Human Cognitive Processes: psyc 345 Ch Human Cognitive Processes: psyc 345 Ch. 10 Visual imagery Takashi Yamauchi © Takashi Yamauchi (Dept. of Psychology, Texas A&M University)

(Q1) How are images represented in the brain? (Q2) How are perception and imagery linked? (Q3) Are the male brain and the female brain different? If so, how? (Q4) Why are there many more autistic boys than girls?

(Q1) How are images represented in the brain? (Q2) How are perception and imagery linked?

DVD: Secrets of the mind Imagery DVD: Secrets of the mind Ch. 10 10 min

How many windows do you have in your house/apartment? How is the furniture arranged in your bedroom? Are an elephant’s ears rounded or pointed?

How did you find that? Did you navigate your rooms one by one? Represent images of your rooms and house, and visit each one, as in a computer game? visual imagery. Experiencing a sensory impression in the absence of sensory input.

What is imagery for? In a memory test, visualizing images of words help remember more accurately. Many top athletes use visual imagery to enhance their athletic performance. People use imagery to solve problems. Einstein developed the theory of relativity by imagining himself traveling beside a beam of light. Good mathematicians are good at visualizing math problems.

Imagery and Perception You get physical input. And your neurons are responding to it. Imagery You don’t have physical input, but your neurons are responding to it.

Imagery and Perception Do they share the same mechanism? How are they related?

Imagery and Perception Can you form imagery of Red apple, green apple, yellow apple, Blue apple, orange apple, purple apple Can you form imagery of a zebra? Can you seen stripes in your zebra? Can you count how many stripes the zebra has?

Imagery debate How do we create mental images? Analogue Propositional Mental images and perceptual images both involve spatial analogs of the stimulus. Propositional Mental images are created by the same mechanism that creates language (propositional mechanism) The spatial experience of mental images are an “epiphenomenon”.

Analog Hypothesis Mental images are internal representations that operate in a way that is analogous to the functioning of the perception of physical objects. Functional-equivalency hypothesis Coglab Mental rotation

Representation Analog vs. digital representation

Analog representation

As with the primary motor cortex in the frontal lobe, a homunculus of the somatosensory cortex maps, in inverted form, the parts of the body from which the cortex receives information. Fig. 2.11, p.53 16

Example: Want to compare whether or not the two figures are the same. How do you make a judgment?

For physical objects, you will simply rotate them, and compare them. Same?

What is the consequence of rotation? The time required for comparison corresponds to the angle of rotation. X axis: The Angular distance between two figures Y axis: Comparison time

Mental rotation experiments Show two objects side by side Subjects were asked to determine whether the two objects were the same.

Do people rotate objects mentally?

What do you measure? What kind of results do you expect? Subjects’ response times for their yes-no judgments. Their response times should be linearly related to the angular departure of the two objects.

Experiment: Subjects were presented with two objects (either together or in sequence). Subjects judged whether or not the two objects were identical. Dependent measure: Response time and accuracy

Results What can you say from these results? The response times observed in this task were proportional to the angular departure of two shapes.

What do this tell you? Does this relate to the functional-equivalency hypothesis? How?

Mental scanning (Kosslyn et al. 1978) Ss were shown a map of an imaginary island. The map showed various objects (e.g hut, tree, hill,..) Ss studied the map until they could reproduce it from memory. After that, Ss were asked to picture the map and mentally scan the picture from one location (tree) to another (hill). When mental scanning was completed, Ss pressed a key

Mental scanning (Kosslyn et al. 1978) Ss scanning times were linearly related to the physical distances between locations Mental scanning (Kosslyn et al. 1978) Mental scanning time Physical distance between locations

Finke & Pinker (1982) Ss first saw (a), and then (b). The task was to judge if the arrow pointed to any of the dot. Ss took longer to respond for greater distances between the arrow and the dot.

The experimenter asked “Does a rabbit have whiskers?” Ss were asked to imagine animals, such as an elephant and a rabbit next to each other. The experimenter asked “Does a rabbit have whiskers?” RT = 2.030 ms Ss were asked to imagine animals, such as a fly and a rabbit next to each other. The experimenter asked “Does a rabbit have whiskers?” RT = 1.870 ms Figure 9.10: These pictures represent images that Kosslyn’s (1978) participants created, which filled different portions of their visual field. (a) Imagine elephant and rabbit, so elephant fills the field. (b) Imagine rabbit and fly, so rabbit fills the field. Reaction times indicate how long it took participants to answer questions about the rabbit.

Implications Ss answered the question about the rabbit more rapidly when it filled more of the visual field. Mental images are spatial just like perception

Imagery and the Brain Compare the brain area that are activated (1) when a person observed perceptions of actual visual stimuli (perception) (2) when the person was imagining the stimulus (imagery)

First, Ss studied stimuli in a booklet (line drawings of 90 objects) Experiment: Imagery and perception conditions were alternated. Perception condition: The name of a picture is presented auditorily. Ss saw a low contrast line drawing, and answered the same question as asked in the imagery condition (such as “Is the object higher than it is wide?” ) Ganis et al. (2004)

First, Ss studied stimuli in a booklet (line drawings of 90 objects) Experiment: Imagery and perception conditions were alternated. Imagery condition: Ss closed their eyes. The name of a picture is presented auditorily. Ss generated the corresponding visual mental image and answered a question such as “Is the object higher than it is wide?” Ganis et al. (2004)

Frontal areas The activation patterns appear identical Perception Imagery Perception - Imagery Frontal areas The activation patterns appear identical

Parietal and temporal areas The activation patterns appear identical Perception Imagery Perception - Imagery Parietal and temporal areas The activation patterns appear identical

Occipital areas The activation patterns appear somewhat different Perception Imagery Perception - Imagery Occipital areas The activation patterns appear somewhat different

Transcranial Magnetic Stimulation Apply a magnetic field to a skull and disrupt the activity of neurons in a particular region. Demo: (4:15) http://www.youtube.com/watch?v=XJtNPqCj-iA

The perception task: Ss were asked to indicate whether the stripes in two of the quadrants (e.g., the stripes in 3 longer than stripes in 2?) The imagery task: = the perception task, but Ss were asked to close their eyes and make judgments based on their mental image of the display. Figure 9.16: (a) Transcranial magnetic stimulation apparatus; (b) stimuli.

TMS was directed to the visual area while Ss were making judgments. Manipulations: TMS was directed to the visual area while Ss were making judgments. TMS was directed to another part of the brain while Ss were making judgments Results TMS slowed Ss’ responses both in the imagery and perception conditions. Figure 9.16: (a) Transcranial magnetic stimulation apparatus; (b) stimuli.

Implications The perception and imagery tasks are carried out by the same brain areas.

Neuropsychological case studies Farah 2000 Patient M. G. S An educated young woman Her right occipital lobe removed as treatment for a sever case of epilepsy. The mental walk task was given before and after the operation

The mental walk task She visually imagined walking toward an animal And estimated how close she was when the image began to overflow. “overflow” means that the mental image was too big so that she could not see the entire animal at once in her mental image.

Mental walk test: before and after the operation. Before the operation, she could mentally walk to the image of a horse within 15 feet before “overflowing”. After the operation, she could mentally walk to the image of a horse within 35 feet before “overflowing”. Explanation: Removing part of the visual cortex reduced the size of her field of view.  The visual cortex is important for imagery Before the operation After the operation Figure 11.1 Specialties in psychology. Percentages are approximate. The percentages shown here are based on membership in the American Psychological Association. The APA welcomes both scientists and practitioners. However, some psychological researchers belong to other organizations, such as the American Psychological Society. As a result, the percentage of clinical and counseling psychologists working in the United States may be a little lower than shown in chart a. Nevertheless, it is accurate to say that most psychologists specialize in applied areas and work in applied settings.

Other case studies Perceptual problems are accompanied by problems with imagery. People who have lost the ability to see color due to brain damage are also unable to create colors through imagery. People who have unilateral neglect in perception also have unilateral neglect in imagery.

Unilateral neglect Often caused by damage to the parietal lobe. People with unilateral neglect pay attention to only one side of the visual field and ignore the other side of the visual field. http://www.youtube.com/watch?v=ADchGO-0kGo

Imagery and unilateral neglect Bisiach & Luzzatti (1978) tested the imagery of a patient with unilateral neglect. The patient imagined himself standing at one of a familiar Piazza and named the objects around the Piazza.

When he imagined himself at B, he could name objects indicated by b’s. When the patient imagined himself standing at A, he could name objects indicated by a’s. When he imagined himself at B, he could name objects indicated by b’s. Figure 9.18: Piazza del Duomo in Milan. When Bisiach and Luzzatti’s (1978) patient imagined himself standing at A, he could name objects indicated by a’s. When he imagined himself at B, he could name objects indicated by b’s. (Reprinted from “Unilateral Neglect of Representational Space,” by E. Bisiach & G. Luzzatti, 1978, Cortex, 14, pp. 129–133. Copyright © 1978 with permission from Cortex.) Fig. 9-18, p. 343

Implications There is a strong correspondence between the physiology of mental imagery and the physiology of perception.

Dissociations Between Imagery and Perception Evidence for double dissociation?

Dissociations Between Imagery and Perception R.M. Damage to occipital and parietal lobes Could draw accurate pictures of objects in front of him Could not draw accurate pictures of objects from memory (using imagery)

Dissociations Between Imagery and Perception C.K. Inability to name pictures of objects, even his own drawings, in front of him He could draw objects in great detail from memory (using imagery)

CK was able to draw objects from memory in rich detail CK labeled (a) as a “feather duster” (the dart), “a fencer mask” (the tennis racket), and a “rose twig with thorns (the asparagus). CK was able to draw objects from memory in rich detail Figure 9.19: (a) Pictures incorrectly labeled by C.K., who had visual agnosia. (b) Drawings from memory by C.K. (Reprinted from “Intact Visual Imagery and Impaired Visual Perception in a Patient With Visual Agnosia,” by M. Behrmann et al., 1994, Journal of Experimental Psychology: Human Perception and Performance, 30, pp. 1068–1087, Figs. 1 & 6. Copyright © 1994 with permission from the American Psychological Association.) Fig. 9-19, p. 344

Neuropsychological Results Evidence for a double dissociation between imagery and perception Indicates separate mechanisms Also evidence for shared mechanisms

The mechanisms of perception and imagery overlap only partially. Perception: mostly lower visual receiving areas and some higher visual areas Imagery: mostly higher visual areas, and some lower visual receiving areas. Figure 9.20: Depiction of the idea that mechanisms serving perception are located both at lower and higher visual centers and that mechanisms serving imagery are located mainly at higher levels (Behrmann et al., 1994). The general locations of damage for C.K. and R.M. are indicated by the vertical arrows. These locations can explain why C.K. has a perceptual problem but can still create images, and why R.M. has trouble creating images but can still perceive.

(Q3) Are the male brain and the female brain different. If so, how (Q3) Are the male brain and the female brain different? If so, how? (Q4) Why are there much more autistic boys than girls?

male brain vs. female brain Verbal abilities: female > male Spatial abilities: male > female Male vs. female http://www.youtube.com/watch?v=NoCPDvQBG5Y&feature=related male vs. female (30 sec) http://www.youtube.com/watch?v=of0SxqoY-Nw&feature=related Autism 1:00 http://www.youtube.com/watch?v=r1KQCJzKaN0&feature=related 3:02 http://www.youtube.com/watch?v=srVKHiEPVss&feature=related http://www.youtube.com/watch?v=filK9gZw4rA

Female brain: empathizing brain Male brain: systemizing brain Baron-Cohen (2002), Trends in Cognitive Sciences The extreme male brain theory of autism (by Baron-Cohen) Autism is an extreme expression of the male brain.

The female brain: empathizing F>M Sharing and turn-taking (F>M) Responding empathically to the distress of other people (F>M) Values in relationships (F>M) Talk about emotion (F>M) babies look longer at faces (F>M) M>F Psychopathic personality disorder (M>F) Competition and rough tumble play (M>F) Aggression (M>F) Murder (M>F) (male-male homicide was 30-40 times more frequent than female-female homicide)

The male brain: systematizing M>F Toy preference – vehicles (M>F) 3D construction (Lego) (M>F) Mental rotation (M>F) Map reading (M>F) Motoric judgments (e.g., judge which objects are moving faster) (M>F) engineering, math, and physics majors (M>F)

The extreme male brain theory of autism (by Baron-Cohen) 1 in 200 children have one of the autistic spectrum conditions. The sex ratio is at least 10 males to every female. Overrepresented in children whose parents / grand parents are engineers (Baron-Cohen et al.; Autism, 1997, 1, 153-163)

Autistic children: Impaired “female brain” / impaired empathizing Mindreading (predicting another’s feelings) F>M>A Reading the mind in the eyes (discrimination emotions from expressions in the eyes) F>M>A Eye contact: F>M>A Language development (vocabulary) F>M>A Preference for rule-based, structured, factual information; A>M>F Preference for constructional toys: A>M>F Collecting: A>M>F Obsession with closed/well-defined systems (e.g., computers): A>M>F

Using imagery to improve memory Using imagery as mnemonics How does it help? (4:20) http://www.youtube.com/watch?v=L1mweFSqACU&feature=related