL or parietal (spoke)

  • When TMS impaired ATL, trouble naming both artifacts and living things

  • When TMS impaired certain parietal area, only trouble naming artifacts

What is mental imagery?

• experiencing a sensory impression without sensory input

• have imagery in various sense modalities (hearing, taste, etc.)

What is visual imagery?

• “seeing” in absence of visual stimulus

• another important form of cognition--nonverbal

What were Wundt’s three basic elements of consciousness?

Sensations, feelings, and images

Describe the overall imageless thought debate

• Aristotle: claimed thought impossible w/out images

• Galton: noted some w/lousy visual imagery think just fine

• Smallwood (recent): good evidence for imageless thought

  • uses random prompts for participants to note ongoing mental processes, sometimes imageless thought reported

Describe Paivio (1963, 1965)’s early cognitive paradigm of paired-associate learning

• Study pairs of words, first word is used as a recall cue at test

• Varied whether words were concrete or abstract

  • Imagery was easier with concrete, versus abstract, words

• Better memory for concrete words

• Conceptual-peg hypothesis

Describe the “conceptual-peg” hypothesis

concrete words allow forming visual images that other words, items, etc. can “hang onto”

Describe Shepard and Meltzer (1971) Mental Rotation Task

• vary angle of comparison shape, measure response RT

• Result: RT increased linearly w/angle (to max--180°)

What is the fundamental question of imagery and perception?

Do imagery and perception share the same mechanisms?

What was Kosslyn (1973) study of picture boat memorization & imagery?

• Participants first focused on one part of the boat, then asked to “look” for another part—measured RT for verifying

• Result: Longer RT to check “longer distances” in image

• Early support for similar imagery/perception mechanisms

Describe counter-evidence against Kosslyn (1973) study of picture boat memorization & imagery

Lea (1975)

• More distractions (e.g., interesting objects along the way) when scanning longer distances may have increased RT

Describe counter-evidence against Lea (1975); Kosslyn’s Rebuttal

• Island with 7 locations, 21 trips

• Note: here, longer distances don’t have more potentially distracting objects along the way

• Result: Still took longer to scan between greater distances

Supports idea that visual imagery is spatial (like perception)

What is the imagery debate?

Is imagery spatial or propositional?

Describe Pylyshyn (1973) Spatial Representation Study

Spatial representation is an epiphenomenon; accompanies real mechanism, but not actually part of it

• Proposed instead that imagery is propositional

• i.e., represented by abstract symbols, language

How did Pylyshyn attempt to argue Kosslyn’s results could be explained using real-world knowledge?

• i.e., when participants asked to (visually) imagine travelling distances, etc., use own knowledge that larger distances take longer to traverse

• “Tacit-knowledge” explanation

Descrbe Finke and Pinker (1982) Dot & Arrow Imagery experiment

• First, briefly presented display w/four dots

• Then, second display w/arrow appears

  • Participants judge whether arrow points to dots previously seen

  • Not instructed to use visual imagery

  • No time to memorize, no (prior) tacit knowledge

• Key result: Longer RT when greater distance between arrow and (previous) dot

  • supports mental spatial/“traveling” imagery idea

What is the relationship between viewing distance and ability to perceive details?

• Imagine small object next to large object

• Quicker to detect details on the larger object

Describe Kosslyn (1978)’s attempt to try apply the spatial aspect of visual perception to imagery

• Imagine two animals (e.g., rabbit/elephant or rabbit/fly)

  • “Zoom in” or “out” until larger animal fills visual field

  • Then...(critical task):

  • Ask questions about rabbit features (e.g., have whiskers?)

  • Result: faster RTs when rabbit “large” vs. “small”

• Support idea that images are spatial, like perception

Describe Perky (1910) study on whether perception and imagery interact

• projected faint images, participants imagined same object

• reported images closely resembled projected ones

• participants didn’t realize projected images were present

• So...images and actual visual stimuli seem confusable/similar

Describe the neuroimaging approaches to the imagery debate

• Kreiman et al. (2000):

  • Record individual neuron responses to perceiving vs. imagining object—same neurons respond

• Le Bihan et al. (1993)—fMRI study

  • Both real & imagined (visual) stimuli activate similar areas in visual cortex

Describe Granis et al (2004) study on perception vs. imagery differences

• again, compare real vs. imagined visual stimuli

• very similar activation for both in front & middle brain

• BUT: much stronger activation for real stimuli in visual cortex (back of brain)

Describe Amedi et al. (2005) study on perception vs. imagery differences

• as usual, various similar activations for real vs. imagined

• BUT: w/imagined, less activity for other sensory areas

• consistent w/imagery being more fragile, need to minimize interference

Describe Kosslyn’s transcranial magnetic stimulation study (1999)

• RT slower for both tasks when TMS applied to visual area, no effect for either perception or imagery task when applied to control brain are

• Suggests visual area brain activity plays causal role for both perception and imagery

Describe the evidence for differences between imagery and perception

• Guariglia et al (1993): patient with unilateral neglect, but only with images (!); perception OK

• patient “R.M.”—damage to occipital and parietal lobes

  • could recognize and draw objects presented to him but—couldn’t draw from memory (which requires imagery)

• C.K.—patient w/visual agnosia

  • couldn’t visually recognize real objects, but could image/draw

What is the summary of the evidence regarding the relationship between perception and imagery?

• evidence suggesting same/shared mechanisms for perception and imagery

• evidence that perception and imagery are dissociable, suggesting separate mechanisms

What is Berhmann'‘s suggested solution to the contradiction in the perception and imagery?

• Perception and imagery mechanisms partially overlap

• Visual perception involves bottom-up processing; located at lower and higher visual centers

• Imagery is a top-down process; located at higher visual centers (only)

How does Berhmann’s top-down theory apply to C.K., R.M., and M.G.S.’s dissociation patterns?

• CK: lower visual damage left (higher-level) imagery OK

• RM’s higher-level damage impaired imagery but not visual processes'

• More trouble explaining M.G.S., who still had imagery problem despite having only lower visual center damage

What is the difference between imagery and perception?

Perception is automatic and stable; imagery is effortful and fragile

How did Chalmers and Reisberg prove the separation of imagery and perception?

• Participants created mental images of ambiguous figures

• Harder to “flip” images vs. perceived ambiguous figures

How can imagery be used to improve memory?

• Method of loci

• Pegword technique

What is the method of loci?

• Placing images at locations

• Visualizing items to be remembered in different locations in a mental image of a (familiar) spatial layout

What is the pegword tehcnique?

• Associating to-be-remembered words w/images

• use standard words rather than locations (e.g., one-bun; two-shoe, three-tree, etc.)

• form visual image of each to-be-remembered word along with “pegword” from your standard list

What are other uses of imagery, in relation to nutrition?

Reduced food cravings

Describe Harvey et al’s (2005) study on how imagery reduces food cravings (vacations)

• Groups either imagined favorite food or favorite vacation

  • Result: Food craving increased for food-imagining group

• Later, food-imaging participants imagined either nonfood visual images or nonfood auditory images

  • Food craving decreased in both groups, more for nonfood visual group

• Consistent w/ Baddely’s WM model (i.e., more interference w/ visual nonfood imagery)

Describe Kemps & Tiggermann (2013) study on how imagery reduces food cravings (dots)

• Participants looked at phone app w/random visual dots whenever felt food craving

• Food cravings, actual consumption went down

  • The random dots interfere w/visuospatial sketchpad

Describe the Gestalt problem-solving framework

• First, ascertain how problem is represented in mind

• To solve, generally need to restructure problem (i.e., change problem representation)

What does the Gestalt problem-solving framework emphasize in solving problems?

• The importance of insight

• Insight: sudden realization of problem solution

  • Often requires restructuring the problem

• So...if insight actually occurs, shouldn’t experience much “warning” prior to insight/solution

Describe the results of Metcalfe and Wiebe (1987) Triangle and Chain problems

• Insight problems solved suddenly

• Noninsight problems solved gradually

Describe the results of Duncker’s (1945) candle problem

Only c. 50% solved; much better (c. 90%) when box empty (matches separate) rather than matches in box

Describe the results of Maier’s (1931) two-strings problem

Less than 50% solved; much better (c. 80%) when “hint” given (“accidentally” hit strings)

Describe the central problem of why initial experimental performance is bad

• Fixation: the person focuses on the aspect of the problem that prevents arriving at a different solution

• Common form: Functional fixedness— restricting the use of an object to familiar functions

What is functional fixedness?

• A particular type of mental set

• Preconceived notion on how to approach a problem

• Based on past experiences with similar problems

Describe the results of the water-jug problem (Luchins, 1942)

• three jugs, hold different quantities of water

• task: obtain desired amount by pouring water back and forth

• Result: (successful) method for earlier problems carried over to final problems, even though latter had simpler solutions

What is the information-processing approach?

• Newell and Simon (1972)

• Models problem solving as a search (for solution)

  • Transform initial state to goal state

Describe the typical problem solving approach of means-end analysis

• takes steps to reduce difference between initial and goal states

• establishes subgoals— intermediate states

Describe the results of Kaplan & Simon (1990) study showing the importance of initial problem representation

• Mutilated-checkerboard problem

• Any domino must cover “pairs” of squares

• Best performance: bread/butter, intermediate: regular & black/white; worst: all white

• Proved: problems easier to solve when closer to key representation

Describe how you can use analogies to solve a problem

• Using a solution to a similar problem can aid solution to new problem

• Example: Russian marriage problem (source problem) mutilated- checkerboard problem (target problem)

What is analogical transfer?

Transfer from one (source) problem to another (target) problem

What were the three steps Gick and Holyoak (1980) proposed in successful analogical transfer?

1. Noticing relationship

2. Mapping correspondence between source and target

3. Applying mapping

Describe Gick and Holyoak (1983) study on what might facilitate noticing/mapping

• Important obstacle: Participants often focus on surface features

  • i.e., specific aspects of particular problem

• Best transfer will occur if underlying structural features (underlying features that govern solution) are used, but this often doesn’t happen

• Hypothesized that better surface or structural feature similarity will improve analogical transfer/target problem solutions

Describe Holyoak and Koh’s (1987) lightbulb problem

• varied surface and source similarity to radiation problem (now used as source problem)

• Result: greater surface or structural similarity improved target solution

  • However, often people have difficulty noticing structural similarities

How can better analogical transfer be facilitated?

One option = analogical encoding training

Describe analogical encoding training

• Gentner and Goldin-Meadow (2003)

• Problems are compared and structural similarities between them are determined

• Such training improves analogical transfer to problems w/similar structural features

Why are experts better at solving problems?

better at noticing structural similarities

What is an expert, as defined for this class?

individuals who have completed extensive study and training and are widely viewed as being extremely knowledgeable, skilled, etc. in their field

• solve problems faster and more accurately than beginners

• possess more knowledge about their fields

• analyze problems using structural features more

• spend more time analyzing problems (although solve faster overall)

What are the limitations to ‘expertise’?

• Experts are only experts in their area

• Experts can be more rigid in ideas

What principles does creativity involve?

• Innovative thinking

• Novel ideas

• New connections between existing ideas