DOC PREVIEW
UNCW PSY 211 - Pattern Recognition

This preview shows page 1 out of 4 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 4 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 4 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

PSY 211 1st Edition Lecture 9Outline of Current Lecture I. What is Pattern Recognition?II. Top-down Vs. Bottom-up Processinga. Semantic PrimingIII. The What vs. Where Systemsa. Visual Agnosiab. Optic Ataxia and Attentional NeglectCurrent LectureWhat is Pattern Recognition?Psychological Consistency despite Environmental VariabilityYou perceive objects as constant despite changes in size, shading, orientation, occlusion, etc. Psychological Variability despite Environmental ConsistencyHowever, the same object can also be perceived differently depending on the context (oryour point-of-view).Pattern Recognition is the assignment of meaning to a stimulus; categorizing it as an instance ofx. Assigning meaning can be thought of as matching a stimulus to a representation in memory. Pattern recognition help identify what is out there, and where something is, localization. Top-down vs. Bottom- up Processing- Association Areas: integration of information across modalities - Secondary Areas: combines basic features- Primary Areas: Basic FeaturesIn bottom-up processing the process starts in the primary areas and works its way up, and in top-down processing the processes starts in the association areas and works its way down.Bottom –Up- Data driven These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Initiated by stimuli in the environment.Top-Down- Concept Driven- Initiated by context, knowledge, and expectationTop-Down InfluencesSemantic Priming in the Lexical Decision Task- Letter strings are presented one at a time.- S’s task is to decide if string is a word or non-word.- Measure = Reaction time.Semantic Priming helps identify and pronounce words faster when they are preceded by semantically related words. Errors from Top-Down Processing- Object identification- Proofreading- Wishful ThinkingThe What vs. Where Visual PathwaysHumans are shown three faces in different places on a computer screen. Then, after a delay, they see a display in which either a face has changed (Faces task), or the position of one of the faces has changed (Locations task), and they must identify the change.The Where Pathway- “occipitoparietal”- “dorsal pathways”- Localization of objects in space- Damage to where pathways: optic ataxia, spatial neglectThe What Pathway- “occipitotemporal”- “ventral pathway”- Object identification (features, colors, shapes, etc.)- Damage to what pathways: visual agnosiaDamage to the “Where” PathwaysPatients with where-system damage can identify objects, but have trouble localizing them in space or acting on them.- Optic Ataxia [cf. Balint's syndrome]: Impairment in the control of eye movement’s visually-guided actions.- Spatial Neglect [aka. Unilateral or Hemi-spatial Neglect]: A failure to acknowledge or attend to objects that are located in the side of space opposite to the brain lesion.Damage to the “What” Pathways- From the Greek, meaning lack of knowledge.- Refers to an inability to recognize (identify) objects even though basic sensation & perception is intact.- Not due to sensory damage, memory impairment, or a deficit in intellectual functioning.- Two basic types... o Apperceptive Agnosia. o Associative AgnosiaApperceptive Agnosia- Most severe form of agnosia.- Patients unable to identify basic/low-level features of objects, showing an "inability to form a stable percept".- Most patients cannot identify basic object features, even when objects are familiar.- Unable to copy simple line drawing.- Patient must use other senses torecognize objects.- Interestingly,some patientsare still ableto drawobjects frommemory,despite beingunabletocopy them.Associative Agnosia- "Perception without meaning".- Basic perception intact, but unable to recognize object.- Can copy objects, but still fail to recognize them.- Prosopagnosia: Agnosia limited to faces; person is unable to I.Dpeople from their face (but may show unconscious response to familiar faces)“Where” (Location) System or “How” (Action System)- Carbon monoxidepoisoning resulting intemporal lobe damage.- Cannot recognizesimple features, lines,shapes, letters, etc.- But can perform on-line visually-guided motor tasks, tasks such as placing ashape in an oriented slot.- Suggests that main role of ventral steam is to support visually-guided actions as much as object


View Full Document

UNCW PSY 211 - Pattern Recognition

Download Pattern Recognition
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Pattern Recognition and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Pattern Recognition 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?