Cognitive Psychology: Chapter 10

Tacit Knowledge Explanation

People know that in the real world it takes longer to travel longer distances, so they simulate this results in Kosslyn's experiment. This is called tacit knowledge because it states that subjects unconsciously use knowledge about the world in making their judgements.

Perception and Imagery

Perception and Imagery lines up perfectly in the first and second thirds of the brain. Not in the third part of the brain

Depictive Representations

Representations that are like realistic pictures of an object, so that parts of the representation correspond to parts of the object

Can Images Be Studied Scientifically? -Bottom line Imagery impacts memory

-Introspectionists said, "Yes" -Behaviorists said, "No" -observable behavior -Alan Paivio (1971) said, "Let's try this again" -Duel-coding (or "conceptual peg") hypothesis -Concrete vs. abstract words in paired-associate learning -Two codes are better than one (1. Verbal and Imagery)

Mental Rotation

-Shepard & Metzler (1971) examined dynamic (not static) imagery -Mental chronometry: measure reaction time to make same/different judgments for shapes that are at different orientations (mental rotation task) -Strong linear relation between reaction time and degree of rotation -The more you have to mentally rotate an image the longer it takes you to make a decision about it

The topographic man

1. Research on the topographic map on the visual cortex indicates that looking at a small object causes activity in the back of the visual cortex, and looking at larger objects causes activity to spread toward the front of the visual cortex. 2. Subjects were then instructed to create small, medium, and large visual images while they were in a brain scanner. The result, is that when subject created small visual images, activity was centered near the back of the brain, but as the size of the mental image increased, activation moved toward the front of the visual cortex, just as it does for perception *Thus, both imagery and perception result in topographically organized brain activation

Is imagery Spatial or Propositional?

1. Spatial (Correct): Representation has the same structure as the thing represented -Retain properties of images 2. Propositional: Representations uses symbols or sentences; non-spatial -Propositions take the form or relation (argument)

Evidence for Spatial Relationships: Brain Imagining Studies

1. fMRI study of visual areas activated by perceptions and visual images (Le Bihan) *Activity in the in the striate cortex increased both when a personed observed presentations of actual visual stimuli (perception) and when the person was imagining this stimulus (imagery) 2. fMRI studies of mental images of different sizes (kasslyn, 1993, 1995) -larger images activated more early visual areas in occipital lope - just like perception -The topographic map refers to the fact that specific locations on a visual stimulus cause activity at specific locations in the visual cortex and that points next to each other on the stimulus cause activity at locations next to each other on the cortex

Cheves Perky

Asked her subjects to "project" visual images of common objects onto a screen, and then to describe these images. Unbeknowst to the subject, Perky was back-projecting a very dim image of this object onto the screen. Therefore, The subjects descriptions of their images matched the images that Perky was projecting. *Not one of Perky's 24 subjects noticed that there was an actual picture on the screen. They had mistaken an actual picture for a mental image.

Mental imagery involves

Experiencing a sensory impression in the absence of sensory input.

Amir Amedi

Found that when subjects were using visual imagery, some areas associated with non-visual stimuli, such as hearing and touch, were deactivated or their action was decreased. This may be because visual images are more fragile than real perception and this deactivation helps quiet down irrelevant activity that might interfere with the mental image.

Finke and Pinker

Four dot display presentation experiment. They argue that because their subjects wouldn't have had time to memorize the distances between the arrow and the dot before making their judgements, it is unlikely that they used tacit knowledge about how long it should take to get from one point to another.

Paivio (1963) proposed the conceptual peg hypothesis. His work suggests which of the following would be most difficult to remember?

Freedom

Giorgio Ganis

His results show activation at three different locations in the brain. 1. Perception and imagery both activate the same areas in the frontal lobe 2. Perception and imagery both activate the same areas in the temporal and parietal lobes of the brain 3. Perception activates more of the brain in the occipital lobe than imagery

Conclusions from the imagery debate

Imagery and perception have many features in common, but there are also differences between them.

How does visual imagery work?

Imagery happens in working memory -Visuospatial sketch pad -Image maintenance & inspection -Central Executive -Image transformation *Baddeley's working memory model

Transcranial Magnetic Stimulation

Kosslyn and coworkers presented transcranial magnetic stimulation to the visual cortex while subjects were carrying out either a perception task or an imagery task. *The results showed that stimulation caused subjects to respond more slowly, and that Kosslyn concluded that the brain activation that occurs in response to imagery is not an epiphenomenon and that brain activity in the visual cortex plays a casual role in both perception and imagery

Imagery Neurons

Kreiman and coworkers found neurons that responded to some objects but not others. -For example, the records show the response of a neuron that responded to a picture of a baseball but did not respond to a picture of a face. The neuron fired in the same way when the person closed his or her eyes and imagined a baseball (good firing) or a face (no firing)

Kosslyn concluded that the image field is limited in size. This conclusion was drawn from the _____ experiment.

Mental Walk

Using imagery to improve memory

Method of Loci: A method for remembering things in which the things to be remembered are placed at different locations in a mental image of a spatial layout. Pegword Technique: A method for remembering things in which the things to be remembered are associated with concrete words.

Piazza del Duomo demonstration

Neglect 1/2 of visual images

Evidence for Spatial Relationships

Overlap between Imagery & Perception -If the mechanisms for visual perception are also used for mental imagery, then predict: -Images should 'act-like' real-world pictures -Images with visual processing ..Right visual cortex may be particularly important for imagery

Evidence for Spatial Relationships: Neuropsychological Case Studies

Perceptual problems are accompanied by problems with imagery -Damage to the parietal lobes can cause unilateral neglect -They ignore/neglect the left half of their visual field -Will only draw half of a flower or clock *It is not blindness

Visual Imagery

Seeing in the absence of a stimulus -Picturing your childhood home

Patient M.G.S.

She had part of her right occipital lobe removed. Removing part of the visual cortex reduced the size of her field of view, so the horse filled up the field when she was farther away. This result supports the idea that the visual cortex is important for imagery

Martha Farah (Proposed a way out of the imagery debate)

She suggested that instead of solely relying on behavioral experiments, we should investigate how the brain responds to visual imagery. *Results of her experiment - accuracy was higher when the letter shown was the same as the one that had be imagined.

Alan Paivio

Showed that it was easier to remember concrete nouns, like truck or tree that can be imagined, than it is to remember abstract nouns, like truth or justice that are difficult to imagine. He used paired-associate learning *Proposed the conceptual peg hypothesis: concrete nouns create images that other words can hang onto

Evidence for Spatial Relationships: Mental Scanning

Task: Commit fictional map to memory (kosslyn et. al. 1978) *Scanning an image into your mind -measuring reaction time -more to scan-longer reaction time **Kosslyn determined the relationship between reaction time and distance shown. Just as in the boat experiment, it took longer to scan between greater distances on the image, a result that supports the idea that visual imagery is spatial in nature

Evidence for Spatial Relationships: Size in visual field

Task: Imagining Animals -Faster decision when image was larger (kosslyn 1978) Task: Image Walk Task -A task used in imagery experiments in which participants are asked to form a mental image of an object and to imagine that they are walking toward this mental image

Mental Imagery

The ability to recreate the sensory world in the absence of physical stimuli, also occurs in sense other than vision -Imagining tastes, smells, and tactile experiences

Which of the following has been used as an argument AGAINST the idea that imagery is spatial in nature?

The tacit-knowledge explanation

Sue-Hynn Lee

They found that activity in the visual cortex in the occipital lobe resulted in the best prediction for what their subject were perceiving, and activity in higher visual areas was the best predictor of what their subjects were imagining

Imageless thought debate

Wundt proposed that images were one of three basic elements of consciousness, along with sensations and feelings. This led to the Imageless thought debate: 1. (Francis Galton) Thought is possible without an image -Galton: people who had great dificulty formnig visual images were still quite capable of thinking 2. (Aristotle) Thought is impossible without an image *The behaviorists branded the study of imagery as unproductive because visual images are invisible to everyone except the person experiencing them.

Make sense of mixed results (look in notes for double dissociation)

You need attention to maintain a mental image -Visual perception necessarily involves bottom-up processing; visual imagery is necessarily top-down *The neuropsychological cases present a paradox: One one hand, there are many case that show close parallels between perceptual deficits and deficits in imagery. On the other hand, there are a number of cases in which dissociations occur, so that perception is normal but imagery is poor, or perception is normal but imagery is poor -The cases in which imagery and perception are affected differently by brain damage provide evidence for a double dissociation between imagery and perception. 1. One way to explain this (Behrmann) is that the mechanisms of perception and imagery overlap only partially, with the mechanism for perception being located at both lower and higher visual centers and the mechanism for imagery being located mainly in higher visual centers

Imagery Debate

Zenon Pylyshyn: proposed another explanation (rather than kosslyn's) a debate about whether imagery is baed on spatial mechanisms, such as those involved in perception, or on mechanisms related to language, called propositional mechanisms. -Just because we experience imagery as spatial, that doesn't mean that the underlying representation is spatial *The spatial experience of mental images, argues Pylyshyn, is an epiphenomenon: something that accompanies the real mechanism but is not actually part of the mechanism -Example: of an epiphenomenon is lights flashing as a mainframe computer carried out its calculations. The lights may indicate that something is going on inside the computer, but they don't necessarily tell is what is actually happening.

Suppose we asked people to form simultaneous images of two or more animals such as a rabbit alongside an elephant. Then, we ask them basic questions about the animals. For example, we might ask if the rabbit has whiskers. Given our knowledge of imagery research, we would expect the fastest response to this question when the rabbit is imagined alongside

a bumblebee

Peggy is participating in a paired-associate learning experiment. During the study period, she is presented with pairs of words such as boat-hat and car-house. While taking the test, she would be presented with

boat_______ - car ________.

Sometimes a behavioral event can occur at the same time as a cognitive process, even though the behavior isn't needed for the cognitive process. For example, many people look toward the ceiling when thinking about a complex problem, even though "thinking" would likely continue if they didn't look up. This describes a(n)

epiphenomenon.

To explain the fact that some neuropsychological studies show close parallels between perceptual deficits and deficits in imagery, while other studies do not find this parallel, it has been proposed that the mechanism for imagery is located at _____ visual centers and the mechanism for perception is located at _____ visual centers.

higher; both lower and higher

In drawing conclusions about the relationship between imagery and perception, a notable difference between them is that

it is harder to manipulate mental images than perceptual images.

Shepard and Meltzer measured the time it took for participants to decide whether two objects were the same (two different views of the same object) or different (two different objects). These researchers inferred cognitive processes by using

mental chronometry.

The scanning task used by Kosslyn involves

mental images.

Kosslyn's island experiment used the ______ procedure.

mental scanning

Unilateral neglect typically occurs after damage to the ______ and results in ______.

parietal lobe ... ignoring one side of visual perceptions and mental images

Perky's imagery study (1910) had participants describe images of objects that were dimly projected onto a screen. The significance of Perky's results was that

people were influenced by the projected images when forming their mental images, even when they were unaware that the projected images were present.

OVER (MOON, MIAMI) is a representation.

propositional

Your text describes the case of M.G.S. who underwent brain surgery as treatment for severe epilepsy. Testing of M.G.S. pre- and post-surgery revealed that the right visual cortex is involved in the

size of the field of view

Correct 1.00 points out of 1.00 Not flaggedFlag question Question text Kosslyn interpreted the results of his research on imagery (such as the island experiment) as supporting the idea that the mechanism responsible for imagery involves ______ representations.

spatial