Lecture 5: Human Information Processing PDF

The human Information i/o … visual, auditory, haptic, movement Information stored in memory sensory, short-term, long-term Information processed and applied reasoning, problem solving, skill, error Emotion influences human capabilities Each person is different...

The human Information i/o … visual, auditory, haptic, movement Information stored in memory sensory, short-term, long-term Information processed and applied reasoning, problem solving, skill, error Emotion influences human capabilities Each person is different 0  Vision Two stages in vision physical reception of stimulus processing and interpretation of stimulus 0  The Eye - physical reception mechanism for receiving light and transforming it into electrical energy light reflects from objects images are focused upside-down on retina 0  Interpreting the signal Size and depth visual angle indicates how much of view object occupies (relates to size and distance from eye) visual acuity is ability to perceive detail (limited) familiar objects perceived as constant size (in spite of changes in visual angle when far away) 0  Interpreting the signal (cont) Brightness measured by just noticeable difference visual acuity increases with luminance as does flicker Colour made up of hue, intensity, saturation cones sensitive to colour wavelengths 8% males and 1% females colour blind 0  Reading Reading involves saccades and fixations Perception occurs during fixations Word shape is important to recognition Negative contrast improves reading from computer screen Hearing Provides information about environment: distances, directions, objects etc. 0  Hearing (cont) Humans can hear frequencies from 20Hz to 15kHz less accurate distinguishing high frequencies than low. Auditory system filters sounds can attend to sounds over background noise. for example, the cocktail party phenomenon. 0  Touch 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. 0 Memory There are three types of memory function: Sensory memories Attention Short-term memory or working memory Rehearsal Long-term memory Selection of stimuli governed by level of arousal. 0  Emotion Implications for interface design stress will increase the difficulty of problem solving relaxed users will be more forgiving of shortcomings in design aesthetically pleasing and rewarding interfaces will increase positive affect 0  Individual differences long term – sex, physical and intellectual abilities short term – effect of stress or fatigue changing – age Ask yourself: will design decision exclude section of user population? 0  Psychology and the Design of Interactive System Some direct applications e.g. blue acuity is poor blue should not be used for important detail However, correct application generally requires understanding of context in psychology, and an understanding of particular experimental conditions 0