May 302014

So proud and delighted to report that Ana Beth Van Gulick successfully defended her PhD dissertation on May 21st, presenting on The Semantic Vanderbilt Expertise Test (there is a longer title, but this is what you really need to remember!).  Huge Congrats to AB!!

May 302014

At VSS2014, Isabel presented a short talk in the exciting and dynamic Individual differences brown bag organized by Jeremy Wilmer. In two minutes, she could do little more than advertise two recent studies from the lab which should be very useful to anyone interested in measuring the failures of selective attention that are a facet of holistic processing. Cognitive psychologists often do not pay as much attention to issues of measurements as their colleagues in other fields of Psychology. Papers that focus on reliability or the magnitude of effect sizes are rare in our field. But like others working on high-level vision who have become recently more interested in individual differences, we have decided to invest more efforts into understanding our measures and so far, it has paid off. We hope this work will be useful to others as well.

Holistic processing is a hallmark of face recognition, and we focused on the composite task, using what Gauthier and Bukach (2007) called the “complete design” version of this paradigm (because it has ALL the possible congruent and incongruent trials rather than half of them as in what we called the “partial design” version of this task). In a recent review and meta-analysis of holistic face processing published in Psychological Bulletin, we explain the difference between the two tasks and present empirical evidence from many studies that the two tasks do not measure the same construct, that the partial design is correlated with response bias across studies (in addition to across subjects as we have shown before). We report on the meta-analytical effect size for the composite task, demonstrating that it is very sensitive in group studies, and offer some advice for maximizing reliability in individual difference studies. Indeed, in another paper recently accepted by Behavioral Research Methods, we quantify the reliability of measurements in this task across several studies, using both the standard subtraction approach, as well as the regression method advocated by Joe DeGutis and colleagues. We show the task often has low reliability regardless of the method used, and we achieve more acceptable levels of reliability using two different manipulations. Together, the two papers should provide a good example for readers to appreciate how the same task can have a large effect size for group studies and low reliability for individual differences (a situation that cognitive psychologists are not accustomed to thinking about, but which we suspect is not rare).

As a preview of things to come, we (Richler & Gauthier) have recently submitted a paper on a new test designed especially for the purpose of quantifying holistic process across individuals, which we argue is preferable on several fronts including reliability. As soon as the paper is accepted, we will make this test available to other scientists. UPDATE: the paper on the Vanderbilt Holistic Face Processing Test is now in press at JOV. Please contact us if you would like to use the test – we expect to have a JAVA version of it very soon, but we can share another version of the test in the mean time.


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.



May 212014

Gender effects for toy faces: quantitative differences in face processing strategies
Katlin Ryan and Isabel Gauthier

Does acquisition of holistic processing for novel objects depend on experience with diagnostic parts?
Kao-Wei Chua, Jenn Richler and Isabel Gauthier

Measurement of semantic knowledge of object categories: creating the Semantic  Vanderbilt Expertise Test (SVET)
Ana E. Van Gulick and Isabel Gauthier

Holistic processing of faces in the composite task depends on size.
David A. Ross and Isabel Gauthier

Modeling the Moderation of Experience in Face and Object Recognition
Panqu Wang, Benjamin Cipollini, Akinyinka Omigbodun, Isabel Gauthier, Gary Cottrell

“Greebling” on Harel, Kravitz & Baker (VSS2014)