Problems recognising faces, brought on by brain injury, could be more prevalent than previously thought. That’s according to Tim Valentine and colleagues who argue there’s been an over-reliance on ‘pure’ cases, and that “it is easy to dismiss a problem with face recognition as uninteresting if it is ‘just’ part of a generalised memory impairment, or ‘secondary’ to poor attention and concentration”.
Valentine’s team recruited 91 patients who had suffered brain injury either through an accident, a stroke or illness, and asked them to complete a raft of face recognition tests and general mental performance tests.
They found 50 per cent of the patients thought they would have trouble recognising people they had met only a few times. And 77 per cent scored significantly worse than the healthy population average when this ability was tested. This was done by presenting them with a large number of unfamiliar faces from which they had to distinguish those that had been shown to them once already from those that were entirely new.
On an easier version of the test that involved fewer faces, or more chances to view some faces, 20 per cent of the patients performed particularly poorly. Those patients who had difficulty learning to recognise new faces also often had general visual processing deficits, and general problems with recognition memory.
The researchers also noted how much variation there was in the sensitivity of the different face-recognition tests they used. “The likelihood of detecting a face recognition impairment in someone with brain injury therefore clearly depends on the particular test which is used” they said, before suggesting possible interventions for affected patients such as “verbally encoding particular facial features” and “using caricatures to accentuate structural properties of to-be-learned faces”.
Valentine, T., Powell, J., Davidoff, J., Letson, S. & Greenwood, R. (2006). Prevalence and correlates of face recognition impairments after acquired brain injury. Neuropsychological Rehabilitation, 16, 272-297.