WP 3: “Dynamic Sampling”

1. WP 3: “Dynamic Sampling” (a.k.a. “Rhythmic attention”) Rufin VanRullen CerCo, CNRS, Universite Paul Sabatier (Toulouse, France) Participants: VanRullen (30 person-months) Hamker (8 p.m.) Cavanagh (4 p.m.) Burgess (2 p.m.)

2. Background: rhythmic attention • Covert attention samples the world rhythmically, just like overt attention does (i.e. eye movements) • The “blinking spotlight” of attention at ~7Hz (VanRullen, Carlson & Cavanagh, 2007) • Pre-stimulus phase at ~7Hz predicts attentional sampling (Busch & VanRullen, 2010) R. VanRullen - WP3 - Dynamic Sampling

3. p<0.05 corrected > Pre-stimulus EEG phase predicts attentional sampling p<.01 • sustained attention samples information periodically at ~7Hz (Busch & VanRullen, PNAS 2010) R. VanRullen - WP3 - Dynamic Sampling

4. Background: rhythmic attention • Covert attention samples the world rhythmically, just like overt attention does (i.e. eye movements) • The “blinking spotlight” of attention at ~7Hz (VanRullen, Carlson & Cavanagh, 2007) • Pre-stimulus phase at ~7Hz predicts attentional sampling (Busch & VanRullen, 2010) • Detection performance oscillates at ~7Hz after an attentional cue (Landau & Fries, 2012) R. VanRullen - WP3 - Dynamic Sampling

5. Detection performance oscillates at ~7Hz after an attentional cue (Landau & Fries, Current Biol 2012) R. VanRullen - WP3 - Dynamic Sampling

6. Background: rhythmic attention • Covert attention samples the world rhythmically, just like overt attention does (i.e. eye movements) • The “blinking spotlight” of attention at ~7Hz (VanRullen, Carlson & Cavanagh, 2007) • Pre-stimulus phase at ~7Hz predicts attentional sampling (Busch & VanRullen, 2010) • Detection performance oscillates at ~7Hz after an attentional cue (Landau & Fries, 2012) • The optimal frequency of the wagon wheel illusion decreases with the number of attended wheels (Macdonald, Cavanagh & VanRullen, 2013) R. VanRullen - WP3 - Dynamic Sampling

7. Attention dynamics in the Wagon Wheel illusion • peak illusion frequency decreases with set size • attention samples the wheel sequentially? (Macdonald, Cavanagh & VanRullen, AP&P 2013) R. VanRullen - WP3 - Dynamic Sampling

8. Background: rhythmic attention • Covert attention samples the world rhythmically, just like overt attention does (i.e. eye movements) • The “blinking spotlight” of attention at ~7Hz (VanRullen, Carlson & Cavanagh, 2007) • Pre-stimulus phase at ~7Hz predicts attentional sampling (Busch & VanRullen, 2010) • Detection performance oscillates at ~7Hz after an attentional cue (Landau & Fries, 2012) • The optimal frequency of the wagon wheel illusion decreases with the number of attended wheels (Macdonald, Cavanagh & VanRullen, 2013) • When multiple targets are competing, attention rapidly converges to a single location (Dubois, Hamker & VanRullen, 2009) • Attention rhythmicity consistent with classic models: • “saliency map” (e.g. Itti & Koch, 2000): iterative “winner-take-all” selection of a candidate target followed by inhibition of return • “reentry model” of spatial attention (Hamker, 2003, 2004, 2005) R. VanRullen - WP3 - Dynamic Sampling

9. WP3: Overview • Background: Attention samples the world rhythmically (e.g. serial scanning) • Remapping of attention pointers must take into account this dynamic representation: rhythmic remapping? • Experiments (EEG + eyetracking in humans): • 3.1. Is remapping periodic? (are there remapping “cycles”, correlated with brain rhythms?) • 3.2. Is remapping sequential? (is a distinct object remapped at each cycle?) • Modelling: how do brain rhythms represent attention pointers? 3.3. Multiplexing of low/high frequency oscillations: • A: rapid cycling (e.g. Jensen et al, 2012) • B: slow switching (e.g. Fries, 2009) • 3.4. Integration into large-scale “SpaceCog” model R. VanRullen - WP3 - Dynamic Sampling

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