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Recognizing configurations is the interaction between perception and memory3)An emerging percept has to mingle with a memory trace of an experience by some function The Three main theories of pattern recognition 1)Template Matching Theory -Pattern recognition would be simple if all patterns were the same, but patterns are not all the same oI.e. there is not just one way a chair appears How are we able to identify them as the same objects? -Theory suggests that we compare the configuration of the current sensory input witha standard configuration we have in memory (prototype or template) oA prototype is an average representation of the object in memory oIf the match is good enough, we recognize the object Hintzman Multiple-trace Memory Model:
-A probefrom primary memory (current experience of the stimulus) activates secondary memory (previous experience of similar stimulus) where memory tracesare activated to the extent that they are similar to the probe -Contributions from the activated memory traces return an echoto primary memoryProbe– A snapshot of information in primary memory that can activate memory traces in secondary memory Echo– When a Probe goes out from primary memory to secondary memory, memory tracesare activated to the extent that they are similar to the probe; made up of all contributions from memory traces Strengths – A simple economical explanation Weaknesses – It would be quite inefficient to build an inventory of templates to classify all the different varieties (too many templates!) What entails a match is not well defined at all. 2)Feature detection theory -We decompose objects in features and we identify them in such a way. -Feature– A very simple element that can appear in a combination with other visual elements across a variety of patterns -So it is the ultimate combination that allows recognition Selfridge’s Pandomenium model 1)Bottom level contains data demons, or images in which pattern of feature is represented 2)Next level contains cognitive demonsready to detect a particular pattern, if detected the demon shouts 3)Top level contains the decision demons, which selects the cognitive demon that is best represented from the second level a.Determine who shouts the loudest ** The Greatest similarity = The louder a cognitive demon will shout Importance of features -Similar to the primary visual cortexwhich has special cells and areas for processing simple visual features Implication of Pandemonium-Parallel processing oPerform many computation at once rather than in a serial manneroFeatures and patterns are being detected in parallel oExplains why we can recognize object quickly and efficiently oEach group of demons are looking for a particular aspect -Perception is a problem to solveoThe solution relies on a group – the cognitive demons oThis is adaptive The match does not have to be an exact match, rather one demon just has to be the loudest
Problems -Feature detection involves some sort of list of defining features…-