Notes: Lecture 1 02/09/2014 2:10 PM Lecture 1: Problems of Consciousness: Introspection The view of consciousness held by philosophers and by Cognitive Scientists are, with a few exceptions, quite different. 1 I will begin with the Cognitive Scientists’ views which, ever the last century have tended to focus on methodological issues, in particular; how we can study consciousness even when we don’t know in any detail what a theory in this area would need to explain. We scarcely have any idea what consciousness is, except, possibly, when it occurs in the mind of the investigator – and even that assumes that it, whatever it is, is something that has a location, at least in the sense entailed by saying it is “in the mind”. In speaking about conscious states we generally begin with first-person descriptions – of what it’s like to be conscious of something. This is already a serious problem as Thomas Nagel has shown (Nagel, 1947). But as a science we want quickly to go beyond describing what it’s like to be in a particular sort of state. The fervent hope is that the description we start off with will capture a natural kind that will eventually connect with other parts of cognitive science and neuroscience. So even when we give first-person accounts we expect there to be core properties that generalize across instances and across individuals and that will eventually ground out in some way in causal properties. In the first part of the course we will begin with a view from psychology. For at least the first half of the 20th century, psychology was focused on describing states of consciousness as such. The method associated with this movement was called introspection and many proponents of this method argued that with proper understanding of this term and with proper training, the method could be an objective way of observing consciousness – its structure and its content (what phenomenal properties it embodies, such as color, shape, movement, and so on). A great deal of time was spent on making introspection reliable (repeatable) and valid (related to the object of the experience in a consistent way). There was also concern with what Titchener called the Stimulus Error , in which observers reported properties of what their conscious states were about – what things in the actual or possible world 2 they depicted – rather than the experience itself (we will have a lot more to say about that when we discuss mental images). We will read parts of papers that argue for the Introspective Method, as well as papers that argue that introspection was doomed as a scientific method because the object of study was essentially private and could not be publically shared. These arguments were conducted with considerable passion and, as far as I can see, did not affect the science of the time. What did affect the science was the obvious historical fact that theories based on introspection seemed to go nowhere and eventually this was seen (correctly) as lack of progress of a science based on introspection (if it was a science). In this course we will encounter many instances of arguments against introspection as a way of accessing mental states. Yet we need to know what mental states the mind goes through in order to understand mental processes. We present a number of arguments against the assumption that introspection gives us direct access to mental states (and therefor mental processes) that are not available by any other means. While the examples illustrate how accepting introspection as a uniquely privileged source of evidence about mental states carries the risk of leading us astray, they fail to do what early stages of science typically do; provide 1 Parts of these notes are taken from (Pylyshyn, 2003, Chapters 6-8). 2 The very idea of a logically possible but nonexistent (imaginary) world that we can experience consciously is problematic. For example, could we imagine invisible physical objects or objects that cannot be examined from different perspectives (e.g., that have no backs or sides)? Or worlds in which there are 4-dimentional objects (as assumed by some Inca mythologies or by special relativity)? Or even higher-order spacetime manifolds, such as the 26 spatial dimensions hypothesized by one version of String Theory ? 1 Notes: Lecture 1 02/09/2014 2:10 PM ways to narrow or circumscribe or idealize the relevant sources of evidence and the relevant phenomena. In the case of consciousness as a natural domain one might have to confine the study to empirically derived domains within which some empirical regularities could be found and to which the grand arguments did not apply (e.g., that did not subsume what some have called the “hard problem” of consciousness) 3. But this is Fodor’s territory. Suppose we accept that there are conscious phenomena that form the core of the patterns of cognition that can be explained in naturalistic terms. There still remains the problem of specifying what these conscious observations (introspections) tell us about mental processes. What they don’t tell us is the most obvious interpretation of our first-person observations. For example, they do not tell us are the form and content of our thoughts. Even less do they tell us why we believe one thing rather than another. Take the question; what are you thinking? People used to say, when they saw you staring into the middle distance, “a penny for your thoughts.” A penny doesn’t buy much these days but you should still take the dare because neither they nor you can say with any confidence whether your report of your thoughts of the moment are veridical. The evidence suggests that what you are doing in answering the question is pretty much the same as what some bystander would do in answering the same question about your thoughts, given that he knows the same relevant details as you do. In other words what both you and the third person would do is compute (or reason, or infer) what must have been going through your mind. There is even evidence (discussed by Gopnik, 1993), that children’s first-person reports are also the result of inferences. In other words what we are doing when we tell someone (e.g., a psychologist studying thinking) our thoughts is we are being scientists ourselves and we infer what thoughts might have led to the experiences and statements we make when asked about our thoughts. Indeed in the Problem Behavior Graph that Allen Newell and Herb Simon (Newell & Simon, 1972) invented is specifically directed at helping the investigator to infer unstated mental states involved in solving a problem. It does this by highlighting observed transitions that lack an appropriate operation or sequence of operations to change the ‘knowledge state ’ associated with that transition. Some of these assumptions mentioned above will become clearer and more directly relevant later when we speak of reports of particular sorts of conscious contents, namely those we call mental imagery . Do we need to appeal to conscious contents in cognitive science? The shadow of Behaviorism no longer haunts cognitive science. When the human observer that we are studying (often called the “subject” but more recently referred to by the more acceptable term “observer”) utters something, we do not merely record it as a response, we consider what the subject was trying to tell us (e.g., I didn’t hear what you said. Or , Did you have garlic for lunch? ). As with many seemingly radical changes, this rediscovery of mentalistic or folk-psychology initially produced a science as radically confused as the one it displaced. In this brave new world we typically take a subject’s statement as a literal report of what he or she was thinking (even putting aside self-promotion or acquiescence). In studying such cognitive processes as those involved in problem solving we often appeal to subjective states of consciousness and we are equally often lead astray when we do so, since reports of the content of conscious mental states are inevitably reconstructions that depend what the observers’ believe might have been involved in the mental processes, or on tacit theories we hold about the role of mental states. And we will see that such tacit theories, often based on folk psychology, are likely more often than not to be false. Yet there are contexts where we appeal to properties of conscious states because there is no other way to obtain evidence of mental 3 An excellent summary of some of the arguments can be found in Fodor’s notes for this class, as well as in Wikipedia (http://tinyurl.com/nmpm64e). 2 Notes: Lecture 1 02/09/2014 2:10 PM processes and because the states that we advert to are our very own mental states , and why would we mislead ourselves (we will see some reasons why later in this chapter). True, in some of these cases the consciously accessible states might provide initial hypotheses that must subsequently be validated. On the other hand so would the day’s news, the weather, recalling a missed appointment, or any other fact you may have in mind. That’s what makes prediction difficult – once you get past the early-vision stage the mind is ever so holistic! Let’s look at some examples of the sorts of theories one might come up with if one takes the content of our conscious experience as primary (and privileged). The description of your experience might be a complex one and might be an accurate characterization of your conscious experience, but not of the way you solve the problem.