Conscious and Unconscious Processes in Attention

1. Conscious and Unconscious Processes in Attention Vaughan Bell vaughan@backspace.org

2. Outline • Attention and Consciousness • Cognitive models of attention • Bottleneck Models • Capacity / Resource Models • Neuropsychological models of attention • Spatial Attention and Neglect • Attention to Action and the Dysexecutive Syndrome

3. Attention and Consciousness • “Paying attention to something” typically refers to one of two things: • Being selective about what we concentrate on • The notion that we can attend to a limited amount of things at once. • This suggests we can make things more or less conscious by focusing on them, or ignoring them. • It could be described as focusing our information processing resources on certain stimuli or actions.

4. Attention and Consciousness • It is now becoming clear that we also need to know about how and how much of the ‘ignored’ information we process. • Data informing our theories of attention have come from two main areas: • Cognitive models of attention from studies on healthy participants • Neuropsychological models of attention from studies on brain injured patients

5. Bottleneck Models • Selective attention tasks have been crucial in driving the development of bottleneck models. • It involves the focusing on one task to the exclusion of irrelevant stimuli.

6. SeeMaryifhadyoua can littlepick lambthisitstext fleeceoutwasfromwhitetheasothersnow words

7. [ Cocktail party effect demo ]

8. Cocktail Party Effect • Allows us to pick out a single conversation among a number of others. • Cherry (1953) simulated this by playing two streams of speech, one to each ear. • Participants were asked to repeat the speech in one ear, and then were asked about the other. • He showed that people might know whether the other voice was male or female. • But might not know what was said, or what language the speaker was talking in.

9. Broadbent’s Filter Model • Donald Broadbent (1958) proposed a filter model of attention to account for these findings. • He argued that we filter out sensory information before it reaches short term memory. • And that this filtering is based on the physical characteristics of the stimuli. • Rather than any semantic content.

10. Broadbent’s Filter Model • In this model, meaning is only processed when we become conscious of the stimuli. • i.e. after is has got through the filter.

11. Criticisms • e.g. Von Wright et al (1975) paired certain words with electric shocks. • Because of conditioning, the words caused a fear response on their own, measurable by GSR. • Using Cherry’s technique, Von Wright found conditioned words in the ignored ear still produced GSR response, even without awareness. • Showing that some meaning must be processed before awareness, and that Broadbent’s model cannot be entirely correct.

12. Treisman’s Attenuator Model • e.g. Treisman’s (1964) alternative argued that instead of a strict filter, processing was attenuated (reduced) for the unattended stimuli. • Therefore, some processing of meaning could take place, albeit in a much reduced fashion. • Accounting for why conditioned words could still cause a fear response when ‘ignored’. • But full sentences could not be understood.

13. Treisman’s Attenuator Model • In this model, some analysis of meaning can take place, although it is attenuated. • Even if we are not aware of it in full.

14. Late Selection Models • The last two are known as ‘early selection models’ because information is selected before it reaches awareness and short term memory. • Deutsch and Deutsch (1963) have argued for a ‘late selection model’. • This is where all information reaches short term memory, but the selection happens at that point. • Supported by experiments that have shown quite sophisticated semantic analysis can happen with unattended stimuli.

15. Capacity or Resource Models • These argue that we only have so many attentional resources that we can use at once. • When we have ‘run out’ we start missing stimuli or making errors on tasks. • Studies have examined the process of carrying out two (or more) tasks at once. • This is known as divided attention and these tasks have been important in driving capacity theories.

16. Capacity or Resource Models • They may seem similar to bottleneck models but have a crucial difference. • Bottleneck models argue for serial processing in streams. • Switching tasks involves focusing a single serial stream to another task. • Capacity models argue that we can process several tasks in parallel, but each more slowly because of the additional information to deal with.

17. Application: Psychopathy • Psychopathy is a forensic diagnosis given to people who: • Commit persistently anti-social acts • Without feelings or remorse, empathy, guilt or responsibility • Despite having normal IQ, good reasoning abilities and low levels of neurosis and anxiety. • Studies suggest that some psychopaths have trouble with selective attention.

18. Application: Psychopathy • Perhaps with over-focused attention: • “I always know damn well I shouldn't do these things … it's just that when the time comes I don't think of anything else. I don't think of anything but what I want now” • Hiatt et al (2004) used various versions of the Stroop Task to test selective attention. • The Stroop Task involves ignoring an automatically processed stimulus to name a conflicting attribute.

19. Stroop Task I XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX

20. Stroop Task II Red Green Blue Yellow Green Red Green Blue Yellow Green Red Blue Yellow

21. Hiatt et al (2004) • People tend to be significantly slower with the second version because of the conflict. • They found that psychopathic offenders showed a normal effect for the standard Stroop task. • But showed much less of an effect than controls (i.e. were quicker) when the components were spatially separated. e.g: RED

22. Hiatt et al (2004) • In other words, they may have differences in attentional filtering or attenuating, particularly involving context. • e.g: anti-social acts may seem like the most direct solution to a particular problem • And other contextual concerns (e.g. pain caused to the victim or consequences) may be less consciously available as a result.

23. Neuropsychological Models • Largely derived from studies of people with brain injury who no longer seem to be able to do certain attentional tasks. • Such as orienting, focusing, multi-tasking and so on.

24. Neglect • Hemi-spatial neglect is one such disorder which particularly occurs after right parietal damage. • [ Sacks excerpt, p73 ]

25. Copied Drawings

26. Copied Drawings

27. Copied Drawings

28. Spatial Attention • This suggests we have attention for particular parts of space. • If the part of the brain is damaged which represents this, we can lose the ability to represent it both perceptually and conceptually. • It can be thought of as being consciously inaccessible.

29. Posner Cueing Paradigm • Posner (1980) has argued that we can demonstrate the orienting of spatial attention independent of eye movements. • In other words, a demonstration of covert attention. • [Posner demo]

30. Posner Cueing Paradigm • Falsely cued trials (where the box appears on the other side from the X) produce longer responses. • Even though we have been told to ignore the box. • This suggests are attention is being unconsciously drawn to a part of space… • …and we have to disengage to respond appropriately.

31. Covert Attention • This covert or unconscious attention to a part of space may be damaged in neglect. • Making patients with neglect unaware that they cannot represent parts of space.

32. Attention to Action • As actions become more practised they tend to become more automatic and less conscious. • e.g. driving, typing etc • However, at times we need to be able to exercise precise or conscious control over normally automatic actions. • Among others, Norman and Shallice (1980) have argued for an executive system that manages other cognitive processes and actions.

33. Dysexecutive Syndrome • This is thought to break down quite dramatically after certain sorts of brain injury. e.g: • Utilisation behaviour is where people are unable to inhibit actions triggered by their environment. • e.g. being unable to not drink hot coffee if it’s place in front of them. • Akinetic mutism where people can’t initiate self-willed action, although they can act reactively. • Or general planning and action organisation problems.

34. Norman and Shallice’s Model • Norman and Shallice (1980) model of the executive system attempts to account for both actions becoming automatic… • …and conscious control where necessary. • It is based on two pivotal components: • Contention Scheduling • Supervisory Attentional System

35. Norman and Shallice (1980) • Contention scheduler: • Mediates the effect of environmental triggers. • To select appropriate actions or ‘action scripts’ called schemas. • Uses mutual inhibition.

36. Norman and Shallice (1980) • Supervisory Attentional System: • Intervenes in non-routine situations. • When actions have to be altered, initiated or inhibited during non-routine situations. • Much more of a conscious process.

37. Norman and Shallice (1980) S A S Contention Scheduler Trigger Data Base Sensory Perceptual Information Environment Action

38. Norman and Shallice (1980) • This system provides a theoretical basis for the executive system. • And accounts for dysexecutive behaviour. e.g. • Utilisation behaviour is a failure in the SAS, so irrelevant routine actions are not inhibited. • Akinetic mutism is a failure of the contention scheduler to initiate schemas to triggers.

39. Application: Role in Schizophrenia • Executive dysfunction has been cited as one of the core deficits in schizophrenia (Chan et al. 2004) • And one of the key predictors of outcome in terms of work and the activities of daily living (Velligan et al, 2000).

40. Conclusions • Different theories of attention have been developed from observations of healthy and impaired people. • Although these are largely complementary. • All theories reflect the idea that we have a limited ability to focus our information processing abilities on certain tasks. • And make them more or less conscious.

41. Conclusions • Cognitive theories • Bottleneck models (Broadbent, Treisman, late selection theories) • Capacity theories • Neuropsychological theories • Spatial attention • Executive system