Recognition

Evolution of Recognition Procedural memory includes perceptual- motor skills Automatic activation of specific actions in response to specific inputs Declarative memory begins with recognition Automatic activation of additional associated perceptual representations in response to specific inputs Orientation to place

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

Feature Analysis scene texture objec t 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. Comparison Stage. Response Stage. Selection & Integration Stage. VisionHearing Occipital CortexTemporal Cortex Medial temporal Cortex: Limbic system + thalamus + surrounding cortex Temporal Cortex Prefrontal cortex

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 dog /dahg/ /ahg / do g /d / ogog d c a b a.Visual whole word c,b. Auditory whole word e,f,b. Letter- sound e e f f /dawg / b

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 CAT Presented Observed Unmasked: CATDOG Presented Observed Backward Masked: XXX DOG CAT XXXX Presented Observed Forward Masked: CAT DOG XXX XXXX

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 dog /dahg/ /ahg / do g /d / ogog d c a b a.Visual whole word c,b. Auditory whole word e,f,b. Letter- sound e e f f /dawg / b

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 dog /dahg/ /ahg / do g /d / ogog d c a b a.Visual whole word c,b. Auditory whole word e,f,b. Letter- sound e e f f /dawg / b

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 dog /dahg/ /ahg / do g /d / ogog d c a b a.Visual whole word c,b. Auditory whole word e,f,b. Letter- sound e e f f /dawg / b

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 dog /dahg/ /ahg / do g /d / ogog d c a b a.Visual whole word c,b. Auditory whole word e,f,b. Letter- sound e e f f /dawg / b

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 criterion activation level

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 boy b__ _o_ __y boy Activation from successive partial matches can accumulate so repeating a briefly presented item causes it to be perceived more clearly.

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 scene texture objec t geons (parts) feature point, triangle star wheel, compass

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 catdog cat Activation spreads among semantically related logogens

Nonvisual semantic information may influence visual recognition

Logogen system dog Motor Planning dig don dot /dawg / /ahg / do g /d / ogog d Decision stage /dawg / /d / /ahg / d dot do n dig cat

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 texture objec t 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 Visual Agnosia LGN of Thalamus Retina Occipital Cortex Surrounding Visual Cortex Mesial Temporal Subcortex Inability to access memory associative agnosia Inability to integrate features simultagnosia Response Selection & Integration Feature Analysis & Comparison: Top-Down Perceptual Processing Bottom up Perceptual Processing

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