1. DEAD ZONE OF VISUAL ATTENTION REVEALED BY CHANGE BLINDNESS Igor S. Utochkin Higher School of Economics, Moscow, Russia isutochkin@inbox.ru

3. Two patterns of attentional allocation around a focus Focus Periphery Gradient pattern (Castiello & Umiltà, 1990; Downing, 1988; Downing & Pinker, 1985; Eriksen & Hoffman, 1972; Eriksen & St. James, 1986; LaBerge, 1983; Mack & Rock, 1998, etc.) Focus Periphery Inhibitory-surrounds pattern (Bahcall & Kowler, 1999; Cave & Zimmerman, 1997; Caputo & Guerra, 1998; Cutzu & Tsotsos, 2003; Mounts, 2000a, b; Müller et al., 2005; Thakral & Slotnick, 2010, etc.)

4. What does determine pattern of allocation? Task difficulty (Thakral & Slotnick, 2010); Attentional saliency of a centrally attended item (Müller, Mollenhauer, Rösler & Kleinschmidt, 2005); Attentional set towards central and peripheral items (focused vs. divided attention) (Müller et al., 2005)

5. Limitation of previous results Gaze fixation; Simplistic arrays of discrete objects; Brief trials; Attentional salience is controlled through external attentional capture What about natural perception? Active looking; Complex continual layouts of various objects; Prolonged observation; Internal control of attentional salience through interests is available Change blindness paradigm Spatial allocation of attention appears necessary to perceive changes (Kahneman et al., 1992; Rensink, 2000; Rensink et al., 1997; Tse, 2004); Direct manipulations with interests are available (Rensink et al., 1997; Jones et al., 2003; Werner & Thies, 2000)

6. Experiment 1 Standard change detection task under flicker conditions: find a single changing detail in a picture as soon as possible and identify it (miss responses are allowed)

7. Stimulation 12 natural scenes with one attractive object or its part Central interests (CI) Marginal interests (MI)

8. Three change instances per a picture CENTRAL CHANGE

9. NEAR CHANGE Three change instances per a picture

10. CENTRAL CHANGE NEAR CHANGEFAR CHANGE Three change instances per a picture

11. Design Independent Variable: Change location (Central vs. Near vs. Far) Dependent Variables: Search time; Miss rate; Misidentification rate (successful detection but incorrect recognition)

12. Results Miss rate Misidentification rate A ‘dead zone’ surrounds center of interest

13. Is attention to CI what actually causes dead zone pattern? CIMI If this is the case…

14. Experiment 2 Looking for a marginal change (near or far) in the presence of a once noticed central change

15. Results A ‘dead zone of attention’ surrounds center of interest

16. Experiment 3 Both marginal changes (near AND far) compete for prior detection

17. Results

18. Thank you for your Attention! For more information about this study see: Utochkin, I.S. (in press). Hide-and-seek around center of interest: Dead zone of attention revealed by change blindness. Visual Cognition.