Visual search

Is there structure in the complicated eye-movements ?
This set of studies explores subtle patterns in complex eye-movements to reveal insights into how the human visual system samples information from the environment. All of the tasks involve challenging search for a particular 'target' item defined by a conjunction of two or more features. Below I show some examples of targets (left), sample displays with target & distractors (center three columns), a brief description of the manipulations (e.g., # search items, blurring), and what these will teach us about underlying visual process driving search (right). The illustrations and descriptions will be elaborated as the research progresses. An additional manipulation (not illustrated here) will assess the role of implicit memory in visual search.

The displays shown below are intended to give a sense of the gaze contingent manipulations & various tests that I have been setting up. Gaze contingent and time series icons are linked to enlarged images where it is easier to see differences in central vs. peripheral blurring. This is especially true when viewing the videos of different conditions where you can get an idea of how the display changes depending on where you scan. Here is some additional background information to learn more about the motivation and theory behind these tasks and what I hope to learn from this set of experiments.
Search task
manipulation of..
permits assessment of..
.

# of search items

 

search

efficiency

 

Find:

'M'

 

 

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.
gaze contingent blurring & scaling
role of attention.

 

Find:

'M'

 

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properties of
central vs. peripheral vision

(e.g., blurring & scaling)

 

Find:

 

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 ClearFovea
Key analysis
 
eye movement time series
 


Are there any patterns in the eye-movement time series?

 

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complex search patterns

Are they fractal?

D.J. Aks
updated 7/31/06

|D.J. Aks | Eye-tracking research | System noise | Time series & fractal analysis | Visual search | Attention | Satellite Imagery | Tumor detection | Web eval & info search | Illusions