Syllabus Consciousness PDF

Chapter learning objectives At the end of this chapter you will be able to: 1 Describe four characteristics of consciousness and some of the major problems of studying it. 2 Explain the relevance of key notions including the Cartesian theatre, the homunculus, the philosopher's zom...

Chapter learning objectives At the end of this chapter you will be able to: 1 Describe four characteristics of consciousness and some of the major problems of studying it. 2 Explain the relevance of key notions including the Cartesian theatre, the homunculus, the philosopher's zombie and animal consciousness. 3 Briefly evaluate the evidence for unconscious processes. 4 Describe different models of attention with supporting experimental evidence. 5 Compare and contrast different states of consciousness including sleep, dreaming, drug intoxication and hypnosis.  s every parent soon discovers, teenagers like their sleep. In that sense, Chloe A Glasson, a 15-year-old from Kirkcaldy in Fife, Scotland, seems like every other normal teenager. The difference is that Chloe falls asleep dozens of times a day at school, on buses and out with friends. According to Chloe: It can happen at any time. I've really been lucky that I've not hurt myself falling asleep while standing up and I ask myself every day how I've managed. At school I'll be sitting at my desk and this wave of tiredness takes over. Then my eyes start to roll and droop and that's when I know what's about to happen. I just go out. Chloe also lapses into an 'automatic behaviour state', which leaves her acting like a robot. As a result, she can't be left alone in a bath or trusted to take public transport herself. Chloe is not a typical teenager. She has narcolepsy, a rare, long-term brain disorder that causes a person to suddenly fall asleep at inappropriate times and affects 0.5% of the population. Although narcolepsy has been linked to specific genes, in Chloe's case she probably developed the disorder as a side effect of the Pandemrix vaccine admin- istered to combat the H1 N1 influenza (more commonly known as 'swine flu') pandemic in Europe in 2009. Other countries including Sweden and Finland also reported an increase in the incidence of narcolepsy associated with the Pandemrix vaccine. Around two-thirds of narcoleptic patients also have cataplexy attacks, which involve a temporary involuntary muscle weakness in response to emotions or the anticipation of emotion. Positive emotions such as laughter are the most potent triggers, although anger, fear, embarrassment and surprise may also provoke attacks. Dr Claire Allen, a 40-year-old research scientist with narcolepsy from Cambridge, loses strength in her hands and nods forward for a few seconds and blacks out around 100 times during the day whenever she laughs. 31 CONSCIOUSNESS Another symptom of narcolepsy is sleep paralysis, where one is fully conscious while drifting off to sleep or on awakening but is unable to move because the muscles are paralysed. This is also quite a common experience in individuals without narcolepsy, and in the past was often attributed to malevolent demons visiting the victims in their beds, as dramatically depicted by Henry Fuseli in his 1781 painting, The Nightmare. Most of the time, of course, consciousness is something we cherish. How else could we experience a favourite work of art, the latest hit record on the radio, the taste of a sweet, juicy peach, or the touch of a loved one's hand? Consciousness is, as you recall from Chapter 1, a person's subjective experience of the world and the mind. Although you might think of consciousness as simply 'being awake'. the defining feature of consciousness is experience, which you have when you're not awake but experiencing a vivid dream. Conscious The Nightmare, painted in 1781 by the experience is essential to what it means to be human. It also makes us unique Anglo-Swiss artist Henry Fuseli (17 41-1825), because it is impossible for one person to experience another's consciousness. Your con- depicts a night demon known as an sciousness is utterly private, a world of personal experience that only you can know. 'incubus' that was believed to sit on the How can this private world be studied? One way to explore consciousness is to exam- sleeper's chest, pinning them down in order to take sexual advantage of them. ine it directly, trying to understand what it is like, how it seems to be created, how it works, and how it compares with the mind's unconscious processes. We'll begin with this direct approach, looking at the mysteries of consciousness and its known properties. Another way to explore consciousness is to examine its altered states, in other words, the cases in which the experience of being human departs from normal, everyday waking. We will probe these changes, beginning with the major alterations that happen during sleep, when waking consciousness steals away only to be replaced by the surreal form of consciousness experienced in dreams. Then we'll look into how we alter our conscious- ness through intoxication with alcohol and.other drugs, and other changes in conscious- ness that occur during hypnosis and meditation. Like the traveller who learns the meaning of home by roaming far away, we can learn the meaning of consciousness by exploring its exotic variations. Conscious and unconscious: the mind's eye, open and dosed What does it feel like to be you right now? It probably feels as though you are some- where inside your head, looking out at the world through your eyes. You can feel your hands on this book, perhaps, and notice the position of your body or the sounds in the room when you turn towards them. If you shut your eyes, you may be able to imagine things in your mind, even though thoughts and feelings come and go all the while, passing through your imagination. Philosopher Daniel Dennett ( 1991) called this CARTESIAN THEATRE (after philosopher 'place in your head' where 'you' are the Cartesian theatre (after philosopher René René Descartes) A mental screen or Descartes) - a mental screen or stage on which things appear to be presentedfor viewing stage on which things appear to be by your mind's eye. The Cartesian theatre, unfortunately, isn't available on DVD, mak- presented for viewing by the mind's eye. ing it impossible to share exactly what's on your mental screen with anyone else. They can't get inside your head to watch the same show. The private, personal nature of consciousness means that although we can tell others what we are thinking, they can never truly share our actual experience. As you'll recall from Chapter 1, Wilhelm Wundt encountered similar problems when studying consciousness and trying to measure personal experience. Even today, while we may be able to record the physio- logical changes in brain activity with modern scanning techniques, researchers cannot measure the actual conscious experience. When you tell someone you are studying psychology, they may often think that you want to 'get inside their head' or 'read their minds'. Nothing could be more difficult when it comes to consciousness. We'll look at the difficulty of studying consciousness directly but also examine the nature of con- sciousness ( what it is that can be seen in this mental theatre) and then explore the unconscious mind ( what is not visible to the mind's eye),  CONSCIOUSNESS Mysteries of consciousness Other sciences, such as physics, chemistry and biology, have the great luxury of studying objects, things we all can see. Psychology studies objects too, looking at people and their brains and behaviours, but it has the unique challenge of also trying to make sense of the subjective experience we all have as conscious individuals and how this is generated by the brain. This is sometimes called the hard problem of consciousness - the difficulty of HARD PROBLEM OF CONSCIOUSNESS The explaining how subjective experience could ever arise ( Chalmers, 1996). A physicist is not difficulty of explaining how subjective experience could ever arise. concerned with what it is like to be a neutron, a biologist does not explain what it must be like to be a plant, but psychologists hope to understand what it is like to be a human, that is, grasping the subjective perspectives of the people they study. So, psychologists hope to include an understanding of phenomenology, how things seem to the conscious PHENOMENOLOGY How things actually person, in terms ofthe quality ofexperience, in their understanding of mind and behaviour. seem in the state of consciousness in terms of the quality of experience. After all, consciousness is an extraordinary human property that could well be unique to us. But including phenomenology in psychology brings up mysteries pondered by great thinkers almost since the beginning of thinking. Let's consider some of the more vexing mysteries of consciousness: the homunculus problem, the problem of other minds and the mind-body problem. Who's in control? For most of us, our daily experience of consciousness feels as if we exist inside our heads, somewhere behind our eyes, experiencing and acting on the world. We are like some driver of a complicated machine, making decisions, controlling actions and feeling what it is like to be us. However, if our personal experience of the Cartesian theatre is an illu- sion, then this sense that we exist inside our heads looking out on the world needs careful consideration. First, the idea of someone inside the head is an example of the homunculus HOMUNCULUS PROBLEM Difficulty problem - the difficulty ofexplaining the experience ofconsciousness by advocating another of explaining the experience of consciousness by advocating another internal self. We encountered the homunculus in Chapter 3 as the distorted representa- internal self. tion of the body's somatosensory cortex - the freaky ghoul who looks like he may have come out of Tim Burton's The Nightmare Before Christmas. In this context, a homuncu- lus is like having a 'mini-me' inside your head making decisions. The homunculus is a problem because if there really was a 'mini-me' inside your head, then who is inside the head of the homunculus and so on and so on? This would become an infinite regress leading to no end. If the homunculus does not exist, then who is in control? This question raises the issue of Spinoza's free will we encountered in Chapter l. Free will is the common assump- tion that individuals are in control of the decisions they make and have the choice to do one thing versus another. However, remember that behaviourists such as Skinner claimed that personal free will was an illusion because behaviour and thoughts could be shaped by reinforcement or punishment from the environment. While cognitive psychology has shown that behaviourism is limited in explaining all human behaviour, research described throughout this textbook continues to reveal how unconscious mechanisms play a role in our decision making. In short, science undermines the reality of free will as a force of personal choice. The trouble is we are so used to our conscious experience of free will that to reject it is something most of us find difficult to accept. Also, without the notion of free will, fun- damental principles of how we treat others begin to look shaky. For example, in law we hold people responsible as individuals for the decisions they take, but if the individual is simply responding to circumstances out of their control, then are they truly responsible? To many of us, the morality of rewards for good deeds and punishment for evil acts seems unwarranted without the concept of free will. Maybe this is why we experience a sense of free will as a useful mechanism that confers social responsibility? While the case for the existence of free will being responsible for decisions may be sci- entifically weak, the personal experience of free will is extremely strong. Most of us feel the experience of conscious free will as we go about our daily basis of making choices: 'We think we did it.' Why is this? It has been suggested that the we think we did it experi- ence could be a useful way of keeping track of our decisions and actions (Wegner, 2002). 31 CONSCIOUSNESS This is because the unconscious influences and processes that lead to these choices are too complicated to monitor, but we can keep track of the outcome as a feeling that we have made the decision. For example, when we laugh at a joke, there are many influences and processes that determine that bizarre bodily convulsion, but the loud guffaw reminds us that we find something funny. In the same way, having a sense of free will over our thoughts and actions binds us to these as the author of these decisions even when that is not the case. In this way, a sense of free will could help us keep track of what we have done, what we have not done, and what we may, or may not, do in the future. After all, it is useful to know who is responsible. The problem of other minds PROBLEM OF OTHER MINDS The One great barrier to getting inside someone else's head is called the problem of other fundamental difficulty we have in minds - thefundamental difficulty we have in perceiving the consciousness of others. How perceiving the consciousness of others. do you know that anyone else is conscious? They tell you they are conscious, of course, and are often willing to describe in depth how they feel, how they think, what they are QUALIA Subjective experiences we have experiencing, and how good or bad it all is. These mental states, or qualia, are the as part of our mental life. subjective experiences we have as part of our mental life. There is a personal quality to qualia - the bitterness of lemon juice, the redness of the colour red or the pain of rejection - that cannot be directly accessed by others, no matter how well you describe the experience. The problem of other minds also means that there is no way you can tell if another person's experience of anything is at all like yours. Although you know what the colour red looks like to you, for instance, you cannot know whether it looks the same to other people. Maybe they're seeing what you see as blue and just calling it red in a consistent way. If their inner experience 'looks' blue, but they say it looks hot and is the colour of a tomato, you'll never be able to tell that their experience differs from yours. Of course, most people have come to trust each other in describing their inner lives, reaching the general assumption that other human minds are very much like their own. But they don't know this for a fact, and they can't know it directly. As we saw in Chapter 4, before syn- aesthesia was recognized as a real phenomena, individuals with this condition were una- ware that most other people did not have the same qualia of experience. Others can tell us about their qualia, but perhaps they are just saying these things. There is no clear way to distinguish a conscious person from someone who might do and say all the same things as a conscious person but who is not conscious. Philosophers have called this hypothetical nonconscious person a 'zombie', in reference to the living-yet- dead creatures of horror films (Chalmers, 1996). A philosopher's zombie could talk about experiences ('The lights are so bright!') and even seem to react to them (wincing and turning away) but might not be having any inner experience at all. The possibility of a nonconscious zombie is often used as an argument against the idea that consciousness is simply something that emerges out of the brain. If a zombie with a dead brain is indis- tinguishable from a conscious human with a living brain, then the argument runs that there must be some additional property independent of brains responsible for conscious- ness. However, Dennett (1991) argues that the philosopher's zombie is not possible and we are falling victim to the illogical error that there must be some additional non-material property to explain mental life. He argues that if a zombie is indistinguishable from a human down to the very cells that make up the brain, then it would be conscious. If the brain were dead, there would be no consciousness. Most neuroscientists also reject these philosophical arguments about hypothetical zombies because research shows that altering brain activity through damage, disease, drugs or direct stimulation alters conscious experience. In other words, 'the mind is what the brain does' (Minsky, 1986, p. 287). This exclusively physical interpretation of mental MATERIALISM Philosophical position that life is known as materialism - the philosophical position that mental states are a product of mental states are a product of physical physical systems alone. Materialism dispenses with any need to explain consciousness in processes alone. terms of some additional property that resides in the brain. This is an idea that most of us find unsettling, because it suggests that our experience of our own mental life, conscious- ness and free will is the product of a complicated 'meat machine' (Minsky, quoted in Turkle, 1997, p. 7) and that is a very dehumanized vision o£ ourselves.  CONSCIOUSNESS 5 Even if consciousness is solely a product of the physical brain, there are still many questions. How does the brain generate consciousness? Do other animals with different brains have conscious experience, and if so, what is it like? In an essay entitled 'What is it like to be a bat r. philosopher Thomas Nagel (1974) wondered what it's like flying around in a dark cave, sensing the walls through the echoes made by your ultrasonic screeches. Would your experience of the cave include visual images, sounds, or something else entirely? It's difficult to imagine, as we're not bats. And if we had the mind of a bat, we would not have the mind of a human, so how could we possibly ever know what it is like to be bat? If bat consciousness is hard to imagine, what about all the other animals? When a puppy looks up at you with those warm brown eyes, seemingly saying 'I love you and everything you stand for', you can't really know what it's like in there - so your appreciation of the puppy's mind reflects what's going on in your head more than in the puppy's. This is a feature of anthropomorphism - the tendency to attribute human quali- ties to nonhuman things. In considering others as having minds, we all too readily assume that they exhibit the same mental life we ourselves experience. It is much easier to inter- act with animals and even babies by assuming that they share the same conscious aware- ness (Dennett, 1991 ), but what grounds do we have for inferring consciousness in others? What is the mental life of an infant or animal like? This leads to the more general question: How do people perceive other minds? Researchers conducting a large online survey asked people to compare the minds of We have a fundamental problem in 13 different targets, such as a baby, chimp, robot, man and woman, on 18 different men- perceiving the consciousness of others. tal capacities, such as feeling pain, pleasure, hunger and consciousness (see FIGURE 8.1) This child will anthropomorphically (Gray et al., 2007). Respondents who were judging the mental capacity to feel pain, for attribute human qualities to the puppy, assuming that animals exhibit the same example, compared pairs of targets: Is a frog or a dog more able to feel pain? Is a baby or mental life we do. a robot more able to feel pain? Is a seven-week-old fetus or a man in a persistent vegeta- tive state more able to feel pain? When the researchers examined all the comparisons on ANTHROPOMORPHISM The tendency to the different mental capacities with the computational technique of factor analysis (see attribute human qualities to nonhuman Chapter 9), they found two dimensions of mind perception. People judge minds accord- things. ing to the capacity for experience, such as the ability to feel pain, pleasure, hunger, con- sciousness, anger or fear, and the capacity for agency, such as the ability for self-control, planning, memory or thought. As shown in Figure 8.1, respondents rated some targets as having little experience or agency ( the dead person), others as having experiences but lit- tle agency (the baby), and yet others as having both experience and agency (adult humans). Still others were perceived to have agency without experiences (the robot, God). The perception of minds, then, involves more than just whether something has a mind. People appreciate that minds have experiences and act as agents that perform actions. We return to this issue in Chapter 12 when we examine the evidence that chil- dren develop this capacity to see others as having minds. Key Baby TIP FIGURE 8.1 Dimensions of mind I Dead woman perception When participants judged Dog the mental capacities of 13 targets, two dimensions of mind perception were Fetus discovered (Gray et al., 2007). Participants Experience Frog perceived minds as varying in the capacif for experience, such as abilities to feel pa Girl or pleasure, and in the capacity for agenc God such as abilities to plan or exert self-contr They perceived normal adult humans (ma Man female or 'you', the respondent) to have I 1! PVS man Robot minds on both dimensions, whereas othei targets were perceived to have reduced experience or agency. The man in a Woman persistent vegetative state ('PVS man'), fo 0'----------------~ example, was judged to have only some 0 Agency You experience and very little agency. 31 CONSCIOUSNESS Ultimately, the problem of other minds is a problem for psychological science. As you'll remember from Chapter 2, the scientific method requires that any observation made by one scientist should, in principle, be available for observation by any other sci- entist. But if other minds aren't observable, how can consciousness be a topic of scientific study? One radical solution is to eliminate consciousness from psychology entirely and follow the other sciences into total objectivity by renouncing the study of anything men- tal. This was the solution offered by behaviourism, and it turned out to have its own shortcomings, as you saw in Chapter 1. Despite the problem of other minds, modern psychology has embraced the study of consciousness. What was once regarded as myste- rious and never open to understanding has, in fact, stimulated debate that questions the way we think about what it is to be human. The mind-body problem MIND-BODY PROBLEM The issue of how Another mystery of consciousness is the mind-body problem - the issue ofhow the mind is the mind is related to the brain and body. related to the brain and body. French philosopher and mathematician René Descartes is famous for proposing, among ocher things, that mind and body are made of different substances. As you read in Chapter 1, Descartes believed that the human body is a machine made of physical matter but chat the human mind or soul is a separate entity made of a 'chinking substance'. He proposed that the mind has its effects on the brain and body through the pineal gland, a small pine-shaped structure located near the centre of the brain. It appears to be unitary, whereas the rest of the brain is split into right and left halves. Descartes reasoned that because it was a unitary structure, this made it the most likely site for the interaction between the body and soul. In fact, the pineal gland is divisi- ble and is not even a nerve structure but an endocrine gland quire poorly equipped to integrate the activity of the neuronal networks of the brain that must be responsible for generating human consciousness. Even if the pineal gland was the site for the conjunction of body and soul, the hard problem remains. How does something like the mind, which has no physical property, emerge from or interact with the physical structures of the body? Most psychologists assume that mental events are intimately tied to brain events, such that every thought, perception or feeling is associated with a particular pattern of activa- tion of neurons in the brain (see Chapter 3). Thinking about a particular duck, for instance, occurs with a unique array of neural connections and activations. If the neurons repeat that pattern, you must be thinking of the duck; conversely, if you think of the duck, the brain activity occurs in that pattern. Studies of the brain structures associated with conscious thinking in particular (as opposed to all the other mental efforts that go on in the background of the mind) suggest that conscious thought is supported widely in the brain by many different structures (Koch, 2004). However, consciousness does not feel like the product of some meat machine that is our body. That is because each of us experiences mental life as something separate to our bodies. When we look in the mirror, we can see how our outward appearance may change but we do not feel that the observer is different. We may change our opinions and thoughts over time, but we still feel like the same 'person' having those thoughts and opinions. Also, our daily, phenomenological experience of body and mind is that the mind is in control of the body. We feel that we exist somewhere behind our eyes, like a ship's captain of the body issuing commands and making decisions. We feel the authorship of our actions. One telling set of studies, however, suggests chat the brain's activities precede the activities of the conscious mind. The electrical activity in volunteers' brains was meas- ured using sensors placed on their scalps as they repeatedly decided when to move a hand (Liber, 1985) (see FIGURE 8.2). Participants were also asked to indicate exactly when they consciously chose to move by reporting the position of a dot moving rapidly around the face of a clock just at the point of the decision (FIGURE 8.2a). As a rule, the brain begins to show electrical activity around half a second before a voluntary action (535 millisec- onds (ms) to be exact). This makes sense since brain activity certainly seems to be neces- sary to get an action started. What this experiment revealed, though, was that the brain also started to show electri- cal activity before the person's conscious decision to move. As shown in FIGURE 8.2b, these studies found that the brain becomes active more than 300 ms before participants report  CONSCIOUSNESS 7 Conscious Brain Finger wish to activity movement act is begins occurs experienced (EEG) (EMG) (clock reading) Time ~ -535 milliseconds -204 milliseconds 0 (a) (b) FIGURE 8.2 The timing of conscious that they are consciously trying to move. The feeling that you are consciously willing your will (a) In Benjamin Libet's experiments, actions, it seems, may be a result rather than a cause of your brain activity. Although your the participant was asked to move fingers personal intuition is that you think of an action and then do it, these experiments suggest at will while simultaneously watching a dot move around the face of a clock to mark the that your brain is getting started before either the thinking or the doing, preparing the moment at which the action was consciously way for both thought and action. More recently, researchers using fMRI demonstrated willed. Meanwhile. EEG sensors timed the chat brain activity seven seconds before a participant felt they had made the conscious onset of brain activation and EMG sensors timed the muscle movement. (b) The decision to choose a button predicted which of the two buttons they would subsequently experiment showed that brain activity press (Soon et al., 2008). Quite simply, it may appear to us that our minds are leading our (EEG) precedes the willed movement of the brains and bodies, but the order of events may be the other way around (Wegner, 2002). finger (EMG), but that the reported time To most of us, our personal experience of consciousness feels like someone is in charge of of consciously willing the finger to move follows the brain activity. decision making, but in fact, consciousness may simply be making sense of our thoughts and actions after they have already been activated by unconscious processes. This after-the-fact interpretive role of consciousness explains a surprising demonstration of choice blindness - when people are unaware of their decision-making processes and justify CHOICE BLINDNESS When people a choice as if it were already decided. Adults were asked to choose which of two female are unaware of their decision-making processes and justify a choice as if it faces was more attractive, as shown in FIGURE 8.3. On some trials, immediately after mak- were already decided. ing their choice, participants were asked to explain why they had selected a particular face. However, by use of sleight of hand, they were sometimes handed the card with the (a) (b) FIGURE 8.3 Choice blindness Participants were shown two female faces (a) and asked to choose which female was more attractive (b) and then justify why they picked one face over another. Every so often the faces were cleverly switched by sleight of hand (c). Most adults did not notice the switch and then explained why the face they had just rejected (d) was the more attractive one (c) (d) (Johansson et al., 2005).  face they had just rejected. Not only were most switches undetected but participants went on to give explanations for preferring the switched face even when they had not chosen it (Johansson et al., 2005). As Steven Pinker (2003, p. 43) put it: 'The conscious mind - the self or soul - is a spin doctor, not the commander-in-chief.' Consciousness gives us this sense of a coherent self, resident within our bodies, having experiences and making decisions. It is an appealing intuition that most of us have about our mental lives, but philosophers and psychologists reveal that many of these intuitions can be easily deconstructed and may even be illusions. It explains many of the uncon- scious influences in our decision making and why, for example, we may say that we are not racist or sexist and yet implicit association tests, considered at the end of Chapter 15, reveal chat these sorts of prejudicial biases are not under conscious control. The way we chink about consciousness may be wrong but it is still a component of mental life, just one chat is not amenable to measurement, which makes it difficult to study. Although researchers may not be able to see the consciousness of ochers or know exactly how consciousness arises from the brain, this does not prevent chem from collect- ing people's reports of conscious experiences and learning how these reports reveal the nature of consciousness. We'll consider chat topic next. The nature of consciousness How would you describe your own consciousness? Researchers examining people's descriptions suggest that consciousness has four basic properties - intentionality, unity, selectivity and transience - chat it occurs on different levels, and includes a range of dif- ferent contents. Let's examine each of these points in turn. Four basic properties Consciousness is often about something. Philosophers call chis first property the inten- tionality of consciousness, the quality of being directed towards an object, which is not to be confused with the more familiar sense of intention as characterizing something done on purpose. Psychologists, in turn, have tried co measure the relationship between con- sciousness and its objects as a process of actively selecting something to attend to, exam- ining the size and duration of the relationship. How long can consciousness be directed towards an object, and how many objects can it cake on at one time? Researchers have found chat conscious attention is limited and chat without it, objects can often fail to reach conscious awareness even when they are staring you in the face (see FIGURE 8.4). CHANGE BLINDNESS When people are The phenomenon known as change blindness, unawareness ofsignificant events changing unaware of significant event changes in full view, reveals chat, without attention, we miss much of what is happening in the that happen in full view. world (Rensink et al., 1997). It's another example of a mindbug chat reflects a feature of the way our minds work. Moreover, we may actually 'fill in' the missing portions of expe- rience by making assumptions in much the same way that we perceptually fill the visual blind spot (see Chapter 4). Despite all the lush detail you see in your mind's eye, the kaleidoscope of sights and sounds and feelings and thoughts, the object of your con- sciousness at any one moment is just a small part of all this. To describe how chis limita- tion works, psychologists refer to three other properties of consciousness: unity, selectivity and transience. FIGURE 8.4 Spot the difference Study the first photograph carefully and see if you can tell what is different from the second photograph. This is made all the more difficult if each photograph is flashed up, one after the other, with a brief (80 ms) blank screen in between. This difficulty in spotting the difference is known as 'change blindness' (Rensick et al., 1997) and demonstrates that attention is necessary for becoming consciously aware of the world around us.  CONSCIOUSNESS ç The unity of consciousness is its resistance to division. This property becomes clear when you try to attend to more than one thing at a time. You may wishfully think that you can study and watch TV simultaneously, for example, but research suggests not. One study had research participants divide their attention by reacting to two games superim- posed on a TV screen. They had to push one button when one person slapped another's hands in the first game and push another button when a ball was passed in the second game. The participants were easily able to follow one game at a time, but their perfor- mance took a nosedive when they tried to follow both simultaneously. Their error rate DICHOTIC LISTENING A task in which when attending to the two tasks was eight times greater than when attending to either people wearing headphones hear task alone (Neisser and Becklen, 1975). In other words, your attempts to study could different messages presented to each ear. seriously interfere with a full appreciation of your TV show! In another classic demon- COCKTAIL PARTY PHENOMENON People stration of the importance of attention for awareness, adults were asked to count the tune in to one message even while they filter out others nearby. number of times that players wearing white Tvshirts passed a basketball to each other. The task was hard because there was another team of players wearing black T-shins that had to be ignored (see FIGURE 8.5). Adults could easily keep track of the number of passes FIGURE 8.5 Gorillas in our midst by concentrating on the white team. However, what half the adults failed to notice was a Participants have to count the number of man wearing a gorilla suit strolling among the players, beating his chest and then stroll- times the ball is passed between players wearing the white T-shirts. Around 50% of ing off again (Simons and Chabris, 1999). The scope of our consciousness is limited and adults fail to notice the gorilla walk on in th this has implications for what we notice in the world. Maintaining a coherent unity of middle of the game, beat its chest and the: consciousness makes it difficult for us to divide attention among differing events. walk off again (Simons and Chabris, 1999). FIGURE PROVIDED BV DANIEL SIMONS WWW.DANSIMONS.COM WWW.THEJNVISIBLEGORILLA.COM The selectivity of consciousness is its capacity to include some objects and not others. This property is shown through studies of dichotic listening, in which people wearing headphones are presented with dijferent messages in each ear. Research participants were instructed to repeat aloud the words they heard in one ear while a different message was presented to the other ear ( Cherry, 1953 ). As a result of focusing on the words they were supposed to repeat, participants noticed little of the second message, often not even real- izing that at some point it changed from one language to another (English to German). So, consciousness.filters out some information including irrelevant messages or even men in gorilla suits. At the same time, participants did notice when the voice in the unat- tended ear changed from a male to a female voice, suggesting that the selectivity of con- sciousness can also work to tune in other information. How does consciousness decide what to filter in and what to tune out? The conscious system is most inclined to select information of special interest to the person, in what has come to be known as the cocktail party phenomenon - people tune in to one message even while theyfilter out others nearby. In the dichotic listening situation, for example, research participants are especially likely to notice if their own name is spoken into the unat- tended ear (Moray, 1959). Perhaps you too have noticed how abruptly your attention is diverted from whatever conversation you are having when someone else within earshot Participants in a dichotic listening experiment hear different messages playe, at the party mentions your name. Selectivity is not only a property of waking conscious- to the right and left ear and may be asked ness, however; the mind works this way in other states. People are more sensitive to their to 'shadow' one of the messages by own name than other names, for example, even during sleep ( Oswald et al., 1960). repeating it aloud. 32 CONSCIOUSNESS The final basic property is the transience of consciousness, or its tendency to change. Consciousness wiggles and fidgets like an impatient toddler. The mind wanders, not just sometimes but incessantly, from one 'right now' to the next 'right now' and then on to the next (Wegner, 1997). This is why, when we are distracted, our ability to concentrate is impaired. William James (1890, p. 239), whom you met in Chapter 1, famously described consciousness as a stream: Consciousness... does not appear to itself chopped up in bits. Such words as 'chain' or 'train' do not describe it... It is nothing jointed; it flows. A 'river' or a 'stream' are the metaphors by which it is most naturally described. However, if consciousness can be considered as a stream, it is a turbulent one, with many eddies and diversions. The stream of consciousness may flow in this way partly because of the limited capac- ity of working memory. Remember from Chapter 5 that you can hold only so much information in your mind, so when more information is selected, some of what is cur- rently there must disappear. As a result, your focus of attention keeps changing. The Necker cube (see FIGURE 8.6) is the visual counterpart to stream of consciousness writing. FIGURE 8.6 The Necker cube This cube Although the cube is a constant object, the stream of consciousness flows, reversing the has the property of reversible perspective, in that you can bring one or the other of its figure. Moreover, the fact that you cannot simultaneously see both versions of the cube two square faces to the front in your mind's reflects the unity of consciousness described earlier. eye. Although it may take a while to reverse The basic properties of consciousness are reminiscent of the 'bouncing ball' that the figure at first, once people have learned moves from word to word when the lyrics of a sing-along tune are shown on a karaoke to do it, they can reverse it regularly, about once every three seconds (Gomez et al., machine. The ball always bounces on something (intentionality), there is only one ball 1995). The stream of consciousness flows (unity), the ball selects one target and not others (selectivity), and the ball keeps bounc- even when the target is a constant object. ing all the time (transience). Levels of consciousness Consciousness can also be understood as having levels, ranging from minimal conscious- ness to full consciousness to self-consciousness. The levels of consciousness that psychol- ogists distinguish are not a matter of degree of overall brain activity but instead involve different qualities of awareness of the world and of the self. In its minimal form, consciousness is just a connection between the person and the world. When you sense the sun coming in through the window, for example, you might MINIMAL CONSCIOUSNESS A low level turn towards the light. Such minimal consciousness is a low level ofawareness that occurs of awareness that occurs when the when the mind inputs sensations and may output behaviour (Armstrong, 1980 ). This level mind inputs sensations and may output behaviour. of consciousness is a kind of sensory awareness and responsiveness, something that could even happen when someone pokes you during sleep and you turn over. Something seems to register in your mind, at least in the sense that you experience it, but you may not think at all about having had the experience. It could be that animals or even plants, for that matter, can have this minimal level of consciousness. In Chapter 5, we learned about the sea slug that learns to withdraw its breathing gill after it is prodded. Does it have any awareness of this event? But, because of the problem of other minds and the notorious reluctance of animals and plants to talk to us, we can't know for sure that they experience the things that make them respond. At least in the case of humans, we can safely assume that there is something it 'feels like' to be them and when they're awake, they are at least minimally conscious. Human consciousness is often more than this, of course, but what exactly gets added? Consider the glorious feeling of waking up on a spring morning as rays of sun stream across your pillow. It's not just that you are having this experience; being fully conscious means that you are also aware that you are having this experience. FULL CONSCIOUSNESS Consciousness in The critical ingredient that accompanies full consciousness is that you know and are which you know and are able to report able to report your mental state. That's a subtle distinction; being fully conscious your mental state. means that you are aware of having a mental state while you are experiencing the mental state itself. When you have a hurt leg and mindlessly rub it, for instance, your pain may be minimally conscious. After all, you seem to be experiencing pain  CONSCIOUSNESS because you are indeed rubbing your leg. It is only when you realize that it hurts, though, that the pain becomes fully conscious. Full consciousness involves not only thinking about things but also thinking about the fact that you are thinking about things (Jaynes, 1976). Full consciousness fluctuates over time, coming and going throughout the day. You've no doubt had experiences of reading and suddenly realizing that you have 'zoned out' and are not processing what you read. When people are asked to report each time they zone out during reading, they report doing this every few minutes. Even then, when an experimenter asks these people at other random points in their reading whether they are zoned out at that moment, they are sometimes caught in the state of having 'zoned out' even before they've noticed it (Schooler et al., 2001 ). It's at just this point - when you are zoned out but don't know it - that you seem to be unaware of your own mental state. You are minimally conscious of wherever your mind has wandered to, and you return with a jolt into the full consciousness that your mind had drifted away from. Thinking about thinking allows you to realize that you weren't thinking about what you wanted to be thinking about. Full consciousness involves a certain consciousness of oneself; the person notices the self in a particular mental state ('Here I am, reading this sentence'). However, this is not Self-consciousness is a curse and a blessin quite the same thing as self-consciousness. Sometimes, consciousness is entirely flooded Looking in the mirror can make people with the self ('Gosh, I'm such a good reader!'), focusing on the self to the exclusion evaluate themselves on deeper attributes such as honesty as well as superficial ones of almost everything else. James ( 1890) and other theorists have suggested that self- such as looks. consciousness is yet another distinct level ofconsciousness in which the person's attention is drawn to the self as an object. Most people report experiencing such self-consciousness when they are embarrassed, when they find themselves the focus of attention in a group, SELF-CONSCIOUSNESS A distinct level when someone focuses a camera on them, or when they are deeply introspective about of consciousness in which the person's attention is drawn to the self as an object their thoughts, feelings or personal qualities. Self-consciousness brings with it a tendency to evaluate yourself and notice your shortcomings. Looking in a mirror, for example, is all it takes to make people evaluate themselves - thinking not just about their looks but also about whether they are good or bad in other ways. People go out of their way to avoid mirrors when they've done some- thing they are ashamed of (Duval and Wicklund, 1972). Self-consciousness can certainly spoil a good mood, so much so that a tendency to be chronically self-conscious is associated with depression (Pyszczynski et al., 1987). However, because it makes people self-critical, the self-consciousness that results when people see their own mirror images can make them briefly more helpful, more cooperative and less aggressive (Gibbons, 1990). In one classic study conducted on Halloween night in Canada, researchers found that children were less likely to be greedy by helping themselves to more sweets even though they had been instructed to take only one if there was a large mirror in the room compared to when no mirror was present (Beaman et al., 1979). Most undergraduate students (71 %) were also found to cheat on an anagram test compared to only 7% who cheated when there was a mirror in the exam room (Diener and Wallbom, 1976). Perhaps everyone would be a bit more civilized if mirrors were held up for them to see themselves as objects of their own scrutiny. Most animals can't follow this path to civilization. The typical dog, cat or bird seems mystified by a mirror, ignoring it or acting as though there is some other creature in there. However, chimpanzees that have spent time with mirrors sometimes behave in ways that suggest they recognize themselves in a mirror. To examine this, researchers painted an odourless red dye over the eyebrow of an anaesthetized chimp and then watched when the awakened chimp was presented with a mirror (Gallup, 1970). If the Researchers are now also conducting chimp interpreted the mirror image as a representation of some other chimp with an mirror self-recognition experiments on no unusual approach to cosmetics, we would expect it just to look at the mirror or per- mammalian species, such as this magpie. haps reach towards it. But the chimp reached towards its own eye as it looked into the PRIOR H.. SCHWARZ A., GÜNTÜRKUN 0. (2008) MIRROR-INDUCED BEHAV10 THE MAGPIE (PICA PICAJ: EVIDENCE OF SELF-RECOGNITION. PLOS BIOL 6(8 mirror - not the mirror image - suggesting that it recognized the image as a reflection E202. 00I:10.1371/JOURNAL.PBI0.0060202. C 2008 PRIOR ET AL THIS IS AN OPEN-ACCESS ARTICLE DISTRIBUTED UNDER THE TERMS OF THE CREATM COMMONS ATTRIBUTION LICENSE (HTTPS://CREATIVECOMMONS.ORG/ of itself LJCENSES/BY/2.0/UK/) 32 CONSCIOUSNESS Versions of this experiment, known as 'the rouge test', have now been repeated with many different animals ( Gallup, 1977), and it turns out that, like humans, animals such as chimpanzees and orangutans, possibly dolphins (Reiss and Marino, 2001) and maybe even elephants (Plotnik et al., 2006) recognize their own mirror images. Dogs, cats, birds, monkeys and gorillas have been tested and don't seem to know they are looking at themselves. Even humans don't have self-recognition right away. Infants don't recognize themselves in mirrors until they've reached about 18 months of age (Lewis and Brooks-Gunn, 1979). The experience of self-consciousness, as measured by self- recognition in mirrors, is limited to a few animals and to humans only afi:er a certain stage of development. Conscious contents What's on your mind? For that matter, what's on everybody's mind? The contents of consciousness are, of course, as rich and varied as human experience itself. But there are some common themes in the topics that occupy consciousness and the form that con- sciousness seems to take as different contents come to mind. One way to learn what is on people's minds is to ask them, and much research has called on people simply to think aloud. A more systematic approach is the experience sampling technique, in which people are asked to report their conscious experiences at particular times. Equipped with electronic beepers, for example, participants are asked to record their current thoughts when beeped at random times throughout the day ( Csikszentrnihalyi and Larson, 1987). Experience sampling studies show that conscious- ness is dominated by the immediate environment - what is seen, felt, heard, tasted and smelled, all are at the forefront of the mind. Much of consciousness beyond this orienta- tion to the environment turns to the person's current concerns, or what the person is thinking about repeatedly (Klinger, 1975). TABLE 8.1 shows the results of a Minnesota study where 175 university students were asked to report their current concerns ( Goetzman et al., 1994). The researchers sorted the concerns into the categories shown in Table 8.1. Keep in mind that these concerns are ones the students didn't mind report- ing to psychologists; their private preoccupations may have been different and probably far more interesting. TABLE 8.1 What's on your mind? University students' current concerns Current concern Example Frequency of students who category mentioned the concern Family Gain better relations with immediate family 40% Flatmate Change attitude or behaviour of flatmate 29% Household Clean room 52% Friends Make new friends 42% Dating Desire to date a certain person 24% Sexual intimacy Abstaining from sex 16% Health Diet and exercises 85% Employment Get a summer job 33% Education Go to graduate school 43% Social activities Gain acceptance into a campus organization 34% Religious Attend church more 51% Financial Pay rent or bills 8% Government Change government policy 14% Think for a moment about your own current concerns. What topics have been on your mind the most in the past day or two? Your mental 'to do' list may include things you want to get, keep, avoid, work on, remember and so on (Little, 1993). Items on the list ofi:en pop into mind, sometimes even with an emotional punch ('The test in this tutorial group is tomorrow!'). People in one study, had their GSR (galvanic skin response) measured to assess their emotional responses (Nikula et al., 1993 ). GSR sen- sors attached to their fingers indicated when their skin became moist - a good indication that they were thinking about something distressing. Once in a while, GSR would rise spontaneously, and at these times, the researchers quizzed the participants about their conscious thoughts. These emotional moments, compared to those when GSR was nor- mal, ofi:en corresponded with a current concern popping into mind. Thoughts that are not themselves emotional can still come to mind with an emotional bang when they are topics of our current concern. Current concerns do not seem all that concerning, however, during daydreaming - a DAYDREAMING A state of consciousness state ofconsciousness in which a seemingly purposelessflow ofthoughts comes to mind. When in which a seemingly purposeless flow of thoughts comes to mind. thoughts drift along in this way, it may seem as if you are just wasting time. However, psychologists have long suspected that daydreams reflect the mind's attempts to deal with difficult projects and problems. A computer program designed to simulate day- dreams works on the basis of this assumption to produce passages that resemble human daydreams (Mueller, 1990). The program draws on the idea that people learn from past experiences by 'replaying' them in daydreams, that they discover creative approaches to the future by imaging fanciful scenarios, and that all this helps them to control and chan- nel their emotions. In one case, the Daydreamer program was given the information that it had been turned down for a date by a famous actress and was then allowed to 'daydream' in response. In a daydream, it imagined that going out with the actress would have been a hassle because of the reporters; this daydream helped to rationalize the failure and make it less disappointing. Another daydream by the program envisioned a new way of asking her out, one that would have secured her phone number so she could have been approached again later on; this response created new information that would be helpful in similar situations in the future. Human daydreams and fantasies, like these computer- simulated versions, may be more useful than they appear at first glance. The current concerns that populate consciousness can sometimes gain the upper hand, transforming daydreams or everyday thoughts into rumination and worry. Thoughts that return again and again,-or problem-solving attempts that never seem to succeed, can come to dominate consciousness. When this happens, people may exert mental control - the attempt to change conscious states of mind. For example, someone MENTAL CONTROL The attempt to troubled by a recurring worry about the future ('What if I can't get a decent job when I change conscious states of mind graduate?') might choose to try not to think about this because it causes too much anxi- ety and uncertainty. Whenever this thought comes to mind, the person engages in thought suppression - the conscious avoidance ofa thought. This may seem like a perfectly THOUGHT SUPPRESSION The conscious sensible strategy because it eliminates the worry and allows the person to move on to avoidance of a thought. think about something else. Or does it? Fyodor Dostoevsky (1821-81), the great Russian novelist, remarked on the difficulty of thought suppression: 'Try to pose for yourself this task: not to think of a polar bear, and you will see that the cursed thing will come to mind every minute.' Inspired by this observation, Daniel Wegner and his colleagues (1987) gave people this exact task in the lab. Participants were asked to try not to think about a white bear for five minutes while they recorded all their thoughts aloud into a tape recorder. In addition, they were asked to ring a bell if the thought of a white bear came to mind. On average, they mentioned the white bear or rang the bell (indicating the thought) more than once per minute. Thought suppression simply didn't work and instead pro- duced a flurry of returns of the unwanted thought. What's more, when some research participants later were specifically asked to change tasks and deliberately think about a white bear, they became oddly preoccupied with it. A graph of their bell rings in FIG- URE 8.7 shows that these participants had the white bear come to mind far more ofi:en than people who had only been asked to think about the bear from the outset, with no prior suppression. This rebound effect of thought suppression, the tendency of a REBOUND EFFECT OF THOUGHT SUPPRESSION The tendency of a thought thought to return to consciousness with greater fequency following suppression, suggests to return to consciousness with greater that attempts at mental control may indeed be difficult. The act of trying to suppress a frequency following suppression. thought may itself cause that thought to return to consciousness in a robust way. 32 CONSCIOUSNESS 6------------------------ 5 f------+-------l _ _J 4- ---r- - - --+-- Bell rings indicating thoughts of a white bear - -----t--- FIGURE 8.7 Rebound effect Research participants were first asked to try not to think about a white bear, and then they were asked to think about it and to ring a bell whenever it came to mind. Compared to those who were simply asked to think 2 3 4 5 about a bear without prior suppression, those people who first suppressed the Minute thought showed a rebound of increased thinking (Wegner et al., 1987). Without suppression After suppression As with thought suppression, ocher attempts to 'steer' consciousness in any direction can result in mental states chat are precisely the opposite of chose desired. How ironic: trying to consciously achieve one task may produce precisely the opposite outcome! These ironic effects seem most likely to occur when the person is distracted or under stress. People who are distracted while they are trying to get into a good mood, for exam- ple, tend to become sad (Wegner et al., 1993 ), and chose who are distracted while crying to relax actually become more anxious than chose who are not trying to relax (Wegner, 1989). Likewise, an attempt not to overshoot a golf putt, undertaken during distraction, IRONIC PROCESSES OF MENTAL CONTROL ofi:en yields the unwanted overshot (Wegner et al., 1998). The theory of ironic processes Mental processes that can produce ironic of mental control proposes that ironic errors occur because the mentalprocess that monitors errors because monitoring for errors can errors can itselfproduce them (Wegner, 1994a, 19946). In the attempt not to think of a itself produce them. white bear, for instance, a small part of the mind is ironically searching for the white bear. This ironic-monitoring process is not present in consciousness. Afi:er all, crying not to chink of something would be useless if monitoring the progress of suppression required keeping chat target in consciousness. For example, if crying not to think of a white bear meant chat you consciously kept repeating to yourself, 'No white bear! No white bear!', you've failed before you've begun: that thought is present in consciousness even as you strive to eliminate it. Rather, the ironic monitor is a process of the mind chat works outside consciousness, making us sensitive to all the things we do not want to think, feel or do, so that we can notice and consciously take steps to regain control if these things come back to mind. The person trying not to chink about a white bear, for example, would unconsciously monitor any signs of the thought and so be prompted to cry con- sciously to chink of something else if it returns. As chis unconscious monitoring whirs along in the background, it unfortunately increases the person's sensitivity to the very thought chat is unwanted. Ironic processes are mental functions chat are needed for effective mental control - they help in the process of banishing a thought from consciousness - but they can sometimes yield the very failure they seem designed to overcome. Ironic processes of mental control are among the mindbugs that the study of psychology holds up for examination. And because ironic processes occur outside con- sciousness, they also remind us chat much of the mind's machinery may be hidden from our view, lying outside the fringes of our experience. The unconscious mind Conscious experience is so central to the human condition that it is easy to see why Go ahead, look away from the book for a minute and try not to think about a white psychologists want to understand it. Ever since Descartes recognized conscious bear. thought as the foundation for proving the existence of oneself, thinkers have had a very conscious-centric view of the mind. Descartes famously questioned the nature of exist- ence by a process of deductive reasoning. He realized chat there were many experiences in life chat one could not necessarily be certain of. For example, as we saw in Chapter 4, perceptual illusions often fool the observer even when they are aware chat things are not what they seem. Descartes began to question everything he had previously held co be true and realized chat nothing about personal experience was logically certain. In his 1641 treatise on the subject, Meditations on First Philosophy, Descartes wrote: 'I have found by experience chat the senses sometimes deceive, and ic is prudent never to crust completely chose chat have deceived us even once.' He went on to argue chat even state- ments such as 'I am sitting here by the fire' may be false since one could be dreaming or hallucinating. In shore, the only certainty of existence one could logically hold to be crue was chat being consciously aware of one's own chinking was proof of existence, hence his now-famous dictum: 'Cogiro ergo sum' (I chink, therefore I am). However, chis emphasis on the conscious mind may be misguided. Many mental pro- cesses are unconscious, in the sense chat they occur without our experience of chem. When we speak, for instance: We are not really conscious either of the search for words, or of putting the words together into phrases, or of putting the phrases into sentences... [The] actual process of chinking... is not conscious at all... only its preparation, its materials, and its end result are consciously perceived. (Jaynes, 1976, p. 40) Just to put the role of consciousness in perspective, chink for a moment about the mental processes involved in simple addition. What happens in consciousness between hearing a problem (What's 4 plus 5?) and chinking of the answer (9)? Probably nothing - the answer just appears in the mind. Bue chis is a piece of calculation chat muse cake at lease a bic of chinking. After all, at a very young age, you may have had to solve such problems by counting on your fingers. Now chat you don't have co do chat anymore, the answer seems co pop into your head automatically, by virtue of a process char doesn't require you to be aware of any underlying steps, and, for chat matter, doesn't even allow you to be aware of the seeps. The answer just suddenly appears. In the early part of the 20th century, when structuralist psychologists, such as Wundt, believed chat introspection was the best method of research (see Chapter 1), research volunteers trained in describing their thoughts tried co discern what happens in these cases - when a simple problem brings to mind a simple answer (for example, Watt, 1905). They drew the same blank you probably did. Nothing conscious seems to bridge chis gap, but the answer comes from somewhere, and chis emptiness points to the uncon- scious mind. To explore these hidden recesses, we can look at the classical theory of the unconscious introduced by Sigmund Freud and then at the modern cognitive psychol- ogy of unconscious mental processes. Freudian unconscious The true champion of the unconscious mind was Sigmund Freud. As you read in Chapter 1, Freud's psychoanalytic theory viewed conscious thought as the surface of a much deeper mind made up of unconscious processes. Far more than just a collection of hidden processes, Freud described a dynamic unconscious - an active system encompass- DYNAMIC UNCONSCIOUS An active ing a Lifetime ofhidden memories, the persons deepest instincts and desires, and the persons system encompassing a lifetime of hidden memories, the person's deepest inner struggle to control theseforces. The dynamic unconscious might contain hidden sex- instincts and desires, and the person's ual thoughts about one's parents, or destructive urges aimed at a helpless infant - the inner struggle to control these forces. kinds of thoughts people keep secret from ochers and may not even acknowledge to themselves. According to Freud's theory, the unconscious is a force co be held in check by repression - a mental process that removes unacceptable thoughts and memoriesfrom con- REPRESSION A mental process that sciousness and keeps them in the unconscious. Without repression, a person might think, removes unacceptable thoughts and memories from consciousness and keeps do or say every unconscious impulse or animal urge, no matter how selfish or immoral. them in the unconscious. With repression, these desires are held in the recesses of che dynamic unconscious. Freud looked for evidence of the unconscious mind in speech errors and lapses of consciousness, what are now commonly called 'Freudian slips'. Forgetting the name of someone you dislike, for example, is a mindbug chat seems to have special meaning. 32 CONSCIOUSNESS Freud believed that errors are not random and instead have some surplus meaning that may appear to have been created by an intelligent unconscious mind, even though the person consciously disavows them. In many instances, these slips reveal taboo urges related to sex and swearing. For example, on BBC Radio 4's Today programme, presenter James Naughtie interviewed Jeremy Hunt, the culture minister. Unfortunately, the vet- eran BBC presenter slipped up and substituted the obscene four-letter 'c' word into his question before quickly correcting himself One experiment revealed that slips of speech can indeed be prompted by a person's pressing concerns (Motley and Baars, 1979). Research participants in one group were told they might receive minor electric shocks, whereas those in another group heard no mention of this. Each person was then asked to read quickly through a series of word pairs, including shad bock. Those in the group warned about the shocks slipped up more ofi:en when pronouncing this pair, blurting out bad shock. Unlike errors created in experiments such as this one, many of the meaningful errors Freud attributed to the dynamic unconscious were not predicted in advance and so seem to depend on clever after-the-face interpretations. That's not so good. Suggesting a pat- tern to a series of random events is quite clever, but it's not the same as scientifically pre- dicting and explaining when and why an event should happen. Anyone can offer a reasonable, compelling explanation for an event afi:er it has already happened, but the true work of science is to offer testable hypotheses that are evaluated based on reliable evidence. Freud's type of interpretation is sometimes called the 'sharpshooter fallacy', based on the story of a Texan who fires several shots into the side of a barn and then draws a bull's-eye around them, claiming to be an expert shot. Such post-hoc ('afi:er-the- fact') analysis was typical of Freud's approach; hence his theory was criticized as being unscientific because of its lack of predictive power (see Chapter 1). Freud's book The Psychopathology of Everyday Life (Freud, 1938) suggests not so much that the dynamic unconscious produces errors but that Freud himself was a master at finding meaning in errors that might otherwise have seemed random. Cognitive unconscious Although heavily criticized, many modern psychologists share Freud's interest in the impact of unconscious mental processes on consciousness and behaviour. However, rather than Freud's vision of the unconscious as a teeming menagerie of animal urges and repressed thoughts, the current study of the unconscious mind views it as the factory that builds the products of conscious thought and behaviour (Kihlstrom, COGNITIVE UNCONSCIOUS The mental 1987; Wilson, 2002). The cognitive unconscious includes all the mental processes that processes that are not experienced by are not experienced by the person but give rise to the person's thoughts, choices, emotions the person but give rise to the person's thoughts, choices, emotions and and behaviour. behaviour. One indication of the cognitive unconscious at work is when the person's thought or SUBLIMINAL PERCEPTION A thought or behaviour is changed by exposure to information outside consciousness. This happens in behaviour that is influenced by stimuli subliminal perception, a thought or behaviour that is influenced by stimuli that a person that a person cannot consciously report cannot consciously report perceiving, which we encountered in the discussion of covert perceiving. advertising in Chapter 4. Worries about the potential of subliminal influence were first provoked in 1957, when James Vicary, a marketer, claimed that he had increased conces- sion sales at a New Jersey theatre by flashing the words 'Eat Popcorn' and 'Drink Coke' briefly on the screen during films. It turns out his story was a hoax, and many attempts to increase sales using similar methods have failed. But the idea of influencing behaviour outside consciousness created a wave of alarm about insidious 'subliminal persuasion' that still concerns people (Epley et al., 1999; Pratkanis, 1992). Subliminal perception does occur (Kihlstrom, 1987), but the degree of influence it has on behaviour is not very large (Dijksterhuis et al., 2005 ). One set of studies exam- ined whether beverage choices could be influenced by brief visual exposures to thirst- related words (Strahan et al., 2002). Research volunteers were asked to perform a computer task that involved deciding whether each of 26 letter strings was a word or not. This ensured that they would be looking intently at the screen when, just before each letter string appeared, a target was shown that could not be consciously perceived: a word was flashed for 16 ms just off the centre of the screen, followed by a row ofXs in 1  CONSCIOUSNESS that spot to mask any visual memory of the word. 5,-------------, For half the participants, this subliminal word was thirst related (such as thirst and dry) and for the 4.5 FIGURE 8.8 Subliminal other half it was unrelated (such as pirate and won). Rating influence Among people Afterwards, when the volunteers were given a of sports drinks subliminally primed with thirst choice of free coupons towards the purchase of pos- 4 words, preference for the thirs sible new spons beverages Super-Quencher ('the quenching beverage Super- best thirst-quenching beverage ever developed') Quencher increased relative t, another sports drink PowerPrc and PowerPro ('the best electrolyte-restoring bever- 3.5 (Strahan et al., 2002). Super-Quencher PowerPro age ever developed'), those who had been sublimi- REPRINTED FROM JOURNAL OF EXPERIMENTAL SOC/1 Subliminal priming condition PSYCHOLOGY, 38/6, STRAHAN, E. J. SPENCER, S. J_ Al nally exposed to thirst words more often chose ZAN NA, M P., SUBLIMINAL PRIMING AND PERSUASIO! STRIKING WHILE THE IRON IS HOT, 556-68, COPYRlGH Super-Quencher (see FIGURE 8.8). Thirst-related primes Neutral primes (2002), WITH PERMISSION FROM ELSEVIER. WWW SCIENCEDIRECT.COM/SCIENCE/JOURNAU00221031 There are two important footnotes to this research. First, the influence of the subliminal persuasion was primarily found for people who reported already being thirsty when the experiment started. The subliminal expo- sure to thirst words had little effect on people who didn't feel thirsty, suggesting that Vicary's 'Drink Coke' campaign, even if it had actually happened, would not have drawn people out to the lobby unless they were already inclined to go. Second, the researchers also conducted a study in which other participants were shown the target words at a slower speed (300 ms) so the words could be seen and consciously recognized. Their conscious perception of the thirst words had effects just like subliminal perception. Subliminal influences might be worrisome because they can change behaviour without our conscious awareness but not because they are more powerful in comparison to con- scious influences. However, some believe that the research into and interpretation of subliminal percep-