Chapter 4
Construction of Consciousness From a Mechanical Device
In the earlier chapters, I showed how schemes may be translated into activity of neuronal networks, how these networks prior to Stage 4 are undifferentiated and global, how during Stage 4 they begin to be differentiated, and how complete myelination of the visual and touch sensory tracts could assist such beginning differentiation. I have not addressed what, if any, parts of these schemes are conscious, or how they could become so.
In this chapter I will propose:
- Beginning in Stage 3, all stage-typical schemes conceptualized by Piaget are conscious schemes, and
- What adults experience as being conscious —awareness or what is referred to by some philosophers as the qualia of consciousness —is the enhancement of activity of the cerebral cortical circuitry by the reticular activating system (RAS).
To make my proposal, I take a constructivist-developmental approach.
Sleeping, Waking, and the Reticular Activating System
To understand my proposal, it is helpful to understand something about the sleep-wake cycle. The suprachiasmatic nucleus —a cluster of neurons at the base of the brain, which receives nerve fibers directly from the retina —acts as a time clock that governs the cyclic activity of the RAS. In turn, the activity of the RAS governs the sleep-wake cycle.
The RAS is an extensive and diffuse network of neurons in the brain stem. See Figure 4. 34 Some fibers from all types of sensory nerves conduct impulses to the RAS. The RAS’s main route to the cerebral cortex is through the intralaminary nuclei of the thalamus. The intralaminary nuclei are complex relay stations that connect to widespread areas of the cerebral cortex.
Before the work of Moruzzi and Magoon (1949), little was understood about the loosely defined networks that make up the RAS. They discovered that severing the RAS in the brain stem of cats resulted in behavioral stupor and an electroencephalogram (EEG) resembling sleep. 35 Initially, Moruzzi and Magoon believed that the awake state was caused by sensory input that activated the RAS. Then, the activated RAS activated the cerebral cortical circuitry. They thought that sleep resulted from absence of activation of the RAS. Later Batini, et al. (1958) found that severing the RAS at a somewhat higher level of the brain stem resulted in the inability to sleep. It was then clear that sleep was actively controlled by its own region of the RAS. Activity of one part of the RAS tended to induce the awake state, and activity of a second part of the reticular system (RSS) tended to induce sleep.
Although this position continues to hold, the control systems are more complex than was originally supposed. For example, some cells that make up a particular region of the reticular system are inhibitory and others are excitatory. So it is the predominance of one type of cell over the other that determines what will happen if that region is severed.
Steriade (2000) found that the predominant effects of RAS activation are twofold. First, RAS activation blocks sleep spindles, which originate in a nucleus of the thalamus called the reticular nucleus. 36 Sleep spindles are repeat EEG wave forms that are most prominent during the second stage of sleep. Second, RAS activation excites neurons of the thalamocortical tracts that, as mentioned, have widespread connections to the neurons of the cerebral cortex. The effect of RAS activation is that cortical neurons are made more excitable —more response ready. 37
A Constructivist View of Consciousness
Along with Piaget, I have proposed that, in the newborn and for some time later, the schemes are not distinct from each other. Here, I will propose that, unless there is a distinction between waking-state schemes and sleeping-state schemes, conscious cognitive-emotional schemes are not distinct from non-conscious cognitive-emotional schemes. It then follows that, when cognitive-emotional schemes and non-conscious cognitive-emotional schemes are not distinct from each other, conscious cognition or conscious emotion has no meaning. This holds unless one assumes that cognition and emotion are always conscious —that non-conscious cognition and emotion never takes place. 38
Before 6 weeks, based on the behavior of the infant, there is little indication that waking-state schemes are differentiated from sleeping-state schemes. After 6 weeks, however, several types of behavior suggest that waking-state schemes are differentiated from sleeping-state schemes.
I propose that, at 6 weeks, the waking-state portion of a scheme is the nucleus of what becomes the what-it-is-like to be conscious, sometimes referred to as the qualia of consciousness —a portion of scheme activity that includes the waking state is what is experienced as conscious cognition (and feelings). Further, I propose that beginning in Stage 3 (5-8 months), all stage-typical schemes that were described by Piaget are conscious schemes. In Stage 3 and thereafter, the generalized facilitation of activation of cerebral cortical cells by the RAS —the waking state —is part of every stage-typical scheme. Put another way, beginning in Stage 3 and continuing thereafter, a portion of all stage-typical schemes is conscious.
When a Stage-3 infant strikes a suspended object with his foot and varies his striking as he watches, and appears to have such a good time doing so, I find it hard to believe that he is not conscious. I assume that some of the parts of this typical Stage-3 scheme must be conscious. It is not obvious what particular part of a scheme the child is conscious of at any moment. Is he conscious of the movement of his foot, of the control involved in the movement of his foot, of the contact of his foot with an object, of the sight of its moving, of his emotion, or of all of these parts of scheme activity? Given the undifferentiation of Stage 3, it is likely that he is conscious of all of these parts or a random selection of them. It is difficult to believe that no part of the activity of this typical Stage-3 scheme is conscious —that he is not aware of some part of his scheme —no matter how undifferentiated his scheme is.
A Dilemma: The Brain is a Mechanical Device .
In chapter 1, I proposed that a scheme is activity of neuronal circuits in the cerebral cortex —the electrochemical transmission of impulses in an organization of neuronal circuits. There is no more reason to assume that such circuit activity is inherently conscious than there is reason to believe that the activity of an electrical circuit in a computer is conscious.
Sometimes a computer seems conscious. When I load paper into my printer, and my computer says, "Thank you," I sometimes respond, "You’re welcome." But activity of neuronal or computer circuitry is no more conscious than a ball rolling down a hill, or the action of the engine’s causing the wheels of an automobile to rotate. The activities of these objects may be explained by mechanics alone. The ball is not aware that it is rolling. The engine is not aware that it is causing the wheels to rotate. I assume that the persons who built the computer and programmed it, those who dropped the ball, and those who built or drove the automobile were conscious. They were aware of what they were doing. I also assume that their conscious cognition and emotions played a role in the control of behavior of the computer, of the ball, and of the automobile.
If persons derive their consciousness from the unconscious mechanics of neuronal circuits, which in themselves are not conscious, how is it possible to explain my assumption that persons, who build mechanical things, such as computers or automobiles, or who drop a ball on a hill, are conscious? Recently, distinguished theoreticians have addressed this question. Sperry (1981) proposed that consciousness emerges from neuronal circuitry, once the neuronal circuitry is large and complex enough. It would be like the steering wheel of a car emerging from a complex organization of molecules. Although a mechanical device may make a steering wheel, I think that a thinking person must design the device. Edelman (1989) proposed that neuronal circuitry activation’s folding on itself —the reentry of activation —gives rise to consciousness. Crick and Koch (1990) inferred that attention —a form of consciousness —results from synchronized activity of neurons that are in different areas of the visual system. They infer that when a number of neurons in these different areas of the cerebral cortex fire electrical impulses at the same frequency —about 40 to 70 times a second —a coherent picture emerges. Searle (1992) argued that consciousness is an irreducible feature of physical reality. He implied that consciousness is a property of nerve tissue, much as contractility is a property of muscle cells; that is, along with transmission of electrical impulses, nervous tissue has consciousness as an inherent property.
As I have already noted, I attempt to answer the question by taking a constructivist view of cognitive development. Importantly, my attempt recognizes that representation need not resemble that which is represented —that representation depends on the medium employed for representation. For example, in a computer, the letter E and what to do with E are represented by patterns of open and closed electrical switches. In the brain, the letter E and what to do with E are represented by neuronal circuit activity patterns. 39
Before I explain how I think consciousness is constructed, I will argue that, although the mechanics of brain function are remarkably complex, they are not inherently mysterious. Then I will note two aspects of the relationship between brain and consciousness that are inherently mysterious.
Brain mechanics are not inherently mysterious
To understand the mechanics of how the brain works involves reverse engineering of a very complex electrochemical system with massive interconnections. In its simplest form, reverse engineering is like figuring out how the switch on the dashboard of the car turns the headlights on and off. To do so, one must trace the circuit, from the source of electricity —the negative pole of the battery —to the switch on the dashboard, to the thin wire inside the headlight, to the frame of the car, and finally through the frame to the positive pole of the battery. When one closes the switch, the circuit is complete. Electrons flow through the circuit, including the thin wire in the headlight. The thin wire heats up and glows; the headlights are on. Trying to reverse engineer my computer —to figure out how my computer works —is more formidable. It is very difficult to trace the organizations of open and closed electrical switches in different locations of my computer that enable my typing on the keyboard to move paragraphs to different parts of a text, change fonts, and so on. Such reverse engineering is complex. But it is not inherently mysterious, though it sometimes looks remarkably mysterious from the outside.
Figuring out the mechanics of how the brain works is even more difficult and more interesting than figuring out how a computer works. We are far from figuring out how the brain works, although considerable stepwise progress has been made. One recent example of a promising, sweeping concept is Coward’s proposal (2005) of a system architecture for the brain in which recordings are not point-localizable. Rather, recordings rely on recommendations of neuronal ensembles. Understanding the mechanics of brain function —how the organizations of excitatory and inhibitory nerve cells allow one to walk to the fridge or to type this sentence —is an extremely difficult task. The mechanics of the neuronal circuits that control the muscles involved in carrying out such activities, however, are not mysterious in themselves.
Two mysteries
The inherent mysteries of brain function are twofold. Both involve consciousness.
First, how can matter give rise to the mind? That is, how can a material structure —the brain —give rise to conscious cognition and conscious emotion? How it is possible for matter to be conscious is a mystery, unless one assumes that rocks and amoebae are conscious, as some people do.
Second, how can the mind —conscious cognition and conscious emotion —influence matter? This is the other mystery. The brain is a material organ, which mechanically, through complex electrochemical means, controls motor action —that is, behavior. How does something as unsubstantial as thinking and feeling influence matter; how do conscious cognition and emotion influence the brain?
I will address these mysteries in this chapter and in the next.
Consciousness Constructed From the Waking State
Qualitative Scheme Changes —Stages 3 to 6
It is not hard to believe that behaviors of stage-typical scheme activation in Stage 1 or Stage 2 could take place mechanically. These behaviors consist mainly of the repetition of adventitious movements. For example, repeatedly sticking out the tongue and sucking it or perhaps even repeatedly striking and grasping the edge of a blanket could take place during sleep or without the infant being aware of either type of behavior.
As already mentioned, it is hard to imagine Stage-3-typical behavior taking place when the child is not conscious or asleep —a state of reduced consciousness. When an infant strikes an object and varies her striking and has such a good time doing so, it is hard to believe that this is just mechanical behavior —that she could do this while she was asleep or that she could do this without being aware of some parts of the spectacle. Portions of her scheme must be conscious.
It is more difficult to imagine subsequent stage-typical schemes outside of consciousness. For example, it is difficult to imagine a Stage-4 child searching for a toy under a screen without a portion of the child’s schemes being conscious. Although toy and screen schemes are significantly undifferentiated from each other in Stage 4, when a child searches under a screen for a toy, the search itself is purposeful. When the child brushes aside an intervening object to obtain a toy, the behavior is purposeful. He has the potential of thinking, "I want this and not that", whatever the make-up of this or that is.
Stage-5 children will search for a toy where it last disappeared under a screen. It is difficult to imagine a child doing this unconsciously. Stage-5 children’s object schemes are no longer successful-action bound. These children do not ordinarily make the A-not-B error. They will search wherever they last saw the toy. They will, however, not search under a screen for a toy that is under a second screen that was hidden under the first screen. If a beret was already under a pillow and the Stage-5 child watches the toy being placed under the pillow, the child will search under the pillow, but not under the beret. Since the children in Stage 5 fail to search under a second screen for a toy, their conscious scheme of an object that they just saw is not yet distinct from their conscious scheme of the object disappearing under the screen. These children do not have object permanence. They do not know that, because they watched the toy disappear under the pillow, the toy must still exist somewhere under the pillow. Neither is their mental image of the toy that they have in their mind separate from their just having seen the toy as it disappeared —that is, separate from their perception of the toy: Their mental image of an object is not distinct from their perception of that object. Nor does their scheme of the toy appear to be separate from their scheme of the pillow under which the toy disappears. The boundaries of the toy scheme and the pillow scheme are permeable.
Another observation gives a sense of the continued permeability of object schemes in Stage 5. As mentioned earlier, a Stage-5 child will attempt to place a ring on a stick by touching the ring to the side of the stick. The schemes of two objects are like two transparencies or two lights that can pass through each other, or like a pebble that passes through water. Baillargeon (1987) and Baillargeon, Spelke, and Wasserman (1985) contended that 3- to 5-month-old infants perceived objects as being solid, because they stared longer at a display of a "drawbridge" that appeared to pass through an object. Rivera, Wattley, and Langer (1999) repeated the drawbridge experiment. They found that the farther the drawbridge traveled, the longer the infants looked at it. This held true, whether the drawbridge traveled through empty space or through an apparently solid object. Their finding does not support Baillargeon (1987) and her colleagues’ contention that 3-to-5-month-old infants comprehend the solid nature of objects. At best, comprehension of the solidity of objects —of their impenetrability —is incomplete at least as late as in Stage 5, as is illustrated by the child’s attempt to pass a ring through a stick. Nonetheless, all of the stage-typical schemes of Stage 5 are conscious.
Unlike a Stage-5 child, a Stage-6 child will search for a toy under a screen that is hidden under another screen — for example, under the beret that is under the pillow. When the child watches a toy placed under a screen and the toy is then displaced without the child seeing where it went, he will search for the toy under any number of screens. Apparently, a Stage-6 child has a scheme of the toy that exists apart from schemes of the screens. To the child, the scheme of the toy still exists somewhere nearby, no matter where he last saw it.
In Stage 6, children have object permanence. Having once seen an object, they understand that the object exists, without having to have seen where it was finally hidden.
In Stage 6, children have mental image schemes of objects, since they are able to hold images of toys in their minds while they search for them under a series of screens. The mental image scheme of the toy is distinct from the perception scheme of the toy, and is distinct from schemes of other objects —for example, the pillow under which the toy disappeared. The distinction between the mental image scheme of an object and the perception scheme of an object is a distinction between two categories of conscious schemes. 40
As measured by search under screens, schemes of the self and schemes of other objects are distinct from each other in Stage 6. 41 Mental images form part of the construct of the self, just as percepts form part of the construct of objects other than the self.
Piaget’s observation that children at this age distinguish a construct of the self from constructs of other objects has since been confirmed. Unaware that an experimenter had placed a mark on his face, a child of this age will wipe off the mark when he looks at his reflection in a mirror (Lewis & Brooks, 1978). A younger child will attempt to wipe the mark off his reflection in the mirror. The Stage-6 child also uses first-person pronouns, such as me and mine. At this age, the child has a reasonably definitive consciousness of self as an object —has the sense that that self believes, wants, and acts, though such attributes are not as yet discrete from one another.
Construction of the Experience of Being Conscious
I will describe how consciousness could be constructed from RAS activation —a facilitation or enhancement of schemes or neuronal circuits during the waking state. .I will propose that the RAS is the nidus or center, around which the experience of being conscious —the qualia of consciousness —is constructed. From the previous examples of behavior of Stages 3 through 6, it appears that all stage-typical schemes are in part or in whole conscious. Are earlier schemes conscious?
I assume that in the newborn, by and large, schemes are not differentiated from one another, including schemes during the waking state and the sleeping state. At about 6 weeks, infant behavior indicates that waking-state schemes have begun to become distinct from sleeping-state schemes. Schemes —part of which is the RAS scheme —are distinct from schemes —part of which is the RSS scheme.
Around 6 weeks, the infant’s behavior involving vision might indicate differentiation of waking-state schemes from sleeping-state schemes. Piaget wrote, "Perception of light exists from birth…All the rest (perception of forms, sizes, positions, distances, prominence, etc. ) is acquired through the combination of reflex activity with higher activities" (1963, p. 62. ) He cited as evidence the fact that Preyer’s 6-day-old son’s turning his head toward the window. Johnson (1998) reported that newborns follow the configuration of a face. Piaget found that at the end of the first week, his son’s expression changed when he was near luminous objects, and that he sought them when they moved, but was unable to follow them. Piaget’s 16-day-old daughter exhibited similar behavior. Both children followed a light by day 21.
These last two behaviors could not be expected from a child who is asleep. Yet, does such behavior indicate consciousness of light? Generally, when a person’s eyes are open, that person is awake. However, when the newborn’s eyes follow a light or a face, it is not entirely clear whether his visual scheme is conscious. Is looking in a direction seeing? As noted earlier, light seeking appears to be a prewired reflex, like sucking and grasping. Some persons who are comatose follow a light with their eyes. Also some persons —usually infants and young children —sleep with their eyes open. In either case, when not dreaming they are not conscious. Also, Johnson (1998) reported that anencephalics follow a facial configuration. Is the anencephalic seeing? It is likely that, to begin with, following of a light is a reflex —is purely mechanical —much like the grasping or sucking reflex.
At about 5 weeks, Piaget’s son interrupted crying and, though he was unsuccessful, attempted to find the source of a voice. At about 6 weeks, when he heard the sound of his rattle, he looked in the right direction. One does not expect such behavior during sleep or without being conscious. However, although it seems unlikely, it is possible that although Piaget’s son interrupted crying and appeared to attempt to localize a sound, the motor and proprioceptive coordination to equalize the sound to each ear and to look in the direction of the sound is merely a mechanical reflex.
Nonetheless at about 6 weeks, visual-hearing schemes might distinguish waking-state cognition from sleeping-state cognition. 42 Two other changes in behavior, however, definitely distinguish waking-state cognition from sleeping-state cognition.
During the first 6 weeks, the sucking reflex can be elicited whether the infant is asleep or awake. However, after 6 weeks, the sucking reflex can be elicited only during sleep (Vaughn & McKay, 1975). So at 6 weeks, when the sucking reflex can no longer be elicited if the infant is awake, there is a difference between the waking- and sleeping-state sucking schemes, with all of their many relationships. 43
Also, at about 6 weeks, Piaget’s son smiled in response to a familiar voice, and generally the smile becomes social at around 2 months. 44 Under ordinary circumstances, the smile is exploited both by the infant and by the caregiver. In time, each discovers what the other finds joyful. First, the mother is captured by the infant’s smile. Later, the infant smiles when the mother smiles.
Rochat sees the infant as having changed markedly at about 2 months. He reported that
By two to three months infants will bring their hands and feet into view for long periods of exploration and will start cooing, babbling, and making all kinds of repetitive sounds with their mouths. They might shake their heads vigorously from side to side, then stop suddenly and burst into a smile. They will repeat the sequence over and over again, like toddlers discovering dizziness by spinning until they fall to the ground with delight. (2001, p. 38)
Rochat interprets this change as an emerging self. I will discuss his interpretation in the next chapter. I interpret this change in behavior at about 6 weeks to 2 months as conscious schemes being more distinct. The behaviors indicate that waking-state, conscious schemes have begun to be separate from sleeping-state, non-conscious schemes.
To Begin with the Schemes are so Undifferentiated that they Fill the Cognitive Space
Between conception and birth great differentiation has taken place in the brain, and presumably in cognition. Nevertheless, following Piaget, I assume that the Stage 1 infant’s brain and cognition are still extremely undifferentiated.
As I have already described, the newborn’s schemes include a great deal more than what we see. We see that, when the region around the mouth is contacted, the newborn sucks. But, his sucking scheme —his cognition —potentially includes/assimilates to it warmth of an adjacent body, position sense, warmth of the milk dribbling down the cheek, and much more, as listed in chapter 1. The sucking scheme assimilates any activation that is cotemporaneous to it or related to it, now or in the past. It follows then that, when the neonate is sucking, the sucking scheme constitutes cognition —that is, it is all of cognition. The sucking scheme could be expected to fill the cognitive space.
Similarly, when the newborn is grasping, the grasping reflex scheme is cognition. It fills the cognitive space.
Each fills all of cognitive space? Given how global the sucking and grasping schemes are, one might anticipate that the sucking and grasping schemes may not be entirely distinct from each other. If, however, the two schemes or neuronal circuits have no connection to each other, then they might as well be in different brains —they might as well constitute completely different cognitive spaces —until they mutually assimilate each other, as when the child sucks his thumb or hand or, still later, when the child brings everything he grasps to his mouth.
The point I want to make here is that, in the early stages, schemes, when active, are the whole of cognition.
The first evidence of differentiation of the sucking scheme is when the hungry 20-day-old extruded the experimenter’s finger. This behavior indicated temporary differentiation of the hungry-sucking-scheme from the not-hungry-sucking-scheme. I say "temporary" because, after a bit, the infant resumed sucking the experimenter’s finger.
Halfway through Stage 2, at six weeks, the differentiation of the sucking scheme —that is, the differentiation of cognition —is more abiding. As already mentioned, the sucking reflex may no longer be elicited during the waking state. However, the reflex may still be elicited during the sleep till 6 months of age. At six weeks, as undifferentiated as the sucking scheme is during the waking state, the scheme has its own distinguishing form and content. When the reticular activating system is activating the cerebral cortex, the reflex part of the sucking scheme is gone. Where has it gone?
Presumably it is inhibited —buried in the mechanics, because it is still manifest during sleep for the next 4 months or so, and because it may reappear when the brain is damaged or during an intoxicated state.
At 6 weeks to 2 months, when the infant exhibits the social smile and when the sucking reflex disappears from the waking-state, waking-state cognition starts to be distinguishable from sleeping-state cognition. Another way of putting this is that the sucking scheme when the RAS scheme is part of it is divided somewhat from the sucking scheme when the RSS scheme is part of it.
I have already argued that, beginning in Stage 3, all stage-typical behaviors, which were described by Piaget, index waking-state schemes —an essential part of such schemes being the activation of the cerebral cortex by the RAS. However, Stage 3 schemes in the waking state continue extremely undifferentiated. Their operational mode is cumulative as they extend cognition to include distal sensory systems. Striking and watching or listening are mutually assimilated to an entire repertoire of behaviors —striking with the foot or arm, arching the back, and so on. See chapter 2. The infant may suck the block she grasps, may strike it on a hard surface, may listen to the noise it makes. As mentioned earlier, in Stage 3 there is no clear division between waking-state schemes —as yet no clear divisions within the waking cognitive space.
In Stage 4, we begin to see such divisions. When the child strikes an object to grasp another and when she searches under a screen for a fully hidden object, we see the beginning of divisions of the waking cognitive space. (In Stage3, a piece of the object had to show, the hand must have grazed the object, or she must be in the process of grasping the object for her to search under the screen —no clear division between the object and the screen or the object and the self. ) In Stage 4, cognitive space in the waking state is beginning to be divided in terms of objects and the self as an object. In both instances, there a division of waking cognitive space into different object schemes —the two different objects, the object and the screen —based on appearance and preference. Also, when the infant strikes one object to grasp another, the striking scheme is exercised before the grasping scheme. There is a division of the waking cognitive space into a beginning self in terms of preferring one object more than another and in an ordering of motor behavior.
I am stressing division here in order to stress the notion that the waking cognitive space is being divided up. But one could say that the schemes are being articulated (ala Piaget) in a way they never were before —that the waking cognitive space is being organized in a way that will lead to separate schemes of objects including the self.
In Stage 5, the waking cognitive space is divided further in terms of objects and in terms of the self as an object. Children no longer make the A-not-B error. Their own past successful action is no longer part of their effort to search for a hidden object. As mentioned in chapter 2, children are advanced students of edges of objects. They pull on a string, a refinement or extension of edges, to obtain an object. They pick up a matchbook that rests on a platform even when the matchbook is not moving, and they may pull on the platform to bring the matchbook within reach. They will search for an object that they watched being hidden under one screen, but will not search under a second screen secreted under the first. The child must have some kind of representation in her mind of the object going behind the screen. In some detail in chapter 5, I will discuss the kind of representation she has.
Finally in Stage 6, activation from the RAS —the RAS scheme —continues as part of the schemes as, in the stages, they were sculpted/constructed from all that was accumulated, past and present, to become mental images that belong to the self and percepts that belong to the outside world —different forms of consciousness. Conscious cognitive space is divided into schemes of different objects that are either mental images or are perceptions.
Along the way from stage 4 to Stage 6, what happens to consciousness —what happens to schemes, part of which is the RAS scheme?
In stage 4, the infant learns to knock aside an intervening object to grasp a toy. The schemes begin to be ordered in ways that work better, to that extent, mere assimilation of one scheme by another is displaced in awareness. Put another way, the RAS scheme —circuitry that is enhanced by activity of the RAS —is part of the striking-then-grasping scheme. To that extent, the RAS scheme is less a part of the mere striking- and-grasping and grasping- and-striking scheme.
She will also search for a toy that is fully hidden by a screen. She appears to have some sort of picture scheme of the toy that is active without seeing the toy. 45 That picture scheme is divided from her schemes of touching of the object, of her making a grasping motion and of her looking at the experimenter’s hand that hid the toy, as they were in Stage 3. The RAS scheme is part of that picture scheme of the toy, which is no longer part of current touching, grasping motion, or looking at the experimenter’s hand schemes. The RAS-picture scheme is, however, still part of the scheme of her past successful retrieval of the toy as evidenced by her making the A-not-B error. It may be noted that the past is still part of the present.
In Stage 5, the child no longer makes the A-not-B error. She searches where ever she last saw the toy disappear. The RAS scheme, which is part of the picture scheme of the toy’s most recent disappearance under a screen, is distinct from any RAS scheme that is part of the scheme of past successful retrieval. In this instance apparently, if the child is aware of her successful past scheme, to some extent, the past scheme is just a memory. However, although she searches where she last saw the toy disappear, she will not search under a second screen if she has not watched it being hidden there. Her picture of the toy is not distinct from her scheme of the screen under which she saw it disappear. The picture scheme of the screen, part of which is the RAS scheme, is not distinct from the scheme of seeing the toy disappear under the screen. Additionally, though it is more limited, the past —the disappearance —is still part of the present.
In Stage 6, the child searches under any number of screens for a toy. The RAS scheme is part of current schemes of self, objects (screens and toys), that are mental images or percepts, each relatively distinct from one another. These conscious schemes are generally distinct from past conscious schemes of successful actions or of pictures, for example the toy having disappeared under a screen.
After Stage 6
It should be noted that in Stage 6 and early in the preoperational period boundaries between waking-state schemes of objects, part objects and attributes are permeable. As examples in chapter 6 will show, a change in clothing, a color or an action may redefine someone or some thing, just as the color grey defined dog. Boundaries between words, part objects, and attributes are blurred.
In later stages, conscious cognitive schemes are divided further, when part object schemes and attribute schemes are more distinct from object schemes and more distinct from one another. Included in attribute schemes are size, color, actions, trustworthy, and so on. Perception and mental image schemes of attributes may then be divided into pieces of a continuum and from one another.
Waking-state schemes are parsed as object schemes, percept schemes and mental image schemes in Stage 6. However as just noted, boundaries of schemes of different objects, part objects, attributes and so on are still blurred in Stage 6 and in the preoperational period. Generally later in development, waking-state schemes of objects, mental images, percepts, words (both thought and heard) are bounded more reliably when attributes, such as size and color, are divided from each other and each is divided along a continuum. Similarly, the RAS scheme would be expected to be divided into pieces of a continuum as part of an attribute of percept schemes and mental image schemes of objects, including the self —the percept or mental image being more or less vivid.
Perhaps at some point consciousness, like the attribute redness, becomes autonomous. Perhaps it becomes distinct from content, and even distinct from the sense of being awake. We certainly are aware of degrees of alertness and of drowsiness.
Usually, however, consciousness is not distinct from what we think of as the content of consciousness —for example, the sense of redness, of an idea, or of a feeling. Usually consciousness is about something —a percept, a mental image, or a thought of something —whether in the present or in the past.
Some persons report states of blank consciousness. When meditating, Yoga experts in one study maintained an EEG characterized by Alpha brain waves —8 to 10 electrical waves per second. They described their state as consciousness that is devoid of content (Anand, Chhina, & Baldev Singh, 1969). Although these types of consciousness appear to be exceptions, and although consciousness is perhaps never entirely free of content, we may speak of consciousness that is devoid of content —that is, phenomenal consciousness.
If one starts with very undifferentiated schemes, one can trace the vicissitudes in the construction of experience of consciousness just as Piaget traced the construction of objects and later attributes of objects, such as redness.
Early in development, the redness scheme assimilates to itself many, related kinds of aliment —includes the sight of red blocks, a red wagon, red balls, and blue balls, along with fun with Daddy, "We don’t cross the street when the light is red," "Look —the sky is red," and the attendant emotions, as well as redness as a mental image or as a percept.
Later, unlike attributes such as redness, consciousness —the RAS scheme —keeps its connections to the sight of red blocks, a red wagon, red balls, and blue balls, along with fun with Daddy, "We don’t cross the street when the light is red," "Look —the sky is red," and the attendant emotions, as well as redness as a mental image or as a percept.46
What about non-conscious schemes —purely mechanical schemes or schemes during sleep. We have no reason to believe that such schemes must necessarily be differentiated into the forms taken by conscious schemes. And we have considerable data from psychoanalytic studies and from manifestations of organic and functional mental disorders to suggest that that often they are not. But this is not our focus here
I have traced the differentiation of schemes that include waking-state activation —that is, consciousness —from the time when waking-state schemes first show some differences from sleeping-state schemes until Stage 6 when, by some measures, conscious object schemes including the self as an object are differentiated from each other, and sketchily into Piaget’s preoperational and concrete operational periods. Chapters 6, 7 and 9 will present a more detailed account of organizations of conscious cognition in these periods.
In chapter 5, I will explain what I think are the mechanics involved in conscious schemes’ differentiation into mental image schemes and percept schemes, and how I think conscious schemes are able to influence behavior.
34 The brain stem is the part of the brain upon which the cerebrum and cerebellum rest. The brain stem —composed of the medulla, pons, and midbrain —rests upon the spinal cord. The neural tracts of brain stem interconnect the spinal cord, the cerebellum, and the cerebrum. The cerebrum is composed of the two cerebral hemispheres and the diencephalon, which sits between and below the two cerebral hemispheres —the outer surface of which is the cerebral cortex. The diencephalon is composed primarily of the thalamus, but also includes the epithalamus, the subthalamus, and the hypothalamus. I will focus on only a few of the many functions that take place in these structures.
35 The EEG records electrical wave activity from the brain. The recording is done from electrodes placed on the scalp, or, rarely, directly on the surface of the brain. The electrical waves are a summation of electrical activity in a large number of dendrites. See Figure 1. The EEG is precise in its timing of electrical activity, but poor in its location of that activity. The wave patterns that typify sleeping and waking EEGs are discussed in chapter 8.
36 The function of this nucleus —not to be confused with the RAS —was a mystery until the clinical observations of Watson, Valenstein, and Heilman (1981), followed by the neurophysiologic work of Steriade (2000), noted above.
37 Steriade (2000) also believes that RAS activation may have short inhibitory effects on some thalamic cells; these effects may improve receptive-field specificity and orientation, which would aid concentration of attention.
Steriade found that high-voltage, slow waves —delta waves —are generated by large numbers of cortical cells firing in synchrony. Presumably, the activation of the thalamocortical neurons disrupts this synchronous firing of cortical cells.
38 I will use the terms non-conscious and unconscious to refer to cognitive and emotional processing that takes place without awareness —not to refer to the unconscious state that is due to head injury or deep anesthesia, in which perhaps no cognitive or emotional processing takes place.
39 It should be noted that my position that neuronal circuit activity is merely the mechanics of brain operation, hence is not conscious, does not distinguish psychodynamic unconscious processing —the bread and butter of psychoanalysis —from any other non-conscious cognitive-emotional processing. For example, my proposal does not distinguish between forbidden impulses that are repressed from other non-conscious cognitive-emotional processing. In chapters 5 and 8, I will explain how psychodynamic unconscious processing is a part of the picture that I sketch.
40 One of my basic assumptions is that cognitive-emotional processing goes on at all times and at all ages. Would that be true for the fertilized egg? I don’t think so. Is it true for the fetus? Yes. What about the time in between? I don’t know. It is possible that, prior to the division between waking- and sleeping-state schemes, there may be schemes that are more conscious than not. Does the fetus experience such schemes? We know that in the last trimester, the fetus appears to sleep at times and exhibits rapid eye movements. Using ultrasound, one can see the fetus suck his or her fingers, and sometimes after birth, the arm shows a bruise from sucking (Rochat, 2001). If we extrapolate backward from the state of the newborn, who is awake 20 % of the time, we may find evidence of waking cognitive life in the fetus. Because the newborn is habituated to the heartbeat of the mother, and because he will turn toward the smell of a pad dampened with his mother’s amniotic fluid, I assume that the fetus responds to sound and to smell. But is the fetus conscious of sound and smell?
Here it is appropriate to note that clownfish embryos "imprint on the squeaks, grunts and whistles of their parents…The hatchlings use tiny stones in their heads called otoliths to pick up the racket and find home". The heartbeats of the "embryos responded strongly to noise of sounds made by their parents, and got better at it as they developed" (Holden, 2003, p. 341). Would we attribute consciousness to the embryo of a clownfish?
In the fetus, there is no evidence of a division between sleeping sucking reflex activity and waking sucking reflex activity. Visual activation is virtually absent. Although present, motor action in utero is restricted. This leaves limited cognitive-emotional scheme activity involving activation of the proprioceptive, auditory, olfactory, and sensorimotor sucking systems.
After birth, more varied and intense activations are part of the waking state. All the systems —visual, auditory, touch, proprioceptive, olfactory, pain, temperature, and postural —are more activated as the infant experiences light, as she is moved about, and as she moves more freely. Any conscious cognition that the fetus might have would be undifferentiated and limited, by comparison.
If the quality of consciousness is constructed from the waking state, then any animal that has a sleep-wake cycle could be expected to have conscious experiences. I assume that no animal at the evolutionary level of fish or below is conscious, since fish do not sleep but merely rest. They do not have discrete sleep-wake cycles. Yet a fish on a hook certainly struggles. Fish appear to experience something. Or are their responses merely automatic responses that serve survival, just as a single-cell organism may move around a sharp object?
I assume that animals above the level of fish and amphibians experience some forms of consciousness. If we watch a dog’s reaction to seeing or smelling another dog, it is difficult to imagine that a dog is not conscious. It is not to be expected that a dog has the same conscious organizations of content that we have. Exactly how the dog thinks about or perceives another dog or the rest of the world, I don’t know. Nonetheless, I have little doubt that a dog has a conscious cognitive-emotional life.
41 Piaget used two other criteria to measure self-object distinction in Stage 6. These were immediate imitation and delayed imitation of acts that the child had never performed before. These two criteria appear to be unsatisfactory measures of Stage 6. The example of immediate imitation cited by Piaget was his daughter’s repeatedly bringing her arms around herself —a warming motion that she saw him do, and that she had not done before. As an example of delayed imitation, he cited her laughing as she imitated her cousin’s temper tantrum, which she had observed the day before. According to Piaget, she, herself, had never had a temper tantrum.
As early as 6 to 9 months, however, children will tend to imitate a novel movement. And, after considerable delay, they will imitate that movement upon seeing the model again (Meltzoff & Moore, 1998). Some of this imitative behavior is context bound. If one changes the surrounding circumstances —for example, from the laboratory to the child’s home —a 6-month-old will not do what the model did (further evidence of the undifferentiation of the infant’s world). But a 12-month-old, who presumably is in late Stage 4 or early Stage 5, will imitate a previously modeled action when the context is completely different.
It should be noted, however, that Meltzoff and Moore’s findings that involve imitation do not invalidate the distinctions between self and object, and between mental image and perception, that occur in Stage 6 as measured by search behavior.
42 In the blind infant, hearing could differentiate waking from sleeping schemes, and in an infant who for some reason cannot suck, sight may substitute for sucking.
43 After 6 months of age, awake or asleep, the sucking reflex can no longer be elicited unless brain function is impaired.
What about the grasping reflex? It plays a role in early cognitive development. Does it in any way indicate when waking-state schemes are differentiated from sleeping-state schemes? Awake or asleep, the grasping reflex can be elicited for the first 6 months or so. Thereafter, like the sucking reflex, it cannot be elicited unless brain function is impaired. Unlike the disappearance of the sucking reflex from the waking state, the disappearance of the grasping reflex does not help us distinguish waking-state schemes from sleeping-state schemes.
44 Initially, it is not clear that the smile indicates that the infant is conscious of a pleasant feeling. Incidentally, the smile is first manifest during rapid eye movement (REM) sleep (Emde, 1984).
45 I have adopted Piaget’s use of the term picture to refer to conscious schemes that are not either percepts or mental images.
46 Perhaps this reference to redness would be clearer, if I describe how I think a child constructs the experience of a color. In order to see how an attribute such as a color is differentiated, it is appropriate to provide a brief review of later stages in cognitive development than have been provided thus far. In the next 3 chapters, I will do a more detailed analysis of these later stages.
In chapters 1 and 2, I described the changes in self-object schemes in the six sensorimotor stages. I see Stage 6 of the Sensorimotor Period (16-24 mo.) and the Symbolic Phase (2-4 yrs.) as qualitatively the same. By then, the child’s object-schemes, including the self-scheme, are generally distinct from one another. Still, in the Symbolic Phase, a shared attribute may blur the boundary between two objects and between object and attribute. Piaget’s daughter explained that a picture of a cat was of a dog because it was grey. The attribute color defined an animal’s type.
In the next phase —the Intuitive Phase (5-7 yrs.) —the child begins to differentiate attributes. She has a beginning notion that attributes such as size and color may be graded and that objects may be classified based on such attributes. For example, the child may arrange several objects according to size or depth of color —for example, shades of grey or red —or sort some objects based on differences in their attributes, but will falter when arranging or sorting a larger group of objects.
In the Concrete Operational Period (8-11 yrs.) the child starts with a plan when arranging or sorting objects in terms of their attributes. The child will start with the smallest or largest, or darkest or lightest and then continue, regardless of the number of objects. She can sort, based on any combination of attributes. Clearly at this point, attributes —such as color —are distinct from any one object and exist on a continuum.
I propose that one’s sense of redness is constructed during the waking state from repeat brain activation of cerebral cortical neuronal circuits that are downstream from red-sensitive retinal cone cells. These red-sensitive retinal cone cells respond to the red portion of the electromagnetic spectrum —that is, the range of colors of light. These red-sensitive cells respond at a lower intensity of red light than they do to other portions of the spectrum. The other retinal cones, although they respond to red light of sufficient intensity, are more responsive either to the green or to the blue portions of the electromagnetic spectrum.
Early in development, considering the infant’s global and undifferentiated schemes, redness is activation of the neuronal circuits downstream from the red cones plus activation of many other circuits. Redness could include activation of neuronal circuits by the sight of red blocks, a red wagon, red balls, and blue balls, along with fun with Daddy, and so on. At that time, activation of each of these diverse and widespread neuronal circuits would be part of redness to a greater or lesser extent, depending on the frequency and salience of their relationship to the activation of neuronal circuits downstream from red cones.
During the awake state, along with the above circuit activation, another part of redness is the facilitation of activation of widespread neuronal circuits and transmission between these neuronal circuits by activation of the RAS through the thalamocortical tracts. With time, the awake-state scheme of redness also includes sounds such as "We don’t cross the street when the light is red," and "Look —the sky is red," the attendant emotions, and so on.
And with more time —assisted by emotions, maturation, and interaction with the environment —the scheme of redness becomes largely distinct from schemes of red blocks, of a red wagon, of red balls, and more so from schemes of blue balls, of fun with Daddy, and of the sounds of "We don’t cross the street" and "look" or "sky."
The conscious experience of redness, however, keeps special relationships to colors, such as blueness and not-redness, as it becomes absolutely tied to past or present activation by the retina’s red-sensitive cone cells of a cortical circuit or scheme, and to that circuit’s being activated by the activity of the RAS. I propose that this sequence constructs our perception of redness. (The mechanics of color processing are known to involve opponent processes that will not be gone into here.)
Schematically, construction of a sense of consciousness is no different from construction of the sense of a color (or of the sense of an emotion —that is, a feeling). Just as the initial experience of redness is all the relationships of circuits downstream from red cones, the initial consciousness is all the relationships downstream from a facilitation of activation of the neuronal circuitry of the brain by the RAS. In time, like redness becomes absolutely tied to activation by the red-sensitive cone cells of the retina, consciousness becomes absolutely tied to activation of the RAS. But, unlike redness, consciousness retains some connections to red blocks, red wagon, red balls, and blue balls, along with fun with Daddy, "We don’t cross the street when the light is red," "Look —the sky is red," and the attendant emotions, as well as redness, although each has become more maturely structured.
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