Posts tagged "cognitive-science"


At present, I write here infrequently. You can find my current, regular blogging over at The Deliberate Owl.

Why did you pick cog sci?

When I can tell a ten-second answer is all that's wanted, I say, "because I took an intro cognitive science class in my first semester of college and loved it."

_yellow-orange gradient background with word cloud showing fields influencing cognitive science: education computer science artificial intelligence neuroscience philosophy anthropology linguistics psychology_

Some people realize I must've had some reason for signing up for an intro cog sci class in the first place. They tend to be satisfied with an answer like "because I read a book on consciousness before college, and wanted to know more."

The real answer, the one that's actually about why, is this:

No one knows yet how or why I'm a self-aware person. And I'd really, really like to find out.

Mysteries and mysteries

A couple years before I ventured across the country to begin my Vassar education, I started reading books about mysteries. Not fiction mystery novels -- actual mysteries, in which no one knows whodunnit yet, though a whole lot of people have theories. Things that are hard to think about, or crazy difficult to conceptualize. The nature of space-time. Infinity. Perception. (My favorite my favorite exhibit at the Exploratorium in San Francisco was always the optical illusions.)

_optical illusion of several rings of color that appear to move when you look at them_

First, it was books like Richard Wolfson's Relativity Demystified, Brian Greene's The Elegant Universe, Michio Kaku's Parallel Worlds, Mario Livio's The Golden Ratio. All the grand mysteries of the universe, its structure, and the math and physics underlying it. I didn't completely grasp the details of the theories, but it was sure fun to try!

Then I decided to read about people. I honestly don't remember why I picked up Susan Blackmore's Consciousness: An Introduction -- was I just browsing the generic non-fiction science books section? I remember the library. I remember kneeling on the carpet, pulling the book off one of the lower shelves.

This book opened my eyes.

At first, I was a little disappointed. Why couldn't Susan tell me how people worked? How I worked? I wanted answers! How am I a person? Why am I a person? Why can I think about myself thinking? Perhaps I'd assumed, up until that point, that scientists had all the hard problems figured out and now were just filling in the details.

My dismay was swiftly and thoroughly overridden by the realization that here was one of the Big Questions in the universe. Still so much left to discover. The twinkling thought: could I help discover it? And utter fascination. I distinctly remember standing on the local community college campus before a class, staring wonderingly at the landscaping, thinking, what is it like to be a tree?

_xray-like image of the human head from profile view_

So I read more. I read what I could find in my local public library system. (I wonder what I would have read and learned had I instead had a proper university library at my fingertips.) I also bought a copy of Douglas Hofstadter's Godel, Escher, Bach, which intrigued and confused me. I was severely disappointed by Andrea Rock's The Mind at Night, because I'd naively assumed that I could read one book and then understand why people sleep and how dreaming works.

I read William Calvin's How Brains Think, which didn't actually tell me how brains think but did introduce me to some relevant terminology. I learned how complicated memory is and how to pronounce aplesia from Eric Kandel's memoir In Search Of Memory. Judith Rich Harris's No Two Alike was part of my introduction to the nature-nurture debates, a lot of twin studies, and just how important the environment and an organism's interactions with it are in determining what the organism is like.

I read Malcolm Gladwell's Blink, Stanislas Dehaene's The Number Sense, and some others, too. As before, I'm quite sure that I did not fully understand any of the theories presented, not having a background in cognitive science, psychology, philosophy, or neuroscience at that point.

Basically, I discovered the mind sciences at an opportune moment, in time to sign up for an introductory cognitive science course my freshman year.

And now?

I still don't know why or how I'm a self-aware person. No one does. I do, however, have a much better idea of the theories other folks have, the problems being tackled, and some of the methodologies being used in the quest. Maybe, now, I'll be able to help solve the mystery myself.


human male asleep in a chair, in the sunshine

Are we out of context?

In the book Evolutionary Medicine and Health: New Perspectives (2008), edited by Wenda Trevathan, E.O. Smith, and James KcKenna, there's a chapter by Carol Worthman titled After Dark: The Evolutionary Ecology of Human Sleep.

Worthman takes a look at how well people's current sleep patterns match up with our ecological and evolutionary history -- the context in which human sleep evolved. Any species with a long history is affected by the long-term development of the species over time in particular environments. When the environment changes dramatically in a relatively short period of time, there's a lag as the species' development catches up, so to speak, adapting to the change in environment. For a while, there's a mismatch between the species' current state and its current context.

The motivating question of Worthman's chapter is are we out of context?

Human sleep

No one actually knows exactly why organisms sleep. Researchers have shown it's essential; they've determined that sleep disruption and deprivation often has negative effects; they've mapped out stages of sleep as characterized by patterns of physiological, behavioral, and cognitive activities. Sleep habits are fairly plastic. We have the capacity to have "sleep debts" and make that up later -- but if sleep is so important, asks Worthman, why is that possible? What kinds of situations provoke sleep restriction? What roles do stress and stress physiology play in disrupted sleep? And, most importantly, how have our sleep habits and the conditions under which we sleep changed in modern times from the context in which we evolved?

Factors that Worthman addresses include:

  • housing, beds, climate control
  • co-sleeping practices
  • material, social, and psychological contexts
  • macrosocial factors such as technology, labor, social structure

How and when a person sleeps is regulated by demands for wakefulness from the circadian system, and demands for rest and slumber. Worthman talks about the evolutionary roots and elements of human sleep ecology. She discusses how sleep settings have tended to be social across societies, even before longhouses and one-room log cabins. We didn't evolve in an environment where we put oursleves in a room to "lie down and die" for the night. Rather, humans tended to live in groups and sleep in groups, with all manner of activity occurring throughout the night -- were fires, noise, other people, conversations, nighttime pests, and more. These were, ecologically speaking, signs of safety and security -- signs that it was okay to sleep and let our own vigilance mechanisms relax.

black cat curled up in a ball, asleep, on top of a patchwork quilt

Now think about insomnia for a moment. In some instances, difficulties getting sleep in our current society may be related to how and where we now sleep. If we close ourselves off from noise, fire, other people (essentially, take ourselves out of an environment in which some of the vigilance is taken care of for us), our vigilance mechanisms go off, so to speak, and attention is focused on the kinds of things about which we should be vigilant.

In these kinds of group settings and active-nightlife contexts, was sleep interrupted? Sure. But rather than just losing sleep, people stayed awake for good reasons -- useful activities, time and energy demands, threats to physical survival, and social challenges. People have adapted to defer sleep to these kinds of activities. An interesting point -- one can recover from lost sleep in far less time than the original deficit. An example Worthman gives is that ten days sleep deprivation can be recovered in one or three eight-hour nights.

A question Worthman asks is just how atypical our sleep patterns are, and whether these patterns are giving us problems we wouldn't otherwise have.

How much do you sleep?

The biggest thing I got out of her article was this: Bedtimes are fluid. In the US, we seem to have the idea that to sleep properly, we have to be dead to the world for a solid chuck of eight hours. But sleep's more fluid than that, and sleep isn't just the time during which you're dead to the world. We probably underestimate the time that we actually spend sleeping, and we probably make a bigger deal than is actually necessary about getting the recommended eight hours.

Take a look at other cultures -- in some, people sleep for five or six hours and night, and maybe have a two-hour nap in the afternoon. Sleep doesn't have to just be in one chunk. Punctuated sleep is fine. Napping is fine. Some college students seem to have figured this one out already.

Essentially, Worthman argues, we should worry about our sleep a little bit less.

Interested in more of the details?

Worthman's chapter is definitely worth a read. Pun intended.


Descartes' mechanical baby in white on blue

The claim

A friend and I had a conversation recently on the use of introspective evidence in logical arguments. Here's the claim:

Introspective evidence cannot be used in sound logical argument because statements that are the result of introspection have unknown truth-values.


  1. Premises used in sound logical arguments must be definitively true.
  2. Statements derived from introspection are sometimes true and sometimes not true.
  3. Introspection alone cannot always determine whether a statement derived thusly is true or not true.
  4. Statements that could either be true or not true have unknown truth-values (are not definitively true).


5) By (2), (3), and (4), statements derived from introspection are not definitively true.

6) By (1) and (5), statements derived from introspection cannot be used in sound logical arguments.

Support for the premises

  1. In formal deductive arguments, for a conclusion to necessarily be true, the argument must be both valid and sound. If valid, the conclusion cannot be false if all the premises are true -- i.e., the premises entail the conclusion. If sound, all the premises are true. Arguments can easily be valid but not sound if one or more premises are false. To know for certain that the argument is sound, one must know for certain that all the premises are true and that the argument is valid.

  2. (a) Definition of introspection: I am defining 'introspection' as a process that gives one knowledge about what's going on in one's own mind. This process may involve self-observation, self-reflection, and self-reports of one's mental states and internal motivations, as well as explanations and reasons for one's thoughts, feelings, and behaviors. This is not a universal definition. (See, e.g., the Standford Encyclopedia of Philosophy for a decent discussion of introspection.) Not all thoughts are introspective; one can think about things other than one's mental states, motivations, feelings, and the causes of these.

    (b) Definition of truth: I am concerned primarily with the accuracy or truth of introspection. For now (until I do more reading and possibly change my mind about what makes sense), I am adhering to a correspondence theory of truth: if one says the world is flat and it is indeed flat, then it is true that the world is flat. If one's internal representation of a thing in the world is consistent with the thing in the world whenever it occurs, then there is a correspondence and the thing is true. E.g., one's introspections about the causes of one's behavior are true if they accurately reflect the causes of one's behavior.

    The problem with this is that we don't know when we've made a mistake, and we don't know for certain that a thing is true even if it is true. The pragmatic theories of truth set out by Peirce, James, and Dewey attempt, in different but related ways, to deal with this issue. You can know when something's false. You can't prove that something's true. I'm planning on reading up on their respective theories.

    Other theories of truth are less appealing (also see Moser & vander Nat, 1987).

    (c) Truth of introspection: The Stanford Encyclopedia of Philosophy summarizes many relevant studies of why introspection doesn't always give us accurate information. It includes descriptions of studies of introspection about causes of behavior, about attitudes, and about conscious experience.

    The seminal paper on why we're not very good at discerning the causes of our thoughts, behaviors, and their underlying processes was Nisbett and Wilson's (1977) work. They re-analyzed the rope-swinging experiment (see this blog for a lovely description of that experiment), which was originally done by Maier in 1931 (see this pop science discussion of Maier's work), as well as many others.

    Wilson has written a bunch of other papers on the subject since.

    There's also Gazzaniga's (1995) fairly famous studies of split-brain patients. Although some might argue that the split-brain research is not relevant to the normal human with the un-lesioned brain, it's just one piece in a larger puzzle, and there's a decent amount of other evidence drawn from pretty average populations of people.

    One might argue that some results of introspection can be trusted. That could be true. How will we know which introspections are trustworthy? I'd be wary of assuming wrongly. The safest assumption is that we don't know whether our introspections accurately reflect the causes of our behavior, our attitudes, or anything else.

  3. As seen in part (2c), we rarely if ever know whether our introspection has resulted in a true statement. Introspection alone cannot reveal the truth-value of our observation (e.g., of our motivation for performing a particular behavior). If you bring evidence from an outside source, e.g., the observation that the experimenter set the rope swinging or that Gazzaniga primed his split-brain patients with a word shown only to one hemisphere, then the truth-value has no longer been determined merely through introspection.

  4. Fairly straightforward, but the change in wording necessitated a further premise.

With all that in mind...

Let's look at my claim again:

Introspective evidence cannot be used in sound logical argument because statements that are the result of introspection have unknown truth-values.

Please note that I am not claiming that introspection fails to be useful in cognitive science, philosophy, psychology, or where have you. It can be a great tool, particularly when studying people's subjective responses to situations.

I am arguing that introspection does not necessarily accurately reflect the true causes of any mental state or process, and thus, that statements derived from introspection about mental states and processes cannot be taken at face value to be necessarily true. Secondly, we generally do not know when or if our introspection reflects true causes or whether our introspection is a confabulation, and as such, we cannot assume any given introspective statement is a true reflection. The truth of any given introspective statement is unknown. Introspective statements about different internal events may be more or less likely to be true (i.e., we may have better self-knowledge of, say, our feelings than we do of the causes of our behaviors).

Recall what I said earlier about sound logical arguments: all the premises must be true and the argument must be valid. If you cannot determine whether one or more of your premises are true, then you do not know whether your argument is sound. If you are using introspective evidence in one or more premises, you cannot know whether your argument is sound. Your argument must be sound for you to be sure that your conclusion is true.

Thus, if you are just using introspective evidence, you cannot know whether your conclusion is true.

And that's why I'd argue that introspective evidence cannot be used in sound logical arguments.


Gazzaniga, Michael S., 1995, Consciousness and the cerebral hemispheres, in The Cognitive Neurosciences, Michael S. Gazzaniga (ed.), Cambridge, MA: MIT, 1391-1400.

Maier, N. R. F. (1931). Reasoning in humans: II. The solution of a problem and its appearance in consciousness. Journal of Comparative Psychology, 12(2), 181-194.

Moser, P., & vander Nat, A. (1987). Human Knowledge. Oxford, NY: Oxford University Press.

Nisbett, Richard, & Wilson, Timothy. (1977). Telling more than we can know: Verbal reports on mental processes. Psychological Review, 84, 231-259. [PDF]


street in Georgetown, dark against a bright sky

Meandering along a street in Georgetown recently, I looked out at the throngs of people, walking in pairs and groups and singly, ethnicities as varied as their unseen motivations in walking out that day. I saw them, and felt apart; not disconnected or of some different species, an outsider looking in, but in the way of feeling that I was more self-aware at that moment. A single cell in a much larger organism, looking out and seeing the workings of all other cells. It was a knowing that I could see us all, self-organizing sacks of meat composed of so many tiny molecules, marvelously complicated and simple at the same time.

Hierarchies of behavior, heuristics for selecting actions, emotions and motivations influencing them all. Somehow self-aware, conscious of being, conscious of our consciousness. And I, in that moment, more conscious than the rest, looking at the curve of the road, the brick buildings squeezed up beside white-painted shops and little restaurants, the cars and trucks speeding by, and the people, all blissfully ignorant of everything at my level of awareness.

It was a feeling of awe. If I were a religious being, perhaps I would say I felt the hand of a god, touching me then, showing me the vast oneness of the universe. But I am not, and so I interpreted the feeling otherwise: not a part of any great unity, no; merely one agent existing in a world and conscious of that existence. Marveling at that existence -- that any clump of matter could build a society, could conquer the land and sea and air, could walk briskly down a cement sidewalk thinking or not thinking of the weird complexities of the animal brain that made any of these accomplishments possible. That we could organize ourselves such that societies are possible, and so are streets, and restaurants, and cars.

Sometimes it strikes me like that: The realization that all we are, all we ever are, are clumps of molecules bumping around. We have motivations, emotions; we have what feels like intentionality and we speak to each other, creating stories and lies and truths. But we are not special. We have no meaning. The most marvelous thing of all is that we have no more meaning than the simple biologically-inspired, behavior-based robots I created for my thesis. Agents, existing in and interacting with a world. Fascinating, brilliant agents.

Moments like these, wondering at how any of us can exist and marveling at how we do and are conscious of it, I know I picked the right thing to study. That I can be here, writing about the meanings we create and believe, is stupefying and wonderful.


Summer plans

My first post-graduation plans have been finalized: I'll be returning to the fine world of software development and robotics for a summer internship at NASA Goddard Space Flight Center. I'll be working with a diverse bunch of engineers and interns on what I expect will be super exciting, super cool projects.


_red and blue simulated robots in a flat simulated world_

On Friday, I turned in my undergraduate cognitive science thesis. It's been a year in the making -- I started brainstorming ideas last April, spent all summer reading up on relevant literature, and all of this school year developing my model, programming the simulation, running experiments, and finally, writing about all of that.

It's a little weird to realize that I don't have to constantly be thinking about this project any more. I don't have to be, but ever since handing it in, my thoughts continue to swirl around what further analyses to do on the data I collected, how to fix up the studies I did to get more powerful results, which studies would make sense as the next step...

Here's the abstract:

A biologically inspired predator-prey study of the effects of emotion and communication on emergent group behavior

Any agent that functions successfully in a constantly changing world must be able to adapt its behavior to its current situation. In biological organisms, emotion is often highlighted as a crucial system for generating adaptive behavior. This paper presents a biologically-inspired predator-prey model to investigate the effectiveness of an emotion-like system in guiding the behavior of artificial agents, implemented in a set of simulated robots. The predator's behavior was governed by a simple subsumption hierarchy; the prey selected actions based on direct sensory perceptions dynamically integrated with information about past motivational/emotional states. Aspects of the prey's emotion system were evolved over time. The first study examined the interactions of a single prey with the predator, indicating that having an emotion system can led to more diverse behavioral patterns, but may not lead to optimal action selection strategies. In the second study, groups of prey agents were evolved. These agents began to utilize alarm signaling and displayed fear contagion, with more group members surviving than in groups of emotionless prey. These results point to the pivotal role emotion plays in social scenarios. The model adds to a critical body of research in which important aspects of biological emotion are incorporated into the action selection mechanisms of artificial agents to achieve more adaptive, context-dependent behavior.