PSY 323: Cognition

1. PSY 323: Cognition Chapter 4: Attention

2. How important is attention? • 1987 Northwest Airlines jet from Detroit crashed moments after take-off • 154 passengers and crew, 2 on ground, died

3. Attention • Close or careful observation or mental concentration • A selective narrowing or focusing of consciousness

4. Different Aspects of Attention • Selective Attention • Visual • Auditory • Divided Attention • Automatic Processing

5. Selective Attention • Focusing our awareness on only part of everything we are experiencing • Trying to attend to one task over another

6. Selective Attention: Visual • The Stroop Test (1935) • Names of words cause a competing response • Flanker compatibility task • Task–irrelevant stimuli are extremely powerful

9. Dalrymple-Alford & Budayr (1966): • First to encourage presentation & timing of stimuli individually. This method now dominates. Stroop effect GREY BLUE

10. interference facilitation GREY BLUE

11. Selective Attention • Neisser et al. (1979) • In this one minute video, there will be two basketball teams • You task is to count the passes of just one team

12. Selective Attention Simons & Chabris (1999)

13. Attention & Visual Perception Mack & Rock (2000) • Research on a phenomenon known as inattentional blindness suggests that unless we pay close attention, we can miss even the most conspicuous events

14. Sights unseen? • Inattentional Blindness • Participants were asked to focus on a cross • They often failed to notice an unexpected object, even when it had appeared in the center of their field of vision  Mack & Rock (2000)

15. Change Blindness • People fail to detect substantial features of photographs and real world experiences • They seem to lack a precise visual representation of their world from one view to the next Daniel Simons Levin & Simons study (1997)  Levin & Simons study (1998) 

16. Choice Blindness Johansson, Hall, Sikstrom, & Olsson (2005) • Participants failure to detect a mismatch from their original choice to what was later presented to them as their original choice (but was not) Petter Johansson 

17. Selective Attention (Auditory) • Dichotic listening task (Cherry, 1953) • Any task where two streams of auditory information are presented simultaneously, one to each ear (generally over headphones). Subjects are required to attend to one ear only. • Shadowing task -- Two messages played, one to each ear. One message has to be "shadowed" by the subject (repeated back out loud). This is called the “attended” message.

18. In Shadowing Task… • Listeners seldom noticed the unattended message being in a foreign language or in reversed speech • However, they nearly always noticed physical changes in the unattended message • Cherry’s conclusion?  • People can shadow accurately but its not easy  • Unattended auditory information receives very little processing

19. Early Selection Model Sensory Memory Filter Detector STM • Broadbent (1958) • Proposed that information passes through these stages • Often referred to as the bottleneck model

20. 0 Limitations to Broadbent’s Model Broadbent’s Model Could Not Explain • Participant’s name gets through • Participants can shadow meaningful messages that switches from one ear to another • Effects of practice on detecting information in unattended ear (e.g., detect digit in unattended ear for naïve and practiced participants) Moray (1959) • The “Cocktail Party Effect” • The phenomenon that occurs when someone is selectively listening to one message among many yet hears their name or some other distinctive message that is not being attended

21. Other Evidence Against Broadbent Gray & Weddeburn (1960) • Response should have been “Dear 7 Jane” Dear Aunt Jane experiment 

22. Attenuation Theory of Attention Treisman (1964) • Proposed that selection occurs in two stages Stage 1 • Replaced Broadbent’s filter with an attenuator • This analyzes incoming message in terms of its physical characteristics, its language, and its meaning • Language and meaning can be used to separate the messages • The analysis of the message proceeds only as far as is necessary to identify the attended message

23. Attenuation Theory of Attention Treisman (1964) Stage 1 • “Leaky filter” – both attended and unattended messages get through the attenuator but only attended message is at full strength • Unattended messages are attenuated (still present but weaker than attended message) • But some of the unattended message gets through

24. Attenuation Theory of Attention Treisman (1964) Stage 2 • The final output is determined when the message is analyzed by a dictionary unit which contains stored words, each of which has a threshold for being activated • Low threshold words can be detected because it is common or especially important See next slide 

25. Attenuation Theory of Attention Treisman (1964)

26. Attenuation: The Dictionary Unit Treisman (1964) • The message gets passed on to the dictionary unit Threshold = Smallest signal strength that can just be detected Easily detected

27. Attenuation explains… Treisman (1964) • Hearing your own name when that stream is supposed to be ignored • Switching channels in order to make a complete sentence

28. 0 Deutsch & Deutsch (1963) Late Selection Model Working Memory Sensory Stores Long Term Memory All stimuli is processed to the level of meaning, relevance determines further processing and action

29. Late Selection Model of Attention Effects of an Unattended Word MacKay (1973) • Attended Ear: • “The boy threw a rock at a bank” • Unattended Ear: • “Scissor...ladder…money…finger • Question: • Where did the boy throw the rock? • Answer: • At a financial bank

30. Late Selection Model of Attention • MacKay (1973) • Attended Ear: “The boy threw a rock at a bank” • Unattended Ear: “ Scissor...ladder…river…finger • Question: Where did the boy throw the rock? • Answer: At the riverbank

31. Perceptual Load Theory • Cognitive Resources • The idea that a person has a certain cognitive capacity which can be used to carry out various tasks • Cognitive Load • The amount of a person’s cognitive resources needed to carry out a particular cognitive task • Low-load task • Easier; cognitive resources are left over • Can process additional information • High-load task • Difficult; requiring most of someone’s cognitive resources • Only selected items are processed

32. Perceptual Load Theory Lavie (2005) • Posits that the amount of cognitive resources that remain as a person is carrying out a primary task determines how well the person can avoid attending to task-irrelevant stimuli

33. Divided Attention • Trying to attend totwo stimuliat once and making multiple responses rather than making one response to multiple stimuli • Can be very difficult

34. “the Mets will win it all next year...” “Better drop this class, Dr. Weiss is the toughest teacher at UIU…” “Dr. Weiss, uh what about the Mets?” Divided Attention

35. Divided Attention • Can we pay attention to more than one thing at a time? • Yes! Think about driving, listening to the radio and planning dinner • What factors affect our ability to divide attention? • Practice • Task Difficulty • Task Type

36. The Effect of Practice Spelke, et. al (1976) • Task: Read short stories and take dictation (write words spoken to them) • At first, performance was awful • After 85 hours of practice, performance was much better

37. Divided Attention Task • Give subjects a “memory set” - up to 4 letters or numbers Schneider & Shiffrin (1977)

38. Consistent Mapping Condition • Then they are presented 20 frames VERY fast • 4 possible positions; any/all filled • Distractors were from the other category • If memory set was numbers, distractors were letters

39. Schneider & Shiffrin (1977): Method • Was an object from the memory set present anywhere in the stream? • When one number/letter was in the memory set, it was never a distractor on the next trial • A distractor on the current trial was never in the memory set on the next trial

40. Schneider & Shiffrin: Results • Beginning: 55% accurate • 900 trials: 90% accurate • 600 trials: Participants reported automatic processing (no need to try hard to do the task) • Occurs without intention • Uses few cognitive resources

41. Automatic performance by 600 trials

42. Automatic processing outside the lab… • Occurs for well-practiced tasks • Examples? • When people starting thinking about things, they make errors • Ever try explaining shoe-tying to a small child?

43. Dual (Automatic) Processing • The ability to search for things rapidly and automatically (effortless) • Does not require attention • Example: Driving a car & listening to the radio

44. Divided Attention & Driving Dingus et al. (2006) • 80% of crashes & 67% of near crashes people were distracted • Cell phones increase the risk of crashes to level similar to BAC of .08

45. Some drawbacks??? • Once automatic, hard to unlearn… • Any examples of when this might be a problem? • Everyday attentional slips • Driving down familiar road when you should be taking the next road • Maybe part of what happened to Northwest Airlines tragedy in 1987 • Can make it difficult to attend when you really need to…

46. Overt Attention • What we are attending to can be seen from our eye movements: • Saccades: rapid shifts of the eyes • Fixations: short pauses on points of interest

47. Spatial Attention Overt attention • Can tell from where you are looking Covert Attention • Can’t tell from where you are looking

48. Eye Tracking • Tracking where the eyes are looking

49. Visualizing Eye Tracking Data • Example: How do people look at a complex schematic?

50. Sequence of fixations of a person making a peanut butter sandwich. The first fixation is on the loaf of bread.