Visual Attention

1. Visual Attention in experimental psychology and cognitive neuroscience Dr Lucy Cragg – Research Fellow, School of Psychology

2. what is psychology? • “psyche” soul, mind and “-logia”study • Aim of psychology as a scientific discipline: understanding human mental processes and behaviour

3. levels of explanation COGNITIVE NEUROSCIENCE understanding mental processes: thinking, perceiving, imagining, memorizing, speaking, acting, planning understanding how brain processes underlie mental processes

4. cognition understanding mental processes: thinking, perceiving, imagining, memorizing, speaking, acting, planning • How to do that? • Introspection (thinking about thinking) is subjective • Use experiments • These are the hallmark of research psychology

5. the brain understanding how brain processes underlie mental processes patients with brain damage recording from brain cells (neurons) Neuroimaging Positron emission tomography (PET) and magnetic resonance imaging (MRI) electroencephalography (EEG)

6. visual attention • What is it? • Behaviour– how do we measure it? • Cognition – how does it work? • Brain – how is it implemented? • The limits of attention

7. what is it? • Sustained attention • Selective attention • “Attention enables one to use information-processing systems with limited capacity to handle vast amounts of information available from the sense organs and memory stores” Colman (2001) Dictionary of Psychology • “Attention is the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things.” Wikipedia • We’re going to concentrate on attention to spatial locations

8. automatic exogenous bottom-up

9. voluntary endogenous top-down

10. CAN WE PAY ATTENTION TO SOMETHING WITHOUT MOVING OUR EYES? OVERT ATTENTION with eye movements COVERT ATTENTION without eye movements

11. behaviour behaviour • How do we measure attention in psychological experiments?

12. how do we measure it? • Spatial cuing paradigm • Developed by Michael Posner in the 1980s • Visual search paradigm • Used by Anne Treisman and colleagues in the 1980s

13. how do we measure it? • Spatial cuing paradigm • Studies the affect of attention on information processing – seeing and responding to something • Psychology experiments try to keep things as simple as possible. Why? • Pretty much all (visual) psychology experiments: • Show you astimulus e.g. a picture • Ask you to make a response • Have an experimental and a control condition • In this experiment people are asked to keep their eyes focussed in the middle of the screen at all times

16. Automatic attention version

17. cue

19. target This was a valid cue because the target appeared on the side that was attended

20. cue in control condition

21. voluntary attention version

22. cue

24. target This was an invalid cue because the target appeared on the side that wasn’t attended

26. cue in control condition

27. spatial cuing paradigm • Voluntary orienting • Performance is faster on valid cues when attention is already at the target location • Performance is slower on invalid cues when attention is not directed to the target location • Automatic orienting • Performance is faster on valid cues when attention is already at the target location • BUT ONLY WHEN THE TARGET APPEARS LESS THAN 300ms AFTER THE CUE

28. inhibition of return • Over time (milliseconds) the automatic capturing of attention subsides and the likelihood that attention will be attracted back to that location is reduced. • Why does this happen? • If it didn’t, we would continually be distracted by unimportant things happening in the world around us.

29. conclusions • ATTENTION ENHANCES INFORMATION PROCESSING • But does it make us see things quicker or respond faster? • We’ll come back to this question later…..

30. how do we measure it? • Spatial cuing paradigm • Developed by Michael Posner in the 1980s • Visual search paradigm • Used by Anne Treisman and colleagues in the 1980s

31. visual search experiment • We’re going to do our own visual search experiment • Get into pairs and label yourself A and B • You will need... • The stopwatch on your mobile phone • Paper and pen

32. visual search instructions • Person A • You will be shown a target • You will then be shown a screen of items • You need to tell person B if the target is present or absent as quickly as possible • Person B • Write down the numbers 1-6 down the side of a piece of paper • Start the stopwatch when the screen of items appears • Stop the stopwatch when person A answers • Write down their time next to the number of the display • Put your hand up • We’ll then repeat this swapping roles

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47. visual search instructions • Person A • Write down the numbers 7-12 down the side of a piece of paper • Start the stopwatch when the screen of items appears • Stop the stopwatch when person B answers • Write down their time next to the number of the display • Put your hand up • Person B • You will be shown a target • You will then be shown a screen of items • You need to tell person A if the target is present or absent as quickly as possible

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