Human cogition. Human Cognition. Optical Illusions. Human cognition. Optical Illusions. Optical Illusions

Transcription

1 Human Cognition Fang Chen Chalmers University of Technology Human cogition Perception and recognition Attention, emotion Learning Reading, speaking, and listening Problem solving, planning, reasoning, decision making Individual difference 1/45 2/45 Human cognition Optical Illusions Why? Understand human cognitive capacity and limitation One importent part in HCI How? own experience? the common sense? Individual difference the Ponzo illusion the Muller Lyer illusion 3/45 Optical Illusions Optical Illusions 1

2 Sensory Store: visual auditory haptic movement Environment Perception Long-Term Information processing Attention and emotion Working memory Recognition Reasoning Problem solving Decision making Response Activation Response Execution Feedback Output On muscles: Muscle and tendon receptors On joints: Changes in joint position Speed of movement Position of the joint Pain sensation The sensors on human body - Sensory modalities On the head Vision Hearing Balance Taste Smell On the skin: Head-cold Pain Touch-Pressure The human brain Optical Illusions 3/5 cortex somatic sensory cortex Light passes through lens Focussed on retina Human Visual System Interpreting the visual signal Visual processing involves the transformation and interpretation of a complete image Expectations affects the way an image is perceived The visual system compensates for: Movement and changes in luminance. Context is used to resolve ambiguity 12/45 2

3 Several stages: visual pattern perceived decoded using internal representation of language interpreted using knowledge of syntax, semantics, pragmatics 13/45 Reading Reading involves saccades and fixations Perception occurs during fixations Word shape and color is important to recognition Negative contrast improves reading from computer screen The ear Physical apparatus: outer ear protects inner and amplifies sound middle ear transmits sound waves as vibrations to inner ear inner ear chemical transmitters are released and cause impulses in auditory nerve Provides information about environment: distances, directions, objects etc. Sound pitch sound frequency loudness amplitude timbre type or quality Hearing Written language is grammatical Speaking has redundant information Writting and speaking 15/45 16/45 The cognitive differences between speech perception and reading text Reading the test Listening to speech Each word can be seen as a whole Spoken word is spread out in time Less ambiguous More ambiguous and unclear signal 3D - audio Interaural time difference, ITD The text can be continuously available There is no so many redundant information behind the word itself Be accessible only in the focus visual area Higher memory demand, the information is transient, a word is heard and then it ends. Contain numerous hints, such as pitch, intonation, stress, timing, to sentence structure and meaning. Can take input from any direction Interaural intensity difference, IID 18/45 3

4 Sound source? Cone of confusion Confusion Provides important feedback about environment. May be key sense for someone who is visually impaired. Stimulus received via receptors in the skin: thermoreceptors heat and cold nociceptors pain mechanoreceptors pressure (some instant, some continuous) Some areas more sensitive than others e.g. fingers. Kinethesis - awareness of body position affects comfort and performance. Touch 19/45 20/45 Movement Time taken to respond to stimulus: reaction time + movement time Movement time dependent on age, fitness etc. Reaction time - dependent on stimulus type: visual ~ 200ms auditory ~ 150 ms pain ~ 700ms Fits law: The time taken to hit a target is a function of the size of the target and the distance that has to be moved There are three types of memory function: Sensory memories Working memory (or short-term memory) Long-term memory 21/45 22/45 Sensory memory Buffers from stimuli received through senses Working memory (short term) small capacity rapid access (~ 70ms) & decay (~200 ms) pass to LTM after a few seconds Long-term memory huge (if not unlimited ) slower access time (~100 ms) w/ little decay , 12, 60, 25, 91, 42, 06,14, 19, 85, 97, 13, 84 cat, house, paper, laugh, people, red, yes, number, shadow, broom, rain, plant, lamp, chocolate, radio, one, coin, jet 23/45 24/45 4

5 The magical number 7 ± , 12, 60, 25, 91, 42, 06,14, 19, 85, 97, 13, 84 Geoger Miller Peopel s immediate memory capacity is very limited Only remember 7 ± 2 chunks (number or words) cat, house, paper, laugh, people, red, yes, number, shadow, broom, rain, plant, lamp, chocolate, radio, one, coin, jet 25/45 26/45 Sensory Image Store Working maintenance rehearsal Stage Theory Long Term Repository for all our knowledge slow access ~ 1/10 second slow decay, if any huge or unlimited capacity Long-term memory (LTM) decay decay, displacement decay? interference? chunking / elaboration Two types episodic serial memory of events semantic structured memory of facts,concepts, skills semantic LTM derived from episodic LTM 28/45 Semantic memory structure provides access to information represents relationships between bits of information supports inference How do you know that animal is a dog, not a cat? 29/45 5

6 LTM - Storage of information LTM - retrieval rehearsal information moves from STM to LTM total time hypothesis amount retained proportional to rehearsal time distribution of practice effect optimized by spreading learning over time structure, meaning and familiarity information easier to remember recall information reproduced from memory can be assisted by cues, e.g. categories, imagery recognition information gives knowledge that it has been seen before less complex than recall - information is cue 31/45 32/45 LTM - Forgetting Thinking decay information is lost gradually but very slowly interference new information replaces old: retroactive interference old may interfere with new: proactive inhibition so may not forget at all memory is selective affected by emotion can subconsciously `choose' to forget Reasoning: inferring new information from what is already known Problem solving: the process of finding a solution to an unfamiliar task, using the knowledge we have 33/45 34/45 Reasoning Deduction: derive logically necessary conclusion from given premises Induction: generalize from cases seen to cases unseen Abduction: reasoning from event to cause 7 E 4 K Wason's cards If a card has a vowel on one side it has an even number on the other Is this true? How many cards do you need to turn over to find out?. and which cards? 35/45 36/45 6

7 Problem solving theories Mental models Gestalt Problem space theory Analogy Skill acquisition inferences about how to carry out tasks. fathom what to do, when something unexpected happens encountering unfamiliar systems. Engineers mental model users mental model. Cognitive models describe and predict users problems solving behaviour with interactive systems. Cognitive models are used to design and improve interactive systems More in Chapter 12 37/45 38/45 Errors Emotion Types of error slips right intention, but failed to do it right causes: poor physical skill,inattention etc. change to aspect of skilled behaviour can cause slip mistakes wrong intention cause: incorrect understanding humans create mental models to explain behaviour. if wrong (different from actual system) errors can occur Various theories cognitive and physical responses to stimuli The biological response - affect Affect influences information process Affect computing 39/45 40/45 How emotions are manifested/measured Attention in perception and display space (1) Physiological response Heart rate Respiration Skin response Blood pressure Questionnaire Facial expression Voice Brain activity Gestures and actions Selective attention Visual sampling Pursuit eye follows a target moving at a constant speed across the visual field Saccadic jumped view Location Supervisory Target search Optimality of selective attention Select the relevant stimuli to attend at the appropriate times Scott Brave and Cliff Nass: Emotion in Human-Computer Interaction 41/45 42/45 7

8 Attention in perception and display space (2) Paralle processing and divided attention Several items within the view field might be processed together Focus attention Goal and information presentation If we know exactly what we want to find out, we try to match this with the information that is available The way information is displayed can also greatly influence how easy or difficult it is to attend to appropriate piece of information 43/45 44/45 Individual differences long term sex, physical and intellectual abilities short term effect of stress or fatigue changing age attention Ask yourself: will design decision exclude section of user population? 45/45 8