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BLEEDING BRAIN December 10, 1996, was the day a blood vessel in Dr. Jill Bolte Taylor’s brain began to bleed. At approximately 7:00 A.M., Dr. Jill awoke to a pain behind her left eye, a stabbing sensation she found similar to the “brain freeze” felt after a hasty gulp of ice cream. It seemed strange for a healthy 37-year-old woman to experience such a terrible headache, but Dr. Jill was not the type to lounge in bed all day. Pushing through the pain, she got up and climbed onto her exercise machine. But as soon as she began moving her limbs back and forth, a weird out-of-body sensation took hold. “I felt as though I was observing myself in motion, as in the playback of a memory,” Dr. Jill writes in her book, My Stroke of Insight. “My fingers, as they grasped on to the handrail, looked like primitive claws” (Taylor, 2006, p. 37).

The pain, meanwhile, kept hammering away at the left side of her head. She stepped off the workout machine and headed toward the bathroom, but her steps seemed plodding, and maintaining balance demanded intense concentration. Finally reaching the shower, Dr. Jill propped herself against the wall and turned on the faucet, but the sound of the water splashing against the tub was not the soothing whoosh she had expected to hear. It was more like an earsplitting roar. Dr. Jill’s brain was no longer processing sound in a normal way. For the first time that morning, she began to wonder if her brain was in serious trouble (Taylor, 2006).

“What is going on?” she thought. “What is happening in my brain?” (Taylor, 2006, p. 41). If anyone was poised to answer these questions, it was Dr. Jill herself. A devoted neuroanatomist, she spent her days studying neurons at a prestigious laboratory affiliated with Harvard Medical School. She now imagined herself rummaging through her mental library for any memories that might help diagnose her condition. This method of recall was something she habitually used, but all the files seemed to be locked. The knowledge was there, but she could not tap into it (Taylor, 2006).

Story and quotations from My Stroke of Insight, by Jill Bolte Taylor, © 2006 by Jill Bolte Taylor. Used by permission of Viking Penguin, a division of Penguin Group (USA) Inc.

Dr. Jill sensed that something was terribly wrong, but she could not help feeling mesmerized by the “tranquil euphoria” of her new state of consciousness. She no longer felt separate from the outside world. Like a fluid running fast and free, her body drifted in and out of surrounding space. Memories of the past floated into the distance, everyday worries evaporated, and the little voices in her mind that normally narrated her train of thought fell silent (Taylor, 2006).

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Wading in a dreamlike fog, Dr. Jill managed to shower and put on clothes. Then, just as she began visualizing the journey to work, her right arm fell limp like a dead fish. It was paralyzed. At that moment she knew: “Oh my gosh, I’m having a stroke! I’m having a stroke!” (Taylor, 2006, p. 44). Her next thought was: “Wow this is so cool! . . . How many scientists have the opportunity to study their own brain function and mental deterioration from the inside out?” (p. 44).

Dr. Jill was indeed having a rare form of stroke caused by a defective linkage between blood vessels in the brain. This faulty connection in the central nervous system, known as an arteriovenous malformation (AVM), is present in a substantial number of people—about 300,000 in the United States alone (around 0.1% of the population). Most individuals born with AVMs are symptomless and unaware of their condition, but about 12% (36,000 people) experience effects ranging from annoying headaches to life-threatening brain bleeds like the kind Dr. Jill was experiencing (National Institute of Neurological Disorders and Stroke, 2015).

Having a backstage pass to her own stroke was a once-in-a-lifetime learning opportunity for a neuroanatomist, but it was also a serious condition requiring an immediate response. Aware of this urgency, Dr. Jill walked into her home office and took a seat by the phone, racking her brain for ideas of how to get help. The usual strategies like calling 911 or knocking on a neighbor’s door simply did not cross her mind. As she gazed at the phone keypad, a string of digits materialized in her brain. It was the phone number of her mother in Indiana. Calling her mom was certainly an option, but what would she say? Dr. Jill didn’t want to worry her mother, so she sat and waited, hoping that another set of digits would appear (Taylor, 2006).

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Finally, another number flickered by in two separate chunks—it was her work number. She scrawled the digits as fast as she could, but looking at what she had written, she only saw cryptic lines and curves. Fortunately, those lines and curves matched the figures she saw on the phone keypad. Dr. Jill picked up the receiver and dialed her coworker and friend, Dr. Stephen Vincent (Taylor, 2006). Steve answered the phone immediately, but his words were incomprehensible to Dr. Jill. “Oh my gosh, he sounds like a golden retriever!” she thought. Mustering all her mental might, she opened her mouth and said, “This is Jill, I need help!” Well, that’s what she hoped she had said. Her own voice sounded like a golden retriever as well (Taylor, 2006, p. 56; TED.com, 2008). Luckily, Steve recognized that the murmurs and cries belonged to his friend Jill, and before long he was driving her to the hospital (Taylor, 2006).

As blood hemorrhaged into Dr. Jill’s brain, she became increasingly unable to process sensory information, tap into memories, and use language. As she later reflected: “In the course of four hours, I watched my brain completely deteriorate in its ability to process all information” (TED.com, 2008). The bleeding was beginning to limit her capacity for cognition.

Cognition. You’ve probably heard the word tossed around in conversation, and perhaps you know that it has something to do with thinking. But what exactly do we mean by cognition, and where does it figure in the vast landscape of psychology?

The study of cognition is deeply rooted in the history of psychology. Early psychologists were intensely focused on understanding the mysterious workings of the mind, often using introspection (examination of one’s own conscious activities) in their studies. With the rise of behaviorism in the 1930s, the emphasis shifted away from internal processes and on to behavior. Researchers shunned the study of thoughts, emotions, and anything they could not observe or measure objectively. In the 1950s, psychologists once again began to probe the private affairs of the mind. Psychology experienced a cognitive revolution, and research on cognition and thinking has flourished ever since.

LO 1 Define cognition and explain how it is related to thinking.

On Day 2 in the hospital, Steve told Dr. Jill that her mother, who went by the name of “G.G.,” would be coming to visit. Dr. Jill found the news perplexing (Taylor, 2006). What on Earth was a mother, and who or what was a G.G.? “Initially, I didn’t understand the significance of G.G.—as I had lost the concept of what a mother was,” she writes (p. 88). The following day, G.G. appeared at the doorway, walked over to her daughter’s bed, and climbed in alongside her. As Dr. Jill recalls, “She immediately wrapped me up in her arms and I melted into the familiarity of her snuggle” (p. 90).

LO 2 Define concepts and identify how they are organized.

Although the touch of G.G. felt familiar, the concept of her had slipped away, at least temporarily. Concepts are a central ingredient of cognitive activity, and are used in important processes such as memory, reasoning, and language (Slaney & Racine, 2011). Concepts are mental representations of categories of objects, situations, and ideas that belong together based on their central features or characteristics. The concept of superhero, for example, includes a variety of recognizable characteristics, such as: has supernatural powers, battles villains, protects innocent people, and wears unbecoming tights. Abstract concepts (such as love, belonging, and honesty) are far harder to pinpoint than concrete concepts (like animals, furniture, and telephones). Personal experiences and culture shape the construction of abstract concepts, and we don’t always agree on their most important characteristics.

Without concepts, it would be quite difficult to understand the tidal wave of data flooding our brains every day. For example, we all know what dessert is. But if the concept dessert did not exist, we would have to describe all the characteristics that we expect of a dessert whenever one comes up in conversation: “Yesterday I ate the most delicious food—you know, those sweet-tasting, mouth-watering, high-calorie items typically consumed after lunch or dinner?” Thanks to our dessert concept, however, we can simply use the word “dessert” as shorthand for all of them. (“Yesterday I ate the most delicious dessert.”) And even if someone offers you an unfamiliar dessert (for example, a chocolate tartelette), you still know that you are being offered a sweet food typically eaten after a meal. Concepts allow us to organize and synthesize information, and to draw conclusions about specific objects, situations, and ideas that we have never encountered before. Imagine how exhausting thinking and talking would be if we did not have concepts to fall back on.

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HIERARCHIES OF CONCEPTS One way to understand concepts is to consider how they can be organized in hierarchies. Generally, psychologists use a three-level concept hierarchy to categorize information.

At the top of the hierarchy are superordinate concepts. This is the broadest category, encompassing all the objects belonging to a concept. The superordinate concept of furniture is depicted at the top of the hierarchy in Infographic 7.1, below. This is a very broad group, including everything from couches to nightstands.

Narrowing our focus to include only couches, we are considering the midlevel or basic level of our hierarchy. This is still a fairly general grouping, but not as broad as a superordinate concept such as furniture.

Subordinate-level concepts are even narrower, in this case referring to specific types or instances of couches, such as a loveseat, a La-Z-Boy, or my own couch with crumbs between the cushions.

The midlevel category is what we use most often to identify objects in everyday experience. Most children learn the midlevel concepts first, followed by the superordinate and subordinate concepts (Mandler, 2008; Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Although a child might grasp the meaning of couch, she may not understand furniture (the superordinate level) or chaise lounge (the subordinate level).

Reconstructing concept hierarchies was a formidable task for Dr. Jill, because so many of their layers had been washed away by the hemorrhage. But with hard work, relentless optimism, and the help of G.G., she slowly reconstructed concepts as diverse as alphabet letters and tuna salad. Using children’s books like The Puppy Who Wanted a Boy, G.G. helped her daughter retrain her brain to read, and by putting together puzzles, Dr. Jill was able to recreate concepts such as right side up and edge (Taylor, 2006). A trip to the laundromat became a lesson in first-grade math concepts—and in the challenges of learning concepts all over again. Putting a few coins in her daughter’s hand, G.G. posed the following question: “What’s one plus one?” Perplexed, Dr. Jill came back with a more basic question: “What’s a one?” (p. 108).

LO 3 Differentiate between formal concepts and natural concepts.

FORMAL CONCEPTS Now let’s take a look at the way concepts develop. Formal concepts are based on rigid and logical rules (or “features” of a concept). When a child learns that 1 is an odd number because, like all other odd numbers, it cannot be divided evenly by 2 without a remainder, she is developing a simple formal concept. An object, idea, or situation must explicitly adhere to strict criteria in order to meet the definition of a particular formal concept. Science uses formal concepts to develop laws, theorems, and rules. Formal concepts introduced in this textbook include the pitch of a sound (defined by the frequency of the sound wave) and iconic memory (with a span of less than 1 second).

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NATURAL CONCEPTS In contrast to formal concepts, natural concepts are defined by general characteristics and are acquired during the course of our daily lives (Rosch, 1973). Identifying objects that fall into such categories is more difficult because their boundaries are imprecise and harder to define; natural concepts don’t have the same types of rigid rules for identification that formal concepts do (Hampton, 1998). This makes them more difficult to outline and therefore less useful in science.

Consider the natural concept of mother. Your concept of mother may be quite different from that of the person sitting next to you. What criteria do you use to determine if someone is a mother? Is it necessary for a person to get pregnant and have a baby? If so, the large group of women who adopt children are not included. What about someone who gives birth but then immediately puts the baby up for adoption—is she a mother?

PROTOTYPES In our daily use of natural concepts, we rely on prototypes, which are the ideal or most representative examples of natural concepts (Mervis & Rosch, 1981). Prototypes help us categorize or identify specific members of a concept. If you were asked to identify the ideal example of a mother, you might very well begin describing the characteristics of your own mother, because she is probably the mother with whom you are most familiar. If we asked you to name an example of a fruit, you would most likely say apple or orange—and not olive, unless, of course, you happen to be from Greece where olives are practically a staple. Infographic 7.1 presents a list of fruit organized from the most frequently suggested prototype—orange—to the least frequently suggested prototype—olive (Rosch & Mervis, 1975).

Items are easier to identify when they closely resemble prototypes. If shown an image of a papaya, many people in the United States would take longer to identify it as belonging to the fruit category than if they were shown an image of a peach (which is more similar to the common prototypes of apples and oranges). We suspect it would take them even longer to identify a durian or rambutan. Because natural concepts develop through daily experiences, prototypes vary from one person to the next. One study comparing adults in the United States and China found cross-cultural differences in the prototypical examples for mythological figures and tropical fish (Yoon et al., 2004).

We now know how the brain organizes information into meaningful categories, or concepts. But how is that information represented inside our heads, even for concepts related to people, places, and things that aren’t present? With the help of mental imagery, another key ingredient of cognition, we see them in our mind’s eye and imagine how they look, sound, smell, taste, and feel.

Dr. Taylor’s stroke devastated certain aspects of her cognitive activity, such as language and memory. But some functions, like her ability to think visually, continued humming along quite smoothly (Taylor, 2006). If asked a question, she would search for answers in her arsenal of mental images. As Dr. Jill describes it, “Language with linear processing was out. But thinking in pictures was in” (p. 78).

When people try to describe cognitive activity, they often provide descriptions of images from the “mind’s eye,” or mental images. Try to imagine, for instance, where your cell phone is right now. Did a picture of your beloved mobile device suddenly materialize in your head? If so, you have just created a mental image. Whether contemplating the whereabouts of cell phones or daydreaming about celebrities walking the red carpet, our brains are constantly whipping up vivid pictures. These mental images are not two-dimensional scenes frozen in time. Our brains have an amazing knack for manipulating them in three dimensions.

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Let’s consider what we do when we examine a new object for the first time. We typically hold it in our hands (if it’s not too heavy) and rotate it to get a better sense of what we are looking at. If the object is too large to hold, we often walk around it to see how it looks from various angles. Researchers are particularly interested in finding out if we mentally behave this way as well, and they have spent a great deal of time studying mental imagery and the rotation of objects.

IMAGINING OBJECTS AND MAPS In one of the earliest studies on this topic, Roger Shepard and Jacqueline Metzler (1971) had eight participants look at 1,600 pairs of object drawings like those displayed in Figure 7.1 and then asked them to mentally rotate one of the objects in the pair to determine if they were identical. In calculating the reaction times, the researchers discovered that the amount of time it took participants to rotate the object depended on the degree of difference between the orientations of the two objects. The greater the rotation, the longer it took participants to decide if the objects were identical.

The ability to mentally rotate objects is extremely useful in everyday life. Remember the last time you tried to fit a large piece of furniture through a doorway, squeeze rolling luggage into the overhead bin of an airplane, or cram just one more container of leftovers into an overflowing refrigerator. In each case, you probably relied on some type of mental rotation to plan how to get each of these objects into or through a small space.

Perhaps you have heard the stereotype that men outperform women when it comes to packing a car or trunk. Research does suggest that men are better than women in tasks requiring the mental rotation of objects (Collins & Kimura, 1997), but this disparity is not absolute. With practice, women may catch up. In one study, women who practiced mentally rotating objects while playing computer games showed greater improvement on measures of mental rotation than did the men (Cherney, 2008).

In another fascinating study on mental imagery, participants were instructed to study a map of a small fictional island (Figure 7.2). The researchers then asked them to close their eyes and imagine the map, first picturing one object (the hut) and then scanning across their mental image of the map until they “arrived” at a second object (the rock). The researchers found that it took longer for participants to “find” objects on the mental map when the objects were farther apart. As with the scanning of real objects, the amount of time it takes to scan a mental image is relative to the distances between the objects in the image (Kosslyn, Ball, & Reiser, 1978). In addition, Kosslyn (1978) suggests that the size of the image is connected to how much detail people can see in their mind’s eye. Fewer details can be detected on smaller images.

AUDITORY IMAGERY Stop for a moment and imagine the smell of chocolate chip cookies baking in the oven, the tang of lemon on your tongue, or the sound of a cat meowing. It is important to remember that not all imagery is visual; other sensory experiences can be used to construct imagery in our minds. A review of research on auditory imagery indicated that auditory images are similar to true auditory stimuli (such as music and language) in their properties (for example, pitch and loudness), and that auditory images involve the brain regions used in auditory perception, such as Broca’s area (Hubbard, 2010). Interestingly, auditory imagery is associated with a person’s musical background and ability. When asked to think about two known song lyrics, study participants with musical training were better than other participants at identifying which of the songs would be sung at a higher pitch (Janata & Paroo, 2006).

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We use mental images all the time—so often it’s hard to conceive of thinking without them. Imagine reading this chapter without being able to visualize Dr. Jill staggering around her house the morning of her stroke. How would your brain interpret the description of Steve’s voice sounding like a golden retriever if you could not “hear” the sound in your mind? Mental images, like concepts, lie at the heart of cognition.

Every cognitive activity we have discussed thus far, from establishing prototypes of fruit to mentally rotating leftovers in the refrigerator, is made possible by the electric and chemical bustle of billions of neurons. Let’s dive into that bustle and get acquainted with the biology of cognition.

LO 4 Describe the biological processes associated with cognition.

Dr. Jill’s story provides a stark illustration of the following principle: If the brain’s biological integrity is compromised, cognition is likely to suffer. The bleeding in her brain began in a small region on the left side of her cerebral cortex but soon spread across large areas of her brain (Taylor, 2006). Among those affected was her left frontal lobe, a part of the brain critical for a broad array of higher cognitive functions such as processing emotions, controlling impulses, and making plans. Remember that Dr. Jill experienced enormous difficulty devising a simple plan to save her own life (for example, she was unable to think of calling 911).

The stroke also ravaged brain regions critical for another major element of cognition: language processing. “As the blood interrupted the flow of information transmission between my two language centers (Broca’s anteriorly and Wernicke’s posteriorly). . . . I could neither create/express language nor understand it,” Dr. Jill recalls in her book (Taylor, 2006, p. 62). Broca’s and Wernicke’s areas work with other parts of the brain to generate and understand language.

COGNITION AND NEURONS The biology of cognition can also be observed on a micro scale. Normally, changes at the level of neurons make it possible to store and retrieve information—like how to call 911 in a dire emergency. Apparently, the stroke had interfered with neurons involved in the retrieval of memories. It is also at the neuronal level where we see the amazing plasticity of the brain at work. Following a stroke, healing and regeneration begin with changes to neurons. These changes include greater excitability of the neurons, rewiring to take advantage of both hemispheres, increases in dendritic connections, and increased efficiency of connections at the synapses (Dobkin, 2005).

MEASURING COGNITION IN THE BRAIN Reading Dr. Jill’s CT scans, the doctors were able to see the cause of all these cognitive malfunctions—an enormous hemorrhage on the left side of her brain: “It didn’t take someone with a Ph.D. in neuroanatomy to figure out that the huge white hole in the middle of the brain scan didn’t belong there!” (Taylor, 2006, p. 68).

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Technologies such as CT are extremely useful for detecting abnormalities like strokes and tumors, but they also tell us a lot about normal cognitive functioning. Many interesting studies on cognition have investigated the biological basis of mental imagery. As it turns out, the brain often displays similar patterns of activity, whether we are imagining something or seeing it in real life.

In one study, researchers implanted electrodes in the brains of participants with severe epilepsy. This allowed the researchers to monitor individual neurons as participants looked at houses, animals, famous people, and other images. They found that some neurons responded to certain objects but not to others. A neuron would fire when the participant was looking at a picture of a baseball but not at an image of a face, for example. The researchers could identify the image the person was viewing simply by observing his brain activity. They also observed that the same neurons that became excited when the person was looking at an actual object also were active when the person was merely imagining that object (Kreiman, Koch, & Fried, 2000).

Using technologies such as PET and fMRI, researchers have found that the visual cortex can be activated by mental imagery as well as by external stimuli (Ganis, Thompson, & Kosslyn, 2004). Information (from either an external stimulus or a mental image) is processed by the visual cortex, which works with other areas of the brain to identify images based on knowledge stored in memory. Researchers have noted that similar areas of the frontal and parietal regions of the brain are activated when study participants look at, for example, an image of a tree and when they imagine a tree. Once again, it appears that perception and imagery use many of the same neural mechanisms (Ganis et al., 2004).

Clearly, there are substantial biological differences between men and women, but how do the sexes compare in their cognitive abilities? In childhood, girls tend to perform better on tests of verbal ability, but the discrepancies are so small that they don’t provide useful information for making educational decisions (Hyde & Linn, 1988; Wallentin, 2009). Meanwhile, boys are able to mentally rotate objects earlier in infancy than girls (Moore & Johnson, 2008). But differences in cognitive development between boys and girls are “minimal,” and are only responsible for a small proportion of the variability in children’s scores on cognitive tasks (Ardila, Rosselli, Matute, & Inozemtseva, 2011).

Research suggests that some cognitive gender disparities carry over into adulthood, with women outperforming men in verbal tasks and men showing greater spatial and mathematical abilities. These gender differences have declined over the past several decades, suggesting changes in sociocultural factors are at work, such as greater availability of advanced math courses and more support for both men and women to pursue careers that interest them (Deary, Penke, & Johnson, 2010; Wai, Cacchio, Putallaz, & Makel, 2010). When it comes to mathematics performance in children, gender is not the best future indicator; environmental factors such as mother’s education, the learning environment of the home, and effectiveness of the elementary school are “far stronger predictors” (Lindberg, Hyde, Petersen, & Linn, 2010).

Question 1

Question 2

1. cognition

2. concept

3. hierarchy

4. mental imagery

Question 3

1. prototype

2. natural concept

3. formal concept

4. cognition

Question 4