1 / 31

Find:

Find:. What does visual search teach us?. Cognitive processes! Speed & Accuracy Mechanisms Automatic or Attention Search strategy Parallel, Serial, random or… ?. Features. Find the odd item Discriminate by.. Color xxxx x xx Size x x xxxxx Orientation ------l--- Depth

Anita
Download Presentation

Find:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Find:

  2. What does visual search teach us? • Cognitive processes! • Speed & Accuracy • Mechanisms • Automatic or Attention • Search strategy • Parallel, Serial, random or…?

  3. Features... • Find the odd item • Discriminate by.. • Color xxxxxxx • Size xxxxxxx • Orientation ------l--- • Depth • Movement xxxx--> x

  4. Look for the red L L L L L L

  5. L L L L L L L L L

  6. Feature search is easy! • Fast (300ms) • Parallel (0-10ms/item) • No attention needed 500 400 300 0 ms/item 5 10 15 # of items

  7. Conjunction Search • Find...combination of features • 2 orientations (particular arrangement) • Find: L among Ts T T L T T

  8. T T T T T T T T T L T T T

  9. +

  10. T T T T L T T T T T T T T

  11. Conjunction search is hard! • Slower • Sequential • Focused attention needed Conjunction 40 ms/item 700 500 Feature 0 ms/item 300 5 10 15 # of items

  12. Feature search is easy • Fast (300ms) • Parallel (<10ms/item) • Focused attention not needed (i.e.,Can use a distributed form of attention ) • Conjunction search is difficult • Slow (>500ms) • Serial (>10ms/item) • Focused attention needed

  13. What guides search? • Environmental information.

  14. What guides search? • Environmental information. • Internal cognitive process • Attention. • Memory? • Deterministic Process: Self-Organized Criticality (SOC)?

  15. Memory for locations in search (Kristjansso,2000) Identity of objects accumulates over time (Treisman & Gelade, 1980) Random repositioning of stimuli does not affect search RTs (Horowitz & Wolfe, 1998) Inattentional amnesia in search (Wolfe, 1999) Memory in visual search? We are able to keep track of where we look!Inhibition of return (Klein, 1982) • Failure to replicate inhibition of return(Wolfe & Pokorny, 1990)

  16. Non-systematic eye-movements Engle, 1977; Ellis & Stark, 1988; Scinto & Pillalamarri, 1986; Krendel & Wodinsky, 1960; Groner & Groner, 1982

  17. Visual Search Task Find the upright “T” T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T T

  18. Map trajectory of eyes: • Duration & x,y coordinates for each fixation.---------------------------------------------------------- • Differences between fixations • xn – xn+1 &yn – yn+1 • Distance =(x2 + y2)1/2 • Direction = Arctan (y/x).

  19. Posner & Raichel, 1994). Images of mind. New York: Scientific American Series. W/ citation in Palmer, S. (1999). Vision Science: Photons to phenomenology. Boston: MIT.

  20. Bluebird contributed by www.Sierra foothill.org

More Related