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Chapter 2. Perceptual Processes I: Visual and Auditory Recognition. Introduction. visual stimuliprevious knowledge perception – pattern recognition – object recognition (1/10 sec) interpretation. Background on Visual Object Recognition. The Visual System - PowerPoint PPT Presentation
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Cognition 7e, Margaret Matlin Chapter 2
CognitionCognition
Perceptual Processes I: Perceptual Processes I: Visual and Auditory Visual and Auditory
RecognitionRecognition
Chapter 2Chapter 2
Cognition 7e, Margaret Matlin Chapter 2
IntroductionIntroduction
visual stimuli previous knowledge
perception – pattern recognition
– object recognition
(1/10 sec)
interpretation
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
The Visual SystemThe Visual Systemdistal stimulus = what is “out there”proximal stimulus = active retina cellsiconic memory = visual sensory memoryoccipital lobe - - primary visual cortexinferotemporal cortex
Cognition 7e, Margaret Matlin Chapter 2
Cerebral CortexCerebral Cortex
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Organization in Visual PerceptionOrganization in Visual PerceptionGestalt Psychology
figure
ground
ambiguous figure-ground relationshipExplanation for figure-ground reversal
1) adaptation of neurons in visual cortex
2) people try to solve the visual paradox
Cognition 7e, Margaret Matlin Chapter 2
Figure-Ground Figure-Ground RelationshipRelationship
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Organization in Visual PerceptionOrganization in Visual PerceptionIllusory Contours (subjective contours)
1) early stages of processing - interpretation
2) later stages of processing - understanding
Cognition 7e, Margaret Matlin Chapter 2
Illusory ContoursIllusory Contours
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Theories of Visual Object RecognitionTheories of Visual Object RecognitionTemplate-Matching Theory
templates
compare stimulus to templates until a match is found
Problemsinflexible
only works for isolated letters, numbers, objects
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Theories of Visual Object RecognitionTheories of Visual Object RecognitionFeature-Analysis Theory
distinctive features
Eleanor Gibson's researchtime to decide if two letters are different (p. 40)
recognizing letters and numbers on envelopes
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Feature Analysis Theory of Visual Object Feature Analysis Theory of Visual Object RecognitionRecognition
Hubel and Wiesel's researchsingle-cell recording technique
feature detector “cells” in primary visual cortex – respond to orientation of a visual stimulus
Feature-Analysis TheoryFeature-Analysis Theory
Problems with Feature-Analysis approach
doesn't account for the relationship between features
doesn't explain recognition of more complex objects
Cognition 7e, Margaret Matlin Chapter 2
Cognition 7e, Margaret Matlin Chapter 2
Background on Visual Background on Visual Object RecognitionObject Recognition
Theories of Visual Object RecognitionTheories of Visual Object RecognitionThe Recognition-by-Components Theory
Irving Biederman
structural theory
Geons = 3-D shapes
combine geons to form objects
Problemstandard viewpoint vs. different viewpoint
Viewer-centered approach
Cognition 7e, Margaret Matlin Chapter 2
GeonsGeons
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
The Distinction Between Bottom-Up The Distinction Between Bottom-Up Processing and Top-Down ProcessingProcessing and Top-Down Processing
bottom-up processingtop-down processingTop-down processing is especially strong when
stimuli are incomplete or ambiguous.Top-down processing is also strong when a
stimulus is registered for just a fraction of a second.
Combining bottom-up and top-down processing
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
Top-Down Processing and ReadingTop-Down Processing and ReadingWe don't read letter-by-letterAnalyzing all the individual features in the letters
of words would be too much work for the perceptual processes
We can still manage to read a sentence, even if some of the middle letters in a word have been rearranged or …
twlv mr ppl @ prty. Brng2 6pks br.
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
Top-Down Processing and ReadingTop-Down Processing and ReadingWord superiority effect
Say the letterSay the letter
OO
RR
CC
Word superiority effectWord superiority effect
Say the RED letterSay the RED letter
CCOOWW
OAOARR
BABACCKK
MRMRDD
SSEEDTDT
Cognition 7e, Margaret Matlin Chapter 2
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
Top-Down Processing and ReadingTop-Down Processing and Reading
The context of a sentence facilitates the recognition of a word in a sentence
Rueckl and Oden's “bears/beans” study
both bottom-up and top-down processing operate in a coordinated fashion
Cognition 7e, Margaret Matlin Chapter 2
Rueckl & OdenRueckl & Oden’’s s ““Bears/BeansBears/Beans”” study study
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
In Depth: Overactive Top-Down Processing In Depth: Overactive Top-Down Processing and Occasional Errors in Object Recognitionand Occasional Errors in Object Recognition
Change Blindnessfail to detect a change in an object or a sceneSimons and Levin's stranger-and-the-door studyDetecting the difference between two scenes
identify important changes more quicklymore likely to notice an improbable changedo not store a detailed representation of a sceneindividual differences
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
In Depth: Overactive Top-Down In Depth: Overactive Top-Down Processing and Occasional Errors in Processing and Occasional Errors in Object RecognitionObject Recognition
Inattentional Blindnessfail to notice when an unexpected but
completely visible object suddenly appears
Simons and Chabris' basketball study
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
In Depth: Overactive Top-Down In Depth: Overactive Top-Down Processing and Occasional Errors in Processing and Occasional Errors in Object RecognitionObject Recognition
Similarities between change blindness and inattentional blindness
both involve top-down processing when an object appears that is not consistent with their
concepts, expectations, and memory, people often fail to recognize this changed object (change blindness) or this new object (inattentional blindness)
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
In Depth: Overactive Top-Down In Depth: Overactive Top-Down Processing and Occasional Errors in Processing and Occasional Errors in Object RecognitionObject Recognition
ecological validityvisual system is accurate in integrating the gist or
general interpretation of a scenefocus on what is importantTheme 2: Our cognitive errors can often be
traced to the use of a rational strategy
Cognition 7e, Margaret Matlin Chapter 2
Top-Down Processing and Top-Down Processing and Visual Object RecognitionVisual Object Recognition
Ecological validityEcological validityWhy Seeing Is Often Not
Believing
Boston police officer Kenneth Conley was convicted of perjury and obstruction of justice because he claimed not to have seen a brutal police beating as he chased a murder suspect. The conviction was later overturned, but a new study re-examines his claim.
(Handout)
Cognition 7e, Margaret Matlin Chapter 2
Face PerceptionFace Perception
Should be a challenging taskRecognizing faces from different angles, in different settings, with different expressions
Recognizing Faces Versus Recognizing Recognizing Faces Versus Recognizing Other ObjectsOther Objects
Face perception as "special"Tanaka and Farah--facial features in context vs. isolation
feature identification vs. holistic approach(Gestalt)
Cognition 7e, Margaret Matlin Chapter 2
Face PerceptionFace Perception
Neuroscience Research on Face Neuroscience Research on Face RecognitionRecognition
Prosopagnosia – non-Gestaltinferotemporal cortexsingle-cell recording technique in monkeysfMRI studies
brain's response to faces in upright and upside-down positions
Cognition 7e, Margaret Matlin Chapter 2
Face PerceptionFace Perception
Applied Research on Face RecognitionApplied Research on Face Recognitioncashiers' judgments about ID photos (Kemp and colleagues 1997)security surveillance systems (Burton and colleagues 1999)
familiarity and expertise
Cognition 7e, Margaret Matlin Chapter 2
Face PerceptionFace Perception
Individual Differences: Face Identification Individual Differences: Face Identification in People with Schizophreniain People with Schizophrenia
schizophreniause of top-down processing in visual perceptiondifficulty perceiving faces
same/different person
same/different emotion
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Record sound vibrations of someone talking Translate vibrations into a sequence of sounds
that you perceive to be speech English: 15 sounds/sec = 900 sounds/min
Distinguish the sound pattern of one word from all other irrelevant words
Separate voice of speaker from background noise, including other conversations
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
What is a speech sound?What is a speech sound? A “phone” is the A “phone” is the smallest identifiable unit found in a stream of smallest identifiable unit found in a stream of speech. (e.g., “k” in Kit vs. Skill)speech. (e.g., “k” in Kit vs. Skill)
What is a phoneme?What is a phoneme? The smallest unit of The smallest unit of sound that enable meaning contrasts (e.g., sound that enable meaning contrasts (e.g., “p” and “t” in Spill vs. Still)“p” and “t” in Spill vs. Still)
How many sounds are there?How many sounds are there?
Speech PerceptionSpeech Perception
According to UCLA Phonetic Segment Inventory According to UCLA Phonetic Segment Inventory Database (UPSID), there are 770 sounds in the world’s Database (UPSID), there are 770 sounds in the world’s languageslanguages
47% are unique (i.e., occur in only one language) Languages average 20 to 27 sounds Approximately 44 phonemes in English
““Smallest” languages: Rotokas (New Guinea) and Mura Smallest” languages: Rotokas (New Guinea) and Mura (Brazil) with 11 phonemes each. (Brazil) with 11 phonemes each.
““Largest” language: !Xu‚) with 141 phonemes. Largest” language: !Xu‚) with 141 phonemes. (a.k.a. !Kung – in parts of Namibia & Botswana)
Cognition 7e, Margaret Matlin Chapter 2
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Characteristics of Speech PerceptionCharacteristics of Speech PerceptionWord Boundaries
Listeners can impose boundaries between words, even when these words are not separated by silence.
Example
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Characteristics of Speech PerceptionCharacteristics of Speech PerceptionWord Boundaries
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Characteristics of Speech PerceptionCharacteristics of Speech PerceptionVariability in Phoneme Pronunciation
Phoneme pronunciation varies tremendously
pitch, tone, and rate
lack of precision,
sloppy pronunciation
coarticulation
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Characteristics of Speech PerceptionCharacteristics of Speech PerceptionContext and Speech Perception
Context allows listeners to fill in missing sounds.
Phonemic restorationWarren & Warren's wheel/heel/peel study
Fail to notice mispronunciations
Role of top-down processing
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Characteristics of Speech PerceptionCharacteristics of Speech PerceptionVisual Cues as an Aid to Speech Perception
Visual cues from the speaker’s mouth help us interpret ambiguous sounds.
McGurk effect
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Theories of Speech PerceptionTheories of Speech PerceptionThe Special Mechanism Approach
speech-is-special approach
1) humans are born with a specialized device that allows us to decode speech stimuli (phonetic module or speech module)
2) we process speech sounds more quickly and accurately than other auditory stimuli
categorical perception
Cognition 7e, Margaret Matlin Chapter 2
Speech PerceptionSpeech Perception
Theories of Speech PerceptionTheories of Speech PerceptionThe General Mechanism Approaches
1) humans use the same neural mechanisms to process both speech sounds and nonspeech sounds
2) speech as learned ability
event-related potential studies
phoneme judgment and visual cues