I’ve been away from Neuroanthropology for a few days, typing my fingers numb working on a grant application for the Australian Research Council. I won’t go into it too much here (maybe later), but I will say that I have NEVER seen a more complicated, bureacratized, byzantine system than the ARC grant competition. I felt semi-conscious when I finished the ‘interactive’ budgeting section alone (I put ‘interactive’ in quotes only because the system would have to give the applicant something back to call it ‘interaction’). Many thanks, especially to Daniel, for covering my absence while I was ‘away,’ or at least pulling out clumps of hair trying to figure out what the instructions on the application were asking me to do.

But I’ve been wanting to post a number of things, including a recent article by Ashley Newton and Jill de Villiers that appeared in Psychological Science. Special thanks to Dave Munger at Cognitive Daily whose posting about this article drew it to my attention. (And Prof. Munger is also responsible for creating the ‘Blogging about refereed research’ system that we’re trying to work with on Neuroanthropology.)

Newton and de Villiers ran experiments in which subjects were asked to solve ‘false-belief’ problems, questions about how individuals would act when it was likely that they had developed false beliefs; for example, if the subject see Max watch Sam put food in one place, then Max leaves the room, only to have Same move the food to a new location. Will Max believe the food is in the first place, or in its actual location, when he returns to the room? These problems test the subject’s ability to reason about another person’s beliefs, even when they are false. Young children tend to get these problems wrong, saying that Max will look for the food in the new location because the child knows the food is there. Very young children do not recognize that Max will have a ‘false belief.’ (Alright, so ‘false belief’ problems aren’t that hard, but the researchers made the tasks a bit more difficult…)

In the experiment, subjects were asked ‘false belief’ questions when asked to do a complicating task, either repeating along after a tape of someone speaking or when tapping along to a rhythm. The verbal shadowing task significantly disrupted the ability of subjects to do ‘false belief’ questions, whereas the rhythmic tapping task did not; neither simultaneous task complicated a complex spatial tracking problem that did not involve false beliefs. Verbal shadowing disrupted a subject’s ability to monitor the beliefs of another person, even if the ‘false belief’ problem was itself non-verbal.

The researchers explicitly linked their project to the question of whether or not language was necessary for thought, the ‘Sapir-Whorf hypothesis’ as it is popularly known (although, as has been pointed out, both Sapir’s and Whorf’s were not advocates of a strong version of the hypothesis now named for them). Newton and de Villiers lay out four contemporary versions of the hypothesis: 1) language is involved in all conceptual thought (but nonverbal infants and primates demonstrate signs of conceptual thought); 2) language may be used for conceptual thought when long inferential chains are involved (Andy Clark supports this option); 3) language could be a ‘cross-modular’ bridge between different cognitive modules (sort of like a ‘meta-modular’ coordinator); and 4) language might be uniquely able to express truth and falsity. In particular, though, theorists have argued that language is especially important representing others beliefs, such as in the ‘false belief’ problem (all this is paraphrased from Newton and de Villiers).

A strong version of linguistic determinism contends that certain critical forms in language provide the representational tools for later theory of mind, especially the understanding of other individuals’ false beliefs… In this view, a child without language is not just deprived of access to the contents of the theory, but lacks the means to hold in mind for further processing the content of other individuals’ beliefs when that content differs from reality…. If language is needed just for acculturation, then it is quite possible that adult reasoning is independent of language….

The experiment is well designed, and really clever, but I’m not sure it proves what it sets out to prove. The researchers suggest that if ‘language resources are tied up,’ then language-dependent functions would be disruptive. The problem, for me, is that the authors seem to assume that there is a ‘language module’ or isolated part of the brain. What if language, instead of being a single module or capacity, is a network that people put together (perhaps in different ways), and it uses up a number of different parts of the brain, some of which might interfere with different tasks? The neural imaging evidence that I’ve seen suggests that language isn’t so much a ‘module’ as a network that makes quite a bit of use of different parts of the brain. Moreover, a lot of these areas do multiple functions, sometimes doing double duty with functions that don’t seem all that closely connected logically.

This is why, even though I told Paul Mason about a year-and-a-half ago that I did support ‘modularity’ theory, that I’ve changed my mind. It seems to me that Fodor uses the term ‘module’ to describe a number of traits of thought that are supported by evidence, but that the term ‘module’ leads some people to think of a little place in the brain, a kind of capsule or neural neighborhood. There are theorists who engage in this kind of ‘nouvelle phrenology,’ seeming to believe that each brain function has its own, exclusive little neural address. In this sense, I don’t think that there is a ‘language module,’ and I’ve become convinced (as Paul gently suggested to me) that the language of ‘modularity’ is itself a bit too slippery a slope to bring the toboggan anywhere close.

For example, one possibility is that one part of the brain that helps to ‘do’ language, especially speech and listening, is a kind of fast sequencer that might have arisen evolutionarily prior to language, perhaps facilitating complex motor tasks. This might explain why I can’t do complicated repairs to the farm equipment when my wife is talking to me, for example (this is all hypothetical). The rhythm task might not need to orchestrate a finely-tuned sequence of diverse tasks (like producing different phonemes, or logical inferences in sequence, or movements of a repair).

In addition, even if the subjects did use language abilities to reason about false beliefs, that does not mean that language is absolutely necessary to accomplish this task; perhaps only people who don’t often have to do this sort of task have this problem. As the researchers point out, aphasics who have lost language ability still seem to be able to perform some false belief tasks, perhaps because they’ve found another way — another network — that they can employ to solve these problems. Subjects in the research couldn’t do it because they had never tried to do these tasks in this way (of course, 15 subjects couldn’t do any of the shadowing tasks and had to be excluded from the pool).

I guess what I’m suggesting is that Newton and de Villiers interpret their data — simultaneous language tasks interfering badly with the ability to deduce false beliefs — through a very specific set of assumptions: uniform human capacities, modules, language as a function rather than itself an outcome of collaboration among many different functional systems. Their experiment seems well designed to me, and the results are fascinating, but have they discerned the way that humans must necessarily perceive the beliefs of others, or have they discovered how subjects do when they are accustomed to depending upon language? The fact that aphasics still have some ability to solve false belief problems need not be disregarded if we recognize that there’s more than one way for the brain to perceive the beliefs of other people, we just don’t usually have to do it any other way.

The implications for anthropology? Well, we can’t necessarily use the experiment to support a strong version of the ‘Sapir-Whorf Hypothesis,’ but we can use the data to show that, acculturated in a language environment, these subjects relied heavily upon this social product (language) to accomplish a very basic mental task (ascertaining someone else’s belief). In other words, in this case, language (and thus acculturation) was fundamental for a crucial social ability, but that might not be the only way that humans can accomplish this sort of feat.

References

Newton, Ashley M., and Jill G. de Villiers. 2007. Thinking While Talking: Adults Fail Nonverbal False-Belief Reasoning. Psychological Science 18(7): 574-579. DOI: 10.1111/j.1467-9280.2007.01942.x