1. Attention as Gain Control Harriet Brown

2. James (1890) “It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought.”

3. James (1890) “It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought.” 1.Voluntary 2.Enhances processing 3.Selective

4. 1.Voluntary and involuntary 2.Enhances processing 3.Selective 4.Flexible 5.Neurobiologically plausible 6.Clear evolutionary motivation

5. Friston (2010) “Attention is the optimisation of estimates of precision during hierarchical inference of the causes of sensory data.”

6. Low precisionHigh precision The quick brown fox jumped over the lazy dog.

7. Backward predictions Forward prediction error precision-weighted prediction error

8. Attend RF, no drug Attend away, no drug Attend RF, scopolamine Attend away, scopolamine No drug Scopolamine Herrero et al. (2008)

9. Jensen, Kaiser & Lachaux (2007) Bauer et al. (2006)

10. Summary Attention is the optimisation of estimates of precision during hierarchical inference of the causes of sensory data (Mathematical) precision is (neurobiological) superficial pyramidal cell gain SPC gain can be altered through long-range neurotransmitters or gamma- synchrony Second-order predictions from higher hierarchical levels transmit top-down attentional effects

11. Posner Paradigm Valid Cue Invalid Cue Cue Target

12. 250 300 350 400 Reaction time (ms) validinvalidneutral

13. vCvC vRvR vLvL +++ === yLyL yRyR yCyC constant xLxL xRxR

15. 50100150200250300 0 hidden causes time (ms) 50100150200250300 0 hidden states time (ms)

16. 50100150200250300 0 hidden causes time (ms)

17. Simulated results

18. Visual Salience ChangeEmotional Valence Task- relevance Attention High-level representation

19. Peristimulus time (ms) Spike rate (Hz) Attend effective Ignore effective Luck et al, (1997) 50100150200250300 0 time (ms) target responses with valid and invalid cues

20. Itti & Baldi, 2009Friston et al., 2012

21. Time Response Time Response Attended Unattended Attended Unattended

22. Cue Target

23. 1.Voluntary and involuntary 2.Enhances processing 3.Selective 4.Adaptable 5.Neurobiologically plausible 6.Clearly motivated

24. Thanks for listening!