May 212014

Harel, Kravitz and Baker recently published an article in Frontiers in Human Neuroscience (2013), Beyond perceptual expertise: revisiting the neural substrates of expert object recognition, which was also a poster at VSS (May19th, 2014).

This is an opinion piece, and I believe that authors are entitled to their opinions, and that debate is generally good for progress in a field. However, under the pretense of proposing a novel framework (see Wong & Wong’s commentary on the article for an explanation that this is not in fact a novel framework), the authors have severely mis-represented the literature on expertise. Next year, at VSS, we will be celebrating the 30th meeting of the Perceptual Expertise Network: so I know this field, and I do not recognize it in the picture painted by Harel et al.

My point here is not to dispute the claims made in the paper. I find it more appropriate to do in empirical demonstrations, such as in this recent paper. Rather, I want to state that my views (and of course those of my co-authors) are misrepresented in this article. I could say ”misunderstood”, but after having discussed this with the first author, and going back to the literature record to make sure that I am not completely wrong about my own work, I think misrepresentation is a fair term.(this is probably too strong, Harel et al. swear they really thought these were appropriate representations of my/our ideas). And I do not believe that such distortion leads to clear debate that is generally good for a field. It is in nobody’s interest that people becoming interested in the study of expertise would be provided with such a distorted picture of the field. I embrace people disagreeing with my views, but only when they are really my views.

Let me focus on two main points:

1. “…attaining any form of visual expertise should be supported primarily by qualitative changes in processing within specific regions of visual cortex (Palmeri and Gauthier, 2004).”

Overall, in this paper (and others by the same authors) as well as in the poster, what we are being associated with is a simplistic theory, something like the main effect of “expertise” (any kind) is changes in one area (the FFA).

This is a strawman we would not want to be associated with. Let me emphasize this:

I would not argue that expertise with all categories are the same behaviorally, nor in the brain.

You will find evidence of this across all these articles:

• James, K. H., James, T. W., Jobard, G., Wong, C.-N., Gauthier, I. (2005). Letter processing in the visual system: different patterns for single letters and strings, Cognitive and Affective Behavioral Neuroscience, 5(4): 452-66. PDF
• James, K.H., Gauthier, I. (2006). Letter Processing automatically recruits a multimodal brain network, Neuropsychologia, 44(14):2937-49. PDF
• Wong, C.-N, Gauthier, I. (2007). An analysis of letter expertise in a levels-of-categorization framework, Visual Cognition, 15(7): 854-879. PDF
• Wong, A.C.-N., Jobard, G., James, K.H., James, T.W., Gauthier,I. (2009). Expertise with characters in alphabetic and non-alphabetic writing systems engage overlapping occipito-temporal areas, Cognitive Neuropsychology, 26(1), 111-127.PDF
• Wong, Y.K., Gauthier, I. (2010). A multimodal neural network recruited by expertise with musical notation. Journal of Cognitive Neuroscience, 22(4), 695-713.PDF
• Wong, A. C.-N., Palmeri, T. J., Gauthier, I. (2009). Conditions for face-like expertise with objects: Becoming a Ziggerin expert – but which type? Psychological Science, 20(9): 1108-1117. PDF
• Wong, A.C.-N., Palmeri, T.J., Rogers, B.P., Gore, J.C., Gauthier, I. (2009). Beyond shape: How you learn about objects affects how they are represented in visual cortex, PLoS One, 2(12), e8405.PDF
• Wong, Y. K., Folstein, J. R., & Gauthier, I. (2012). The nature of experience determines object representations in the visual system. Journal of Experimental Psychology: General. 141(4):682-698. PDF

Second, I do not believe that the primary result of expertise is necessarily selectivity in the FFA.

 I started my career asking why faces appeared to be special in specific ways. Why do they show holistic processing? Why do they engage the FFA? These are questions that some of our research specifically addresses. When trying to test the claim that faces are special because of a specific effect, it is more than appropriate to look at that effect/area. By showing that there is no clear dissociation (between faces and objects of expertise) in that effect/area, you address that specific claim. That’s it. It doesn’t make any prediction about expertise not having other behavioral or neural effects.

 Have we published studies focusing on the FFA’s role in expertise? For sure! But these particular papers address a very strong claim that is not ours: One that suggests face perception is “a cognitive function with its own private piece of real estate in the brain” (Kanwisher, 2000; 2010).  If there is a claim here that is “face-centric”, or “FFA-centric”, it is that original claim, which we are challenging.

Importantly, we have not only addressed this question. We have reported, starting in 1999 in our work on Greeble expertise, and in 2000 in our work on car and bird experts, other areas than the FFA that show expertise effects. We have continued to do so for different kinds of expertise since then (see papers cited above).

2.” …expert processing under this perceptual view is automatic and stimulus- driven, with little impact of attentional, task demands or other higher-level cognitive factors (Tarr and Gauthier, 2000; Palmeri et al., 2004).

The Wong & Wong commentary on the Harel et al. paper does a good job of outlining how those of us who have been studying perceptual expertise for years have been looking both at the automatization of processing with expertise, and have studied the interaction of perception with high-level factors.

For recent examples: our work on selectivity for musical note expertise (Wong et al., in press) specifically focuses on the influence of top-down influences; In Wong, Folstein & Gauthier (2012), where we compare perceptual expertise and perceptual learning, we discuss how experience interacts with attentional set to determine the pattern of training effects in the brain; and in McGugin et al., (2012), we discuss the possibility that semantic knowledge interacts with perceptual expertise to lead to a more bilateral representation.

Instead of calling those of us who have been studying expertise for more than 15 years “face-centric”, Harel et al. could have actually covered some of the work we (and others) have done that already goes well beyond faces and FFA. Instead they focused only on those papers that specifically address the theory that “FFA is a unique face module”, and ended up presenting a very skewed view of what this field has been all about.

I waited a while before “greebling” about this one – but Harel and colleagues seem intent on framing their own contributions against this face-centric view of the perceptual expertise literature. I am sending them the link to this clarification, and I hope that they stop misrepresenting my contributions as face-centric. If you have opinions about this, one way or another, I have posted a comment on the Wong & Wong opinion on the Frontiers web site, you can add yours.

References without links:

Kanwisher N (2000) Domain specificity in face perception. Nat Neurosci 3:759763

Kanwisher, N. (2010). Functional specificity in the human brain: a window into the functional architecture of the mind. PNAS107(25), 11163-11170.