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Scientific Dream Interpretation and Analysis |
SP r = √SSxSSy |
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Scientific Dream Interpretation and Analysis |
SP r = √SSxSSy |
Brain Lateralization
In the 1960s Dr. Roger Sperry and his students Michael Gazzaniga and Jerre Levy began their historic split-brain experiments. In these experiments, they were able to test separately the thinking abilities of the two surgically separated halves of the human brain.
In 1964, an operation was performed by Dr. Joseph Bogen, then a young, enthusiastic neurosurgeon, and his mentor and partner, Dr. Philip Vogel on a fourteen- year-old patient, "AA," that became famous not as much because of its therapeutic benefit as more because of the subsequent studies performed on the patient after recovering from the surgery. The neurosurgical procedure, known as a commissurotomy, involved cutting the large nerve bundle, the corpus callosum, which connected the left and right hemispheres of the brain. The operation was performed on the boy, who was desparately suffering from epilepsy which was not relieved by conventional treatments, because it was reasoned that the operation could prevent the spread of a seizure from one hemisphere to the other, thus, containing it. The doctors hoped that limiting the spread of the seizures might reduce the epilepsy generally. The results showed that not only were the seizures decreased, but also the patient did not seem adversely affected by the radical surgery. Subsequently, many more patients were treated employing this procedure.
Roger Sperry, neuroscientist and colleague of the doctors, was awarded, in 1981, the Nobel Prize for the pioneering studies of the 1960s on these "split brain" patients. The commissurotomy made it possible for the patients to live a normal life after the operation, but it was only when carrying out these experiments Sperry noticed their somewhat "odd behavior." Each hemisphere is still able to learn after the split brain operation but one hemisphere has no idea about what the other hemisphere has experienced or learned. Today, new methods and technology in split brain operation make it possible to cut off only a tiny portion and not the whole of the corpus callosum of patients.
The studies demonstrated that the left and right hemispheres are specialized in different tasks. The left side of the brain is normally specialized in taking care of the analytical and verbal tasks. The left side speaks much better than the right side, while the right half takes care of the space perception tasks and music, for example. The right hemisphere is involved when you are making a map or giving directions on how to get to your home from the bus station. The right hemisphere can only produce rudimentary words and phrases, but contributes emotional context to language. Without the help from the right hemisphere, you would be able to read the word "pig" for instance, but you wouldn't be able to imagine what it is.
For over a century it has been known that human powers of speech reside primarily in the left hemisphere (about 5% of the population, one third of all left-handed people, have speech in the right brain and nonverbal thinking in the left): Injuries on the left side cause speech damage, while right-brain injuries leave speech intact. In 1861, Paul Broca, noted French surgeon and anthropologist, presented two cases of patients diagnosed independently as having a loss of speech. Both of them had suffered damage to the left frontal part of the brain. Their right hemispheres were intact. Soon afterwards, Broca proclaimed a rule that in right-handers, speech is represented in the left side of the brain, and in left-handers it is in the other side. Loss of normal speech is called aphasia. A Broca's aphasic has difficulty in articulating speech but not in understanding it. Speech is halting and completely lacking in grammatical niceties. Often sentences sound much like a telegram with all but the most basic words omitted. Broca's aphasics are aware of their difficulty and are usually quite frustrated.
Carl Wernicke, German neurologist, in 1874, described another type of aphasia in which the mechanisms of speech production are intact but the thought processes of the left brain are disordered. The result is a "word salad" - an impressive-sounding stream of double-talk which makes little or no sense. In this case the patient's understanding of language is also impaired. The patient is not aware that there is any difficulty, nor is the patient frustrated, for the speech mechanisms are truly expressing the jumbled stream of verbal consciousness.
While the Wernicke's aphasia victim may have practically no understanding of spoken language, there is paradoxically one area where understanding remains intact: "Whole body" commands such as "stand up," "stand at attention," and "assume the position of a boxer" may be understood and obeyed with an understanding well above the patient's normal language comprehension ability. It seems possible that this is the language ability of the intact right hemisphere in action. The right hemisphere's language ability is generally passive. However, control of the "whole body" positions is very well integrated in the brainstem, with inputs from both the left and the right hemispheres. Right-brain initiation of whole body movements in response to verbal commands not understood by the left brain thus seems possible.
Another paradox with Wernicke's aphasia victims is their ability to detect spelling errors in written material even though their own spelling is abominable. Their own spelling is, of course controlled by their damaged left hemisphere. The still intact right brain, however is able to recognize and point out spelling errors at a glance.
The following is excerpted from:MICHAEL S. GAZZANIGA, professor of cognitive neuroscience and director of the Center for Cognitive Neuroscience at Dartmouth College. He received his Ph.D. at the California Institute of Technology, where he, Roger W. Sperry and Joseph E. Bogen initiated split-brain studies. Since then, he ahs published in many areas and is credited with launching the field of cognitive neuroscience in the early 1980s. Gazzaniga likes to ski and to arrange small, intense intellectual meetings in exotic places.
About 30 years ago in these very pages, I wrote about dramatic new studies of the brain. Three patients who were seeking relief from epilepsy had undergone surgery that severed the corpus callosum - the superhighway of neurons connecting the halves of the brain. By working with these patients, my colleagues Roger W. Sperry, Joseph E. Bogen, P.J. Vogel and I witnessed what happened when the left and right hemispheres were unable to communicate with each other.
It became clear that visual information no longer moved between the two sides. If we projected an image to the right visual field - that is, to the left hemisphere, which is where information from the right field is processed - the patients could describe what they saw. But when the same image was displayed to the left visual field, the patients drew a blank: they said they didn’t see anything. Yet if we asked them to point to an object similar to the one being projected, they could do so with ease. The right brain saw the image and could mobilize a nonverbal response. It simply couldn’t talk about what it saw.
The same kind of finding proved true for touch, smell and sound. Additionally, each half of the brain could control the upper muscles of both arms, but the muscles manipulating hand and finger movement could be orchestrated only the by contralateral hemisphere. In other words, the right hemisphere could control only the left hand and the left hemisphere only the right hand.
Ultimately, we discovered that the two hemispheres control vastly different aspects of thought and action. Each half has its own specialization and thus it’s own limitations and advantages. The left brain is dominant for language and speech. The right excels at visual-motor tasks. The language of these findings has become part of our culture: writers refer to themselves as left-brained, visual artists as right-brained.
In the intervening decades, split-brain research has continued to illuminate many areas of neuroscience. Not only have we and others learned even more about how the hemispheres differ, but we also have been able to understand how they communicate once they have been separated. Split-brain studies have shed light on language, on mechanisms of perception and attention, and on brain organization as well as the potential set of false memories. Perhaps most intriguing has been the contribution of these studies to our understanding of consciousness and evolution.
The original split-brain studies raised many interesting questions, including ones about whether the distinct halves could still "talk" to each other and what role any such communication played in thought and action. There are several bridges of neurons, called commissures, that connect the hemispheres. The corpus callosum is the most massive of these and typically the only one severed during surgery for epilepsy. But what of the many other, smaller commissures?
Remaining BridgesBy studying the attentional system, researchers have been able to address this question. Attention involves many structures in the cortex and the subcortex - the older, more primitive part of our brains. In the 1980s Jeffrey D. Holtzman of Cornell University Medical College found that each hemisphere is able to direct spatial attention not only to its own sensory sphere but also to certain points in the sensory sphere of the opposite, disconnected hemisphere. This discovery suggests that the attentional system is common to both hemispheres - at least with regard to spatial information - and can still operate via some remaining interhemispheric connections.
Holtzman’s work was especially intriguing because it raised the possibility that there were finite attentional "resources." He posited that working on one kind of task uses certain brain resources; the harder the task, the more of these resources are needed - and the more one half of the brain must call on the subcortex or the other hemisphere for help. In 1982 Holtzman led the way again, discovering that, indeed, the harder one half of a split brain worked, the harder it was for the other half to carry out another task simultaneously.
Recent investigations by Steve J. Luck of the University of Iowa, Steven A. Hillyard and his colleagues at the University of California at San Diego and Ronald Mangun of the University of California at Davis show that another aspect of attention is also preserved in the split brain. They looked at what happens when a person searches a visual field for a pattern or an object. The researchers found that split-brain patients perform better than normal people do in some of these visual-searching tasks. The intact brain appears to inhibit the search mechanisms that each hemisphere naturally possesses.
The left hemisphere, in particular, can exert powerful control over such tasks. Alan Kingstone of the University of Alberta found that the left hemisphere is "smart" about its search strategies, whereas the right is not. In tests where a person can deduce how to search efficiently an array of similar items for an odd exception, the left does better than the right. Thus, it seems that the more competent left hemisphere can hijack the intact attentional system.
Although these and other studies indicated that some communication between the split hemispheres remains, other apparent interhemispheric links proved illusory. I conducted an experiment with Kingstone, for instance, that nearly misled us on this front. We flashed two words to a patient and then asked him to draw what he saw. "Bow" was flashed to one hemisphere and "arrow" to the other. To our surprise, our patient drew a bow and arrow! It appeared as though he had internally integrated the information in one hemisphere; that hemisphere had, in turn, directed the drawn response.
We were wrong. We finally determined that integration had actually taken place on the paper, not in the brain. One hemisphere had drawn its item - the bow - and then the other hemisphere had gained control of the writing hand, drawing its stimulus - the arrow - on top of the bow. The image merely looked coordinated. We discovered this chimera by giving less easily integrated word pairs like "sky" and "scraper." The subject did not draw a tall building; instead he drew the sky over a picture of a scraper.
Hemispheric differences have proven more complex than scientists originally suspected or than left brain-right brain popularizers portrayed them. Findings now suggest that clipping the corpus callosum-a structure that in fact connects only the halves of the brain's outer layer, or cortex-indeed produces two systems for handling sensations and perceptions. However, a brain mechanism shared by both hemispheres metes out the amount of attention each system can draw on the theorizes.
In this scenario, the right hemisphere handles sensory information in basic ways, such as recognizing faces and sorting through pieces of a visual scene. Its part on the left appears compelled to analyze and group sensations in ways that allow for finer-grained decisions.
A study conducted in 1995 offers a peek at the contrasting approaches of the two hemispheres. Three split-brain patients and 10 people with no neurological problems attempted to identify unique elements in visual arrays presented to one side of the visual field. So-called standard search trials contained a black circle surrounded by clusters of gray circles and black squares, each about equal in number. Guided search trials presented a black circle with a few black squares and a much larger number of gray circles; this pattern enabled volunteers to home in on the black circle by concentrating only on the small group of black items.
Split-brain patients and controls were adept at using either hemisphere to conduct standard searches. On guided search trials, the control group responded more quickly than they had on standard searches, though just as accurately, regardless of which side of their brains the researchers recruited. But split-brain volunteers showed comparable improvement only when using their left hemispheres.
Results such as these indicate that the right hemisphere contains mechanisms for soaking up the raw material of sensory experience, Gazzaniga suggests, whereas the left hemisphere favors more complex sensory strategies.
For instance, each isolated hemisphere can recognize a specific letter in genuine words more easily than in nonsense words or in random letter strings. But the right hemisphere takes longer than the left to perform this task and requires considerably more time to "make up its mind" as words get longer.
The right hemispheres of split-brain patients also consistently falter on grammatical tasks, such as changing verb tenses, constructing plurals, and indicating possessives. Such findings support the notion that the left brain harbors an evolved mechanism for understanding grammatical principles common to all spoken languages.
Perhaps most crucial to the human species, the left brain houses the main components of people's ability, to interpret the behavior and emotional states of themselves and others, as well as to make inferences about how the world works.
The Limits of ExtrapolationIn addition to helping neuroscientists determine which systems still work and which are severed along with the corpus callosum, studies of communication between the hemispheres led to an important finding about the limits of nonhuman studies. Humans often turn to the study of animals to understand themselves. For many years, neuroscientists have examined the brains of monkeys and other creatures to explore the ways in which the human brain operates. Indeed, it has been a common belief - emphatically disseminated by Charles Darwin - that the brains of our closest relatives have an organization and function largely similar, if not identical, to our own.
Split-brain research has shown that this assumption can be spurious. Although some structures and functions are remarkably alike, differences abound. The anterior commissure provides one dramatic example. This small structure lies somewhat below the corpus callosum. When this commissure is left intact in otherwise split-brain monkeys, the animals retain the ability to transfer visual information from one hemisphere to the other. People, however, do not transfer visual information in any way. Hence, the same structure carries out different functions in different species - an illustration of the limits of extrapolating from one species to another.
Even extrapolating between people can be dangerous. One of our first striking findings was that the left brain could freely process language and speak about its experience. Although the right was not so free, we also found that it could process some language. Among other skills, the right hemisphere could match words to pictures, do spelling and rhyming, and categorize objects. Although we never found any sophisticated capacity for syntax in that half of the brain, we believed the extent of its lexical knowledge to be quite impressive.
Over the years it has become clear that our first three cases were unusual. Most people’s right hemispheres cannot handle even the most rudimentary language, contrary to what we initially observed. This finding is in keeping with other neurological data, particularly those from stroke victims. Damage to the left hemisphere is far more detrimental to language function than is damage to the right.
Nevertheless, there exists a great deal of plasticity and individual variation. One patient, dubbed J.W., developed the capacity to speak out of the right hemisphere - 13 years after surgery. J.W. can now speak about information presented to the left or to the right brain.
Kathleen B. Baynes of the University of California at Davis reports another unique case. A left-handed patient spoke out of her left brain after split-brain surgery - not a surprising finding in itself. But the patient could write only out of her right, nonspeaking hemisphere. This dissociation confirms the idea that the capacity to write need not be associated with the capacity for phonological representation. Put differently, writing appears to be an independent system, an invention of the human species. It can stand alone and does not need to be part of our inherited spoken language system.
Brain ModulesDespite myriad exceptions, the bulk of split-brain research has revealed an enormous degree of lateralization - that is, specialization in each of the hemispheres. As investigators have struggled to understand how the brain achieves its goals and how it is organized, the lateralization revealed by split-brain studies has figured into what is called the modular model. Research in cognitive science, artificial intelligence, evolutionary psychology and neuroscience has directed attention to the idea that brain and mind are built from discrete units - or modules - that carry out specific functions. According to this theory, the brain is not a general problem-solving device whose every part is capable of any function. Rather it is a collection of devices that assists the mind’s information-processing demands.
Within that modular system, the left hemisphere has proved quite dominant for major cognitive activities, such as problem solving. Split-brain surgery does not seem to affect these functions. It is as if the left hemisphere has no need for the vast computational power of the other half of the brain to carry out high-level activities. The right hemisphere, meanwhile, is severely deficient in difficult problem solving.
Joseph E. LeDoux of New York University and I discovered this quality of the left brain almost 20 years ago. We had asked a simple question: How does the left hemisphere respond to behaviors produced by the silent right brain? Each hemisphere was presented a picture that related to one of four pictures placed in front of the split-brain subject. The left and the right hemispheres easily picked the correct card. The left hand pointed to the right hemisphere’s choice and the right hand to the left hemisphere’s choice.
We then asked the left hemisphere - the only one that can talk - why the left hand was pointing to the object. It really did not know, because the decision to point to the card was made in the right hemisphere. Yet, quick as a flash, it made up an explanation. We dubbed this creative, narrative talent the interpreter mechanism.
For instance, one man had a picture of a chicken claw flashed to his left hemisphere and a picture of a snow scene presented to his right hemisphere. From the ensuing selection of pictures, he correctly chose a shovel with his left hand (controlled by the right hemisphere) and a chicken with his right hand (controlled by the left hemisphere). When asked to explain his choices, he responded: "Oh, that's simple. The chicken claw goes with the chicken, and you need a shovel to clean out the chicken shed."
The conclusion was that the left brain observed the left hand's choice of a shovel - which stemmed from the right brain's nonverbal, inaccessible knowledge - and proffered an explanation based its own information.
This fascinating ability has been studied recently to determine how the left hemisphere interpreter affects memory. Elizabeth A. Phelps of Yale University, Janet Metcalfe of Columbia University and Margaret Funnell, a postdoctoral fellow at Dartmouth College, have found that the two hemispheres differ in their ability to process new data. When presented with new information, people usually remember much of what they experience. When questioned, they also usually claim to remember things that were not truly part of the experience. If split-brain patients are given such tests, the left hemisphere generates many false reports. But the right brain does not; it provides a much more veridical account.
This finding may help researchers determine where and how false memories develop. There are several views about when in the cycle of information processing such memories are laid down. Some researchers suggest they develop early in the cycle, that erroneous accounts are actually encoded at the time of the event. Others believe false memories reflect an error in reconstructing past experience: in other words, that people develop a schema about what happened and retrospectively fit untrue events - that are nonetheless consistent with the schema - into their recollection of the original experience.
The left hemisphere has exhibited certain characteristics that support the latter view. First, developing such schemata is exactly what the left hemisphere interpreter excels at. Second, Funnell has discovered that the left hemisphere has an ability to determine the source of a memory, based on the context or the surrounding events. Her work indicates that the left hemisphere actively places its experiences in a larger context, whereas the right simply attends to the perceptual aspects of the stimulus. Finally, Michael B. Miller, a graduate student at Dartmouth, has demonstrated that the left prefrontal regions of normal subjects are activated when they recall false memories.
These findings all suggest that the interpretive mechanism of the left hemisphere is always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none - which leads it continually to make mistakes. It tends to overgeneralize, frequently constructing a potential past as opposed to a true one.
The Evolutionary PerspectiveGeorge L. Wolford of Dartmouth has lent even more support to this view of the left hemisphere. In a simple test that requires a person to guess whether a light is going to appear on the top or bottom of a computer screen, humans perform inventively. The experimenter manipulates the stimulus so that the light appears on the top 80 percent of the time but in a random sequence. While it quickly becomes evident that the top button is being illuminated more often, people invariably try to figure out the entire pattern or sequence - and they deeply believe they can. Yet by adopting this strategy, they are correct only 68 percent of the time. If they always pressed the top button, they would be correct 80 percent of the time.
Rats and other animals, on the other hand, are more likely to "learn to maximize" and to press only the top button. It turns out the right hemisphere behaves in the same way: it does not try to interpret its experience and find deeper meaning. It continues to live only in the thin moment of the present - and to be correct 80 percent of the time. But the left, when asked to explain why it is attempting to figure the whole sequence, always comes up with a theory, no matter how outlandish.
This narrative phenomenon is best explained by evolutionary theory. The human brain, like any brain, is a collection of neurological adaptations established through natural selection. These adaptations each have their own representation - that is, they can be lateralized to specific regions or networks in the brain. Throughout the animal kingdom, however, capacities are generally not lateralized. Instead they tend to be found in both hemispheres to roughly equal degrees. And although monkeys show some signs of lateral specialization, these are rare and inconsistent.
For this reason, it has always appeared that the lateralization seen in the human brain was an evolutionary add-on - mechanisms or abilities that were laid down in one hemisphere only. We recently stumble across an amazing hemispheric dissociation that challenges this view. It forced us to speculate that some lateralized phenomena may arise from a hemisphere’s losing an ability - not gaining it.
In what must have been fierce competition for cortical space, the evolving primate brain would have been hard-pressed to gain new faculties without losing old ones. Lateralization could have been its salvation. Because the two hemisphere are connected, mutational tinkering with a homologous cortical region could give rise to a new function - yet not cost the animal, because the other side would remain unaffected.
Paul M. Corballis, a postdoctoral fellow at Dartmouth, and Robert Fendrich of Dartmouth, Robert M. Shapley of New York University and I studied in many split-brain patients the perception of what are called illusory contours. Earlier work had suggested that seeing the well-known illusory contours of Gaetano Kanizsa of the University of Trieste was the right hemisphere’s specialty. Our experiments revealed a different situation.
We discovered that both hemispheres could perceive illusory contours - but that the right hemisphere was able to grasp certain perceptual groupings that the left could not. Thus, while both hemispheres in a split-brain person can judge whether the illusory rectangles are fat or thin when no line is drawn around the openings of the "Pacman" figures, only the right can continue to make the judgment after the line has been drawn. This setup is called the amodal version of the test.
Our uniquely human skills may well be produced by minute and circumscribed neuronal networks. And yet our highly modularized brain generates the feeling in all of us that we are integrated and unified. How so, given that we are a collection of specialized modules?
The answer may be that the left hemisphere seeks explanations for why events occur. The advantage of such a system is obvious. By going beyond the simple observation of events and asking why they happened, a brain can cope with these same events better, should they happen again.
Realizing the strengths and weaknesses of each hemisphere prompted us to think about the basis of mind, about this overarching organization. After many years of fascinating research on the split brain, it appears that the inventive and interpreting left hemisphere has a conscious experience very different from that of the truthful, literal right brain. Although both hemispheres can be viewed as conscious, the left brain’s consciousness far surpasses that of the right. Which raises another set of questions that should keep us busy for the next 30 years or so.
Gazzaniga 1
Gazzaniga 2
Subliminal perception occurs whenever stimuli presented below the threshold or limen for awareness are found to influence thoughts, feelings, or actions. The term subliminal perception was originally used to describe situations in which weak stimuli were perceived without awareness. In recent years, the term has been applied more generally to describe any situation in which unnoticed stimuli are perceived.
In 1980, Kunst-Wilson and Zajonc, attempted to demonstrate that unconsciously perceived stimuli can influence affective reactions. More recently, Murphy and Zajonc (1993) obtained more convincing evidence for the importance of unconscious perception in determining affective reactions by showing that affective reactions are more likely to be influenced by unconsciously perceived stimuli than by consciously perceived stimuli.
In the experiments conducted by Murphy and Zajonc (1993), subjects were showna clearly-visible, Chinese ideograph on each of a series oftrials.The subjects were asked to indicate on a five-point scale whether they thought each ideograph represented a "good" or a "bad"concept.The critical aspect of the experiment concernedwhat happened immediately before each ideograph was presented. For one group of subjects, the presentation of each ideograph was preceded by a picture of a human face that expressed either happiness (e.g. a smile) or anger (e.g. a scowl). For this group of subjects, each face was presented for such a brief duration (i.e. 4 msec) that no subject reported awareness of the faces. For the second group of subjects, the same deographs and faces were presented, but the duration of each face (i.e. 1000 msec) was sufficiently long so that all subjects reported awareness of the faces. The subjects in this second group were told to ignore the faces and to concentrate solely on rating the ideographs. The important result found by Murphy and Zajonc is that only the brieflypresented, unconsciously perceived faces influenced the subjects. ratings of the ideographs. When the subjects were unaware of the faces, they were more likely to rate an ideograph as representing a .good. concept if it was preceded by a smiling face and they were more likely to rate an ideograph as representing a .bad. concept if it was preceded by a scowling face. In contrast, when the faces were clearly visible and therefore consciously perceived, the faces had little or no influence on the subjects. ratings of the ideographs. Thus, the subjects were able to ignore consciously perceived faces and not let these faces influence their ratings of the ideographs. However, when the subjects were unaware of the faces, the emotion expressed by the faces coloured their judgments of the ideographs. These results demonstrate an important qualitative difference between conscious and unconscious perception in that our affective reactions to stimuli may be influenced to a much greater extent by unconsciously perceived information than by consciously perceived information.
An interesting qualitative difference first demonstrated by Groeger (1984; 1988) is that unconsciously perceived words are coded differently than are consciously perceived words. In an experiment using visual stimuli, Groeger (1984) presented a single target word on each experimental trial and required subjects to select the target word from a matrix of 24 words that was presented immediately following the target word. The critical aspect of the experiment was that the matrix never contained the actual target word presented on the trial. Rather, the matrix included some words that were semantically similar to the target word and some words that were structurally (i.e. visually) similar to the target word. For example, if the target word was town, then a semantically similar foil was city and a structurally similar foil was time. The results of this experiment showed that in a situation in which the target words were presented for such a brief duration that the subjects did not report any awareness of the target words, the subjects tended to select the semantically similar foils. However, in a situation in which the target words were presented for a duration that was sufficiently long for the subjects to report awareness of the target words, the subjects tended to select the visually similar foils. Groeger (1988) found parallel results when he presented the words auditorially rather than visually; semantically related foils were selected when words were perceived without awareness, and phonologically similar foils were selected when words were perceived with awareness. Taken together, the results of these experiments suggest that the way a stimulus is coded varies depending on whether it is unconsciously or consciously perceived. When a stimulus is unconsciously perceived, meaning or semantics is the predominant code. However, when a stimulus is consciously perceived, structural or surface characteristics become more important. Thus, different aspects of a perceived stimulus may determine action depending on whether the stimulus is consciously or unconsciously perceived.
Poetzl (1917/1960) studied the impact of unconscious perception on the manifest content of dreams. In his study, subjects were shown a complex picture of a natural scene for a brief, 100-ms exposure duration. Immediately following the presentation of the picture, Poetzl measured the subjects. conscious recollection of what they had seen by asking them to describe and to draw everything they remembered about the picture. Poetzl then asked the subjects to record any dreams they had that night and to return the following day. When the subjects returned the next day and described their dreams, Poetzl discovered that the dream imagery contained aspects of the original picture that the subjects had failed to report the previous day when he had asked them to indicate everything they remembered regarding the picture. For present purposes, the important implication of Poetzl.s findings is that unconsciously perceived information can remain in memory for many hours. Although there have been failures to replicate Poetzl.s results (e.g. Johnson & Eriksen, 1961), Poetzl.s critical finding that unconsciously perceived information can appear in the manifest content of subsequent dreams has been replicated a number of times by a number of different investigators (e.g. Fisher, 1954; 1956; Shevrin & Luborsky, 1958). In addition, the conclusion that unconsciously perceived information remains in memory longer than a few seconds is supported by the results of a series of studies conducted by Erdelyi (Haber & Erdelyi, 1967; Erdelyi, 1970). In these studies, Erdelyi showed that recall of the details of tachistoscopically presented pictures improved when subjects engaged in a period of free association between their first and second recall attempts. Taken together, the weight of the evidence from these studies inspired by Poetzl suggests that unconsciously perceived information can have an impact that lasts considerably beyond two or three seconds.
To date, a number of qualitative differences between conscious and unconscious perception have been established. Not only do these qualitative differences show how conscious and unconscious perception differ, but they also provide stronger evidence for the existence of unconscious perception than was ever obtained in experiments designed to demonstrate unconscious perception directly.
Studies of perception without awareness and studies of perception without attention address a similar underlying concept of awareness. Results suggest that perception with and without awareness and perception with and without attention are equivalent ways of describing the same underlying process distinction.
Merikle
In a recent experiment, psychologists at Yale altered people’s judgments of a stranger by handing them a cup of coffee.
The study participants, college students, had no idea that their social instincts were being deliberately manipulated. On the way to the laboratory, they had bumped into a laboratory assistant, who was holding textbooks, a clipboard, papers and a cup of hot or iced coffee — and asked for a hand with the cup.
That was all it took: The students who held a cup of iced coffee rated a hypothetical person they later read about as being much colder, less social and more selfish than did their fellow students, who had momentarily held a cup of hot java.
Findings like this one, as improbable as they seem, have poured forth in psychological research over the last few years. New studies have found that people tidy up more thoroughly when there’s a faint tang of cleaning liquid in the air; they become more competitive if there’s a briefcase in sight, or more cooperative if they glimpse words like “dependable” and “support” — all without being aware of the change, or what prompted it.
Psychologists say that “priming” people in this way is not some form of hypnotism, or even subliminal seduction; rather, it’s a demonstration of how everyday sights, smells and sounds can selectively activate goals or motives that people already have.
More fundamentally, the new studies reveal a subconscious brain that is far more active, purposeful and independent than previously known. Goals, whether to eat, mate or devour an iced latte, are like neural software programs that can only be run one at a time, and the unconscious is perfectly capable of running the program it chooses.
The give and take between these unconscious choices and our rational, conscious aims can help explain some of the more mystifying realities of behavior, like how we can be generous one moment and petty the next, or act rudely at a dinner party when convinced we are emanating charm.
“When it comes to our behavior from moment to moment, the big question is, ‘What to do next?’ ” said John A. Bargh, a professor of psychology at Yale and a co-author, with Lawrence Williams, of the coffee study, which was presented at a recent psychology conference. “Well, we’re finding that we have these unconscious behavioral guidance systems that are continually furnishing suggestions through the day about what to do next, and the brain is considering and often acting on those, all before conscious awareness.”
Dr. Bargh added: “Sometimes those goals are in line with our conscious intentions and purposes, and sometimes they’re not.”
Priming the UnconsciousThe idea of subliminal influence has a mixed reputation among scientists because of a history of advertising hype and apparent fraud. In 1957, an ad man named James Vicary claimed to have increased sales of Coca-Cola and popcorn at a movie theater in Fort Lee, N.J., by secretly flashing the words “Eat popcorn” and “Drink Coke” during the film, too quickly to be consciously noticed. But advertisers and regulators doubted his story from the beginning, and in a 1962 interview, Mr. Vicary acknowledged that he had trumped up the findings to gain attention for his business.
Later studies of products promising subliminal improvement, for things like memory and self-esteem, found no effect.
Some scientists also caution against overstating the implications of the latest research on priming unconscious goals. The new research “doesn’t prove that consciousness never does anything,” wrote Roy Baumeister, a professor of psychology at Florida State University, in an e-mail message. “It’s rather like showing you can hot-wire a car to start the ignition without keys. That’s important and potentially useful information, but it doesn’t prove that keys don’t exist or that keys are useless.”
Yet he and most in the field now agree that the evidence for psychological hot-wiring has become overwhelming. In one 2004 experiment, psychologists led by Aaron Kay, then at Stanford University and now at the University of Waterloo, had students take part in a one-on-one investment game with another, unseen player.
Half the students played while sitting at a large table, at the other end of which was a briefcase and a black leather portfolio. These students were far stingier with their money than the others, who played in an identical room, but with a backpack on the table instead.
The mere presence of the briefcase, noticed but not consciously registered, generated business-related associations and expectations, the authors argue, leading the brain to run the most appropriate goal program: compete. The students had no sense of whether they had acted selfishly or generously.
Carey
Patients who are effectively blind owing to damage to the higher visual parts of the brain will report that they have no visual sense whatsoever. When asked to reach for an object will report that they have no visual sense whatsoever. When asked to for an object in their visual field, such as a penlight, they will say, "What can you possibly mean? I can't see a thing!" If however, they are told to just take a guess and try anyway, they can usually succeed at this task at a rate much higher than would be due to pure chance. In fact, some patients can grasp the penlight 99% of the time, yet will report each time that they have no idea where the target is and they are guessing randomly. The explanation seems to be that the ancient visual system in the midbrain is intact in these patients and guides their reaching, yet because this region is not interconnected with the higher areas of the brain, these people have no conscious awareness of the penlight's location.
Many philosophers and cognitive scientists approach perception as if it were completely objective and logical process. In their view, perception can sometimes trigger emotions but it is possible to divorce emotion from perception and act on perceptions in a purely unemotional fashion.
A patient who sustained damage to the visual cortex, referred to above, was asked to guess the emotions expressed in photos of human faces. These faces, which were both male and female, showed typical expressions of fear, sadness, happiness, and anger. He was able to guess the correct emotion about 60 percent of the time. This was not a perfect score but was significantly better than the outcome obtained by chance. When this task was repeated in an fMRI machine to scan brain activity, significant activation was seen in the right amygdala for emotional faces, with the strongest activation produced by fearful expressions.
These clinical examples show that for both the ancient midbrain visual system and the modern cortical system, the amygdala is activated to engage emotional responses. It is likely that the amygdala is not the only region engaged in the triggering of emotional responses by visual information. The important point here is that visual information is rapidly fed into emotional centers in the brain, which makes it impossible to separate emotion from perception in experience.
This principle applies broadly to all of our senses: emotion is integral to sensation and the two are not easily separated.
The Accidental Mind, David J. Linden, The Belknap Press of Harvard University Press, 2007. (ISBN-10 0-674-02478-8)
An excellent demonstration of blindsight may be found at the following website:
http://serendip.brynmawr.edu/bb/blindsight.html
A fascinating personal account by someone suffering from prosopagnosia (face-blindness) can be found at the following website:
http://www.choisser.com/faceblind/
We are not too much puzzled by myths. If they are made respectable as part of our religion, we give them a conventional and superficial acknowledgement as part of a venerable tradition; if they do not carry such traditional authority, they are taken for the childish expression of the thoughts of man before he was enlightened by science. At any rate, whether ignored, despised, or respected, myths are felt to belong to a world completely alien to our own thinking. Yet the fact remains that many of our dreams are, in both style and content, similar to myths, and we who find them strange and remote when we are awake have the ability to create these mythlike productions when we are asleep.
In the myth, too, dramatic events happen which are impossible in a world governed by the laws of time and space: the hero leaves his home and country to save the world, or he flees from his mission and lives in the belly of a big fish; he dies and is reborn; the mythical bird is burned and emerges from the ashes more beautiful than before.
Of course, different peoples created different myths just as different people dream different dreams. But in spite of all these differences, all myths and all dreams have one thing in common, they are all "written" in the same language, symbolic language.
The myths of the Babylonians, Indians, Egyptians, Hebrews, Greeks are written in the same language as those of the Ashantis or the Trukese. The dreams of someone living today in New York or in Paris are the same as the dreams reported from people living some thousand years ago in Athens or in Jerusalem. The dreams of ancient and modern people are written in the same language as the myths whose authors lived in the dawn of history.
Symbolic language is a language in which inner experiences, feelings, and thoughts are expressed as if they were sensory experiences, events in the outer world. It is a language which has a different logic from the conventional one we speak in the daytime, a logic in which not time and space are the ruling categories but intensity and association. It is the one universal language the human race has ever developed, the same for all cultures and throughout history. it is a language with its own grammar and syntax, as it were, a language one must understand if one is to understand the meaning of myths, fairy tales and dreams.
The Forgotten Language, Erich Fromm, Grove Press, Inc., 1951 (ISBN 080213050X)
Science’s study of the brain has yielded some tantalizing clues about how the mind works. Neuroscientists say people actually feel more than they think, and that emotion plays a crucial role in all decision-making. Although science has been uncovering the brain’s secrets, especially over the last decade, the advertising industry has been slow to leverage the possibilities, industry advocates say. Traditional questionnaires and focus groups, they say, have been considered a simpler and less expensive route than high-tech machines to gauge consumer response to ads.
That is now changing. Concern that focus groups and copy-testing methods can result in bland and predictable ads is prompting agencies and advertisers to consider using physiological measures to analyze consumer reactions to products and to develop new ones. At this point, industry associations are testing these measures to not only see how people respond to ads, but are using the data to create them. Beyond putting people in MRI machines to see which parts of their brain light up, consumers are also being hooked up to electrodes to measure skin changes and heart rates. Even the movement of a person’s facial muscles, imperceptible to the human eye, is being analyzed.
One big spark for agency interest in the value of such methods came when Ken Kaess, CEO of DDB Worldwide, argued in a speech at the 4A’s Management Conference in April 2004 that traditional testing methods were contributing to the growing mediocrity in advertising. Later that year, a task force called "Emotional Response to Advertising" was created by the Advertising Research Foundation and the 4A’s. Over the past year, the task force has conducted studies of ads using biological measurements. The preliminary results show why agencies need to put more emphasis on consumers when creating and testing ads, proponents say.
Account planners like Alice Sylvester, a task force co-chair and account planning director at Foote Cone & Belding in Chicago, who advocate these new methods, argue that emotion, not reason, is the prominent factor in making buying decisions. Bombarding consumers with the same commercial message over and over again isn’t enough. Creating ads based on the old AIDA model — building awareness, interest, desire and action — is obsolete. Traditional copy-testing methods are not enough to unlock the buying secrets buried in the unconscious mind.
This year, the task force will delve deeper into the unconscious mind. Account planning directors are dusting off copies of classic psychological texts like Joseph Campbell’s The Hero With a Thousand Faces and Carl Jung’s Man and His Symbols to better understand how newer methods of tapping into the unconscious work to glean which metaphors, archetypes or stories are important to consumers. The goal is to make the consumer a much more active participant in the creation of new ads, products and brands.
In late 2004, the emotional-response task force invited market researchers like Gallup & Robinson, Millward Brown, MSW Research, and ConsumerWorks, along with university professors, to measure consumers’ physiological and emotional response to ads. Four beer ads that the 4A’s and ARF deemed successful were subjected to physiological tests last year that ranged from brain scans with MRI to facial response tests. The ads included three storytelling or emotional ads — Budweiser’s 60-second "Whassup," Bud Light’s 30-second "Ice," and Heineken’s 30-second "The Weasel" — and one set of 15-second cognitive or more rational ads — Miller Lite’s "Each Hand" and "Great Taste."
Researchers found that consumers reacted more favorably to ads like Budweiser’s "Whassup," which used storytelling to elicit emotion, than they did to ads that compared one product to another, like the two Miller Lite ads. Whether a consumer liked the main character in an ad was an important predictor of whether they responded favorably to the entire ad.
To convince advertisers of the importance of emotion, ConsumerWorks’ Randazzo uses the Subaru example. In 1993, Subaru sales were in a death spiral, company figures show. Enter the actor Paul Hogan of Crocodile Dundee fame who started pitching for Subaru’s Outback in 1996, and sales increased over the next seven years.
The Crocodile Dundee story is based on an archetypal theme of the stranger in a strange land. The psychologist Rapaille, who is president of Archetype Discoveries Worldwide in Tuxedo Park, N.Y., considers archetypes, or universal stories, to be the central way advertisers should appeal to consumers. Rapaille bases his theory on what he describes as the old or reptilian brain, where emotions reside. When it comes to decision-making, "the reptilian brain always wins," Rapaille argues.
Brown-Forman began working with Rapaille in 2003, using his archetype discovery process to redesign its logo for Jack Daniel’s. Through Rapaille’s work, Jack Kennard, Brown-Forman’s director of global marketing services, says the company learned that Jack Daniel’s is associated with the freedom of the West in American culture and relates to the rebel within. As a result, Brown-Forman’s ad agency, Arnold Worldwide in Boston, designed ads that ran last year featuring a man walking down the street with a guitar case displaying the Jack Daniel’s logo. The copy reads: "Mr. Jack Daniel was no saint. But he did start something of a religion."
By tapping into the universal theme of the rebel, Kennard says that Brown-Forman has seen a six to seven percent growth in revenue for Jack Daniel’s.
Melillo
Harvard Business School professor Gerald Zaltman says that 95 percent of our purchase decision making takes place in the subconscious mind. For example, many consumers report handling competing brands and comparing prices at the point of purchase. However, observations of these same consumers often reveal that they don't even look at alternatives to the chosen brand. Another option uses physiological or response latency measures. These often reveal that what consumers actually believe or think, as measured by unconscious physical reactions, contradicts what they say when asked directly. The insights offered by methods that probe the unconscious mind are relevant at all stages of the product life cycle. Other firms use the hidden treasures of the unconscious mind to identify new product opportunities. Using metaphor-elicitation techniques, firms providing farming supplies, home appliances, office systems, and beauty care have identified important unmet needs. R&D departments use information about the architecture of these needs to identify opportunities for new products and services.
Metaphors do not exist as words in memory, but as networks of abstract understandings that constitute part of our mental imagery. We call these networks consensus maps when a group of people shares them.
Mahoney
Marketer and advertiser interest in the psychology of consumer buying is not new. Discussion of this interest goes back at least 50 years:
The Hidden Persuaders, Vance Packard, 1957. (ISBN 0-671-53149-2)
Subliminal Seduction, Wilson Bryan Key, 1973. (ISBN 0451061489)
"The Split Brain Revisited," Michael S. Gazzaniga, World Wide Web.
"WHOLE-BRAIN INTERPRETER," Michael Gazzaniga, Science News, February 24, 1996, World Wide Web.
"PSYCHOLOGICAL INVESTIGATIONS OF UNCONSCIOUS PERCEPTION," Philip M. Merikle, Journal of Consciousness Studies, 5, No. 1, 1998, pp. 5.18, World Wide Web.
"Who’s Minding the Mind?," Benedict Carey, New York Times, July 31, 2007, World Wide Web, World Wide Web.
Preconscious Processing, Norman Dixon, John Wiley & Sons, 1981. (ISBN 0 471 27982 X)
The Right Brain, Thomas R. Blakeslee, Anchor Press/Doubleday 1980. (ISBN 0-385-15099-7)
Two Sides of the Brain, Sid J. Segalowitz, Prentice-Hall Inc., 1983. (ISBN 0-13-935296-1)
The Accidental Mind, David J. Linden, The Belknap Press of Harvard University Press, 2007. (ISBN-10 0-674-02478-8)
The Forgotten Language, Erich Fromm, Grove Press, Inc., 1951 (ISBN 080213050X)
"Inside The Consumer Mind; What Neuroscience Can Tell Us About Marketing," Wendy Melillo, Adweek, January 16, 2006, World Wide Web.
"The Subconscious Mind of the Consumer (And How To Reach It)," Manda Mahoney, Working Knowledge, January 13, 2003, World Wide Web.