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									Recognition
Visual Recognition
   Sensory Registration
   Feature Analysis
       Patterns are constructed from features activated
        by visual inputs.
   Shape Construction
Feature Analysis
         scene




                 object        texture




                     geons
                     (parts)




                    feature
Visual Recognition
   Sensory Registration
   Feature Analysis
   Shape Construction
       Comparison
            Input patterns are compared with patterns in memory.
       Response
       A match is found and associated patterns in memory are
        activated to create a meaningful representation of the world
        (perception/consciousness).
       Selection & Integration
       The new representation is integrated into an object/scene
        representation that is used to direct action.
    Stages Of Recognition
   Feature Analysis Stage.
             Vision               Hearing
         Occipital Cortex      Temporal Cortex


   Comparison Stage.
                  Medial temporal Cortex:
      Limbic system + thalamus + surrounding cortex


   Response Stage.
        Temporal Cortex           Prefrontal cortex

   Selection & Integration Stage.
Stages of Recognition Process
   Comparison Stage
       Input patterns are compared with patterns in memory.
   Response Stage
       A match is found and associated patterns in memory are
        activated to create a meaningful representation of the world
        (perception/consciousness).
   Selection & Integration Stage
       The new representation is integrated into an object/scene
        representation that is used to direct action.
Stages of Recognition Process
   Comparison Stage
       Multiple patterns for the same input may
        be constructed. Each pattern is part of a
        different pathway to recognition.
       Logogens compare input patterns with
        patterns in memory.
   Response Stage
   Selection & Integration Stage
Redundant pathways in word
recognition
                                       /dahg/


a. Visual              b               /dawg                     f
    whole word                         /

c,b. Auditory                  b
                                                    f
                                                            /d           /ahg
    whole word   dog
                                                            /            /


e,f,b. Letter-             a
                                       c
                                                        e

    sound                              do                            e
                                       g

                                   d            o
                                                g
Stages of Recognition Process
   Comparison Stage
       Multiple patterns for the same input may be
        constructed. Each pattern is part of a different
        pathway to recognition.
            Masked priming reveals form effects when words share
             same pattern that provide evidence of the letter
             sequence pathway.
       Logogens compare input patterns with patterns in
        memory.
   Response Stage
   Selection & Integration Stage
Priming
   When two inputs are presented in succession,
    the effect of one on the perception of the
    other is called priming.
       A facilitory effect is call (positive) priming and an
        inhibitory effect is called negative priming.
       The effect of the first input on the second is called
        (forward) priming and the effect of the second
        word on the first is called (backward) priming.
Priming Tasks & Measures
   Verbal report of what is seen.
       Accuracy
   Choice reaction time. For example, press the
    right button if the string is a word and the left
    button if it is a nonword.
       Reaction time & Accuracy
   Naming. Read word you see aloud.
       Voice Onset Latency
 Masked and Unmasked Primes
Unmasked:
Presented               CAT         DOG
Observed                            DOG
                              CAT
 Forward Masked:
Presented          XXX CAT          DOG
Observed                       XXXX DOG
Backward Masked:
Presented          CAT XXX         DOG
Observed                      XXXX DOG
Types of Priming
   Unmasked. For example, 60 millisecond word
    prime immediately precedes target. Both
    prime and target are visible.
   Masked. For example, 400 millisecond mask
    (XXXX) immediately precedes prime, which
    immediately precedes target. Only mask and
    target are visible.
Priming Relationships
   Masked primes activate
       perceptual relationships (form priming).
            Shared onsets are effective primes, e.g., bell – book,
             stray – stroke.
            Priming is cross-modal, so huevo primes wave in
             bilinguals.
       Semantic/associative relationships
            cat primes dog
            Boeing primes 747
       Masked primes only operate over short, unfilled
        intervals.
Redundant pathways in word
recognition
                                       /dahg/


a. Visual              b               /dawg                     f
    whole word                         /

c,b. Auditory                  b
                                                    f
                                                            /d           /ahg
    whole word   dog
                                                            /            /


e,f,b. Letter-             a
                                       c
                                                        e

    sound                              do                            e
                                       g

                                   d            o
                                                g
Stages of Recognition Process
   Comparison Stage
       Multiple patterns for the same input may be constructed.
        Each pattern is part of a different pathway to recognition.
            Masked priming reveals form effects when words share same
             pattern that provide evidence of the letter sequence pathway.
            Masked auditory priming provides evidence of the auditory
             whole-word pathway.
       Logogens compare input patterns with patterns in memory.
   Response Stage
   Selection & Integration Stage
Priming Relationships
   Masked primes activate
       perceptual relationships (form priming).
            Shared onsets are effective primes, e.g., bell – book,
             stray – stroke.
            Priming is cross-modal, so huevo primes wave in
             bilinguals.
       Semantic/associative relationships
            cat primes dog
            Boeing primes 747
       Masked primes only operate over short, unfilled
        intervals.
Redundant pathways in word
recognition
                                       /dahg/


a. Visual              b               /dawg                     f
    whole word                         /

c,b. Auditory                  b
                                                    f
                                                            /d           /ahg
    whole word   dog
                                                            /            /


e,f,b. Letter-             a
                                       c
                                                        e

    sound                              do                            e
                                       g


                                   d            o
                                                g
Stages of Recognition Process
   Comparison Stage
       Multiple patterns for the same input may be constructed.
        Each pattern is part of a different pathway to recognition.
            Masked priming reveals form effects when words share same
             pattern that provide evidence of the letter sequence pathway.
            Masked auditory priming provides evidence of the auditory
             whole-word pathway.
            Word superiority effect reveals the visual whole-word pathway.
                  A briefly presented letter is more likely to be perceived in the
                   context of a word than by itself. E/O versus READ/ROAD
       Logogens compare input patterns with patterns in memory.
   Response, Selection, & Construction Stage
   Decision Stage
Redundant pathways in word
recognition
                                       /dahg/


a. Visual              b               /dawg                     f
    whole word                         /

c,b. Auditory                  b
                                                    f
                                                            /d           /ahg
    whole word   dog
                                                            /            /


e,f,b. Letter-             a
                                       c
                                                        e

    sound                              do                            e
                                       g

                                   d            o
                                                g
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
       Multiple patterns for the same input may be constructed.
        Each pattern is part of a different pathway to recognition.
            Masked priming
            Word superiority effect
            Frequency effect reveals visual whole-word pathway.
                  Briefly presented high frequency words more likely to be seen
                   than low frequency words or nonwords.
       Logogens compare input patterns with patterns in memory.
   Response, Selection, & Construction Stage
   Decision Stage
Redundant pathways explanation
of frequency effect
                                       /dahg/


a. Visual              b               /dawg                     f
    whole word                         /

c,b. Auditory                  b
                                                    f
                                                            /d           /ahg
    whole word   dog
                                                            /            /


e,f,b. Letter-             a
                                       c
                                                        e

    sound                              do                            e
                                       g

                                   d            o
                                                g
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
       Multiple patterns for the same input may be constructed.
        Each pattern is part of a different pathway to recognition.
            Masked priming
            Word superiority effect
            Frequency effect reveals visual whole-word pathway.
            Whole-word pathway makes skilled reading possible.
                  When asked to detect Ts, readers miss many in high frequency
                   words, e.g., the.
       Logogens compare input patterns with patterns in memory.
   Response, Selection, & Construction Stage
   Decision Stage
Evidence of Whole-Word
Pathway


 Aoccdrnig to rscheearch at an Elingsh uinervtisy, it deosn't mttaer in
 waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht
 the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl
 mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae we
 do not raed ervey lteter by it slef but the wrod as a wlohe.
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
       Multiple patterns for the same input provide
        different pathways to recognition.
       Logogens compare input patterns with patterns in
        memory.
   Response Stage
   Selection Stage
Logogen Theory
   The brain is a continuously sensitive receiver.
    When the match between an input an pattern
    in memory exceeds some criterion,
    perception of the pattern occurs.
   Other names for logogens
       Perceptrons
       Demons (“Pandemonium”)
       Neural Net
       Connectionist Model
Logogen
                         boy




                         boy
   boy
             criterion

          activation
          level

                         boy
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
       Multiple patterns for the same input provide
        different pathways to recognition.
       Logogens compare input patterns with patterns in
        memory.
            Repetition effect
   Response Stage
   Selection & Integration Stage
Repetition effect
Activation from successive partial
matches can accumulate so repeating
                                        boy
a briefly presented item causes it to
be perceived more clearly.


   boy                       boy        boy




   b__                      _o_          __y
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
   Response Stage
       Logogens are part of semantic network.
            When a logogen responds associated
             representations are also activated.
            Masked and unmasked semantic priming
             reveals the spread of activation.
   Selection & Integration Stage
         Response
                                                  wheel, compass
                  scene




 star                     object        texture




point, triangle               geons
                              (parts)




                             feature
Priming Relationships
   Masked primes activate
       Perceptual relationships (form priming).
       Semantic/associative relationships
            cat primes dog
            Boeing primes 747
       Masked primes only operate over short,
        unfilled intervals.
Priming Relationships
   Unmasked primes activate semantic
    relationships, such as boy – girl.
       Unmasked primes can be effective over
        long, filled intervals.
Explanation of semantic
priming
     cat   Activation spreads among
           semantically related logogens


     cat                        dog




    cat
Nonvisual semantic information
may influence visual recognition
Logogen system

                                 Decision                    Motor Planning
                                 stage


                                                     /dawg            /d        /ahg
                                                     /                /         /
                cat
                                                /dawg            /d           /ahg
                                                /                /            /
                                  dog
                      dig



                                   dig          do
          don                                   g
                            do
    dot                     n               d            o             d
                  dot                                    g
Stages of Recognition Process
   Comparison Stage
   Response Stage
       Logogens are part of semantic network.
   Selection & Integration Stage
       Some of the activated representations are
        combined into a single larger
        representation
            Words into sentences
            Objects into a scene
Selection & Integration
         scene




                 object        texture




                     geons
                     (parts)




                    feature
Spatial context in visual
recognition
   The elements of a scene semantically
    prime each other
   Memory is a part of scene analysis
       So we may construct a meaningful scene
        out of meaningless parts
       Perception and recognition can not be
        separated into successive processing
        stages
Stages of Recognition Process
   Feature Analysis Stage
   Comparison Stage
   Response Stage
       Logogens are part of semantic network.
   Selection and Integration Stage
       A structural description is used to combine
        individual representations into a larger
        meaningful representation.
Structural Description
   A structural description describes the
    relative locations of different categories
    of objects that are identified through
    feature representations.
       Faces, scenes
Structural Description
   A structural description describes the
    relative locations of different categories
    of objects that are identified through
    feature representations.
   Structural descriptions make it possible
    to recognize an infinite number of
    things categorically, hence semantically.
Structural Description
   A structural description describes the relative
    locations of different categories of objects that are
    identified through feature representations.
   Structural descriptions make it possible to recognize
    an infinite number of things categorically, hence
    semantically.
   The categorical structural descriptions that
    are used to construct representations are part
    of procedural memory but the instance
    representations constructed with the
    structural descriptions are part of declarative
    memory.
 Types of                                      Inability

 Visual
                               Mesial          to access
                              Temporal         memory

 Agnosia
                              Subcortex       associative
                                                agnosia



        Response Selection   Surrounding
          & Integration      Visual Cortex

Feature Analysis &
Comparison: Top-Down           Occipital
Perceptual Processing           Cortex           Inability
                                               to integrate
                                                 features
           Bottom up
                                             simultagnosia
           Perceptual          LGN of
           Processing         Thalamus


                               Retina
Summary
   Comparison between representation of
    perceptual input and representations in
    memory
       Redundant pathways increase probability of match
   Response includes multiple associated
    representations
       Priming, agnosia, and apraxia provide evidence of
        specific pathways and associations
   Selection of context-appropriate
    representation is integrated with structural
    description
       Orients you to place

								
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