towards a characterization of minimal consciousness

Pergamon New Ideas in Psychol. Vol. 14, No. 1, pp. 63-80, 1996

Copyright © 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved

0732-118X/96 $15.00 + 0.00 S0732-118X(96)00004-9

T O W A R D S A C H A R A C T E R I Z A T I O N O F M I N I M A L C O N S C I O U S N E S S

PHILIP DAVID ZELAZO Department of Psychology, University of Toronto, Toronto, Ontario, Canada M5 S 1A 1

Abstract- Intentionalistic explanations of infant behavior are underdetermined and their legitimacy depends upon whether there is independent motivation for the characterizations of consciousness that they entail. I survey several aspects of adult consciousness and consider whether these aspects might be attributed to infants. It is suggested that infants experience minimal consciousness, which is likened to the experience that underlies implicit information processing in a variety of domains. A characterization of minimal consciousness is the first step towards an account of the development of consciousness and intentional action. Copyright © 1996 Elsevier Science Ltd.

INTRODUCTION

For at least the past two decades, developmental psychologists have promoted intentionalistic explanations of infant behavior (i.e. explanations in terms of mental states). Unlike the sensori- motor infant described by Baldwin (e.g. 1892) and Piaget (e.g. 1952), today's infant is said to engage in remarkably sophisticated forms of mental activity, including (to name only a few) imi- tating the actions of others (Meltzoff & Moore, 1977), reasoning about the physical properties of unseen objects (Baillargeon, 1987), adding and subtracting (Wynn, 1992), and participating in intersubjective exchanges with caretakers (Trevarthen, 1979).

Intentionalistic explanations of infant behavior typically presuppose complex forms of consciousness. Consider, for example, the phenomenon of social referencing, in which a 12-month- old infant faced with an unfamiliar or ambiguous situation, such as the presence of a stranger or a toy robot, looks to his or her mother, and reacts differently to the situation depending upon the mother's facial expression (Feinman, 1982). Although social referencing could simply reflect a learned relation between a stimulus and a response (Bradley, 1991), many authors have interpreted it as a deliberate attempt to assess another's perspective in order to use that assessment as a basis for action (e.g. Bretherton, 1992; Feinman, 1982). This account implies that infants are not only conscious, but also conscious of their own uncertainty, conscious of the mental states of others, and able to use conscious representations to control their behavior. For example, following a description of social referencing in an idealized 12-month-old he calls "Joey", Stern (1990) writes:

Joey has discovered what philosophers call the theory of separate minds: that he and his parents have different mindscapes but can also share the same mindscape. His discovery of intersubjectivity constitutes an enormous change in his development. Beginning now, and probably for the rest of his life, he will interpret human actions, at least in part, in terms of the mental states behind the actions" (p. 86; italics in original).

In this example, as in others, an intentionalistic explanation involves the attribution of a fairly sophisticated form of awareness (see Searle, 1990, on the relation between intentional explanations and consciousness). Of course, there are authors who would probably find such an attribution to be entirely gratuitous (e.g. Bradley, 1991; Kessen, 1990; Lockhart, 1984; Schacter &

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Moscovitch, 1984). I suspect, however, that even the most "tough-minded" critic would grant that human infants, like other mammals, possess at least some minimal form of consciousness; surely, few are inclined to believe that infants are mere automata. On what grounds are particular attributions of consciousness to infants justified?

Although consciousness has lately received considerable attention from a wide variety of perspectives (Baars, 1988; Block, 1995 [now published]; Crick & Koch, 1992; Dennett, 1991; Edelman, 1989; Humphrey, 1992; McGinn, 1991; Searle, 1990), few attempts have been made specifically to address infant consciousness. Discussions of consciousness in nonhuman animals (e.g. Carruthers, 1989; Gallup, 1978; Edelman, 1989; Griffin, 1984; Povinelli, 1993; Regan, 1982) are far more abundant, and they are relevant insofar as they raise many of the method- ological issues that make infant consciousness particularly perplexing (e.g. how to assess consciousness in nonverbal organisms). However, these discussions are potentially misleading if they are applied in an uncritical fashion to human beings: Homo sapiens may be qualitatively distinct from other species; ontogeny need not recapitulate phylogeny; and monkeys never become men and women, whereas infants do. The present paper is a preliminary effort to treat the question of infant consciousness on its own terms.

ASPECTS OF CONSCIOUSNESS

Consciousness is notoriously difficult to define and numerous writers have suggested that such ambiguity is inescapable. For example, Sir William Hamilton (1863) stated definitively and pes- simistically that, "Consciousness cannot be defined; we may be ourselves fully aware what consciousness is, but we cannot, without confusion, convey to others the definition of what we ourselves clearly apprehend" (p. 162). In the present paper, I do not presume to offer a definition of consciousness. Instead, I follow Dewey (1906), Natsoulas (1978, 1983), and Toulmin (1982) on a course that proceeds from a catalogue of some of the things that have been attributed to consciousness - - what I will call aspects o f consciousness.* (Dewey and Natsoulas consider stan- dard English dictionary definitions of the term.) I take the term "aspects" to be more general than "forms" (or ways of experiencing--e.g, reflectively or unreflectively) and "contents" (or what is experienced--e.g, a table or awareness o f a table), and to be orthogonal to the distinction between cognition and affect. My survey of various aspects of consciousness represents a cur- sory attempt to deconstruct (in some sense) ordinary adult consciousness.

One aim of the deconstruction is to clarify the construct of consciousness in order to encourage its careful coordination with developmental data. Part of the problem surrounding the interpretation of infant behavior may be due to the fact that consciousness is not likely to be a unitary phenomenon (cf. Block, 1996). Instead, varieties of consciousness are likely to differ along a number of dimensions and may even admit of qualitatively distinct types. Explanations of infant behavior require a clear consideration of the particular characterizations of consciousness that they entail. By addressing various aspects of consciousness, I aim to make it easier to articulate the difficult questions concerning the behavioral criteria for the acquisition of different aspects. However, I will leave it to others to answer these questions. This paper will simply highlight some

*I tend to rely for my examples upon turn-of-the-century American authors (especially James, Dewey, and Baldwin). Toulmin (1982) has suggested that it was James who first appropriated the term "consciousness" and put it to work in its most common contemporary capacity--capturing the distinctive characteristic(s) of subjective experience.

Minimal consciousness 65

theoretical alternatives to the rather simplistic notion that infants either are, or are not, conscious in an adult-like sense.

There is an additional aim of the paper, however: to propose that adult-like consciousness is the product of a protracted developmental process. I am inclined to reject the notion that the newborn enters the world fully conscious in the adult sense.* Although it is beyond the scope of the paper to evaluate critically the empirical evidence for particular aspects of consciousness in infants, I suggest that the attribution of adult-like consciousness to infants is neither parsimonious in light of the available data nor logically necessary, in the sense that it is possible to imagine simpler sorts of consciousness that are not incoherent. A desire for parsimony and coherence motivates the elimination of aspects of our ordinary characterization of adult consciousness from a characterization of infant consciousness. One question addressed in this paper, then, may be phrased as follows: If one assumes that infants have some subjective experience, what is the minimal (or least sophisticated) conceptually-coherent sort of experience that we might grant them? I will refer to this type of consciousness as minimal consciousness, and I will attempt to describe it, at least in outline form.

For an adequate theory of the development of consciousness, the origin of minimal consciousness cannot be an unanalyzed postulate. In James' (1890/1950) words, "Consciousness, however small, is an illegitimate birth in any philosophy that starts without it, and yet professes to explain all facts by continuous evolution" (Vol. 1, p. 149). However, if one assumes the existence of minimal consciousness, then it is possible to explain changes in the structure of consciousness that have implications for the development of cognition and behavioral control; it is possible to get here from there.

I will consider seven aspects of consciousness (see Table 1). Although I believe this list suf- fices for the present purpose, it is not exhaustive, and it will become clear that some aspects have sub-aspects that need to be considered as well (e.g. conation will be discussed under the rubric of volition). At some point, the logical relations among aspects ought to be determined. However, in this paper, I will simply describe each aspect and then ask whether it is a characteristic of the simplest type of experience that we might attribute to infants.

Aspect 1: Shared knowledge ( intersubjectivity)

Etymologically, the term "consciousness" is derived from the Latin con- (from cum-; together with) and scientia (knowledge) or scire (to know), conjointly meaning, "shared knowledge" or "to be privy to a thing with another" (Hoad, 1986).t Shared knowledge is present when individuals conspire or participate in a shared plan or come to some consensus (Dewey, 1906; Klein, 1984; Natsoulas, 1978, 1983; Toulmin, 1982). Philosophers and psychologists often use the term intersubjectivity to refer to this aspect, which is essentially interpersonal and communicative (e.g. Bruner, 1975; Habermas, 1970). Natsoulas (1987, p. 291) explicates this aspect of consciousness (which he calls "consciousness1") as follows:

1.

2.

A(B) knows B(A) knows a certain fact or set of facts about X (which can be anything, including A or B, A and B, or something else). A(B) knows B(A) knows that A(B) knows the facts about X mentioned under 1.

*This notion is tantamount to Falstaff's declaration that he was born "at about three of the clock in the afternoon, with a white head, and something of a round belly" (Henry IV, Part 2, I, ii, 213). t Alternatively, con- may be interpreted reflexively, as referring to intra-individual, as opposed to interindividual, knowledge (Hoad, 1986). Conscientia would thus be knowledge that I have with me. See aspects 4 and 5, later in the article.

66 P. D. Zelazo

Table 1. Seven aspects of consciousness

Shared knowledge (intersubjectivity) Volition Articulateness Consciousness of a Self Reflectivity Intentionality Being-like-something

. At those moments when consciousness~ is an activated rather than latent, cognitive interpersonal relation (such moments must occur from time to time in order that the relation be more than potential), A(B) is occurrently aware of the relevant facts about X and B(A) (i.e. those mentioned under 1 and 2) while being veridically aware that B(A) also is actively apprehending them.

Shared knowledge implies that the individuals having mutual knowledge know that their con- spirators share their knowledge. Further, it logically presupposes that the individuals sharing the knowledge have some understanding of themselves and others as epistemic agents (i.e. it presupposes that they have a theory of mind; see, e.g. Astington, Olson & Harris, 1988; Frye & Moore, 1991). Despite its complex structure, however, shared knowledge has often been attributed to infants (e.g. Bretherton, 1992; Stem, 1990; see the description of social referencing above) and is sometimes believed to be both innate and present at birth (Trevarthen, 1979). Trevarthen (1979, p. 322) suggests that infants as young as 1 month of age have been observed to "share mental control with other persons" in communicative interactions that he describes as "intersubjective". He writes that, "In the second month after birth their reactions to things and to persons are so different that we must conclude that these two classes of object are distinguished in the infant's awareness . . . " (pp. 322-323).*

Is shared knowledge a necessary aspect of consciousness? There are a number of influential accounts according to which consciousness is intrinsically social (e.g. Baldwin, 1897; Burrow, 1927; Leont'ev, 1978; Mead, 1934; Vygotsky, 1962), and it might be supposed that these accounts argue for the necessity of intersubjectivity. However, these accounts address either the transcendental (i.e. background) conditions of consciousness, or the causes of consciousness, rather than the phenomenological character of experience itself. Thus, social contact is either seen as a precondition for what is essentially an individual consciousness, or the social element is internalized and it remains implicit in individual consciousness.

For those who would follow these socially-oriented accounts and apply them to an interpretation of infant consciousness, one potential pitfall is what James (1890/1950) calls "the psychologist's fallacy": "the confusion of [the psychologist's] standpoint with that of the mental fact about which he is making his report" (Vol. 1, p. 196; italics in original). This is a confusion of third- and first-person perspectives. The psychologist stands outside of the state of consciousness that he or she studies. Both the state itself and the object of the state are objects for him or her. James cautions, "We must avoid substituting what we know the consciousness is, for what it is a consciousness of. . ." (Vol. 1, p. 197; italics in original). Thus, for example, Baldwin (1897)

*Although it is beyond the scope of the paper to critique this work, I will note that these findings, like many of the others mentioned in the paper, are highly controversial. For example, some authors have failed to replicate results indi- cating early object-person discrimination (Frye, Rawling, Moore & Myers, 1983) and others have suggested plausible alternative interpretations of the discrimination that do not involve the attribution of intersubjectivity (Sylvester-Bradley, 1985).


makes the claim that for older infants, consciousness is shared knowledge (in the sense that ego and alter necessarily coexist), but not that is it of shared knowledge. Likewise, none of the other socially-oriented approaches mentioned above really makes the case that consciousness necessarily involves shared knowledge. Because minimal consciousness includes only those aspects that are a necessary part of the simplest coherent form of consciousness, we can eliminate shared knowledge from our characterization. The question for those would attribute shared knowledge to infants is: What nonlinguistic behaviors imply intersubjectivity as it outlined above?

Aspect 2: Volition Volition and voluntary movement are interdefined: whatever else volition may be, it is that

which underlies voluntary movement. The close connection between voluntary movement (land hence volition) and consciousness is emphasized by James, for whom the "pursuance of future ends and the choice of means for their attainment" (James, 1890/1950, Vol. 1, p. 8; italics in original) is taken to be the principal behavioral index of mentality (which he holds to be coextensive with consciousness--see James, 1890/1950, Vol. 1, p. 162ff; and Flanagan, 1984, p. 25). A useful, preliminary analysis of volition and voluntary movement is advanced by Baldwin (1892), who writes, " . . . Three elements of the voluntary process are desire, deliberation, and effort" (p. 286). Desire refers to the conscious representation of a goal. Deliberation refers to the active consideration of alternative means and ends (see also Baldwin, 1901/1960). Effort accompanies the selection and execution of a plan. On this account, volition is not only conscious, it is represen- tational; there is a representation of a goal. Further, volition involves deliberation and choice. In Baldwin's terms, a state of polyideism is transformed into a state of mono-ideism via volition.

Numerous psychologists have viewed goal-directed behavior in infancy as voluntary--that is, as implying a conscious representation of a goal and a choice of means. One experimental para- digm that would seem to require volition is the delayed response task (Hunter, 1917); another is imitation or observational learning (Baldwin, 1892; see also Edelman, 1989, pp. 171-172). On the basis of performance in these domains, some psychologists (e.g. Baldwin, 1892; Piaget, 1952) have located the origins of volition in the second half of the first year of life. However, other authors have suggested that volition is present at birth or soon thereafter (e.g. Butterworth & Hopkins, 1988; Bruner, 1973; Meltzoff & Moore, 1977). In a famous paper on matching behavior in newborn babies, Meltzoff and Moore (1977) interpret the babies' tendency to stick out their tongues after observing tongue protrusion as genuine imitation, despite the sophisticated form of consciousness that this interpretation entails.* Likewise, Bruner (1973) describes several behavioral criteria for "intention" and then proceeds to write, "It can be argued from evidence that the capacity for all of these is present from b i r t h . . . " (p. 2; italics in original).

Is volition a necessary aspect of consciousness? The traditional developmental literature would suggest that it is not. On several accounts, infant behavior is described as being controlled by external stimuli, reflexes and habits (e.g. Baldwin, 1892; Piaget, 1952). Further, there are a number of mechanistic models, including powerful connectionist models of learning (e.g. Shultz, Schmidt, Buckingham, & Mareschal, 1995 [now published]), that provide ready alternatives to characterizations of infant consciousness as volitional. Of the elements of volition described by

*In his review of the literature on newborn imitation, Anisfeld (1991) found little support for the imitation of gestures other than tongue protrusion; evidence for the "imitation" of tongue protrusion was found in 12 of the 26 experiments reviewed, including a study by Jacobson (1979), who found that tongue protrusion could also be elicited by other stimuli, such as a moving pen.

68 P.D. Zelazo

Baldwin, deliberation, especially, can be regarded as a sophisticated activity performed only by rational agents. There seems to be no reason to regard the capability of conscious choice as a necessary element of consciousness.

However, it is important to note that excluding volition from infant consciousness is not intended to exclude the possibility that such consciousness (whatever it might be) figures in causal chains resulting in behavior. Nor is it meant to dissociate entirely infant consciousness and conation. In contrast to deliberation, the elements desire and effort would seem to be more fun- damental aspects of consciousness. In fact, a number of authors have noted strong reasons to consider these conatative, motivational aspects of consciousness to be essential to the evolutionary emergence of consciousness (e.g. Baldwin, 1894; Dewey, 1896; Edelman, 1989). We may want to construe infant behavior as unanalyzed, unreasoned, and unplanned, but not unwanted [cf. Searle, 1983: "Only someone in the grip of a philosophical theory would deny that small babies can literally be said to want m i l k . . . " (p. 5)].

Conation emphasizes the contributions of the organism to the production of behavior. Perhaps it is possible to salvage James' (1890/1950) notion of consciousness as inherently striving while discarding the more self-conscious and self-controlling aspects of voluntary action, including expectations about means to ends and a conscious choice among means. Taylor (1982) seems to do something like this when he suggests that the fact that organisms imbue things (stimuli, events, etc.) with "significance" is "something we attribute to agents in general, including those that are minimally conscious" (p. 49).

All of the mechanistic alternatives to volitional consciousness, ranging from Baldwin's circular reactions to simple stimulus-response accounts, imply that organisms experience some things as significant. Perhaps all that needs to be included in minimal consciousness is awareness of things as either wanted (pleasurable) or unwanted (painful). Such awareness may influence behavior without allowing the organism to control its behavior in the light of that awareness; that is, without allowing the organism volitionally to act (or not to act) according to its awareness of ends. Baldwin (1894) makes a case for the primacy of pleasure and pain, as well as motivation pertaining to them, when he writes,

• . . If consciousness was present from the first, and if development depended upon the repetition of useful reactions, then that which throughout the whole animal series and in man constitutes the index in consciousness of profit and loss and so serves as its selective cr i ter ion--pleasure and pa in - -mus t have had the same place and role then as now (p. 38; italics in original).

It may be worth noting that research on neonatal pain (e.g. Anand & Hickey, 1987), which suggests that newborn infants have the anatomical and functional capabilities for pain perception, and behave as if such perception occurs, supports the inclusion of a conative aspect of consciousness in minimal consciousness.

The distinction between volition and conation is sometimes blurred, and I believe that such obscurity underlies Dewey's (1896) argument for the primacy of volition from a Darwinian perspective. In a review of Stanley's (1895) Studies in the Evolutionary Psychology of Feeling, which attempts to trace the phylogeny of consciousness from the terminus a quo of bare, undif- ferentiated pain, Dewey stresses that consciousness is inherently functional and thus tied to behavioral consequences. He writes:

It must be remembered that the one phase [of consciousness] which has the floor at any or all periods of development, is action corresponding to present voli t ional consciousness . . . . Some functional activity, that of the food process, must be predicated at the outset, or there is no organism to feel, and no biological point of view to take. It appears much more natural, then, to build up our hypothetic consciousness


by reference of feeling to actions performed with reference to food and reproduction, than vice versa... (p. 294).

The functional consciousness to which Dewey refers, however, cannot properly be said to be volitional. Baldwin's analysis is far more sensitive to the complex nature of volition. All that Dewey needs to postulate is the motivation to reduce pain and maximize pleasure; he need not introduce conscious choice.

To summarize, there are reasons to consider conation, but not volition, to be a necessary aspect of consciousness. Minimal consciousness must involve some simple sense of pleasure and pain, but need not be capable of deliberation and intentional actions.

Aspect 3: Articulateness

The ability (at least potentially) to report one's experiences is often taken to be a criterion of consciousness. For example, Russell (1921, p. 31) writes, "A desire is 'conscious' when we have told ourselves that we have it". Likewise, Piaget (1964/1967, p. 19) states that, " . . . thought becomes conscious to the degree to which the child is able to communicate it". In general, this aspect of consciousness is emphasized (in some cases to the exclusion of other aspects) by theorists who view consciousness as a product of language and, hence, social interaction. A motley crew of theorists fits this description. For example, Toulmin (1982) proposes that articulateness corresponds to the use of the term 'consciousness' by social constructionists attempting to capture culturally-specific (i.e. theory-laden) modes of interpretation. Natsoulas (1978) notes that according to Skinnerian radical behaviorism, consciousness comprises a particular type of verbal behavior, namely verbal behavior that is descriptive of "private events". Only by becoming a member of a verbal community does one thus learn to be conscious. Similarly, in Freudian psy- choanalysis (Freud, 1938), the transition from a primary- to a secondary-process representation of (say) a wish is typically achieved through verbal interaction with an analyst.

In normally functioning adults, verbal reportability is not an altogether useless criterion; usu- ally, we can say what it is that we are experiencing (cf. Dennett, 1978, p. 170). Consider the case of a novice attempting to discriminate between two wines. One might suggest, with some plau- sibility, that if he or she cannot employ the terms of a connoisseur, then he or she cannot really experience the full distinction; the novice may be limited to perceiving merely that the two wines are different.

However, reportability is clearly inappropriate for considerations of consciousness in infants (who are, by definition, without language). Further, there are strong reasons to reject it as a pre- requisite of minimal consciousness. First, we frequently suppose that when we describe our experiences, we are describing something that exists in consciousness prior to, and is the object of, our description. Second, we sometimes seem to have ineffable experiences. Third, in many accounts of consciousness that emphasize the necessity of language, there seems to be a sense in which one may be conscious of something before one has come to understand it in the context of a linguistic or cultural system. Thus, when Mead (1934) relates consciousness to the use of significant (or signifying) symbols (such as words or gestures), he is careful to admit the existence of some sort of non-significant experience: "The conversation of gestures is not significant below the human level because it is not conscious, that is, not self-conscious (though it is conscious in the sense of involving feelings and sensations)" (p. 81; italics in original).

Articulateness refers to the reportable or describable character of the contents of consciousness. Although infants clearly cannot speak, perhaps articulateness in a language of thought (LOT) is a necessary aspect of consciousness; perhaps infants must soliloquize silently if they

70 P.D. Zelazo

are to be conscious at all. Fodor (1975, 1987) has argued that language learning, concept acquisition, and representation could not get off the ground without some LOT in which concepts, hypotheses, and other "sentences" are articulated. On this account, even simple experiences, such as the experience of pain, must be described as pain in a LOT in order to be experienced as pain. These arguments are controversial, but perhaps we can forestall descent into a difficult discussion by suggesting that they do not apply to subjective experience simpliciter--that is, to minimal consciousness. Instead, if they are valid, then they suggest that articulateness is a necessary aspect of a relatively sophisticated form of thought.

Consider the popular (basically Kantian; see Kant, 1781/1927, pp. 40--41) distinction between knowledge-by-acquaintance and knowledge-by-description, or knowledge about (James, 1890/1950; Russell, 1912). Russell writes," We say that we have acquaintance with anything of which we are directly aware, without the intermediary of any process of inference . . . . Thus in the presence of [a] table I am acquainted with the sense-data that make up the appearance of the table--its colour, shape, hardness, smoothness, etc . . . . . My knowledge of the table as a physical object, on the contrary, is not direct knowledge" (Russell, 1912, pp. 46--47), but rather is knowledge-by-description. This distinction is partially captured in French by connaitre versus savoir, where knowledge-by-description corresponds to savoir. Both James and Russell follow Kant in claiming the primacy of direct, knowledge-by-acquaintance. James writes, "Our earliest thoughts are almost exclusively sensational" (1890/1950, Vol. 2, pp. 3-4; italics in original). Any meaning that knowledge-by-description may have, ultimately derives from acquaintance with some of the terms in the description (e.g. Russell, 1912, p. 58). James (1890/1950) describes knowledge- by-description as operating on the things that we have in acquaintance. Following James, we may suppose it to be at least possible to have nondiscursive--and (presently) inarticulable--experiences.* LOT arguments for the necessity of articulateness apply to knowledge-by-description but not to unmediated acquaintance.

In saying that minimal consciousness is pre-linguistic, however, perhaps we need not say that it corresponds to pure sensation, prior to any interpretation or perception. Knowledge-by- acquaintance provides a useful contrast to articulateness, in that it captures the fact that minimal consciousness is not mediated by concepts. However, knowledge-by-acquaintance need not exclude from experience any inference whatsoever, including automatic, non-verbal inferences based on innate processes and learning. One might doubt that an adult could ever really have knowledge-by-acquaintance (James 1890/1950, Vol. 1, p. 221). Previous experience, and the words contained in our language, seem to rush in automatically and color our perceptions. One rarely if ever seems to have mere sensations.

Do newborns have mere sensations, mere acquaintance? What sorts of things would they have acquaintance with? I might borrow a phrase from Dewey (1884/1973) and suggest that the content of their experience would be "a blind rhapsody of particulars" (p. 17). James's rhetorical vari- ation on Dewey's rhapsody is "blooming buzzing confusion" (James, 1890/1950, Vol. 1, p. 488). Both Dewey and James seem to believe that in the absence of any description, experience would have to be chaos.

There are difficulties associated with the postulation of a "primordial chaos of sensations" (James, 1890/1950, Vol. 1, p. 288) as the primary form of experience. Koffka (1925) suggests that experience is configurational from the start--that it is experienced as qualities or figures

*The separate issue of whether all experiences are in principle reportable does not seem to be the sort of thing that can be determined apriori. There may be some things (e.g. what it is like to see red) that simply cannot ever be captured dis- cursively. On the other hand, it may be simply a matter of finding the right, diffficult-to-find words.


upon a ground. Leaving aside behavioral evidence, it will suffice for the present purposes simply to state that there may be "inferential" processes that operate automatically on sense-data but do not result in knowledge-by-description (cf. Haith, 1980, for a discussion regarding endoge- nous, unintentional "rules" that newborn babies look by). Further, it seems at least possible that experience could be structured not only by innate processes, but also by learning, without impli- cating a LOT. Connectionism points to a solution to the problem of learning in the absence of a LOT (e.g. Churchland, 1986).

In fairness to James, it might be noted that in his account of the stream of consciousness (James, 1890/1950), he too indicates (after Hodgson) that consciousness is inherently structured and complex in that it involves a succession of different sensations and a sense of passing time. In The knowing of things together, he returns to this notion, writing, "The tiniest feeling that we can possibly have involves for future reflection two sub-feelings, one earlier and the other later, and a sense of their continuous procession" (James, 1895, p. 111). (The role of awareness of change in minimal consciousness will be considered in the final section.) This echoes the point made above about intrinsic constraints on experience. Various automatic inferential processes may serve to structure consciousness (cf. Kant's idea of categories) without requiring a LOT-- that is, without articulateness.

Aspect 4: Consciousness of Self Consciousness of Self refers to having a sense of a "me" or an " I" or a "personality" that has,

or is the subject of, one's experiences.* It refers to awareness of a thing that thinks and that might be said to have personal identity over time. There is a long tradition (beginning with Descartes' res cogitans) of deeming reference to an ego (or, in archaic terminology, a soul) the sine qua non of consciousness. Although many psychologists, including Kagan (1981, 1989) and Lewis (e.g. Lewis & Brooks-Gunn, 1979) argue that an analysis of children's behavior supports the idea that consciousness of Self emerges sometime toward the end of the second year of life, psychologists such as Butterworth (1990), Neisser (1991), Stem (1985), and Trevarthen (1979) assume that some aspects of the Self (e.g. the self as agent) are available to infants' awareness from birth. Stem (1985) suggests that infants experience " . . . the senses of agency, of physical cohesion, of continuity in time" and other "senses of the self" (p. 6) well before the acquisition of language. Likewise, Butterworth (1990) proposes that newborn babies are aware of the "distinction between self as experiencer and the external objects of experience" (p. 128). He is referring here to "the self as an agent of activity" (p. 128). Leaving aside the putative behavioral evidence for such claims, let us ask, is a sense of Self a necessary aspect of consciousness?

There are numerous approaches to the Self according to which the consciousness of Self is not an a priori condition of consciousness, but rather is essentially a theory of one's own mind that is gradually constructed as a function of experience and inference. Strong (1903, p. 198) criti- cizes the case for necessary consciousness of Self as follows: "Soul is not an empirical fact, but an inference. This appears from Descartes' argument for it, the famous 'cogito ergo sum'. Here

*Some authors (e.g. Hatter, 1983) follow James (1890/1950), and Kant (1781/1927) before him, in distinguishing between the subjective Self or " r ' (or transcendental unity of apperception, in Kantian terms) and the empirical "me". The distinction is a tricky one and not useful for the present purposes. The subjective Self (insofar as we know it at all --insofar as it is not purely transcendental) represents a core fraction of the empirical "me", because the subjective Self is known--empirically by each of us - - to be characterized at least by the existential predicate ("I exist"). The empirical "me" includes the subjective Self, but is also characterized by a number of additional predicates. Similar considerations hold for Lewis and Brooks-Gunn's (1979) existential and categorical selves.

72 P.D. Zelazo

the conclusion, the 'sum' does not simply mean 'my thought exists', it means that there is a 'res cogitans', distinct from the 'cogitatio', and not immediately given as the 'cogitatio', is given". I follow Strong, and others, including Hume, James, and Dewey in suggesting that the attribution of the continuous stream of consciousness to an entity, to an "I" , depends first upon the existence of experience per se (cogitatio or "passing thoughts" in James' terms), second upon reflection on that experience, and third upon the inference to a theoretical construct that explains and contains that experience. Clearly it is possible to have consciousness without consciousness of Self.

Consciousness of Self is conceptually distinct from reflective (or reflexive) consciousness (thought that knows that it occurs), although the distinction is often blurred by promiscuous use of the ambiguous term "self-consciousness". Despite this conceptual distinction, some authors suggest that in practice the two are inseparable. While McGinn (1982) admits the possibility of nonreflective experience (in animals and children), he claims that in fact it is not possible to have reflective experience without reflecting on an "I", without having consciousness of a Self. The logical and practical separability of consciousness of Self and reflective consciousness becomes clear, however, when one recognizes that the latter is a form of experiencing and the former is a content of experience, and when one takes care to avoid the psychologist's fallacy. There may well be some sort of synthesizing agent (in Kantian terms) that makes reflective thought possible, but it does not seem to be necessary that thought reflecting upon itself be aware of (or believe in) this agent. I take this to be James' (1950) point when he declares that " . . . as psychologists, we need not be metaphysical at all. The phenomena are enough, the passing Thought itself is the only verifiable t h inke r . . . " (Vol. 1, p. 346; italics in original). The Self is a metaphysical construct; it is a fairly sophisticated idea, rather than a necessary aspect of consciousness. Thus, it can be excluded from our characterization of minimal consciousness.

Aspect 5: Reflectivity As discussed above, consciousness of Self presupposes reflective consciousness, or thought

that knows that it occurs, either immediately or retrospectively.* Many authors, throughout history, have regarded reflectivity--immediate or delayed--to be a necessary component of consciousness. According to Locke (1690, II, S 10. p. 63), " . . . [A person] cannot think at any time, waking or sleeping, without being sensible of it". Likewise, Freud (1923) suggests that if we were not conscious of being conscious, then we would be unconscious of consciousness, which would be absurd. Insofar as theorists insist on the reflectivity of consciousness simply in order to capture the fact that the contents of consciousness are (by definition) conscious or apparent, then such a claim is really uncontentious. I suspect that this may be what Sartre (1953) means by pre- reflective or non-positional consciousness of a positional consciousness. In my consciousness of a table, it is not really that I am additionally and simultaneously conscious of being conscious of the table, it is just that the table is apparent to me. However, if the claim truly is that any consciousness entails consciousness of that consciousness, then there are some serious conceptual difficulties that need to be addressed, including the equivocation with respect to the term "consciousness", and the susceptibility to infinite regress (Holt, 1937, p. 38).

In contrast to the notion of necessarily conscious consciousness, numerous authors acknowl- edge the possibility of consciousness that does not posit itself as an object. James (1890/1950), for example, maintains that it is possible to have experience that is not analyzed by reflective

*There is some debate (e.g. Natsoulas, 1989) about the possibility of immediately self-intimating consciousness on account of the fact that the moment of which I speak is already past (cf. James, 1890/1950, Vol. 1, p. 608).


thought into subjective and objective ingredients [see also his second entry under "experience" in Baldwin' s (1960) Dictionary]. James (1890/1950) writes that a mental state may "grasp what we call its own content, and nothing more" (Vol. 1, p. 197). There seems to be no logical counter- argument to this claim: One may be conscious simpliciter of a painting (say), or one may be conscious of a painting while (or very soon before) being conscious of being conscious of that painting. Arguments to the contrary contain obvious flaws such as the susceptibility to regress.*

Russell (1912) also examines reflective consciousness, and treats the developmental question phyiogenetically. He uses the term "self-consciousness" in this context, but not in a way that necessarily implies postulation of a Self to contain reflective experiences (see p. 50.) "It seems natural", he writes," to suppose that self-consciousness is one of the things that distinguish men from animals: animals, we may suppose, though they have acquaintance with sense-data, never become aware of this acquaintance" (p. 49).

Consider further the primacy of reflective consciousness in terms of the expressions used to refer to it, namely, "reflective consciousness", "self-consciousness", and "conscious experience" (also "acquaintance-by-introspection", e.g. Russell, 1912, p. 49). Each of these expressions, if they are not to be considered redundant, imply two things: an experience plus an additional experience of that experience. Logically, then, reflexive consciousness is not primary. And several authors, as we have seen, give accounts of consciousness that eliminate this aspect, at least under some circumstances.

What would count as behavioral evidence of reflectivity in infants? This question is extremely difficult to answer. It may help, however, to distinguish between two types of reflective experience-sophisticated and simple. First, experiences may be reflected on as such (sophisticated). That is, one may reflect on an experience and know it to be an experience--at a minimum, know it to be distinct from that which is experienced. This type of experience entails knowledge of the distinction between thought and things (Baldwin, 1906). The second type of reflective experience, simple reflective experience, requires no theoretical knowledge about the nature of experiences. It simply requires access to the contents of one's experiences (cf. Carruthers, 1989). In this sort of experience, one need only have experiences that have as their content the content of previous experiences--for example, noticing that the sky is blue and then later remembering that the sky is blue. If the contents of one's experiences were fleeting and uncoverable, as may happen in the course of executing an overlearned task such as driving a car, then one could not have simple reflective experience of those experiences (Armstrong, 1980).

Does learning imply at least simple reflectivity? Learning may indicate that the contents of minimal consciousness can be modified, but learning need not involve a representation to consciousness of a past experience. A growing corpus of evidence indicates that some types of perception can occur without full awareness (Goodale, Milner, Jakobson & Carey, 1991; Weiskrantz, 1980) and that some types of learning and memory can occur in the absence of sub- sequent conscious access to the contents of past (training) experiences (e.g. Cohen & Squire, 1980; Corkin, 1968; Graf, Squire & Mandler, 1984; Tranel & Damasio, 1985). For example, amnesic patients can learn a variety of motor skills (Corkin, 1968) and semantic associations (Tulving, Hayman & Macdonald, 1991), despite being unable to recall ever having seen the test

*In fact, some authors have expressed scepticism concerning the possibility of fully reflective consciousness. Consciousness is "diaphanous" (Moore, 1922/1951, p. 25); we look through consciousness (and thus, in some sense, are aware of it), but when we attempt to look at it, it disappears. It is the last lens, as it were, and there is no further lens through which we may view it. For the present purpose, we may comfortably restrict our discussion to partially- reflective consciousness.

74 P.D. Zelazo

items or test situation. Similar dissociations between learning and memory, on the one hand, and awareness, on the other, have frequently been documented in normal adults (e.g. Berry & Broadbent, 1984; Graf, Mandler & Hayden, 1982; Reber, 1989). For example, Lewicki, Czyzewska and Hoffman (1987) found that their subjects were able to abstract a complex spatial pattern from a visual array without being consciously aware that the pattern existed (but see Shanks & St. John, 1994, for a critique). In these examples, the subject is conscious in some sense, but not in others (Tulving, 1985, distinguishes different types of consciousness). Even in the simplest case, where behavioral routines are elicited directly and automatically, they are elicited as a function of consciousness of immediate environmental stimuli. Thus, learning can occur without reflective consciousness, so we can exclude this aspect from minimal consciousness. On the other hand, even implicit learning and memory require minimal consciousness (this issue will be addressed again later). Implicit processing does not occur in a zombie-like fashion; it is simply unreflective.

Aspect 6: lntentionality Brentano (1874/1973) suggested that intentionality is the criterion of the mental (defined as

the complement of the merely physical). For Brentano (1874/1973), the intentionality of mental states consists in their reference to something that is (seemingly) beyond themselves though actu- ally contained in (in-existence) the state itself (e.g. desiring water or believing that the King of France is bald). One does not simply desire, rather, one desires something (viz. the intentional object). There is considerable controversy regarding whether unconscious phenomena may properly be called intentional,* but a more important question for our purposes is whether any conscious thing is necessarily intentional. I f it is, then intentionality ought to be included in our characterization of minimal consciousness.

In his description of intentional phenomena, Brentano (1874/1973) includes presentations, such as "hearing a sound, seeing a colored object, [and] feeling warmth or cold" (p. 78). He also flatly contests the claim that some conscious phenomena (namely pleasures and pains) lack intentionality (see p. 89 ff). Thus, far from applying only to propositional attitudes, such as knowing and believing, Brentano's concept of intentionality seems intended to characterize even the simplest conscious sensations (or qualia).

However, the suggestion that all conscious states are intentional is often rejected. Searle (1983) proposes that although we are always conscious o f something, this sense of "of" is different from the sense of "of" in which intentional states are of (or directed at) something. He gives the example of generalized anxiety and distinguishes it from a conscious fear of snakes, noting that, " . . . in the case of anxiety, the experience of anxiety and the anxiety are identical; but the fear of snakes is not identical with snakes" (p. 2). In contrast to Searle, Brentano would

*For example, Zelazo and Reznick (1990) claim that nonconscious behavior can be exhaustively explained in terms of neurophysiological states and their functional history. The functional history accounts for the non-arbitrary connection between nonconscious brain states and aspects of the physical world (i.e. it accounts for symbol grounding; see Harnad, 1990). If putatively "mental" states are nonconscious, then they are not of anything in the way that distinguishes mental states from merely physical ones (i.e. in Brentano's 1874/1973, sense). However, because they act and interact as symbols--relating to their referents under particular descriptions, nonconscious brain states exhibit referential opacity: nonconscious knowledge about Orcutt is not recognized as knowledge about the man in the brown hat, if the man in the brown hat is not recognized as Orcutt. Truly intentional states are those characterized by Brentano's of. At present, the category of the mental serves as a sort of repository for that which is not captured by physical explanations; we are far from being able to cash in the intentional of, but it is a useful index of a realm for which purely physical and causal explanations are presently unavailable.


probably treat generalized anxiety and a fear of snakes as similar in the important respect of being experiential and different only in the complexity or specificity of the content of experience. He might further claim that the experience of anxiety and the anxiety are not identical: anxiety is a physiological state (increased heart rate, etc.) to which one may attend or fail to attend. If one attends to it, then one's experience is directed at it. The debate is not merely terminological; it is a matter of capturing useful distinctions.

Intentionality a la Brentano is useful in that it captures the fact that any experience, no matter how attenuated, is experience of something--it has content, whether that content be a proposi- tion regarding the King of France, or simply generalized anxiety. The same cannot be said of things that are merely physical. Brentano's intentionality is thus a ground-level characteristic of consciousness and must be included in minimal consciousness. Searle's concept of intentionality makes a finer distinction than does Brentano's.

On this account, although there must be something that the infant is conscious of, the infant would not necessarily recognize the fact that it is conscious of something (for this would entail reflective consciousness). Thus, for example, an infant who is minimally conscious of pleasure would experience simply: [pleasure]. He or she would not experience: [consciousness of pleasure], or: [l(as a conscious subject) am conscious of pleasure]. Figuratively speaking, a minimally conscious organism would look through the lens of minimal consciousness at some content, but it would not see the lens, let alone see itself looking through that lens. It follows that such an organism could not recognize the content of minimal consciousness as content.

Aspect 7: Being-like-something Being-like-something is perhaps the most obvious and the most difficult to define of all the

aspects of consciousness because it corresponds to whatever is peculiar to a first-person account of experience and thus, it is arguably beyond the reach of an objective, third-person account (i.e. a scientific one). In his essay on the mind-body problem, Nagel (1974) suggests that there is something that it is like to be a conscious organism, however lowly (phylogeneticaUy speaking) the organism may be. Much has been made of this manner of speaking about the subjective, phenomenological feel of experience (i.e. of qualia). In fact, Carruthers (1989) suggests," Since Thomas Nagel's sem- inal p a p e r . . , it has become generally accepted that a creature may be said to have experiences if and only if there is something that it is like to be that thing (even if we cannot know what)" (p. 258).

Nagel (1974) does not argue for the necessity of being-like-something; rather he simply asserts that this is what we mean when we talk about experience. Carruthers (1989) appears to agree that conscious experiences entail being-like-something, but he maintains that some experiences are not conscious, and he reviews evidence for these "nonconscious experiences", which he suggests have no phenomenology. The primary evidence that Carruthers considers is the case of "blind- sight". Patients with lesions to the striate cortex may deny that they can see anything in a particular part of their visual field. Nonetheless, if they are asked to guess, they are often quite good at describing features of objects in that field. For Carruthers, these states are nonconscious insofar as they are not "available to be consciously thought about" (p. 263). That is, according to Carruthers, in order to believe consciously that P, the belief that P must be "apt to emerge in a conscious thinking with the same content" (p. 263). Because of the alleged complexity of conscious states, Can'uthers suggests that nonhuman animals are limited to nonconscious experiences. He then reasons that because it does not feel like anything to have a nonconscious experience, there is nothing that it is like to be a nonhuman animal. Further, Carruthers extends his account to include the experiences of infants. He writes, " I presume that the pains of babies, too,

76 P.D. Zelazo

are nonconscious; for no one will seriously maintain that they consciously think things to themselves" (p. 269).

Is it like something to be an infant? Carruthers' account of conscious states can be challenged, as can his presumptions concerning nonconscious experience; a criticism of the one entails a criticism of the other. Consider the notion that in order to be conscious, a state must be available to be consciously thought. Either there are two processes (or states) involved or such a notion is entirely circular. If two processes are involved, then something like the following must happen. One has a belief that the end is near, and then one has a different belief that the end is near. For Carruthers, if the first belief is conscious then as a matter of fact one is likely to have the second in a similar situation. Why does he believe this? Presumably, because we can in fact recover or repeat some mental states and not others and because by definition, the ones we cannot recover are unconscious. But are they really unconscious, or are they simply unrecoverable? And further, do they lack phenomenology?

Certainly it is possible that some of our conscious thoughts are fleeting and unrecoverable. Consider this mundane example of a so-called nonconscious experience. You take a shower and in the process you forget whether or not you have washed your hair. You might look around for signs of suds-- some remnant of the forgotten act. In this situation, if you were absorbed in a particular train of thought, you might have proceeded to carry out the complex and sophisticated behavior of hair washing without, seemingly, being conscious that you were doing so. Now, in this example, as in other examples of the phenomenon, you were undoubtedly conscious of something, and could report about this something. So, after your shower, you could tell someone about the train of thought that you were following while you inadvertently washed your hair. More importantly, however, if you were interrupted while reaching for the shampoo, you would in fact recover your intention to do so. Because the overlearned activity of hair-washing (or driving a car or whatever) was not the focus of attention, the experience underlying it was not easily retrieved in memory, but it would be a mistake to assume that the washing was executed in a zombie-like fashion without any conscious awareness at all.

Likewise, in the cases that appear in the literature, subjects (or patients) are in fact conscious in some sense, but not in others (e.g. Tranel & Damasio, 1985). In order for the appropriate behavioral routines to be elicited (even "directly"), there must be some consciousness of the appropriate eliciting stimuli in the environment. This consciousness may be extremely attenuated, and memory for this consciousness may be lacking altogether, but the consciousness is nonetheless there. Carrnthers suggests that because one cannot reflect upon an experience, one did not experience that experience and thus, there was nothing that it was like to be the one who had that experience. On the contrary, on the present account, minimal consciousness always underlies unreflective behavior (e.g. so-called implicit learning and memory), and following Nagel (1974), being-like-something--that is, having some subjective feel--is precisely the sort of thing that would seem to be a ground-level characteristic of consciousness. It seems reasonable to suppose that when one does not reflect upon a mental state, it was in fact like something to be in that state, although one may not know that it was like something (for that would be reflective), and one may not later remember that it was like something.

TOWARDS A CHARACTERIZATION OF MINIMAL CONSCIOUSNESS

The theoretical approach employed in the present paper has led to the exclusion from minimal consciousness of shared knowledge, volition, articulateness, consciousness of Self and


reflectivity, on the grounds that consciousness that lacked them would be coherent and thus, they are not logically necessary aspects of consciousness. Further, at first glance, it would not seem to be parsimonious to attribute these excluded aspects to infants, although the question of evidence for different aspects needs to be addressed directly. On the positive side, it has been suggested that minimal consciousness is structured by the operation of inferences, such as those cre- ating a figure and a ground, and that minimal consciousness contains conatative aspects that motivate approach and avoidance behavior. Further, the concepts of intentionality and being-like- something are such that they would seem to be part of any type of experience, however attenuated it may be.

It was suggested that minimal consciousness underlies implicit behavior. Precisely because this behavior is implicit, and minimal consciousness lacks reflectivity, it is difficult to say much about the phenomenology of minimal consciousness. Still, we may be able to learn something from descriptions of a phenomenon that Goethe (as described in Holt, 1937) called "pure activity". Holt (1937) writes, " . . . Where the mind is working at its highest efficiency, there is no immediate memory, no intercurrent reminiscence, and no sense of an active Self" (p. 46). During pure activity, the subject has a conscious experience, but the experience is not available for further conscious reflection. In pure activity, as in minimal consciousness, one would be conscious of what one saw, but would not be conscious of seeing what one saw. Further, an organism whose experiences were associated with pure activity might make automatic perceptual and cognitive inferences, and might learn (implicitly), but it would not know that it was learning, and might later suffer infantile amnesia, as human beings are believed to do (e.g. Campbell & Spear, 1972; Nadel & Zola-Morgan, 1984).

Development from a state associated with pure activity might be conceptualized as an increase in the limits of conscious past- and future-orientation, measured in terms of how far into the past or future one could direct one's attention; it could be conceptualized as an increase in the possible distance from the exigencies of the immediate situation, to borrow a phrase from Dewey (1960, p. 104). The notion of present-oriented consciousness needs to be explored further. As mentioned above, James (1890/1950, 1895) suggests that all experience involves a sense of passing time. This suggestion is meant to capture the fact that consciousness must be consciousness of change, because, in Dewey's (1960) words, " . . . If there is one unbroken luminosity, or one unbroken monotony of sound, there is no perception, no consciousness" (p. 308). The idea that consciousness is inherently dynamic raises the difficult question of how wide is the window of the present moment in momentary non-reflective experience. It could be that in the minimal sense of noticing a transition from one state of affairs to another, minimal consciousness must be reflective, even if it cannot itself be reflected upon.

The present characterization of minimal consciousness is designed to provide a first step towards a story of the development of consciousness. Clearly, this approach is the result of a number of assumptions, and different assumptions would lead to different results. Fortunately, there are relatively few degrees of freedom underlying potential speculations about the development of consciousness. One alternative would be to assume no consciousness until certain behavioral criteria were met. Exercises starting with this assumption might proceed upwards from a point of no consciousness and attempt to determine when various aspects of consciousness (such as intentionality) emerge.

If one assumes some type of minimal consciousness, then it seems possible to indicate criteria for other aspects of consciousness. If one does not, then one opens the door to the issue of how consciousness emerges (Baldwin, 1894). The difference, in causal terms, between something lacking any type of experience (such as rock) and something that has some experience (such as,

78 P.D. Zelazo

presumably, a rat) is entirely mysterious and the transition from no awareness to awareness of even minimal conscious content (e.g. pain) still seems miraculous. Thus, given the limitations on

our ontological characterization of consciousness, a temporary sidestepping of the mind-body

problem is welcome. (The illegitimate birth of consciousness awaits us further down the

ontogenetic ladder.) Explanations of infant behavior require a clear consideration of the particular characteriza-

tions of consciousness that they entail. These characterizations ultimately determine the types of

explanations of behavior that one is able to give. The present paper provides some independent justification for an alternative to adult-like consciousness that might be parsimoniously attributed

to infants. This account would restrict the range of intentionalistic explanations of infant behav-

ior. However, the character of infant consciousness ultimately needs to be assessed empirically. In the words of the behaviorist Clark Hull ," Instead of furnishing a means for the solution of prob-

lems, consciousness appears to be itself a problem needing solution" (Hull, 1937, p. 30). Hopefully the foregoing analysis will encourage developmental psychologists to recognize the

possibility that adult-like consciousness is the product of a protracted epigenetic process that

begins with something similar to minimal consciousness.

ACKNOWLEDGEMENTS

I would like to thank Rudiger Bittner, Doug Frye, Chris Green, Bill Kessen, Letty Naigles, Steve Reznick, and the members of the Yale Infant Intentionality Group for their generous criticism of this paper.

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