Sunday, August 28, 2016

התפקיד של דימוי מנטלי בהבנת הנקרא



זהו פוסט מס. 5 בנושא דימויים מנטלים.  לפוסט מס. 4 לחץכאן. 


ראינו בפוסט הקודם, שניתן להבחין בין שני סוגים של דימויים מנטלים:  דימויים מנטלים של אובייקטים ודימויים מנטלים של יחסים במרחב.   היכולת ליצור דימויים מנטלים של אובייקטים היא היכולת לדמות את הצורה של אובייקטים, הצבע שלהם, הטקסטורה שלהם, הריח שלהם ופרטים נוספים שלהם.  זו, למשל, היכולת לדמיין ורד אדום במלוא חיותו וריחו.   היכולת ליצור דימויים מנטלים של יחסים במרחב היא היכולת לדמות את המיקום היחסי של אובייקטים במרחב (מיקומם זה ביחס לזה), היכולת לדמות תנועה של האובייקטים זה ביחס לזה ולדמות שינויים באובייקטים.  זו, למשל, היכולת לדמות את מראה הגן כולו עם שיחי ורדים, עצים, ספסלים וכו'.  זו היכולת לדמות היכן נמצא שיח הורדים ביחס לאובייקטים האחרים הנמצאים בגן, והיכולת לדמות את הרוח מעיפה את עלי הכותרת של הורדים.   

החוקרת RENATE BROSCH מציעה שבעת קריאת רומן, אנו יוצרים רצף של דימויים מנטלים מסוג מרחבי.  את הדימויים אנו דולים מתוך "מחסן" של פרוטוטיפים (אבות – טיפוס) מקובלים בתרבות שלנו שיש לנו במאגר הידע המגובש.  למשל, דימוי טיפוסי של "קאובוי" או של "דינוזאור" (בהתאם למתרחש בספר).  מתקבל רצף דימויים שהם לא מאד מפורטים, אותם אנו יכולים לשנות ולעדכן בקלות יחסית, בהתאם למה שקורה בסיפור.  רצף זה מלווה את ההתרחשויות בעלילת הסיפור ומסייע לנו לעקוב אחר המיקום היחסי של הדמויות והאובייקטים, לדמות תנועה המתרחשת בסיפור ולדמות את הסביבה הפיסית הרחבה בה העלילה מתרחשת. 

אבל מדי פעם, הרומן "רומז" לנו לשנות את סוג ההדמיה המנטלית מדימויים מרחביים לדימויים של אובייקטים.  הרמזים הם בדמות האטה של רצף הפעולות וצמצום של המיקוד (למשל, רגעים של שיחה, רגעים שבהן הדמות מהרהרת או מביטה בנוף וכדומה).  דימויים סטטים יחסים, או לפחות דימויים של התרחשות בקצב איטי, כמו שיחה, הם ברורים יותר וקל יותר לדמות אותם מאשר דימויים של דברים שנעים או מתרחשים במהירות.  דימויים אלה הם בעלי רמה גבוהה יותר של "חיות" VIVIDNESS:  אנחנו "רואים" אותם בפרטי פרטים, בצבעים חיים, מדמים ריחות, טעמים קולות וצלילים שמתרחשים בסצינה, וכן מדמים את הרגשות שחשות הדמויות השונות.  רגעים אלה של דימויים חיים, מסוג הדמיה של אובייקטים, הם הדברים העיקריים שנזכור כאשר ניזכר ברומן.  

RENATE BROSCH נותנת, כדוגמה לרגע כזה בו הטקסט מזמן יצירת דימויים חיים של אובייקטים, סצינה מתוך הספר "צפון ודרום" מאת אליזבת גסקל.  הספר מומלץ מאד – זהו סיפור אהבה על רקע המהפכה התעשייתית באנגליה.  הנה הקטע אותו תרגמתי לעברית כמיטב יכלתי:

"היא נראתה כאילו אינה מקשיבה לשיחה, אלא עסוקה רק עם ספלי התה, ביניהם נעו ידי השנהב העגולות שלה בעדינות נאה ושקטה.  היה לה צמיד על אחת מזרועותיה, שהיה נופל מדי פעם על פרק כף היד העגול שלה.  מר ת'ורנטון צפה בהחזרתו של פריט קישוט מטריד זה בקשב רב הרבה יותר מאשר הקדיש להאזנה לאביה.  נראה שהוא הוקסם לראות איך היא דוחפת את הצמיד למעלה בחוסר סבלנות, עד שהוא לוחץ על עורה הרך, ואז להבחין בדרך בה הצמיד מתרופף ונופל".

שקופיות ופס הקול של ההרצאה של RENATE BROSCH בנושא זה נמצאים כאן:



Wednesday, August 24, 2016

The possible influences of mental images on a child's functioning in school and out of it


This is a fourth (and last?) of a series of posts on mental imagery. 

People don't always like to see movies based on books they have read.  They are afraid that the movie would look different than the way they saw things in their mind's eye.  Sometimes they express disappointment at a character's  appearance:  "He is not supposed to look this way!"  When reading we form mental images of the characters and the surrounding.  We don't only "know" how things look, by the descriptions in the book.  We "see" them in our mind's eye. 

When reading, we do not only form visual images but auditory images as well.  A few years ago my daughter burst out laughing when reading a book (silently).  It turned out that she read the question "What happened?" as a shout, and then saw that the next words were "he whispered".  At first, the character was shouting in her mind's ear. 

Does it mean that individual differences in the ability to form mental images affect their reading comprehension?  Does a person who forms mental images which are less vivid or precise understand the scene less well?  Would a person who finds it hard to control the mental image of a scene (for example, to see it from different angles, to update the image when new information unfolds) understand it less well?

When we remember events from our past, we may recall some of them in great detail.  For instance, when we recall an event that took place by the beach, we see with our mind's eye the specific beach where the event happened, and the people and objects that participated in it.  We can form auditory images of the seagull cries, olfactory images of the salty smell of the sea, and these mental images may help us to remember what we thought and felt during the event.  Mental images are probably part of the way we store and retrieve information in memory.

As we've seen in the first post, mental images are processed in brain areas devoted to perception.   For example, when a person forms a visual image he activates brain areas that are activated during visual perception.  Furthermore: brain areas related to visual perception are activated during retrieval from episodic memory (memory for our life events).  Thus damage to brain areas that support visual perception leads both to visual imagery loss and to episodic memory loss.  According to Dr. Zeman, people with permanent attenuation in the ability to form visual images are at a greater risk for poor memory for their life events.  The opposite also seems to be true:  people with extremely poor episodic memory report having poor ability to form visual images.

What about thinking about the future and decision making?  The ability to remember the past and to think about the future are linked.  Episodic memory and the ability to project ourselves into the future (to think about the future with ourselves in it) appear at a similar period of development – around age four.  People who, following brain damage, are not able to remember their personal past usually have difficulty imagining possible future experiences.  Thus it's possible that people who have difficulty forming mental images also have difficulty imagining the future and projecting themselves into the future. 

The ability to imagine the future affects our ability to make decisions.  Prof.  Bence Nanay argues that we make decisions by forming a mental image of each possible alternative and placing ourselves in it.  For example, if a child has to choose an afterschool activity, he forms mental images of himself in each activity.  These images help him to make the decision.

Ernest argued in 1977 that individual differences in the ability to form mental images can significantly influence a range of cognitive functions such as learning, memory, perception and problem solving. 

Yet no correlation was found between the ability to form mental images (as reported by questionnaires) and people's level of performance on tasks that allegedly require imaging, for example, mental rotation, visual memory and visual recognition.  No correlation was found between the reported vividness of mental images and people's performance in terms of speed or precision on visual spatial tasks and on problem solving tasks that seem to require the formation of mental images. 

Galton wrote in the 19th century:  ‘Men who declare themselves entirely deficient in the power of seeing mental pictures can nevertheless … become painters of the rank of Royal Academicians’

How do we explain this?  Here are several possibilities:

A.  People can perform tasks that allegedly require mental imagery in other ways, without the formation of mental imagery.  These ways may be less effective, but they nevertheless enable them to perform the tasks.

B.  Tests that supposedly require the formation of mental images do not resemble everyday functioning.  The manipulations of imagery required in these tasks is different in kind and complexity from manipulations of mental images in everyday life.

C.  People who report having no mental imagery do form images but are not aware of it.

D.  Questionnaires that measure the quality of mental imagery measure different phenomena than is measured by tests that allegedly require the formation of mental images.

E.  Questionnaires that were used in some of the studies did not differentiate between different kinds of mental images.

It's possible to identify two kinds of mental imagery:  mental imagery of objects and mental imagery of spatial relations.  The ability to form object imagery is the ability to image the form of objects, their color, texture, scent and other details.  This is the ability to form a mental image of a rose in its full vividness and scent.  The ability to form spatial relations imagery is the ability to form an image of the relative placement of objects in space, the ability to mentally move the objects in relation to each other and to image changes in objects.  This is, for instance, the ability to image the look of the whole garden, with shrub roses, trees, benches and so on.  This is the ability to image where the shrub roses are placed relative to other objects in the garden, and the ability to image the wind blowing the rose petals.  Maybe these different kinds of images affect performance on tests that require the formation of mental images in different ways. 

Sixth grade children were given math word problems and then were asked to describe the way they solved them.  For instance, they solved the following problem:  "At each of the two ends of a straight path, a man planted a tree, and then every 5 meters along the path he planted another tree. The length of the path is 15 meters. How many trees were planted?"

Children who used spatial imagery used gestures in their descriptions that showed the spatial relations between objects in the problem, or reported having spatial images of the relations in the problem.  For example:  "I had a [mental] picture of the path, not the trees, and it had something 5 meters along, not trees, just something."  Children who used spatial imagery also created drawings of the problem that depicted the relations between objects.

Children who used object imagery reported images of objects or people mentioned in the problems, and not the relations between them.  For instance:  "I saw the man planting a tree".

Children who used spatial mental imagery did better on the word problems than children who used object imagery.  The researchers argue that forming object images turns attention away from the relations between objects in the problem.

In another study with adults, it was found that scientists and engineers excel in spatial imagery and prefer spatial strategies, whereas visual artists excel in object imagery and prefer object-based strategies.

To sum up, mental images assist in everyday functioning.  People differ in their ability to have mental images and in the kinds of mental images they form.  Different kinds of mental images can help to perform different kinds of tasks.  People who can't form mental images can succeed in the same tasks, probably by using other strategies.

Zeman, A., Dewar, M., & Della Sala, S. (2015). Lives without imagery–Congenital aphantasia. Cortex, 3.

Sheldon, S., Amaral, R., & Levine, B. (2016). Individual differences in visual imagery determine how event information is remembered. Memory, 1-10.

Hegarty, M., & Kozhevnikov, M. (1999). Types of visual–spatial representations and mathematical problem solving. Journal of educational psychology, 91(4), 684.http://www.nmr.mgh.harvard.edu/mkozhevnlab/wp-content/uploads/pdfs/types_visual1999.pdf

Kozhevnikov, M., Kosslyn, S., and Shepard, J. Spatial versus object visualizers:  a new characterization of visual cognitive style. Memory and Cognition 2005, 33(4), 710-726.  http://nmr.mgh.harvard.edu/mkozhevnlab/wp-content/uploads/pdfs/spatial_versus2005.pdf





Saturday, August 20, 2016

Are there differences in people's ability to form mental images?




This is post no.3 on mental imagery.  Post no. 1 is here

In 2005, a 65 year old retired building inspector approached neurologist Adam Zerman with the complaint that following coronary angioplasty he no longer could form mental images.  Dr. Zeman could not find any description of such a phenomenon in the literature.  He tested this man with a series of tests.  Apparently, this man had good memory for his age, and good performance in a variety of cognitive tests.  The only problem he had was his inability to form mental images.
 
Dr Zeman and his team showed the man pictures of well known people and asked him to identify them.  He did that easily and when doing so, he had activation in the same brain areas that are activated during visual processing in most people.  But when he read names of known people and was asked to form a visual image of their faces, he said he couldn't do it.  The areas in the brain that are usually activated during visual imagery were not activated in his brain during this task.

Thus, beyond the subjective report of that man about his loss of the ability to form mental images, researchers saw that brain areas normally activated during the formation of mental images were not activated in his brain.  Nevertheless, he was able to perform tasks that allegedly require the formation of mental images.  He could state the color of the eyes of a well known person.  He could say which letters in English have downward "tails" (like the letters "g" or "j").  Apparently, he performed these tasks in a different way, without mental imagery. 

Journalist Carl Zimmer wrote about this research in the New York Times in 2015.  Following his article, people approached Dr.  Zeman and reported having the same phenomenon (without the coronary angioplasty).  Some of these people discovered for the first time that they were different in this respect from most people.
 
Blake Ross, a writer and programmer, a former Director of Product at Facebook, and the cofounder of Firefox,  wrote this in his facebook page: 

"If you tell me to imagine a beach, I ruminate on the “concept” of a beach. I know there’s sand. I know there’s water. I know there’s a sun, maybe a lifeguard. I know facts about beaches. I know a beach when I see it, and I can do verbal gymnastics with the word itself."
"But I cannot flash to beaches I’ve visited. I have no visual, audio, emotional or otherwise sensory experience. I have no capacity to create any kind of mental image of a beach, whether I close my eyes or open them, whether I’m reading the word in a book or concentrating on the idea for hours at a time—or whether I’m standing on the beach itself".
  
Ross writes that he does not usually remember dreams, and when he does, there is no visual or sensory component to them.  He has difficulties navigating directions.  When he reads a book, he skips the descriptions.  He has trouble remembering events from his own past (retrieving episodes from his episodic memory).
Apparently, people who cannot form mental images (a condition named APHANTASIA) are at one end of a spectrum.  Galton, the great 19th century scholar, who was one of the founding fathers of the study of intelligence, noticed the existence of individual differences in the ability to form mental images.  Contemporary researchers argue these differences encompass three aspects:
 1) Imagery Vividness. Mental Imagery vividness relates to the clarity of the mental images evoked by an individual   or the liveliness and similarity to the actual percept.

2) Imagery Control. This is the extent to which one can manipulate, transform, and hold images in mind at will.  Imagery control is the individual’s ability to self-generate a mental image or to perform certain manipulations, such as mental rotation.

2) Imagery Processing Style. Some people form detailed images of objects.  Others tend to form images of relations between objects in space (for example, a mental map).  People who tend to form object images tend to form relatively static mental pictures, which are detailed and highly vivid.  People who tend to create images of relations between objects in space tend to form dynamic images.

These differences (in the general ability to form mental images and in these three aspects) are usually measured with questionnaires, like the ones in this paper.

 h
What are the possible implications of this to the functioning of a child in school? To be discussed in the next post.

Zeman, A. Z., Della Sala, S., Torrens, L. A., Gountouna, V. E., McGonigle, D. J., & Logie, R. H. (2010). Loss of imagery phenomenology with intact visuo-spatial task performance: a case of 'blind imagination'. Neuropsychologia, 48, 145-155. 
 
D’Argembeau, A., & Van der Linden, M. (2006). Individual differences in the phenomenology of mental time travel: The effect of vivid visual imagery and emotion regulation strategies. Consciousness and cognition, 15(2), 342-350.  

Woojin Lee, Ulrike Gretzel.  Individual Differences in Mental Imagery Ability: Implications for Online Media Consumption.   




Thursday, August 18, 2016

Research on mental imagery and tests presumably requiring the use of it



This is post no.2 on mental imagery.  Post no. 1 is here.

Mental imagery seems like a completely subjective phenomenon.  Can its existence be proven or at least can its influences be objectively studied?  Maybe so!

Research findings on auditory imagery

Participants were presented with the beginning of a familiar tune (the researchers used wordless movie themes or classical music).  They were asked to "play" the rest of the tune in their mind up to a specific point in it.  When they reached that point, they pushed a button.  The time lapse until the button was pushed was proportional to the duration of the segment the participants were asked to complete!

The time needed to say the ABC twice and to mentally say the ABC twice is identical.
Participants were asked to say specific words and to imagine they are saying other words.  Later they could hardly distinguish between the words they said and the words they imagined they said.

When adults were awakened from REM sleep, 13% of them reported having a nonverbal auditory image in their dream, and 94% reported they talked or had conversations in their dreams.

Research findings on visual imagery

Mental rotation is the ability to mentally rotate representations of two and three dimensional objects.  This ability helps us recognize objects that we see.  As we saw in the previous post, in tasks like the one in the picture below, a person is asked to decide which of the four stimuli on the right is identical with the stimulus on the left.  People usually solve this task by mental rotation – mentally rotating the stimuli on the right until they are parallel (or not) with the stimulus on the left.





Shepard and Metzler (1971), who were pioneers in this field of research, discovered that the time needed to decide whether a rotated stimulus is identical with a given stimulus is proportional to the degree of rotation!  This means that we rotate the object in our mind's eye in a steady pace.  Men are slightly better on this task than women.   This ability is found in five months old babies.  It peaks in early adulthood and then begins to deteriorate.

Examples of familiar tests in which performance may be aided by mental imagery





In order to solve this matrix, we have to place in our mind's eye the middle stimulus in every row on the left stimulus in that row.  The solution (the right stimulus in each row) is composed of the un-parallel lines in both stimuli.  Thus the answer is no. 8.  When we mentally place image on image and analyze the result we are manipulating mental images.
 
Learning an association between two concepts or a word/concept list – mental imagery can help us learn concept pairs (for instance, if I want to learn the pair "tree" and "cup" I can imagine a tree that grows cups instead of fruit.  The image should be amusing and impossible to be retrieved easily).  Similar techniques help us learn word lists (for instance, we can mentally assign words to places on a list of places on a mental fixed path.  We form visual images linking each word to its place.  When we retrieve the words we "walk" down the mental path and "pick" the word from each pair).

Retrieval of visual stimuli – when we draw a visual stimulus which we saw or copied in the past, we usually form a visual image of the stimulus and "copy" it to the paper.

Phonological segmentation – we can use mental imagery in various phonological tasks.  For instance, in order to choose from the pictures below the two that begin with the same sound, we can say the object names in our mind's ear and analyze the first sound.  This will lead us to choose "cup" and "cane" which both begin with the sound /k/.

Mental images assist in solving these tests, but research reveals that people who report having poor imagery ability can solve these tests with a similar degree of success.  They probably do it in different ways. 

Hubbard, T. L. Auditory Imagery: Empirical Findings. Psychological Bulletin 2010 American Psychological Association 2010, Vol. 136, No. 2, 302–329. http://timothyhubbard.net/hubPB10.pdf

SHEPARD, R. N. & METZLER, J. Mental rotation of three-dimensional objects. Science, 1971.701-703

Wednesday, August 17, 2016

The Eye's Mind: Visual Imagination, Neuroscience and the Humanities



 

 עוד על דימויים מנטליים באתר זה 

המאגד חומרים מהכנס שפרטיו למטה: 
 


The Eye's Mind: Visual Imagination, Neuroscience and the Humanities

An international conference at Sainsbury Centre for Visual Arts, University of East Anglia, Norwich, UK

21 - 22 May 2016

The visual imagination is one of the most powerful human capacities.
It plays a vital role in art and literature, religion and science, and has been studied and celebrated by artists, writers, philosophers, psychologists, and, now, neuroscientists.
The event, which is the culmination of the AHRC-funded research project, 'The Eye’s Mind', brought together leaders in all these fields to shape a new and more integrated understanding of this mysterious mental resource.
Keynote speakers included Paul Broks (psychology), Joel Pearson (neuroscience) and Michael Tye (philosophy).

Mental images – what are they? How are they related to perception?








Mona Lisa Rasee is one of Marcel Duchamp's variations on the Mona Lisa.  This is a black and white photograph of the original painting.  The only difference between it and the original is the caption.  The caption "Mona Lisa Rasee" makes us see the painting differently, since it invokes the visual image of the Mona Lisa bearded and mustached.

Marcel Duchamp did create a bearded and mustached Mona Lisa before creating "Mona Lisa Rasee".  People who knew this version may have formed a visual image of the Mona Lisa with the specific beard and mustache that Duchamp painted on it.

What are mental images?  According to Prof.  Bence Nanay from Antwerp University, mental imagery is perceptual processing not triggered by corresponding sensory stimulation in the relevant sense modality.

What does this mean?  If the image is visual, for instance, it is not identical with a visual stimulus that we may concurrently see (we do not actually see the beard when we looked at the picture above and form the image of the bearded Mona Lisa).

This definition implies that a mental image is processed in the sensory processing systems.  When we form a mental image we activate the same brain areas that are activated when we process a perceptual stimulus.  When we form a visual image, we activate brain areas that are activated during visual processing.  When we form an auditory image, we activate brain areas that are activated during auditory processing, and so on. 

Mental images have five features:

1.  They can be formed in all modalities.  There are auditory images, olfactory images, flavor images tactile images.    We can play a song in our mind's ear, form an image of the scent of cinnamon or of the touch of a feather. 

2.  They can be involuntary.  A song we heard in the morning may involuntarily replay itself in our mind's ears throughout the day.   On a sadder note, people may have involuntary flashbacks of traumatic events that they've been through.

3.  They don't have to be placed in a specific spatial place.  If we see an apple in our mind's eye, it won't necessarily be "placed" anywhere specific in space.  We can manipulate an image from an egocentric point of view (imagining taking a different perspective in space) or from an allocentric point of view (mentally manipulating objects from a stationary point of view ).

4.  Usually they don't generate a sense of presence.  Usually we know that the mental image does not exist in reality.  But there are forms of mental image that do have a sense of presence, like dreams.

5.  They can be unconscious.  As defined above, a mental image is a perceptual process.  Since perceptual processes can be unconscious, mental images can also be unconscious.  Some people have a condition called Aphantasia.   These people can perform tasks that allegedly require the formation of mental images, but they do not report experiencing mental images.  Researchers have differing views on this:  some say these people have mental images that they are not aware of.  Others say they perform these tasks using other cognitive skills.

What cognitive tasks allegedly require the formation of mental images?

Tasks like this one:



In this task, the person is asked to decide which of the four stimuli on the right is identical to the stimulus on the left.  People usually solve this kind of problem by mental rotation – they mentally rotate the stimuli on the right until they are parallel (or not) with the stimulus on the left.

Prof. Nanay argues that mental images are an integral part of our perceptual processes.  We cannot perceive (almost) any stimulus without mental imagery taking a part in our perceptual process.  Why?  It's easy to explain with visual images.  Look around you.  Almost any object you see occludes other objects which lie behind it, and also occludes the back side of itself.  Using mental imagery we "complete" the background objects or the back side of objects.  Furthermore:  we experience everything in more than one sense modality.  But usually we don't get information about every object from all sense modalities.  We represent the information we don't get from our senses by forming multimodal mental images of objects.  For example, I can form a mental image of the tactile feeling of the tree trunk that is seen from my window.  If the window is closed, I can form an auditory image of the rustling of the tree's leaves in the wind.  The tactile and the auditory images are combined with the visual perception of the tree to create my experience of the tree.

Are you familiar with the phenomenon, that when you read an email written by someone you know, you read the message in that person's "voice"?  This is another example of the way a mental (auditory) image is involved in perceptual processes.

This is probably the reason visual processing (as a CHC ability) is defined this way:  "The ability to make use of simulated mental imagery (often in conjunction with currently perceived images) to solve problems".  Visual processing is what the mind does with the information coming from the eyes, sometimes a long time after the information arrived.  Likewise is the case with auditory processing.  Auditory processing is what the mind does with auditory information, sometimes a long time after it arrived.  That's why Beethoven managed to write such great music when he was already completely deaf.  He used auditory imagery.  And when he did that, he was engaged in auditory processing.


Reference:  video posts by Prof. Bence Nanay