Chapter 3 – Attention in Perception and Display Space Flashcards
- Selective visual orientation
General orientation and scene scanning, supervisory control, noticing, searching, reading, confirming
- Area of interest AOI
physical location where specific task-related info can be found
- Dwell time
maximum scanning rate is roughly three fixations or dwells per second, so the dwell time on an AOI would be one-third a second
- SEEV Model
Combines 4 factors to predict the distribution of attention and periods of neglect
change blindness
situations when changes in environment are not noticed (factors that influence likelihood on 116-117)
- A model of noticing – N-SEEV
computational model that identifies and quantifies the variables that enhance or degrade noticing (determines eccentricity) o Beyond eccentricity, there are three additional factors that influence the eccentricity function on noticeability The expectancy of events The salience of events can be objectively characterized by functions derived from computational vision In combining the two influences above, salience can be tuned to certain perceptual properties based on expectancy
o SEEV
context in which change occurs
o N = noticeability of the “to be noticed event” (TBNE)
within the context of ongoing scan path predictions by SEEV
- In-attentional blindness
can look but fail to see something in our field of view, even if it is large, unusual, dynamic object (gorilla/basketball example)
- Visual Search
search time for finding a particular object is a function of how many total items there are (the target + distractors) and the time to inspect each non-target (equation pg. 122)
Useful field of View
- defined as the visual angle within which a target can be detected if it is present, or a non-target identified if it is not
- Variations in search speed and accuracy (that might make this equation inaccurate)
- Exhaustive search
- Parallel search
- Conjunction search
- Homogenous vs. heterogenous distractors
- If target has additional feature vs. feature absent
Accurate searches tend to be slow, and rapid searches tend to produce errors, usually misses
- The miss errors in search are typically of two classes (p126-127)
- Inattentional blindness (miss rates for fixated targets high as 30-70%)
- Stopping policy of the searcher
Clutter
different factors that influence ability to pick out target in sea of distractors (127)
Guiding attention
- combines change blindness and N-SEEV – how events can capture attention (129)
- Guides design of systems that call attention to critical info
- Performed by some form of automation – what are the costs of being wrong? Benefits of being correct?
Central vs. peripheral cues
- cue reliability (129-130)
- Conclusions on attentional cueing (131)
Parallel processing and divided attention
- Visual processing of multiple element world has two main phases
- Preattentive phase that automatically organizes visual world into objects and groups of objects
- Selective attention to certain objects within the preattentive array for further elaboration
- Because all items of an organized display must be processed together to reveal the organization, preattentive processing is sometimes called global or holistic processing, in contrast to the local processing of a single object within a display
Concepts of global and local processing are closely related to emergent features discussed in previous chapter (133)
Space-based attention
dimension of attention in visual angle of space)
object based attention
- (we allocate attention to objects, not regions of space) (135)
- Example of HUD in aviation in spatial nature of attention
- But impairs ability to detect expected stimuli – placing info closer together leads to interference, a disruption of focused attention
- Example of HUD in aviation in spatial nature of attention
- But impairs ability to detect expected stimuli – placing info closer together leads to interference, a disruption of focused attention
- Testing of object based attention – If display elements are combined into a single stimulus object
- Test where someone has to cay the color of a bunch of words, which are all the names of the colors
- Suggests there is another dimension besides space that can affect both focused and divided attention (whether B belongs to the same object as A)
- Examples of object based attention on 142-143
- Flanker Paradigm
- Response Time (RT) (137)
- Flanker effects can be substantially reduced by cueing observers about target positions
- Role of distance in attentional spotlight can be readily translated to third dimension, depth
- Proximity Compatibility Principle (PCP)
- For divided attention tasks, performance is better when elements on a display are closer together
- For focused attention tasks, only one element should be focused on and the others should be ignored
- Lower spatial proximity is better
- All different types of “proximity” – Space, Color, Connections, Abutment, hetero/homo features (list on 146)
- Auditory attention
- Same issue of either divided attention among limited number of events (operator listening to several communication channels simultaneously) or selectively listening to one specific event, while trying to ignore the others
