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Visuospatial Sketchpad (VSP ) & The Central Executive

Visuospatial Sketchpad (VSP ) & The Central Executive. Psychology 355: Cognitive Psychology Instructor : John Miyamoto 04/28 /2014: Lecture 05-2.

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Visuospatial Sketchpad (VSP ) & The Central Executive

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  1. Visuospatial Sketchpad (VSP)& The Central Executive Psychology 355: Cognitive PsychologyInstructor: John Miyamoto04/28/2014: Lecture 05-2 This Powerpoint presentation may contain macros that were used to create the slides. The macros aren’t needed to view the slides. If necessary, you can disable the macros without any change to the presentation.

  2. Outline • Brooks’ image scanning experiment: Contrasting working memory for sentences and images • Brief introduction to the central executive # Psych 355, Miyamoto, Spr '14

  3. Baddeley-Hitch Working Memory (WM) Model Next • Phonological Loop (PL) • Visuospatial Sketch Pad (VSP) • Short-term storage of visual & spatial information • Manipulation of visual images and spatial information. 3. Central Executive Next What evidence shows that WM has a separate VSP component? Review of Findings for Brandimonte’sMental Subtraction Experiment Psych 355, Miyamoto, Spr '14

  4. Brandimonte’s Mental Subtraction Experiment • The stimuli were designed so that subjects could name the object before "subtracting" the second image. • E.g., with stimulus 1, a subject might think "headphones". • If a subject silently says "headphones" while looking at the left part of stimulus 1, it is harder to see ice cream cones after subtracting the right part of the stimulus. • Saying "la, la, la, la, ...." suppressed the tendency to name the left part of the stimulus, so the subject relies only on the visual image in VSP. This makes the subtraction task easier. Goals of Brooks’ Image Scanning Experiment Psych 355, Miyamoto, Spr '14

  5. Next: Brook’s Image Scanning Experiment Brooks, L. R. (1968). Spatial and verbal components of the act of recall. Canadian Journal of Psychology, 22, 349-368. • Purpose #1: To show that there are 2 different stores: VSP and PL • Purpose #2: To show that ... • Performing two different tasks in VSP interfere with each other. • Performing two different tasks in PL interfere with each other. • Performing one task in VSP and a different task in PL does not cause as much interference Image Scanning Experiment Psych 355, Miyamoto, Spr '14

  6. Image Scanning (Brooks) • Experiment has 4 conditions. • 2 types of stimulus: Diagrams or Sentences • 2 types of responses: Pointing or Vocal Response* • Dependent variable = time to perform a task • Next: Explain the different stimulus types and response modes Response Mode Pointing VocalDiagrams 28.2 11.3Sentences 9.8 13.8 Stimulus Types NextSlide * There was actually a third response type, “tapping”, but it will not be discussed here – it turned out not to be very informative. Explain Diagram Stimulus x Vocal Response Psych 355, Miyamoto, Spr '14

  7. Image Scanning (Brooks, cont.) Condition: Diagrammatic Stimulus & Vocal Response • Memorize the figure. Then it is removed. • Start your scan at the star and (mentally) move clockwise around the figure. • Say "OUT" when you reach an outside corner.. • Say "IN" when you reach an inside corner. • Correct response: out, out, in, in, out, out, in, out, out, out • Dependent variable: Response time (time to complete the task) Explain Diagram Stimulus with Pointing Response Psych 355, Miyamoto, Spr '14

  8. Image Scanning (cont.) • Next: Diagrammatic stimulus combined with pointing response: Response Mode Pointing VocalDiagrams 28.2 11.3Sentences 9.8 13.8 StimulusType PreviousSlide NextSlide Psych 355, Miyamoto, Spr '14

  9. Image Scanning (Brooks, cont.) Condition: Diagrammatic Stimulus & Pointing Response • Memorize the figure. Then it is removed.Same as before • Start your scan at the * and (mentally) move clockwise around the figure. Same as before. • Point to "Out" when you reach an outside corner. • Point to "In" when you reach an inside corner.. • Correct response: (See diagram)out, out, in, in, out, out, in, out, out, out • Dependent variable: Response time (time to complete the task) Stimulus Respond by pointing to letters on this sheet. Transition to Next Condition: Sentence Stimulus & Vocal Response Psych 355, Miyamoto, Spr '14

  10. Image Scanning (cont.) • Explain sentence stimulus combined with vocal response: Response Mode Pointing VocalDiagrams 28.2 11.3Sentences 9.8 13.8 StimulusType PreviousSlide NextSlide Condition: Sentence Stimulus & Vocal Response Psych 355, Miyamoto, Spr '14

  11. Image Scanning (Lee Brooks, cont.) Condition: Sentence Stimulus & Vocal Response • Memorize the sentence. Then it is removed. • Now work from the beginning to the end of the sentence. Say "yes" each time you encounter a noun; say "no" when you encounter a word that is not a noun. • Correct response: • Dependent variable: Response time (time to complete the task) Sentence Stimulus A bird in hand is worth two in the bush. no, no, no, yes, no, no, no, no, yes, yes Transition to Condition with Sentence Stimulus & Pointing Response Psych 355, Miyamoto, Spr '14

  12. Image Scanning (cont.) StimulusType Condition:Sentence Stimulus & Vocal Response Response Mode Pointing VocalDiagrams 28.2 11.3Sentences 9.8 13.8 NextSlide PreviousSlide Psych 355, Miyamoto, Spr '14

  13. Image Scanning (Lee Brooks, cont.) Condition: Sentence Stimulus & Pointing Response • Memorize the sentence. Then it is removed. • Work from the beginning to the end of the sentence. Point to "yes" each time you encounter a noun; say "no" when you encounter a word that is not a noun.. • Correct response: no, yes, no, yes, no, no, no, no, no, yes Sentence Stimulus: A bird in hand is worth two in the bush. Respond by pointing to letters on this sheet. Image Scanning Results Psych 355, Miyamoto, Spr '14

  14. Results: Image Scanning (Lee Brooks) Faster Slower StimulusType Slower Faster Response Mode Pointing Vocal Diagrams 28.2 11.3Sentences 9.8 13.8 Same Slide: Why is Pointing Slower than Vocal For Diagrams & Opposite for Sentences? Psych 355, Miyamoto, Spr '14

  15. Results: Image Scanning (Lee Brooks) Faster Slower StimulusType Slower Faster Response Mode Pointing Vocal Diagrams 28.2 11.3Sentences 9.8 13.8 • Why is diagram/pointing slower than diagram/vocal?Why is sentence/vocal slower than sentence/pointing? Discussion of Results Psych 355, Miyamoto, Spr '14

  16. Why is Diagram/Pointing Slower than Diagram/Vocal? Faster Slower StimulusType Response Mode Pointing Vocal Diagrams 28.2 11.3Sentences 9.8 13.8 • Diagram/Pointing: The stimulus and response compete for a common cognitive resource, representation in VSP. Information processing bottleneck causes slower response. • Diagram/Vocal: Stimulus & response use separate cognitive resources. No bottleneck. Why is sentence/vocal slower than sentence/pointing? Psych 355, Miyamoto, Spr '14

  17. Why is Sentence/Vocal Slower than Sentence/Pointing? StimulusType Slower Faster Response Mode Pointing Vocal Diagrams 28.2 11.3Sentences 9.8 13.8 • Sentence/Vocal: Again, stimulus and response compete for a common cognitive resource, representation in PL. Information processing bottleneck causes slower response. • Sentence/Pointing: Stimulus & response use separate cognitive resources. No bottleneck. xxx Psych 355, Miyamoto, Spr '14

  18. Brooks' experiment supports the existence of a visuospatial sketch pad (VSP) because .... • If there were only one STM store (not separate PL & VSP), then the effect of the pointing response would be the same in the visuospatial task and the verbal task. Similarly for the effect of the verbal response. • WM model assumes multiple memory stores – this lets WM predict conflicts between similar mental codes. • The preceding experiment illustrates a basic principle: A response in one modality (verbal or spatial) will interfere more with a memory representation in the same modality than with a memory representation in a different modality. Summary - END Psych 355, Miyamoto, Spr '14

  19. Summary: Comparison Between PL & VSP Phonological Loop CommonCharacteristics Differences Visuospatial Sketchpad CommonCharacteristics Differences Comparison of PL & VSP - END Psych 355, Miyamoto, Win '13

  20. Summary: Comparison Between PL & VSP Phonological Loop • Limited capacity • Information is retained by an active process (verbal rehearsal) • Information is highly accessible • Multiple verbal inputs interfere with each other. • PL processes linguistic information; Visuospatial Sketchpad • Limited capacity • Information is retained by an active process (manipulation of mental imagery) • Information is highly accessible • Multiple visual inputs interfere with each other. • VSP processes visual imagery and spatial information. Verbal processing does not interfere as much with visual processing Different areas of the brain show enhanced activity during verbal and visual/spatial rehearsal. Introduction to the Central Executive Psych 355, Miyamoto, Spr '14

  21. Baddeley-Hitch Working Memory (WM) Model • Phonological Loop (PL) • Short-term storage • Rehearsal • Manipulation of verbal information • Visuospatial Sketch Pad (VSP) • Short-term storage of visual & spatial information • Manipulation of visual images and spatial information. • 3. Central Executive • Directs activity within the PL or VSP. • Coordinates activity between PL or VSP, and between these components and long-term memory (LTM). Baddeley's List of Functions of the Central Executive Psych 355, Miyamoto, Win '13

  22. Baddeley’s List of Functions of the Central Executive • Only partially understood. Very active area of current research. • Alan Baddeley – chief developer of working memory theory(Baddeley calls the theory of the central executive a "ragbag") • Controlling and allocating attention. • Selection and launching of responses. • Inhibiting associated but inappropriate responses. • Task switching. Multitasking. • Coordinating current activity of working memory with goals. • Controlling the interface between STM stores and LTM, especially LTM search & retrieval. • Chunking Evidence for Executive Functions from Deficits in Alzheimer’s Psych 355, Miyamoto, Win '13

  23. Arguments for a Central Executive • Conceptual Argument: The brain somehow controls activity in WM. (See Baddeley's list of types of controls on preceding slide). • Let's give this controlling mental function a name: The Central Executive. • Evidence from clinical neuropsychology: • A variety of pathologies have been found that relate to the functions of the central executive. • These pathologies are often related to injury to the frontal lobe of the brain. Especially, to the prefrontal cortex. Diagram of the Lobes of the Brain Psych 355, Miyamoto, Win '13

  24. Frontal Executive Hypothesis & Frontal Lobe Syndrome • Frontal Executive Hypothesis: The idea that every executive process is primarily mediated by the prefrontal cortex (PFC). This head is facing to your left. Frontal Lobe Syndrome – List of Symptoms Psych 355, Miyamoto, Win '13

  25. Frontal Executive Hypothesis & Frontal Lobe Syndrome • Frontal Executive Hypothesis: The idea that every executive process is primarily mediated by the prefrontal cortex (PFC). • Frontal Lobe Syndrome:Results from damage to the frontal lobes, especially, the PFC. • Constellation of symptoms: • Impaired Working Memory, especially Central Executive: Impaired ability to plan; lack of inhibition; impulsiveness; boastfulness; perseveration • Other Symptoms (not necessarily related to WM): Antisocial behavior, depression • Often, but not always, caused by closed head injury – severe bump on head. Combat veterans. Head on collisions. • Neuropsychological tests for executive processing are used to diagnose frontal lobe damage. Strange Case of Phineas Gage Psych 355, Miyamoto, Win '13

  26. Neuropsych Evidence for Control Functions of PFC: The Strange Case of Phineas Gage • Phineas Gage, railway worker in 1848. Worked with dynamite. • Accidental explosion blew a metal rod through his skull. • He lived for 12 years after the accident. • Before injury: Calm, trustworthy, hardworking, reasonable person. • After injury: Irresponsible, impulsive, fits of temper, profanity, stubborn yet vacillating. Photo Image of Phineas Gage Psych 355, Miyamoto, Win '13

  27. Phineas Gage Post-Accident • Image from Boston.com http://www.boston.com/news/health/articles/2009/07/22/newly_discovered_image_offers_fresh_insights_about_1848_medical_miracle/ • It is claimed that this photo shows Phineas Gage holding the iron bar that pierced his skull. Dr. P – Another Example of Frontal Lobe Syndrome Psych 355, Miyamoto, Win '13

  28. Another Example of Impaired Cognitive Control Functions:The Case of Dr. P • Dr. P: Successful modern day surgeon. Suffered frontal lobe damage due to loss of oxygen during surgery. After frontal lobe damage, .... • IQ was still above average. • Severe impairment to ability to plan and adapt to changing circumstances. Had to follow a rigid routine as a delivery truck driver. • Had difficulty initiating actions. (Others would tell him what to do next). • Had difficulty switching from one task to the next. • Relatively unaware of his cognitive deficits (self-monitoring deficit). Stroop Task Psych 355, Miyamoto, Win '13

  29. Stroop Task • Name the color that the word is printed in. Ignore the meaning of the word. Incompatible Condition BLUEGREENREDBLACKGREENREDetc Compatible Condition BLUEGREENREDBLACKGREENREDetc • Obviously, the incompatible condition is harder (slower). • What does this have to do with executive processes? • Frontal lobe damage – much slower in the incompatible condition.Why? – Stroop task requires self-control. Wisconsin Card Sort Task & Frontal Lobe Syndrome Psych 355, Miyamoto, Win '13

  30. Tuesday, April 29, 2014: The Lecture Ended Here Psych 355, Miyamoto, Spr '14

  31. Wisconsin Card Sort Task • Match new card to the “correct” old card. • Criterion for “correct” old card keeps changing over blocks of trials. OldCards NewCard Block 1: “Correct” responses based on matching shape. Block 2: “Correct” responses based on matching color. fMRI Study of Inhibition of Irrelevant Scene Stimuli Psych 355, Miyamoto, Win '13

  32. Wisconsin Card Sort Task • Normal performance: Subjects can learn to switch the criterion for a new block of trials. • Frontal lobe damage – normal performance on first block of trials, but they have exceptional difficulty when the experimenter changes the rule. Block 1: “Correct” responses based on matching shape. Block 2: “Correct” responses based on matching color. fMRI Study of Inhibition of Irrelevant Scene Stimuli Psych 355, Miyamoto, Win '13

  33. fMRI Study of Inhibition of Irrelevant Information Gazzaley, A., Cooney, J. W., Rissman, J., & D'Esposito, M. (2005). Top-down suppression deficit underlies working memory impairment in normal againg. Nature Neuroscience, 8, 1298-1300. fMRI measurement of brain activity in left parahippocampal/lingual gyrus (overlaps the parahippocampal place area/PPA). Specialized for place perception. Remember Faces Just Watch Definition of Face-Relevant & Passive Viewing Conditions Psych 355, Miyamoto, Win '13

  34. fMRI Study of Inhibition of Irrelevant Information Face Relevant Condition: Remember faces; ignore scenes. Later tested for recognition of a face. Passive Condition: Simply view the stimuli. Later tested on whether the arrow points left or right. Remember Faces Just Watch Definition of Good Suppressors & Poor Suppressors Psych 355, Miyamoto, Win '13

  35. fMRI Study of Inhibition of Irrelevant Information • Good Suppressors – People whose brain activity was less when the scene was irrelevant than when scene was passively viewed. Lower Lower Remember Faces Just Watch Higher Higher Results of fMRI Study of Inhibition of Irrelevant Scene Stimuli Psych 355, Miyamoto, Win '13

  36. fMRI Study of Inhibition of Irrelevant Information • Good Suppressors – People whose brain activity was less when the scene was irrelevant than when scene was passively viewed. • Poor Suppressors – People whose brain activity was greater when the scene was irrelevant than when scene was passively viewed. Higher Higher Remember Faces Just Watch Lower Lower Results of fMRI Study of Inhibition of Irrelevant Scene Stimuli Psych 355, Miyamoto, Win '13

  37. Results of fMRI Study of Inhibition of Irrelevant Information • Good suppressors are better at recognizing faces. • Proposed explanation: Good suppressors have better central executive function; they are better at inhibiting irrelevant information. Summary re Frontal Lobe Syndrome & Central Executive Psych 355, Miyamoto, Win '13

  38. Frontal Lobe Damage & Impaired Functioning of the Central Executive • Central executive controls attention to relevant information and responses.Inhibits irrelevant information and responses. • Frontal lobe damage leads to difficulty inhibiting irrelevant information and responses. • Stroop task, Wisconsin card sort task, face recognition with irrelevant scenes: To respond correctly, you need to inhibit a response. People with frontal lobe damage have difficulty inhibiting tempting wrong responses. • People differ in how effective they are at inhibiting irrelevant information. Return to Baddeley’s List of Central Executive Functions - END Psych 355, Miyamoto, Win '13

  39. Baddeley’s List of Functions of the Central Executive • Only partially understood. Very active area of current research. • Alan Baddeley – chief developer of working memory theory(Baddeley calls the theory of the central executive a "ragbag") • Controlling and allocating attention. • Coordinating current activity of working memory with goals. • Task switching. Multitasking. • Selection and launching of responses. • Inhibiting associated but inappropriate responses. • Controlling the interface between STM stores and LTM, especially LTM search & retrieval. • Chunking END Psych 355, Miyamoto, Win '13

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