Cognitive Psych Exam 3

visual imagery

“seeing” in the absence of a visual stimulus

mental imagery

experiencing a sensory impression in the absence of sensory input

what does imagery do for us?

it provides a way of thinking that adds another dimension to the verbal techniques usually associated with thinking

the imagery debate

is imagery based on spatial mechanisms (like perception) or propositional mechanisms (like language)

zenon pylyshyn

argued that imagery is propositional and spatial representation is an epiphenomenon

propositional

when relationships can be represented by abstract signals, like when words represent objects

epiphenomenon

something that accompanies a real mechanism but isn’t actually a part of it

stephen kosslyn

argued that imagery is depicted (can be shown like a picture) and uses spatial representations

spatial representations

different parts of an image can be described as corresponding to specific locations in space

kosslyn (1973) image-scanning experiment

participants took longer to mentally move long distances than shorter distances, provided evidence that imagery is spatial

mental scanning

create images and scan them in one’s mind

lea’s (1975) alternate explanation for mental scanning

more distractions when scanning longer distances may have increased reaction time

kosslyn et al. (1978) scanning experiment

it took longer to scan between greater distances, even without distractions. visual imagery has overlapping mechanisms with perception (spatial)

there is more support that imagery is…

spatial, as opposed to propositional

although mental images aren’t as vivid and long lasting, imagery and perception share properties (kosslyn 1973)

spatial experience for both perception and imagery matches the spatial layout of the actual stimulus

shepard and metzler (1971)

mental and perceptual images involve spatial representation of a stimulus (suggest same mechanisms)-people mentally rotate objects

relationship between viewing distance and ability to perceive details

moving closer to an object causes it to fill more of your visual field and makes it easier to see and detect details

kosslyn (1978) imagining 2 animals

viewing distance impacts the ability to see details in mental images, suggests same mechanisms as perception

farah’s (1985) letter visualization experiment

accuracy is higher when target letter was the same as imagined letter, suggests shared mechanisms between imagery and perception

perky (1910)

descriptions of imagined image match projected image, and participants mistake actual picture for mental image-perception affects imagery

differences in experiences of perception vs imagery

perception is automatic and stable, while imagery is effortful and fragile

chalmers and reisberg (1985) mental images of ambiguous figures

easy to flip between perceptions, but difficult to manipulate mental images, perception and imagery appear to rely on the same mechanisms

kreiman et al. (2000)

implanted electrodes in medial temporal lobe; neurons respond the same way to perceiving and imagining an object

le bihan and coworkers (1993) using an fMRI in visual cortex

brain activity increases during the presentation of a visual and imagining a stimulus; both perception and imagery activate the visual cortex

kosslyn et al. (1995)

the visual cortex is organized as a topographic map and imagery, like perception, results in a topographically organized brain activation

topographic map

specific locations on a visual stimulus causes activity at specific locations in the visual cortex

small objects activate the…

back of visual cortex

large objects activate the back and…

activation spreads to the front

kosslyn and coworkers (1999) and TMS

the visual area of the brain plays a casual role for both perception and imagery

transcranial magnetic stimulation (TMS)

high-powered magnetic pulses that can decrease brain functioning in a particular area for a short time

unilateral neglect (aka hemispatial neglect)

patient ignores objects in one half of their visual field in perception and imagery- damage to parietal lobe

bisiach and luzzatti (1978)

patients neglected the left side of location they pictured and only named objects to their right

ganis et al. (2004) and fMRI

* complete overlap of perception and imagery in the frontal lobe


* there are differences in the visual cortex and occipital lobe

areas of the brain don’t completely overlap for perception and imagery

charles bonnet syndrome

visual hallucinations caused by the brain’s adjustments to significant vision loss

dissociations between imagery and perception (R.M and C.K)

RM had damage to occipital and parietal lobes that caused a lack of ability to draw from memory, while CK couldn’t name pictures of objects but could draw from memory

the method of loci

visualizing items to be remembered in different locations in a mental image of a spatial layout

imagery to improve memory

method of loci, pegwood technique

pegwood technique

associate items to be remembered with concrete words, helps identify items based on order of list

language

a system of communication using sounds or symbols that allows us to express feelings, thoughts, ideas, and experiences

key property of human language…

creativity

the creativity of human language

language allows for the creation of new sentences through the hierarchical nature of language and the rule-based nature of language

hierarchical nature of language

language consists of a series of small components that can be combined to form larger units

rule-based nature of language

there are rules in languages specifying acceptable ways to arrange words and phrases

b.f skinner (1957) and verbal behavior

language is learned through reinforcement

noam chomsky (1957) and syntactic structures

* language is coded in genes, so the underlying basic of all languages are similar
* studying language is a way to study the mind
* children produce original, non-reinforced sentences
* brought psycholinguistics

psycholinguistics

the psychological study of language, with the goal of discovering psychological processes by which humans acquire and process language

comprehension

processing language sounds, words, and sentences

representations

how words are grouped together to create meaning and connections

speech production

physical and mental processes of making speech

acquisition

acquiring new languages, either as adults or children

lexicon

all words a person understands, a mental dictionary

semantics

the meaning of language- words and sentences

lexical semantics

the meaning of words, when each word has one or more meanings

word frequency

relative usage of words in a particular language

word frequency effect

phenomenon of faster reading time for high frequency words than for low frequency words

past experiences with words influences our ability…

to access their meaning

lexical decision task

decide as quickly as possible if strings of letters are words or non words

lexical decision task and response time

slower response time if asked about low frequency words

rayner and duffy (1986)

readers look at low frequency words longer because they need more time to access their meaning- the word frequency effect affects our ability to understand words

how do we understand words with unfamiliar pronunciation?

context

speech segmentation

perception of individual words even though there are no silences between spoken words

what organizes sound?

meaning

how do we segment sentences?

based on our knowledge of meaning/concepts

factors in understanding spoken words

1. how frequently we’ve encountered a word in the past
2. the context in which words appear
3. our knowledge of statistical regularities in our language
4. our knowledge of word meaning

all factors in understanding spoken words involve…

knowledge achieved through experience with language

lexical ambiguity

words can have multiple meanings- context normally clears things up

meaning dominance

relative frequency of the meanings of ambiguous words

biased dominance

when words have 2+ meanings with different dominance levels

balanced dominance

when words have 2+ meanings with about the same dominance levels

meaning dominance if there is no prior context (balanced dominance)

competition between equally likely meanings of a word with balanced dominance results in slow access

meaning dominance if there is no prior context (biased dominance)

activation of only the most frequent meaning of a word with biased dominance results in fast access

if there is context before a word with biased dominance…

activation of both the less frequent and the most frequent meanings result in slow access, but activation of only the most frequent meaning results in fast access

accessing the meaning of ambiguous words while reading a sentence is determined by

1. the words dominance
2. the context created by the sentence

the ability to access the correct meaning of a word depends on…

* word’s frequency
* context
* meaning dominance

sentences

strings of words in sequences

syntax

rules for combining words into sentences- understand what cues languages provide to show how words related to one another

parsing

mentally group words into phrases; helps create meaning

garden path sentences

sentences that begin by appearing to mean one thing, but end up meaning something else

temporary ambiguity

when the initial words are ambiguous, but the meaning is made clear by the end

heuristics

rules of thumb that provide best guesses

garden path model of parsing

listeners use heuristics to group words into phrases

the goods and bads of the garden path model of parsing

it is good for interpreting sentences quickly, but its bad because it can result in incorrect decisions

what determines parsing?

grammatical structure (syntax)

late closure

parser assumes the new word is part of the current phrase; can fix the problem by considering meaning

constraint-based approach to parsing

information in addition to syntax helps process sentences

(word meaning and scene context, additional information to make predictions, meaning to process sentences)

tanenhaus and trueswell (1995) and the visual word paradigm

context prevents participants from going down the garden path, eye movements are influenced by scene contents

visual word paradigm

determining how subjects are processing information in a scene as they respond to instructions related to the scene

linguistic information

information provided by syntactic structure of the sentence

non-linguistic information

information provided by the scene

narrative texts

stories that progress from one event to another

coherence (important properties of narrative texts)(inferences can facilitate coherence)

representation of the text in one’s mind that creates clear relations between parts of the text and the stories main topic

inference

process by which readers generate information that is not explicitly stated in the text

anaphoric inferences

connecting objects/people

instrumental inferences

tools or methods

casual inferences

events in one clause caused by events in the previous sentence

fletcher (1994)

different representations for different aspects of the text

surface form

specific words and syntax in the text

text base

meaning of sentences

situation model

representation in terms of people, objects, locations, and events described in the story

factors of a situation model

* incorporates prior knowledge to represent events as if you are experiencing the situation
* mental representation of what a text is about
* point of view of the protagonist