Feature Integration Theory

Transcription

1 Feature Integration Theory Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/12/2018: Lecture 03-4 Note: This Powerpoint presentation may contain macros that I wrote to help me create the slides. The macros aren t needed to view the slides. You can disable or delete the macros without any change to the presentation.

2 Outline Treisman s Feature Integration Theory Role of Attention in Binding Features to Objects Automatic and Controlled Processes Briefly discuss Midterm 1 (Monday April 16) If necessary, I will omit this from the lecture; it will still be on the exam Object-Based Attention Contrasted with Feature Integration Theory (of Objects) Psych 355, Miyamoto, Spr 18 2

3 Attention and the Perception of Objects Object-Based Attention: Attention is structured around representations of objects. Feature Integration Theory: Attention helps in the creation of the representations of objects Features are integrated into mental representations of objects. E.g., I look at a jacket. It has many features: + Blue color + Shape features + Shiny (zipper) + etc. I have to combine these features into the percept of this particular jacket. Psych 355,, Miyamoto, Spr '18 3 Feature Integration Theory

4 Feature Integration Theory (FIT): Figure 4.30 Anne Treisman hypothesized that attention plays a critical role in combining features into objects (binding features to objects). Preattentive Stage Automatic; effortless; unaware of process; object's features are detected by the visual system. Focused Attention Stage Feature binding occurs here Attention plays key role; features are associated with (bound to) objects Same as This Slide But Without the Emphasis Red Rectangles Psych 355, Miyamoto, Spr '18 4

5 Feature Integration Theory (FIT): Figure 4.30 Anne Treisman hypothesized that attention plays a critical role in combining features into objects (binding features to objects). Preattentive Stage Automatic; effortless; unaware of process; object's features are detected by the visual system. Focused Attention Stage Feature binding occurs here Attention plays key role; features are associated with (bound to) objects Describe Task in Schmidt & Treisman Experiment Psych 355, Miyamoto, Spr '18 5

6 Treisman & Schmidt Experiment Next you will see 2 numbers and 4 objects. The numbers are next to the objects. 5 1 YOUR TASK Make sure that you notice and remember the numbers. Then try to remember as much as you can about the objects. When the display is gone, write down the numbers, and describe the objects as best you can. Prepare to Respond Slide Psych 355, Miyamoto, Spr '18 6

7 Psych 355, Miyamoto, Spr '18 7 Actual Trial Begins on Click The First Trial is Slow Prepare for the First Trial (a Slow Trial) The stimulus will appear about here. The trial will start when I say go. When I say go (click), a display will appear and then disappear.

8 Example of Treisman Display 8 5 Psych 355, Miyamoto, Spr '18 8

9 Pattern Mask Psych 355, Miyamoto, Spr '18 9

10 Dependent Variables What were the numbers in the display? Write them down. What did the objects in the middle look like? Write down some notes about them. Actual Display: The next display is presented much faster so be ready. Prepare to Respond Slide Psych 355, Miyamoto, Spr '18 10

11 Psych 355, Miyamoto, Spr '18 11 Similar Trial But Display Duration is Much Shorter Prepare for the Second Trial (a faster trial) The stimulus will appear about here. The trial will start when I say go. When I say go (click), a display will appear and then disappear.

12 Treisman Display Psych 355, Miyamoto, Spr '18 12

13 Pattern Mask Psych 355, Miyamoto, Spr '18 13

14 Dependent Variables What were the numbers in the display? Write them down. What did the objects in the middle look like? Write down some notes about them. Actual Display: Did any of you see the correct features but have them associated with the wrong object? This illustrates feature migration and illusory conjunctions (of features). Illusory Conjunctions & Feature Integration Theory Psych 355, Miyamoto, Spr '18 14

15 Illusory Conjunctions and the Binding Problem Features occasionally "migrate" from one object to another. Illusory conjunctions people see the right features but attach them to the wrong objects. Feature Integration Theory (FIT due to Anne Treisman): There is a stage in perceptual processing where features are represented independently from "binding" to objects. Features can still float from one object to another. (Preattentive Stage) It takes attention to bind features together into objects. (Focused Attention Stage) Conclusions re Feature-Integration Theory Psych 355, Miyamoto, Spr '18 15

16 Conclusion re Feature Integration Theory (FIT) Main Hypothesis: Focused attention helps bind features to objects. Comment: Much easier to create illusory conjunctions with abstract objects like or than with familiar objects like or. Comment: Why did I ask subjects to identify the numbers on either side of the display? 5 1 Example of Balint's syndrome: Patient with Balint's syndrome has difficulty focusing on individual objects. Patient with Balint's syndrome is especially prone to seeing illusory conjunctions. Automatic and Controlled Processes Psych 355, Miyamoto, Spr '18 16

17 Automatic versus Controlled Processes Automatic processes are processes that occur without conscious control. Controlled processes are processes that require conscious attention in order to carry them out. Examples: Learning to touch type at a keyboard. Initially requires controlled processing, then become automatized with lots of practice. Stroop effect reading word meaning is an automatic process. book rock bird hair knot blue green red blue green Is Driving a Car an Automatic or Controlled Process? Psych 355, Miyamoto, Spr '18 17

18 Example: Is Driving a Car an Automatic or Controlled Process? Assume that the driver is an experienced driver but not a professional driver, i.e., not a taxi driver or race car driver, but also not a novice. The cognitive processes of an experienced driver are a mixture of automatic and controlled processes. Driving is almost a purely automatic process when the driving is extremely simple, e.g., driving down a straight level highway with no other cars. If the driving is complicated and involves challenging decisions, then the driving requires a good deal of controlled processing as well as automatic processing. With practice, the mental processes in driving become increasingly automated. Dividing Attention Between Automatic Processes or Between Controlled Processes Psych 355,, Miyamoto, Spr '18 18

19 It is easier to share attention between automatic processes than between controlled processes. "Automaticization": The transformation of controlled processes to automatic processes through practice. Example: Mr. X is driving in complex traffic while having a conversation with a passenger in his car. Easier Task Mr. X is a very experienced driver, e.g., a taxi cab driver. Mr. X is speaking in his native language. The topic of conversation is not complicated. Harder Task Mr. X is a relatively inexperienced driver. Mr. X is speaking a non-native language (for him). The topic of conversation is complicated, e.g., solving a math problem. Psych 355,, Miyamoto, Spr '18 19 Examples of Activities that Involve Divided Attention

20 Examples of Activities that Involve Divided Attention Doing several different tasks concurrently. Lecturing on statistics while writing at the blackboard Driving while talking on the cell phone. Doing housework while listening to talk radio. Thinking about your social life while doing a job. Characteristics of Automatic and Controlled Processes Psych 355, Miyamoto, Spr '14 20

21 Characteristics of Automatic and Controlled Processes Characteristics of Automatic Processes: Examples: reading, comprehending spoken language, identifying a friend can be initiated without intention;... operate very rapidly;... operate without conscious control of the process Characteristics of Controlled Processes: Examples: Writing a letter, solving a problem (usually), making a big decision usually initiated intentionally;... often occurs slowly;... require conscious control (usually);... require attention to execute the components of the action or thought process; Schneider & Shiffrin Some tasks cannot be automated Psych 355, Miyamoto, Spr '18 21

22 Some Tasks Can Be Automated; Others Cannot Schneider & Shiffrin (1977): Search for a target letters in displays that contain distractors (non-targets). Consistent mapping condition: Letters that are used as targets are never used as distractors. Varied mapping condition: Letters that are used as targets are also used as distractors on other trials. Psych 355 students: I won't ask you for the details of the Schneider & Shiffrin (1977) study. I might ask: Is it always possible to automate any series of mental operations if one practices enough? Answer: No, Schneider & Shiffrin (1977) showed that this is not always possible. Schneider & Shiffrin - Findings Psych 355, Miyamoto, Spr '18 22

23 Some Tasks Can Be Automated; Others Cannot (cont.) Consistent Mapping Condition: After many thousands of trials (thorough training), accuracy was just as good when searching 4 positions as when searching 1 or 2 positions. Varied Mapping Condition: After many thousands of trials (thorough training), accuracy still got worse and worse as the number of positions to search increased from 1 to 2 to 4. Interpretation: The search became automatic in the consistent mapping condition, but could not be automatized in the varied mapping condition. Psych 355 students: I won't ask you for the details of the Schneider & Shiffrin (1977) study. I might ask: Is it always possible to automate any series of mental operations if one practices enough? Answer: No, Schneider & Shiffrin (1977) showed that this is not always possible. Psych 355, Miyamoto, Spr '18 23 Summary re Automatic & Controlled Processes

24 Summary re Automatic and Controlled Processes Divided attention (task sharing) becomes easier and performance improves as tasks become automatized. Obviously practice promotes automatization. Some tasks cannot be automatized. The automatic/controlled distinction has many important applications Effects of practice on skill learning Psych 355 students: These two points are the only things that I want you to know about the Schneider & Shiffrin (1977) study. Automatic social responses, e.g., prejudiced responses (racial/gender/ethnic) that are masked by more acceptable responses. Automatic inferences in decision making are sometimes very helpful and are sometimes very misleading. Depends on the situation. Info re Midterm 1 - END Psych 355, Miyamoto, Spr '18 24

25 Psych 355, Miyamoto, Spr '18 25 Continue This Slide - END Midterm Exam: Monday April 16 Format: Multiple choice, true/false, short answer Time allowed: whole class period (50 minutes) ** Bring a scantron form and #2 pencil to the exam ** What will be on the test? Textbook, chapters 1-4, lectures, sections, CogLab assignments The main Psych 355 webpage has a link to a document that is titled "What will be covered on Midterm 1?". The url for this document is but it is probably easier to find the link on the Psych 355 webpage.

26 Study materials on the Psych 355 website Download pdf's of the study guides for Chapters 1 4 from the Psych 355 website. See Midterm 1 from Spring First, study the version without an answer key. Later, use the answer key to check your thinking. See quizzes 1 and 2 from Spring The document "What will be covered on Midterm 1?" (see link on preceding slide) contains suggestions regarding the most effective way to study for this exam. Psych 355, Miyamoto, Spr '18 26 END