The Concept of Consciousness

The Concept of Consciousness The first and foremost concrete fact which everyone will affirm to belong to his inner experience is the fact that consciousness of some sort goes оп. "States of mind" succeedeшh other in him. If we could say in English "it thinks," as we say "it rains" or "it Ьlows," we should Ье stating the fact most simply and with the minimum of assumption. As we cannot, we must simply say that thought goes оп (William James 1892/1984, р. 140). Consciousness is the fundamental fact of human existence, from the viewpoint of persons examining their own experience. Taking the viewpoint of outside observers, scientists have concentrated on studying the human brain and behavior objectively. In doing so they have largely ignored con­ sciousness, since they cannot directly observe other people's conscious ехре· rience. Yet the fact of consciousness remains, and no account of human life can Ье complete if it ignores consciousness. It is psychology's particular re­ sponsihility, among all the sciences, to try to come to grips with the fact of consciousness. What is it? What are its forms? What does it do? What is its origin? In their research and clinical practice, psychologists have learned а great deal about various aspects of consciousness, such as perception, mental imagery, thinking, memory, and emotion. But in most of the theoretical dis­ cussions of these topics, the concept of consciousness has been merely im- plicit, not explicit. Though psychology originated in the late nineteenth cen· tury as the science of consciousness, consciousness per se was largely ignored through most of the twentieth century, until recently. This avoidance of con· sciousness was particularly true of experimental psychology in North Amer­ ica, which was dominated until recently Ьу behaviorism, а school maintain­ ing that psychology is about behavior, not about the mind. The reasons why most psychologists have avoided discussing con­ sciousness are complex and historical. They boil down to the fact that con· sciousness is one of the most difficult of all scientific proЫems. The first dif• ficulty is the conceptual proЫem: What do we mean Ьу "consciousness"? What is it that we are trying to understand? А second difficulty is the meth­ odological proЫem. Since we cannot objectively observe other people's con· scious experience, how can we study it? А third proЫem is the enormous variety of conscious experiences, both within individual persons from one moment to another, and between different persons. The methodological proЫems are formidaЬle, and there are no perfect solutions. Yet the meth­ odological proЫems must Ье faced if we are to gain а scientific understand­ ing of the causes, and effects, of the variety of conscious states. In recent years more and more psychologists have been willing to face the proЫems of studying consciousness and theorizing about it. The change has соте about for а variety of reasons, including recent developments within psychology and associated areas of cognitive science, brain science, and philosophy. One factor in the change is an increased realization that the subject matter of psychology-human behavior and experience-is unique. Psychology can no Jonger try to model itself after classical physics, but must devise its own methods of research and theorizing. ТНЕ PSYCHOLOGY OF CONSCIOUSNESS The psychowgy of consciousness is the branch of psychology that is concerned with proЫems of consciousness. Psychologists may not agree on а definition of "consciousness" or of "the psychology of consciousness," but they can, to а large degree, agree on which topics and proЫems are included within the oomain of the psychology of consciousness (Natsoulas 1981). Among the proЫems are: What do we mean Ьу the concepts of mind and consciousness? What methods can Ье used for studying consciousness, and what are the ad­ vantages and disadvantages of each? What are the different forms and as­ pects of consciousness? What factors influence the stream of conscious• ness-moment to moment changes in the content of consciousness? What is the relatiOnship between conscious and nonconscious (unconscious) mind, and what are the varieties of nonconscious processes? What is the relation· ship between cOnsciousness and the brain? Between consciousness and per­ ception? Between consciousness and behavior? Between consciousness and language? How does consciousness develop in the individua\? What is the role of consciousness in the human mind/brain system? Among the most distinctive topics of the psychology of consciousness are the "altered states" of consciousness. Altered states of consciousness are temporary, reversiЫe conditions in which one's pattern of subjective experi­ ence, and sometimes the aЬility to control one's own behavior, appear to Ье different than in one's normal waking state. Among the altered states are sleep and dreaming, hypnosis, meditative and mystical states, and states in­ duced Ьу psychoactive drugs and Ьу restricted environmental stimulation. Besides being of interest in their own right, altered states are relevant"to un• derstanding the basic nature of consciousness. Also, altered states may have practical applications, as in dinical applications ofhypnosis. Altered states will Ье а major topic in this book. The psychology of consciousness is concerned mainly with conscious­ ness in normal people, though it has connections with abnormal psychology and psychopathology. Also, research оп brain-damaged patients Ьу neu­ ropsychologists has important implications for understanding· norma] con­ sciousness, In fact, the psychology of consciousness has connections with most branches of psychology, though in this book the emphasis will Ье on topics that are central to understanding consciousness but that are not dis­ cussed extensively in textbooks for other psychology courses. The psychol­ ogy of consciousness also has important connections with the philosophy of mind, and some topics of mutual interest to the different disciplines will Ье discussed in this book. Overview of This Book In this chapter I will discuss the meaning of consciousness and related concepts, such as mind and awareness. 1 will present а levels-of-conscious­ ness model to describe the relationship between conscious and noncon­ scious mind. Chapter 2 describes several higher-order characteristics of con­ sciousness-such as selectivity, change, and continuity-as well as some more specific features of conscious experience-such as mental imagery, verbal thought, and volition. In Chapter 3 I will discuss introspection, the method of studying consciousness Ьу "looking within" and trying to describe one's own conscious experience. Several introspective methods will Ье dis• cussed, along with their limitations. Chapter 4 is about the mind-body prob­ lem, an ancient philosophica] proЬ!em concerning the re]ationship between the mind and the body or brain, which has implications for both religious beliefs and the psychology of consciousness. Chapter 4 also considers the other-minds proЫem: the question of how we сап recognize consciousness in other beings, including animals and children that cannot speak to de­ scribe their conscious experiences. Chapter 5 is about neuropsychological research on split-brain patients and its implications for understanding consciousness. Of special interest is the question whether split-brain patients have two minds in one body. Chap­ ter 6 presents evidence for nonconscious information processing. lt dis­ cusses dissociations between consciousness and behavior (such as 'Ъlind­ sight" and amnesia) in brain-damaged subjects, as we11 as several types of evidence from normal subjects (such as suЫiminal perception). Chapter 7 ("Introspection II") discusses research on the question of whether we have introspective access to the causes of our own behavior. Chapter 8 is about daydreaming and the stream of consciousness, including research on personal and situational factors that influence daydream fre­ quency and content. Chapter 8 also discusses the effects of sensory depriva­ tion on consciousness and behavior. In Chapter 9, I present some general considerations about altered states of consciousness, such as dimensions of subjective change in altered states, before discussing specific altered states in later chapters. Chapters 10 through 13 are about sleep and dreaming, topics that have fascinated people for centuries, and which are favorite topics of many stu­ dents of the psychology of consciousness. Chapter 10 is about sleep, includ­ ing the physiological correlates of different sleep stages, the effects of sleep deprivation, and sleep disorders. Chapter 11 discusses modern sleep· laboratory research оп dreaming, including the characteristics of dreams and factors that influence dream contents, including nightmares as well as normal dreams. Chapter 12 discusses some of the major theories of dream­ ing-from the psychoanalytic, neurophysiological, and cognitive view­ points-and related research, including research оп dreaming in children. Chapter 13 considers two special topics: the proЫem of dream recall and forgetting, and lucid dreaming, in which you know you are dreaming as you sleep and dream. Chapters 14 through 16 are about hypnosis, another favorite topic among students, and currently the most active area of research and theoreti­ cal debate among the altered-states-of-consciousness topics. Chapter 14 is а general overview of the basic principles of hypnosis and factors related to individual differences in hypnotizaЬility. It also discusses clinical applica­ tions of hypnosis, and the question of whether hypnosis is dangerous. Chap­ ter 15 goes into more detail оп recent theories of hypnosis and related research on hypnotic analgesia (pain control) and amnesia, and the contro­ versy whether hypnosis is really an altered state of consciousness. Chapter 16 is about two special topics, hypnotic age regression and hypermnesia-the use of hypnosis in attempts to improve memory recall, which has implica­ tions for psychotherapy and criminal investigations. • Chapter 17 describes basic meditation practices and their effects on consciousness, and practical applications such as reduction of stress and anxiety. Characteristics of mystical states-sometimes reached through med­ itation-are also described. Chapters 18 and 19 are about psychedelic drugs and their effects on consciousness and behavior. Chapter 18 is about mari­ juana, а widely used minor psychedelic; Chapter 19 discusses the major hal­ lucinogens, with emphasis оп the hallucination experience. Now, let us turn to the question ofthe meaning of consciousness, mind, and related concepts. Over the years philosophers, psychologists, and brain scientists have devised dozens of definitions of these terms. I do not want to get too bogged down in arguments about definitions, so I will explain how I intend to use these terms in this book and contrast my definitions with а few of the most important altemative definitions. Then I will introduce the idea of leyels of consciousness, which will help to relate several important con­ cepts to each other. MIND Consciousness is not the same as mind. Mind is the broader concept: it in• c]udes both conscious and nonconscious mental processes. Dona]d НеЬЬ de­ fined mind as folJows: Mind is the capacity for thought, and thought is the integrative activity of the brain-that activity up in the control tower that, during waking hours, over• rides reflex response and frees behavior from sense dominance (НеЬЬ 197 4, р. 74). Here is my definition: Mirui is thefunctioning oj the brain to process informa• tion and control action in аflexiЫe arui adaptive manner. ВоtЬ my definition and Hebb's are materialistic in tЬat they say tЬat mind is а resu]t of brain activity and cannot exist apartfrom tЬе Jiving brain, which is а materia] object. 1 ВоtЬ definitions arefunctional in that tЬеу say what mind does: it processes infor· mation (inc]uding perception, memory, and tЬinking) and contro]s action. FurtЬer, tЬеу state tЬat flexiЫe behavior is an indicator of mind: an organ· ism witЬ mind does not behave in а pure]y reflexive manner, always reacting to the same stimulus in the same way. Rather, the creature with mind uses tЬought processes to adjust its behavior to suit tЬе situation. The concept of mind implies menta] processes. А mental process is а more-or-Jess specialized program or procedure used in processing informa· tion (as in perception, memory, and thinking) and controШng speech and otЬer actions. Mental processes use symbo]s orrepresentations for objects, con• cepts, events, actions, and so on. Cognitive psychologists try to discover and describe tЬе various types of menta] processes (or cognitive processes), and tЬе interactions between tЬem, that are necessary to explain human percep• tions, thoughts, and actions. At the psychologica] level, mental processes can Ье described in terms of tЬeir functions, including the type of information tЬеу rake in, tЬе types oftransformations they effect, and tЬе types of outputs or responses they make. Neuropsycho]ogists and other brain scientists are concerned with discovering the specialized brain structures and processes tЬat carry out the various mental functions. Sometimes I wШ use the term mind/Ьrain system when I want to emphasize the point tЬat menta] processes are carried out Ьу tЬе brain-a blologica] entity.2 None of tЬese definitions of mind or mental processes say anything about consciousness. Mind is а broader concept ihan consciousness. Mind includes both conscious and nonconscious щ.ental processes. CONCEPTS OF CONSCIOUSNESS It is harder to define consciousness than it is to define mind. It is not possiЫe to specify precise objective criteria for identifying consciousness. Nor сап consciousness Ье given а clear functional definition, since its specific func· tion within the mind system is still а matter of controversy.3 Consciousness is one of those concepts that we understand intuitively, but it is difficult or impossiЫe to describe it adequately in words. We сап describe many conscious contents, such as sensory perceptions or mental im­ ages, in а fairly straightforward way. And we сап talk indirectly about other conscious experiences, such as love and pain, using metaphors to liken the experience to something else. ("Му headache makes me feel like I have а tight metal band around my head.") The best we сап do in trying to describe consciousness per se is to resort to metaphors. For example, to say that con· sciousness has contents is to make an analogy to а vessel or space. Julian Jaynes (1976, 1986) pointed out that much of our language for describlng mind and consciousness is based оп visual-spatial metaphors ("mind· space"), and mental acts are described Ьу analogy to behavioral acts in the visua] world. We "see" solutions to proЫems, the best ofwhich may Ье "brilliant" or "clear" or possiЫy "dull," "fuzzy/' "obscure." These words are а11 metaphors, and the mind-space to which they apply is generated Ьу metaphors of actual space. In that space we can "approach" а proЫem and " grapple" with its difficulties. Every word we use to refer to mental events is а metaphor or analog of some­ thing in the behavioural world. And the adjectives that we use to describe phys­ ical behaviour in real space are analogically taken over to describe mental behaviour in mind•space. We speak ofthe conscious mind as being "quick" or "slow", or of somebody being "nimЫe•witted" or "strong-minded" or "weak­ minded" or "broad•minded" or "deep" or "open" or "narrow-minded." And so like а real space, something сап Ье at the "back" of our mind, or in the "inner recesses" or 'Ъeyond" our minds (Jaynes 1986, р. 132).4 But while metaphors are useful for enaЫing some conscious creatures to talk with each other about their conscious experiences, they are not suffi· cient for а good objective definition of consciousness. Consciousness isn't really quite like anything else. Consciousness is, in а sense, the fundamental fact of human existence, as William James pointed out in the quote at the beginning of this chapter. At the same time, the concept of consciousness is а very high level abstraction: it is what all of our conscious contents and ех• periences have in common. We соте to know the meaning of consciousness intuitively, through experience, rather than through definition. Psychologists are more likely to agree that thinking or consciousness of some sort goes on than they are to agree on а particular verbal definition of consciousness.5 Nonetheless, 1 believe that to facilitate communication I should present а working definition of consciousness, and try to Ье consis­ tent in the way I use the term in this book. In the next section I will define consciousness in terms of subjective awareness. Then I will describe two major alternative meanings of consciousness-as wakefulness and as an ех• ecutive control system-and relate those rneanings to my definition. Consciousness as Awareness As а working definition, consciousness i.s the subjective state ofbeingcurrently aware oj something, either within oneself or outsiдe of oneself. In this case, being aware or having awareness refers to cognizance or knowing. Consciousness is always about something. lt concerns perceptions, thoughts, feelings, and actions. Consciousness has contents.6 The variety of contents is enormous. Consciousness can include perceptual awareness of objects and events in our immediate environment, as well as body sensations such as joint pains and tummy rumЫings. Consciousness can also include memories of personal past events or impersonal factual knowledge. Also imaginary scenes, as in our daydreams and night dreams, which may Ье ei­ ther realistic or fantastic. Consciousness includes emotional feelings and inner speech, such as thoughts about personal proЫems and goals. But while consciousness can have an enormous variety of contents, it cannot have very many contents at one time. As we will see, the selectivity of consciousness is one of its main features. Conscious knowledge is knowledge that is "currently present."7 At any moment most of our knowledge is nonconscious; it is stored in long-term memory and we are not aware of it at that particular moment, though we could quickly recall much of it given the right retrieval cues. То remember something means to retrieve it into consciousness. Consciousness involves subjective experience, which means that it is di­ rectly accessiЬle only to the person having the experience. It cannot Ье di­ rectly observed Ьу other people. In humans, at least, conscious experience typically invo\ves some sort of self reference, either explicit or implicit.8 Nortnal adult humans can usually make some sort of verbal report about the contents of consciousness-their immediate, or past, subjective ex­ perience. The introspective verbal report is the primary criterion for detecting the existence of consciousness, and the main way to know about the contents of another person's consciousness. Of course, some things cannot Ье de­ scribed very well in words, and sometimes we forget what we were thinking before we can report it. (In Chapters 3 and 7 I will discuss the uses and limi• tations of introspective reports in some detail.) The definition of consciousness in terms of awareness of content links consciousness to the proЫem of representation ofknowledge-how knowl• edge is coded in memory-which is а fundamental proЫem for cognitive psychology. Consciousness always involves some form of representation of objects, ideas, events, and so on. But consciousness is more than just aware­ ness of individual objects and events. It also involves comprehension, relat• ing various objects and events to each other and to prior knowledge and past experiences. Conscious experience is not just а passive response to stimuli. It is-or results from-an active process of interpretation and construction in which we use availaЫe data from sensory inputs and memory and search for new pertinent data to produce а comprehensiЫe view of the world (that is, our social and physical environments) or to construct imaginary worlds in which to act. (We wi\l encounter the theme of consciousness as а product of interpretive and constructive processes in later chapters.) An important implication of the definition of consciousness as aware• ness of something is that-contrary to the teachings of certain meditation systems-it is meaningless to speak of"pure consciousness" or "pure aware­ nessн (consciousness or awareness without content). We can discuss con­ sciousness as an abstract concept without referring to any particular content. But in actual instances of consciousness in persons, consciousness always has contents. The meditator who thinks "Wow, my mind is empty! I have reached the state of pure consciousness!" does, in fact, have consciousness with con• tents. Consciousness without contents is conceivaЫe only in an altogether different sense ofthe term consciousness-consciousness as wakefulness. Consciousness as Wakefulness One of the most common meanings of"consciousness" is in the sense of wakefulness. In this usage, а person who is awake is conscious, whereas one who is asleep, in а coma, or knocked out Ьу а Ыоw to the head, is uncon• scious. Wakefulness,_or being awake, is а region on а contiouum of arousal ranging from hyper-aroused wakefulness, through normal wakefulness, to the hypnagogic state (between waking and sleep), sleep, and finally, coma. Wakefulness and sleep сап Ье distinguished Ьу а comblnation ofbehavioral (responsiveness to external stimuli) and physiological (brain wave) criteria, though there is а transition period in which one is neither clearly awake nor clearly asleep. Consciousness in the sense of wakefulness is not the same thing as con• sciousness in the sense of awareness of something. Occurrences of conscious­ ness in these two senses are correlated to а degree, in that when we are awake we usually are aware of something. Оп the other hand, being asleep does not necessarily imply an absence of awareness. The mind/Ьrain system is in• tensely active during sleep. Dreaming involves awareness of something, namely visual and auditory mental images linked together in а story-like manner. Thus, consciousness as awareness of content сап go with uncon­ sciousness in the sense ofbeing not-awake (asleep). These two meanings of"corisciousness"-as awareness and as wakeful• ness-can Ье so contradictory that I will avoid using нconsciousness" in the sense of wakefulness. When I wish to distinguish the waking state from the sleeping state I will say "wakefulness" or "awake." I will reserve the term con­ sciousness to refer to the state of being subjectively aware of something. Thus, it will Ье possiЫe to ask without contradiction of terms whether there are instances in which an individual may Ье awake but without conscious­ ness, that is, awake but with no subjective awareness of anything. Similarly we will Ье аЫе to ask about consciousness during sleep. Consciousness as an Executive Control System Making decisions and initiating voluntary actions are important as­ pects of conscious experience. It is natural, therefore, to think of conscious­ ness as the decision maker, the executive that chooses among various alter­ native goals and courses of action to reach those goals. Thus, one of the most common meanings of "consciousness" is an executive control system that supervises and coordinates the activities ofthe overall mind/Ьrain system. Consciousness as an executive control system fits well with the notion that consciousness is active. Consciousness is not merely а passive·recipient ofsensory input and memories, nor а passive commentator on experience. Rather, consciousness chooses goals, seeks out information relevant to those goals, and initiates actions. The idea of consciousness as an executive control system has been par­ ticularly important in cognitive psychological theories that have developed under the influence of an analogy between the human mind and computer system. For example, Tim Shallice (i978) saw consciousness as the selector of the "dominant action system," from among а myriad of relatively indepen­ dent, competing action production systems. Ernest Hilgard (1977) andJohn Kihlstrom (1984) emphasized two related functions of consciousness: "Moni­ toring ourselves and our environment, so that percepts, memories, and thoughts come to Ье accurately represented in phenomenal awareness; and controlling ourselves and our environment, so that we are аЫе to voluntarily initiate and terminate behavioral and cognitive activities" (Kihlstrom 1984, р. 150). Hilgard (1977) suggested that hypnosis involves а dissociation or dis­ connection between monitoring and control aspects of consc_iousness. (His ideas will Ье discussed in the hypnosis chapters, particularly Chapter 15.) Philip Johnson-Laird (1983, 1988) suggested that the mind/Ьrain sys­ tem operates as а hierarchically organized parallel-processing system whose highest level, the operating system, corresponds to consciousness. The con­ scious operating system controls behavior Ьу interacting with various non­ conscious, lower-level subsystems or modules. It receives processed inputs (such as percepts) from subsystems, and selects and coordinates actions (such as memory retrieval and overt responses) to Ье executed Ьу subsystems, with­ out knowing the details of the subsystems' operations. Subjective awareness corresponds to the contents of the operating system-more precisely, its working memory. Self-awareness corresponds to the systems' knowledge of its cuттent situation, current operating status, and its capabllities, predil_ec­ tions, and preferences. Whether "consciousness" is to refer to subjective awareness or to an executive control system is а matter of preference, but it·is important to note that subjective awareness and control functions are not equivalent concepts. Johnson-Laird and others are рrоЬаЫу correct in arguing that the human mind/Ьrain system has some sort of executive control system, and that there is an important relationship between subjective awareness and the contents or activities of the executive system. The nature of that relationship is still а matter of theoretical controversy. In any case, I believe I am consistent with the most common usage of "consciousness" Ьу restricting it to subjective awareness. For clarity, it would Ье best if the executive control system were given а separate, distinctive name. I should warn you that many writers slip back and forth between two or more of the meanings of consciousness (such as awareness, wakefulness, con­ trol system), including some writers who will Ье cited in this book. Such os­ cillation can Ье confusing. In trying to limit the use of "consciousness" to awareness I do not mean to deny the importance of the ideas behind the other uses of the word. Consciousness in Cognitive Psychology Some cognitive psychologists try to avoid using the word "conscious­ ness" due to the conceptual and methodological proЫems that it presents. However, the subjective fact of consciousness cannot Ье denied, and а satis- factory theory of the human mind/Ьrain system must find а place for it. In considering the place of consciousness in the human information process­ ing system (mind system). cognitive psychologists have linked consciousness with three closely related concepts: working memory, attention, and con· trolled (effortful) processing (Кihlstrom 1984; Кlatzky 1980, 1984). In the multistore theory of human information processing, working memory (also called short-term memory, STM) is distinguished from long• term memory (Atkinson & Shiffrin, 1968). Long-term menwry (LТМ) is the rel· atively permanent storehouse ofknowledge about our past experiences, the meaning of words, miscellaneous facts, and procedures for doing things. Workingmenwry is а system that caпies out various cognitive (mental) control processes, such as processes for solving proЫems, making decisions, and ini• tiating actions. Also, working memory temporarily stores recent perceptions and retrieved memories to Ье used in these processes. The capacity of work­ ing memory is severely limited, and its contents are lost within а few seconds once you stop rehearsing or thinking about them. For example, if you look up an unfamiliar telephone number you have to keep rehearsing it until you dial it; if something interrupts the rehearsal process (for example, someone asking you а question), then you will рrоЬаЫу forget the number before you can dial it. Consciousness can Ье related to working memory in two ways. In terms of the definition of consciousness as awareness, the current contents of con­ sciousness are equivalent to the cuттent contents of working memory. In teпns of consciousness as an executive control system, consciousness is largely equivalent to working memory as а general-purpose, high-level, or final-stage information processing system that makes decisions and initiates actions. Some psychologists have argued that it is misleading to link conscious­ ness with working memory, if working memory is thought of as а р!д,;е in the information processing system. George Mandler argued that а content is not conscious merely because it is in shon-term (working) memory. Rather, "con• sciousness is а nwtk of processing." (1984, р. 89) Conscious contents are con· tents that are undergoing the conscious mode of processing. The capacity of consciousness is limited because of limitations on the conscious-processing mode. The levels-of-processing model of memory (Craik & Lockhart 1972) does not distinguish between STM and LTM, but postulates а single storage system. In terms of the levels-of-processing model, consciousness can Ье largely identified with primary menwry, the cuпently activated contents of the memory storage system. In а related idea, Schneider and Shiffrin (1977) explained several as­ pects of humau performance in terms of а distinction between controlled (or effortful) processes (limited capacity, flexiЫe, slow) and automatic processes (practically unlimited capacity, relatively inflexiЫe, fast). Consciousness is associated with controlled processes, such as flexiЫe thinking for solving new proЫems, whereas automatic processes, such as those that execute ha­ Ьitual responses and highly learned skills, operate outside of conscious awareness. In everyday speech, consciousness is related to "attention." То рау at- tention to something is to Ье consciously aware ofit. ln cognitive psychology there are two different but related meanings of attention. First, attentional capacity refers to а general-purpose, limited-capacity information processing resource that is critically important for carrying out many cognitive tasks, especially those that require flexibllity for dealing with novel situations. If we try to do two tasks at the same time (such as listening to а lecture and writing а letter), then the tasks will interfere with each other if, together, they require more attentional capacity than is availaЫe. Kahneman (1973) identi­ fied limited attentional capacity with mental effort, v-.rhereas other cognitive processes are effortless, such as rapid pattern identification and rapid mem­ ory retrieval. Under most conditions, using attentional capacity for а task, such as reading, is a�sociated with conscious awareness of the information being processed. The older and more common meaning of"attention" concerns selective attcntion, which is а set of processes that determines which of the many com­ peting stimuli get through to consciousness. The classic example of selective attention is the cocktail pany situation, in which several people in the room are talking at once and you can selectively focus оп one voice at а time while ignoring the others. In terms ofthe multistore theory, sel"ective attention se­ lects inputs to working memory. Because of the limited capacity ofworking memory, it is necessary to select inputs according to some sort of priority system. The three cognitive psychology concepts of working memory (STM), controlled processing, and attentiona] capacity were developed in different theoretical and research contexts. However, for our purposes we may regard them as essentially equivalent. They have in common the characteristics of being general in purpose, limited in capacity, and necessary for tasks in which flexiЫe information processing-thinking-is required. All three concepts are closely associated with conscious awareness, оп the assumption that conscious contents (words and images, for example) refer to infoпna­ tion currently being processed (that is, processed in working memory or with attentional capacity or controlled processing). Like its cognitive psychology counterparts, consciousness, too, is limited in capacity, general in purpose, and associated with higher-level thought processes. All three cognitive con­ cepts allow for other types of cognitive processes-such as long-term mem­ ory and automatic processes-that occur nonconsciously, that is, outside of conscious awareness. А LEVELS OF CONSCIOUSNESS MODEL Figure 1.1 shows а levels-of-consciousness model that indicates the relation• ship between different leve]s of conscious and nonconscious mind. The model is based on а comЬination of introspection and psychological theory and research. The different levels of consciousness have to do with different degrees of (Cl}ailaЬility or retrievabllity of contents from those levels to reflec­ tive consciousness and introspective reporting (Kihlstrom 1984). The levels model does not attempt to explain the different levels of consciousness. Rather, it is а descriptive model that shows what needs to Ье exp]ained.