Monday, December 17, 2012

Gender equality in science

An interesting post over at BishopBlog takes on the lack of men in Psychology. One of the reasons BishopBlog is a favorite of mine is that you get real data along with interpretations and opinions. Two points in the post strongly resonated with my experience. 

One is the decline of women in science by career stage. A few years ago, the NSF did a major study of women and minorities in science and identified attrition as a key reason for the under-representation of women in science. Following Dr. Bishop's example, a little complementary data (from 2010; these and lots more data are available here): in Neuroscience, the graduate student population was slightly biased toward women (52.7% are female), but the postdoctoral fellow population was biased toward men (only 45.7% were female). Given the fairly large sample sizes (2798 graduate students and 818 postdocs), this difference was highly reliable (chi-square test of independence, p < 0.001). 

The second is the effect of sub-field. I am particularly sensitive to this because I seem to work in two of the most gender-biased sub-fields: computational modeling seems strongly male-dominated, but cognitive neuropsychology seems strongly female-dominated. I couldn't find data for those fields exactly, but the APA membership data that Dr. Bishop mentioned show a huge disparity: women make up only about 25% of the members in Experimental Psychology and Behavioral Neuroscience, close to half in Clinical Neuropsychology, and about 70% in Developmental Psychology.

This issue is certainly complex and there is no simple solution. That said, there are some strategies that we know would help and can be implemented relatively easily. For example, we know that there is bias in the review process (e.g., Peters & Ceci, 1982), so why not make it double-blind? This is already the standard in some fields, but remains generally optional or unavailable in cognitive science and cognitive neuroscience. It is true that reviewers may be able to guess the identity of the author(s) some of the time, but isn't guessing correctly some of the time better than knowing all of the time? This would (partially) level the playing field between genders as well as between junior and senior scientists and should lead to a more fair system.

Peters, D. P., & Ceci, S. J. (1982). Peer-review practices of psychological journals: The fate of published articles, submitted again. Behavioral and Brain Sciences, 5, 187-255.

Friday, December 14, 2012

Lateralization of word and face processing

A few weeks ago I was at the annual meeting of the Psychonomic Society where, among other interesting talks, I heard a great one by Marlene Behrmann about her recent work showing that lateralization of visual word recognition drives lateralization of face recognition. Lateralization of word and face processing are among the most classic findings in cognitive neuroscience: in adults, regions in the inferior temporal lobe in the left hemisphere appear to be specialized for recognizing visual (i.e., printed) words and the same regions in the right hemisphere appear to be specialized for recognizing faces. Marlene and her collaborators (David Plaut, Eva Dundas, Adrian Nestor, and others) have shown that these specializations are linked and that the left hemisphere specialization for words seems to drive the right hemisphere specialization for faces. It's a nice combination of: 
  1. Behavioral experiments showing that lateralization for words develops before lateralization for faces, and that reading ability predicts degree of lateralization for faces (Dundas, Plaut, & Behrmann, 2012).
  2. ERP evidence also showing earlier development of lateralization for words than for faces.
  3. Computational modeling showing how this specialization could emerge without pre-defined modules (Plaut & Behrmann, 2011).
  4. Functional imaging evidence that the lateralization is relative: the right fusiform gyrus is more involved in face processing, but the left is involved also (Nestor, Plaut, & Behrmann, 2011).
It's a beautiful example of how different methods can come together to provide a more complete picture of cognitive and neural function.

Less than one week after I posted this, there is a new paper by Behrmann and Plaut (in press, Cerebral Cortex, doi:10.1093/cercor/bhs390) reporting further evidence, this time from cognitive neuropsychology, that lateralization of face and word processing is relative. They tested a group of individuals with left hemisphere damage and deficits in word recognition ("pure alexia") and a group of individuals with right hemisphere damage and deficits in face recognition ("prosopagnosia"). The individuals with pure alexia exhibited mild but reliable face recognition deficits and the individuals with prosopagnosia exhibited mild but reliable word recognition deficits.

ResearchBlogging.orgDundas EM, Plaut DC, & Behrmann M (2012). The Joint Development of Hemispheric Lateralization for Words and Faces. Journal of Experimental Psychology: General. PMID: 22866684. DOI: 10.1037/a0029503.

Nestor A, Plaut DC, & Behrmann M (2011). Unraveling the distributed neural code of facial identity through spatiotemporal pattern analysis. Proceedings of the National Academy of Sciences, 108(24), 9998-10003 PMID: 21628569

Plaut DC, & Behrmann M (2011). Complementary neural representations for faces and words: a computational exploration. Cognitive Neuropsychology, 28(3-4), 251-275 PMID: 22185237