Chapter 3 Agile Software Development Slide 1 Chapter 3 Agile Software Development.
Chapter 3 - Slide 1
Transcript of Chapter 3 - Slide 1
Cognition Ch. 3
Sensation, Perception and Attention
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Modeling the Perceptual System
Our brains must convert physical energy to internal codingThis broad processes involves subprocesses:
The ability to perceive and store informationThe ability to translate that information into codeThe ability to derive meaning and utility from that codeThe ability to reproduce the original information
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Sensation to Perception
Sensation involves the detection of physical energyPerception involves higher-order cognition that “organizes” this energy
Be careful not to draw too solid a boundary between the two…
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Vision - Structure
Retinal stimulation creates a chain reactionRods and cones, ganglion cellsLateral geniculate nucleus (LGN)Visual cortex
The image is “disassembled” into its component parts (features)Reconstructed with interpretations installed
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The Marriage of Sensation and Perception
Illusions are good examples of this dynamicExamples
Muller-LyerFigure-groundPerceptual setsSignal detection
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From “Out There” to “In Here”
Perceptual span – how much we can experience at a brief exposure
Utilizes a sensory store to hold this information, but only brieflyEarly studies 4-5 letters was capacity, based on brief presentation followed by oral reportsEarly studies built foundation for “box” models of cognition
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Iconic Storage
Sperling what if some data is lost from the iconic store while the participant is reporting other data?
50 ms presentation of letter lists (3x3 matrix)Immediately following – one of three tones linked to rowsThe letters were recalled at close to 100% accuracyCaveat tone delay reduced recall
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Memory for Sounds
Moray et al (1965)Four speakers presenting messages simultaneouslyLetter strings presented through 2-4 channelsLights were used as cues for recall
Darwin et al (1972)Auditory analog to the Sperling studiesLeft ear, right ear, both ears – visual cue (stimulus position on screen)
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Attention
The concentration of mental effort on sensory or mental eventsFive major aspects
Processing capacity/selective attentionLevels of arousalAttention controlConsciousnessCognitive neuroscience
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Capacity and Selective Attention
Capacity – ability of the cognitive architecture to handle incoming dataAttention – concentration of cognitive energy on specific aspects of the environment
Attention is selective some stimuli are chosen, others are ignoredThe “bottleneck” metaphor
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Experimental Evidence
Cherry (1953, 1966) – shadowing techniqueMoray (1959) – cocktail party effectsLessons about selection
We prefer single streams of dataSome unattended information may “leak” throughRepeating information as presented may not translate into encoding that information
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Modeling Selective Attention
Broadbent (1958) – filter theory (Fig 3.10) -- capacity restricted by cognitive architecture
Data enters a short term storeA selective filter attends to the data based on its featuresData moves through channel to begin a closed-loop control function
Moderated by past probabilities
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Modeling Selective Attention
Treisman (1964) – attenuation model – attention is a function of activation thresholds
All data is sent to the attentional channelFiltered not by characteristics but by perceived importanceFilter reduces S/N ratio to produce the conscious realization of inattention
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Visual Attention
Serial v. parallel visual search (Treisman, 1988)Initial preattentive process that detects basic features of the environmentLate v. early filter theoriesLate filter or rapid trace decay?
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Automatic Processing
With practice, behaviors require less effortful attention to be producedConsiderable practice is required – some say 10 years or moreThree characteristics
Occurs without intention“Concealed” from consciousnessConsumes few cognitive resources