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eye movements has shifted from tasks that correlate with either stimulus-driven or goal-driven

eye movements has shifted from tasks that correlate with either stimulus-driven or goal-driven stimulus-driven and goal-driven saccades varies depending on the duration of the saccade latency. Theeuwes , 2010 A schematic drawing of the classic two-stage model of visual selection. .

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eye movements has shifted from tasks that correlate with either stimulus-driven or goal-driven

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  1. eye movements has shifted from tasks that correlate with either stimulus-driven or goal-driven • stimulus-driven and goal-driven saccades varies depending on the duration of the saccade latency.

  2. Theeuwes, 2010 • A schematic drawing of the classic two-stage model of visual selection.

  3. Van Zoest & Donk, 2008

  4. Van Zoest & Donk, 2008EXP1 • make a speeded eye movement toward the most salient

  5. Van Zoest & Donk, 2008EXP2

  6. This decrease appears to be a general phenomenon,the question rises whether it is the result of time-related aspects of processing visual information.

  7. About speed… • low-spatial-frequency (LSF) stimuli > high-spatial-frequency (HSF) stimuli • higher-contrast stimuli > lower-contrast stimuli

  8. Schyns and Oliva (1994)

  9. Schyns and Oliva (1994) • short presentation durations • LSF • coarse-to-finescene recognition

  10. Information that will be processed at different speeds in the same location in the visual field.

  11. EXP1 • whether temporal aspects of encoding visual information govern saccadic target selection. • If saccadic selection is indeed limited by the temporal aspects of processing, a bias toward the deviation in the LSF grid should appear following short saccade latencies.

  12. This suggests that the attraction toward the most-salient element was a side effect of this element being processed faster than a less-salient element. • Rather than a competition between elements for attention, some elements were processed and others had not yet been processed at the time the saccadic decision was made.

  13. EXP 2 • High-contrast stimuli are processed faster than low-contrast stimuli ( Albrecht, 1995 ; Carandini, Heeger, & Movshon, 1997 ) • To exclude effects of contrast, we equalized the root-mean-square contrast of both the LSF rectangles and the HSF rectangles

  14. (a) the LSF-contrast condition (b) the HSF-contrast condition.

  15. in the LSF-contrast condition, the bias toward the LSF target did not disappear completely following long saccade latencies. • the decision to initiate an eye movement toward the LSF target was made before the presence of the HSF target was detected.

  16. The experiments reported in this article provide converging evidence that not all targets have been detected at the moment of the saccadic decision. • Saliency is not an entity as such but a time-dependent phenomenon.

  17. A top-down decision is always made, but it depends on the state of bottom-up processing; • ongoing bottom-up processes continually reveal more information, and this allows for a more-informed saccadic decision.

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