4.30.2008

If you're happy and you don't know it, clap your hands!

A recent paper on unconscious emotional processing (Ruys & Stapel, 2008) has been getting a good amount of attention, and I thought I'd weigh in on it. You can find the abstract here.

The researchers flashed scary (e.g. a growling dog), disgusting (e.g. a dirty, unflushed toilet), or neutral (e.g. a horse) images on the screen, and they did this at two different speeds: quick and super-quick. Both of these speeds were quick enough that participants couldn't consciously perceive the content of the pictures. The participants were simply asked to judge whether the picture was flashed on the left or the right side of the screen.
The participants were then given a barrage of behavioral and cognitive measures. Here's one of them: When given the choice to complete either a "strange food test" or a "scary movie test", the people who were given scary priming images were more likely to choose the "strange food test" over the "scary movie test". The situation was reversed with the people who were given the disgusting priming images. This was, of course, the expected result. After all, who wants to think about food when there are "unflushed toilet" neurons firing in the brain?

The one message I get from this is that networks in the dorsal visual processing stream ("vision for perception"), which carry the bulk of the responsibility for processing object identification and the semantic content of visual information, may have one temporal threshold for explicit awareness and another, lower temporal threshold for implicit awareness (implicit awareness being a sort of non-thematic experience of responsiveness to specifics in the environment). The content may not be accessible to explicit awareness, but the content is still "in the brain", triggering cascades of activity that eventually result in content-based physiological, behavioral, and psychological changes.

(I wonder if the same thing would happen with spatial thresholds? If you introduce noise into the image and gradually reduce or elevate the levels of noise, would you reach a point at which people are still explicitly unaware of the content of the image, but are at some level responding to the content of the image? I might just pilot it and see . . . )

The results are interesting, but it was the discussion that really caught my eye. The authors gave the following description of unconscious emotions:

Emotions might be viewed as unconscious
when they are detected by indirect behavioral or physiological
measures, without being accompanied by conscious emotional
experience. However, what does it mean when only indirect
measures suggest the presence of an emotion?We think that the
range of emotional measures that are affected depends on an
emotion’s intensity. When emotions are full-blown, people become
aware of their emotions by perceiving their own actions
and bodily reactions. When emotions are weak, people fail to
notice their weakly related actions and bodily reactions.
This represents a turning point in the paper. Up to this point, the authors had been defining conscious and unconscious emotions on the basis of whether or not the participant was consciously aware of the content of the stimulus that induced the emotion. Here, they switch gears and define unconscious emotions as those emotions that are not accompanied by "conscious emotional experience", but which can be detected by indirect behavioral or physiological measures like the ones they used.

I assume that all emotions, conscious or unconscious, could be detected by indirect behavioral or physiological measures. If this is the case, then the only distinction being made between conscious and unconscious emotions is that the unconscious ones aren't accompanied by, well, conscious emotional experience. Quite the tautology.

This isn't the worst of it, though. It seems that defining unconscious emotions in such a way that they can be detected by others but not by oneself will lead to undesirable situations. To clarify: the problem isn't that we have behaviors and physiological responses that others are in a better position to notice than we ourselves sometimes are; rather, the problem is that we are allowing 'emotions' to slide into this category. Would it be problematic, for example, if the experimenter told the subject, "You don't know it yet, but you are afraid," and the subject happened to disagree? Or can we guarantee that these unconscious emotions are so self-evident upon reflection that the subjects would never disagree? I don't think that guarantee can be made, and I find that troubling.

The issue, I think, is the ubiquitous practice, within cognitive science, of augmenting or replacing folk-psychological definitions with the neural processes that underly the original referent(s) of the term. There is the experience of the emotion. Then there is the biological basis of that emotion. Two distinct things, and I get anxious when the boundary between them isn't respected. Even before we understood anything about the brain's role in emotion, there really was something like experiencing an emotion, and I'm guessing that this is what makes emotions interesting to cognitive scientists in the first place.

Ruys, K. I., & Stapel, D. A. (2008). The secret life of emotions. Psychological Science, 19(4), 385–391.

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4.29.2008

a skilled introduction

I have given 4 or 5 talks during my first year of graduate school. I've learned that one of the hardest questions you can get after the talk is, basically, "What's the point?" Man, I hate that question. The point is that I'm doing it, so it must be cool.

This may not be a hard question for some people who happen to have a clearly articulated result in mind every time they begin a study. But for me people like me -- people who have to find out what they're trying to do by looking at what they've been doing for the past five years -- it is a taxing question.

One of the benefits of (and, indeed, one of my motivations for having) this blog is that it gives me a good reason to engage in this kind of teleological retrospective. I think (and I hope) this blog will be as formative as much as it is informative. For now, I think it's safe to say that my interests have lately converged on the general topic of skills, broadly construed.

I became interested in skills while studying phenomenology with Mark Wrathall (a "California" phenomenologist who studied with Dreyfus and Davidson at Berkeley, spent some time teaching at BYU, and recently moved to the Phil department at UC Riverside). Mark introduced me to Mel Goodale, a neuroscientist (and a darn good one, too) who studies the visual and motor systems of the brain. I ended up in Mel's lab, and now I find myself doing a study that explores how the brain helps us choose between grip postures when we are faced with an ambiguous object (or with an object at an awkward orientation). I started looking at this because I was interested in tool-use; I wanted to explore the brain areas that are responsible for developing "tool" skills and their related grip postures. (The phenomenologist in me is curious about the role of these brain areas in the perception of the tool itself -- i.e., how much does the content of our perceptual experience of a pair of scissors depend upon skills that we have developed with scissors?).

Sometimes I have crazy ideas about skills, even to the point of constructing rough sketches of a theory of perception that is entirely based on skills. Luckily, I've developed the skill of knowing when to shut up.

So, what's the point? Skills. That's the point.

I want this blog to cover a wide range of topics in philosophy and neuroscience, but be warned -- it's possible that, for the time being, the majority of posts will be part of an attempt to convey my passion for the topic of skill.

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4.28.2008

raison d'etre

I started my first blog, Maieutica, with the intention of making it into a platform for my latest philosophical/scientific interests. It has gradually and unwaveringly evolved into a semi-humorous diary blog. I get about 300 hits a day on that blog -- a fact that made me feel pretty funny until I installed some free statistical tracking software and discovered that roughly 95% of the visitors were coming to see a picture of a French Bulldog that I pulled off Google Images.

The time has come to resurrect my original intention. Welcome to the brain and the sky -- my philosophy/science blog. Hope you're not here for the bulldogs, 'cause there ain't any.

* A note on the title:
It was inspired by an Emily Dickinson poem.

"The Brain"

The brain is wider than the sky,
For, put them side by side,
The one the other will include
With ease, and you beside.

The brain is deeper than the sea,
For, hold them, blue to blue,
The one the other will absorb,
As sponges, buckets do.

The brain is just the weight of God,
For, lift them, pound for pound,
And they will differ, if they do,
As syllable from sound.

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