Archive for February, 2008

Autism / Psychosis: Agency and Joint Attention

A recent study by Tomosello’s group indicates that children with autism, can help a stranger pick a pen (and thus can apparently infer goal and intentional states of others), but cannot indulge in co-operative behavior that may involve shared goals and shared attention.

As per Translating Autism blog:

This fresh-off-the-press article comes to us from Dr. Michael Tomasello’s group at the Max Planck institute in Germany. The authors present the results of two studies looking at helping and cooperation in children with autism. The first study compared 15 children with ASD (14 with Autism and 1 with PDD-NOS) with 15 children with other non-ASD developmental delays (40 months of age average). During this study the children were place in situations that either called for helping behaviors (such as picking up a pen that the researcher dropped and could not reach) or a similar situation that did not necessarily call for helping behaviors (such as when the researcher threw the pen on purpose and did not attempt to pick it up). Both groups (children with Autism and children with other developmental delays) showed more helping behaviors when placed in the situation that called for such behaviors. That is, when the experimenter was “trying” to reach an out-of-reach object, both groups were more likely to help than when the experimenter was not trying to reach for the object. The authors concluded that these behaviors showed that both groups understood the adult’s goals and were motivated to help her. In the second study, the same children were placed in situations that called for “cooperative” behaviors, such as a task requiring them to work with the researcher by simultaneously pulling at two cylinders to reach a toy. The results showed that children with autism were less likely than kids with other developmental delays to successfully complete the cooperation tasks. Furthermore, the children with autism were less likely to initiate additional attempts to complete the task when the task was interrupted. The authors concluded that, at least at this developmental period, children with autism seem to understand the social components of situations that call for “helping” behaviors and engage in helping behaviors, but only when such help does not require interpersonal cooperation. However, when cooperation is required to complete the task, these children are less likely to correctly engage with another partner, possibly because the unique “shared” component of cooperation. That is, cooperation requires shared goals, shared attention, and a shared plan of action, processes that seem to be affected in children with autism.

Here is the abstract of the Tomosello paper:

Helping and cooperation are central to human social life. Here, we report two studies investigating these social behaviors in children with autism and children with developmental delay. In the first study, both groups of children helped the experimenter attain her goals. In the second study, both groups of children cooperated with an adult, but fewer children with autism performed the tasks successfully. When the adult stopped interacting at a certain moment, children with autism produced fewer attempts to re-engage her, possibly indicating that they had not formed a shared goal/shared intentions with her. These results are discussed in terms of the prerequisite cognitive and motivational skills and propensities underlying social behavior

From the above it is clear that children with Autism lack shared attention: a pre-requisite for language and their language impediments may also be due to this fact. If we contrast this with Schizophrenia/ Psychosis ( and assuming they are at opposite ends) it is not hard to see that with too much shared goals/ intentions/ attention, one may likely confuse between one’s own goals and those of others and in a joint scenario be more susceptible to delusions of control/ though insertion, wherein the shared space has become so vast that one seems to be controlled by the other or intruded by the other. thus , I propose that children susceptible to psychosis should show enhanced cooperating behavior indicating an overactive shared goals/ attention module.

Another interesting study I would like to discuss is the recent reporting of a dysfunctional ‘self’ module/model in a Trust game as compared to the ‘other’ module/ model. Here is how the Science Daily describes the Trust game that was used in the game.

In the trust game, one player receives an amount of money and then sends whatever amount he or she wants to the other player via computer message. The amount sent is tripled and the player at the other end then decides how much of the tripled amount to send back. The game has several rounds.

The ‘self’ module was identified as the brain areas (cingulate cortex) involved when making the decision to share the initial amount of money with another person. The ‘other’ module was defined as network region activated when the decision of the other player was revealed to them.

It was found that autistics showed lowered activity in the ‘self’ module. The authors construe this as evidence that they have a defective self concept.

“To have a good self concept, you have to be able to decide if the shared outcome is due to the other person or due to you,” said Montague. “If people can’t see themselves as a distinct entities at deeper levels, there is a disconnect.”

I beg to differ. In my view the findings can be explained using the joint attention / goal/ outcome defect outlined above. Although I believe that their explanation that people with autism may have a diminished sense of self or Agency also makes intuitive sense and I have argued the same previously. I contrast that with the Psychotic case where one attributes too much agency- even to inanimate objects or animals for example. However, in this case a more parsimonious explanation can be that the autistics were not able to model the others goal as their own (the familiar simulation argument) and could not indulged in joint goal intention and thus failed to optimally use the ‘self’ module i/e failed to take whatever actions were needed for a co-operative and trustful behavior .

The Friths adequately sum that up:

In a preview in the journal Neuron, Chris and Uta Frith wrote, “This is an exciting result because it suggests that some mechanisms of social interaction are intact in these high-functioning cases. What is the critical difference between the self phase and the other phase? We believe that the simple distinction of self versus other is not adequate. “It involves higher-order mentalizing: you care what another person thinks of you, and even further, you care that the other person trusts you. You would not do this when playing against a computer. In autism there is no difference,” wrote the Friths, who are at University College London.

Russsinas have a richer discriminative experience of light and dark blue qualia

I have blogged extensively earlier regarding language, color and the sapir -whorf hypothesis. My position in the above is clear, I lean towards the sapir-whorf hypothesis and a mild form of linguistic determinism. Now a new study (which I had missed earlier) by Lera Boroditsky presents further corroborating evidence that language influences even such basic functions as color perception. As per their 2007 PNAS paper, Russians are better (more speedily) able to distinguish between the light blue and dark blue color in an objective color perception task, thanks to the fact that Russian has a different color term for dark blue and a different one for the light blue. It is an excellent paper and I present some excerpts from the introduction:

Different languages divide color space differently. For example,the English term ‘‘blue’’ can be used to describe all of the colors in Fig. 1. Unlike English, Russian makes an obligatory distinction between lighter blues (‘‘goluboy’’) and darker blues (‘‘siniy’’). Like other basic color words, ‘‘siniy’’ and ‘‘goluboy’’ tend to be learned early by Russian children (1) and share many of the usage and behavioral properties of other basic color words (2). There is no single generic word for ‘‘blue’’ in Russian that can be used to describe all of the colors in Fig. 1 (nor to adequately translate the title of this work from English to Russian). Does this difference between languages lead to differences in how people discriminate colors?

The question of cross-linguistic differences in color perception has a long and venerable history (e.g., refs. 3–14) and has been a cornerstone issue in the debate on whether and how much language shapes thinking (15). Previous studies have found cross-linguistic differences in subjective color similarity judgments and color confusability in memory (4, 5, 10, 12, 16). For example, if two colors are called by the same name in a language, speakers of that language will judge the two colors to be more similar and will be more likely to confuse them in memory compared with people whose language assigns different names to the two colors. These cross-linguistic differences develop early in children, and their emergence has been shown to coincide with the acquisition of color terms (17). Further, cross-linguistic differences in similarity judgments and recognition memory can be disrupted by direct verbal interference (13, 18) or by indirectly preventing subjects from using their normal naming strategies (10), suggesting that linguistic representations are involved online in these kinds of color judgments.

Because previous cross-linguistic comparisons have relied on memory procedures or subjective judgments, the question of whether language affects objective color discrimination performance has remained. Studies testing only color memory leave open the possibility that, when subjects make perceptual discriminations among stimuli that can all be viewed at the same time, language may have no influence. In studies measuring subjective similarity, it is possible that any language-congruent bias results from a conscious, strategic decision on the part of the subject (19). Thus, such methods leave open the question of whether subjects’ normal ability to discriminate colors in an objective procedure is altered by language.

Here we measure color discrimination performance in two language groups in a simple, objective, perceptual task. Subjects were simultaneously shown three color squares arranged in a triad (see Fig. 1) and were asked to say which of the bottom two color squares was perceptually identical to the square on top.

This design combined the advantages of previous tasks in a way that allowed us to test for the effects of language on color perception in an objective task, with an implicit measure and minimal memory demands.

First, the task was objective in that subjects were asked to provide the correct answer to an unambiguous question, which they did with high accuracy. This feature of the design addressed the possibility that subjects rely only on linguistic representations when faced with an ambiguous task that requires a subjective judgment. If linguistic representations are only used to make subjective judgments in ambiguous tasks, then effects of language should not show up in an objective unambiguous task with a clear correct answer.

Second, all stimuli involved in a perceptual decision (in this case, the three color squares) were present on the screen simultaneously and remained in full view until the subjects responded. This allowed subjects to make their decisions in the presence of the perceptual stimulus and with minimal memory demands.

Finally, we used the implicit measure of reaction time, a subtle aspect of behavior that subjects do not generally modulate explicitly. Although subjects may decide to bias their decisions in choosing between two options in an ambiguous task, it is unlikely that they explicitly decide to take a little longer in responding in some trials than in others.

In summary, this design allowed us to test subjects’ discrimination performance of a simple, objective perceptual task. Further, by asking subjects to perform these perceptual discriminations with and without verbal interference, we are able to ask whether any cross-linguistic differences in color discrimination depend on the online involvement of language in the course of the task.

The questions asked here are as follows. Are there crosslinguistic differences in color discrimination even for simple, objective, perceptual discrimination tasks? If so, do these differences depend on the online involvement of language? Previous studies with English speakers have demonstrated that verbal interference changes English speakers’ performance in speeded color discrimination (21) and in visual searching (22, 23) across the English blue/green boundary. If a color boundary is present in one language but not another, will the two language groups differ in their perceptual discrimination performance across that boundary? Further, will verbal interference affect only the performance of the language group that makes this linguistic distinction?

They then go on to discuss their experimental setup (which I recommend you go and read). Finally they present their findings:

We found that Russian speakers were faster to discriminate two colors if they fell into different linguistic categories in Russian (one siniy and the other goluboy) than if the two colors were from the same category (both siniy or both goluboy). This category advantage was eliminated by a verbal, but not a spatial, dual task. Further, effects of language were most pronounced on more difficult, finer discriminations. English speakers tested on the identical stimuli did not show a category advantage under any condition. These results demonstrate that categories in language can affect performance of basic perceptual color discrimination tasks. Further, they show that the effect of language is online, because it is disrupted by verbal interference. Finally, they show that color discrimination performance differs across language groups as a function of what perceptual distinctions are habitually made in a particular language.

They end on a philosophical note:

The Whorfian question is often interpreted as a question of whether language affects nonlinguistic processes. Putting the question in this way presupposes that linguistic and nonlinguistic processes are highly dissociated in normal human cognition, such that many tasks are accomplished without the involvement of language. A different approach to the Whorfian question would be to ask the extent to which linguistic processes are normally involved when people engage in all kinds of seemingly nonlinguistic tasks (e.g., simple perceptual discriminations that can be accomplished in the absence of language). Our results suggest that linguistic representations normally meddle in even surprisingly simple objective perceptual decisions.

To me this is another important paper that puts sapir-whorf hypothesis on the forefront. I would love to hear from those who do not endorse the spair-whorf hypothesis as to what they make of these results?

hat tip: Neuroanthropology blog.

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