ARVO 2014 Poster

For the past few days, I’ve been at the annual meeting of the Association for Research in Vision and Ophthalmology. Tomorrow is the final day, and I’m presenting my poster in the session just before the closing keynote. It’s titled Cortical patterning genes are associated with individual differences in visual orientation perceptionPDF of session abstracts ]I’ll be in Exhibit Hall SA from 10:45–11:45 am for the all posters session, then again from 12:00–1:45 pm.


Talk at UC Riverside

Next week, I’m leaving to spend a few weeks in the U.S. My first stop is the Department of Psychology at the University of California, Riverside—we collaborate with Sara Mednick‘s team of sleep researchers there. I’m going to give a brown bag lunch talk on Wednesday, April 30th at 12:10pm in the Goldman Library.

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Australasian Cognitive Neuroscience Conference 2013

I’m at the annual meeting of the Australasian Cognitive Neuroscience Society at Monash University in Melbourne. Tomorrow, I’m presenting a poster based on our work investigating the genetic basis of a visual phenotype related to autism and schizophrenia.

You can download the poster here.

Poster Session 1: Friday 29th November 2013 at 15:00–16:30
Location: Building K, Monash University, Caulfield Campus
Poster 015: Genetic associates of a visual endophenotype of autism and schizophrenia

Variants in the 1q21 risk region are associated with a visual endophenotype of autism and schizophrenia

I’ve recently published a paper with my Cambridge collaborators in the journal Genes, Brain and Behavior. There is a lot of research currently looking into the genetics of psychological disorders. But we now know that most result from a very complex interplay of multiple genetic and environmental factors, which makes traditional genetic approaches less useful than we might hope. One promising approach is to investigate the genetics of psychological endophenotypes—these are traits linked to a disorder, but which are likely to have a relatively simple relationship with genetic mechanisms. Basic visual functions seem to be ideal candidates for this sort of study, because in many cases we know a lot about the underlying physiology.

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Correlating angles (circular variables)

I’ve been trying to find a sensible correlation coefficient to assess the reliability of the cylindrical axis on an optometric prescription. Glasses can have spherical correction, which has equal refractive power in all axes; but they can also have cylindrical correction, which has power in a specific axis to correct for astigmatism. So a prescription might include one or more cylindrical lenses, which need to be set at a specific angle. In our PERGENIC work, we corrected participants’ vision when necessary, but we wanted to be sure that we were doing it reliably. We asked 10% of participants to return for a second session, and when they came back we performed a second refraction without referring to the results of the first one—that way, we could compare the two sets of data to make sure they were consistent.

So far, so good. But you run in to a problem if you try to calculate, say, a Pearson product-moment coefficient.1 Here’s the problem: an angle is modular. For a cylinder angle, 0° is exactly the same as 180°. So if the first time I prescribe correction at 179°, and the second time I prescribe correction at 1°, there’s only a 2° difference. But it looks like a 178° difference. Which is not very good.

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