slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Attention and spatial resolution PowerPoint Presentation
Download Presentation
Attention and spatial resolution

Loading in 2 Seconds...

play fullscreen
1 / 13

Attention and spatial resolution - PowerPoint PPT Presentation


  • 116 Views
  • Uploaded on

Attention and spatial resolution. Landolt squares. Vernier. Broken lines. : p<0.05 ; : p<0.1. *. Performance. Eccentricity (in deg). Spatial resolution. Our ability to resolve small details ( spatial resolution ) is maximal at fovea and declines as we move away from fixation.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Attention and spatial resolution


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Attention and spatial resolution

    2. Landolt squares . Vernier Broken lines : p<0.05 ; : p<0.1 * Performance Eccentricity (in deg) Spatial resolution • Our ability to resolve small details (spatial resolution) is maximal at fovea and declines as we move away from fixation Antis, 1974 • Most everyday life tasks benefit from heightened resolution Acuity tasks: 2 Yeshurun & Carrasco, 1998

    3. Attention and spatial resolution • Attention improves performance in tasks limited by the visual system‘s spatial resolution, which decreases with eccentricity: • Visual search • Acuity tasks • Texture segmentation

    4. Visual search • Performance decreases with target eccentricity • Attention reduces this performance decrement, consistent with enhanced spatial resolution Carrasco & Yeshurun, 1998

    5. Acuity task • Attention improves performance in Landolt-square (acuity) and Vernier (hyperacuity) tasks • Effect increases with eccentricity Yeshurun & Carrasco, 1999

    6. Acuity task attention decreases gap threshold at cued location and increase it at uncued location Montagna, Pestilli, & Carrasco, 2009

    7. . : p<0.05 ; : p<0.1 * Spatial resolution • However, heightened resolution is not always optimal

    8. Performance periphery fovea Eccentricity Texture segmentation task + performance peak

    9. + Performance performance peak periphery fovea Eccentricity Texture segmentation task resolution too low resolution too high e.g., Gurnsey et al. 1996; Joffe & Scialfa 1995; Kehrer 1989, 1997; Morikawa 2000; Potechin & Gurnsey 2003 Performance due to the mismatch between texture scale and average size of spatial filters as a function of eccentricity. Central performance drop (CPD):due to spatial resolution being too high at central locations. Average spatial filter size

    10. valid SMALL TEXTURE SCALE (viewing distance: 57 cm) LARGE TEXTURE SCALE (viewing distance: 28 cm) neutral Attention & Texture segmentation • Exogenous attention automatically enhances resolution, even when it impairs performance • e.g., Yeshurun & Carrasco 1998; 2000; Talgar & Carrasco, 2002 10

    11. valid neutral Attention & Texture segmentation • Exogenous attention enhances resolution by increasing the sensitivity of high spatial frequency selective filters: • adapting to high (but not to low spatial frequencies) eliminates the CPD and the central attentional impairment • Carrasco, Loula & Ho, 2006 Low Spatial Frequencies High Spatial Frequencies Baseline

    12. valid valid small texture scale (viewing distance: 100 cm) large texture scale (viewing distance: 50 cm) neutral neutral Attention & Texture segmentation • Endogenous attention benefits performance at all eccentricities, suggesting a more flexible mechanism • Yeshurun, Montagna & Carrasco 2008 12

    13. valid + + neutral _ _ EXOGENOUS ENDOGENOUS Performance at central locations impairs improves Performance at peripheral locations improves improves either increased or decreased? increased Spatial resolution small filters sensitivity FLEXIBILITY? AUTOMATICITY Spatial resolution: increase + Performance decrease? _ Eccentricity Eccentricity Yeshurun, Montagna & Carrasco (2008) Carrasco, Loula & Ho (2006) Yeshurun & Carrasco (1998; 2000)