Not connecting with faces in the street and in the brain

Not Exactly Rocket Science has a great write-up of a recent study that may explain why some people are born without the ability to recognise faces – a condition known as congenital prosopagnosia.

Face recognition is particularly associated with a part of the temporal lobe called the fusiform gyrus. Although it’s controversial whether this area is specifically for faces, or is more generally specialised for perceptual expertise of which faces are just the most important example, it’s clear that it is key for understanding faces.

Cibu Thomas from Carnegie Mellon University discovered the problem by focusing on two major white matter tracts that link the fusiform area to other parts of the brain. Both have names that positively trip off the tongue – the inferior longitudinal fasciculus (ILF) and the inferior fronto-occipito fasciculus (IFOF). Thomas studied the tracts using a technique called diffusion tensor imaging (DTI), which measures the flow of water along their length.

The flowing water revealed severe problems with the structural integrity of both white matter tracts in the brains of prosopagnosics. Normal individuals didn’t show any problems, nor did areas of white matter in the prosopagnosics that connected areas completely unrelated to face processing.

In other words, the fibres that connect important perceptual areas in the brain may be much thinner in people who have problems recognising faces.

The image on the left shows the connections between the temporal and the occipital lobes in the participants with the condition and the controls.

As usual, the Not Exactly Rocket Science write-up is clear, concise and engaging, and if you’d like to know a bit more what it’s like to live without recognising faces The Guardian recently published a personal account of day-to-day life from someone with prosopagnosia who can’t even recognise himself in the mirror.

Link to ‘Faulty connections responsible for inherited face-blindness’.
Link to Guardian article ‘I don’t recognise my own face’.

One Comment

  1. Mexican Pharmacy
    Posted November 30, 2008 at 1:39 am | Permalink

    Hi Vaughan,
    Been a fan of Mind Hacks since 2005. Absolutely loved that case study from awhile back about the woman who believed she was being sent emails directly to her mind.
    I started having problems with facial recognition a few years ago. Nothing major. But it’s still a strange experience, made me worry about what was going on in my brain…
    At any rate, I have bipolar disorder but have been stable and on meds for several years (though I had several manic and depressive episodes on and off for about 10 years before achieving stability).
    Just googled “bipolar disorder fusiform” –

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T4S-4P53RR2-2&_user=10&_origUdi=B6VM1-4N2DRH6-49&_fmt=high&_coverDate=10%2F15%2F2007&_rdoc=1&_orig=article&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=85f7b1c6cafa85c92396313f9639d6f4

    Here are the conclusions to this study:
    Conclusions
    Patients with BPD lose hippocampal, fusiform and cerebellar gray matter at an accelerated rate compared with healthy control subjects. This tissue loss is associated with deterioration in cognitive function and illness course.
    (excerpt from the link above)
    That may explain my mild facial recognition difficulties. But as we know mood stabilizers are neuroprotectants… I’m lucky to have found a good doctor and be able to take the right medications.
    Awesome website, love the book.


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