Age-related delay in information accrual for faces: Evidence from a parametric, single-trial EEG approach

Rousselet, G. , Husk, J., Pernet, C., Gaspar, C., Bennett, P. and Sekuler, A. (2009) Age-related delay in information accrual for faces: Evidence from a parametric, single-trial EEG approach. BMC Neuroscience, (doi: 10.1167/9.8.545)

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Abstract

Background: In this study, we quantified age-related changes in the time-course of face processing by means of an innovative single-trial ERP approach. Unlike analyses used in previous studies, our approach does not rely on peak measurements and can provide a more sensitive measure of processing delays. Young and old adults (mean ages 22 and 70 years) performed a non-speeded discrimination task between two faces. The phase spectrum of these faces was manipulated parametrically to create pictures that ranged between pure noise (0% phase information) and the undistorted signal (100% phase information), with five intermediate steps. Results: Behavioural 75% correct thresholds were on average lower, and maximum accuracy was higher, in younger than older observers. ERPs from each subject were entered into a single-trial general linear regression model to identify variations in neural activity statistically associated with changes in image structure. The earliest age-related ERP differences occurred in the time window of the N170. Older observers had a significantly stronger N170 in response to noise, but this age difference decreased with increasing phase information. Overall, manipulating image phase information had a greater effect on ERPs from younger observers, which was quantified using a hierarchical modelling approach. Importantly, visual activity was modulated by the same stimulus parameters in younger and older subjects. The fit of the model, indexed by R2, was computed at multiple post-stimulus time points. The time-course of the R2 function showed a significantly slower processing in older observers starting around 120 ms after stimulus onset. This age-related delay increased over time to reach a maximum around 190 ms, at which latency younger observers had around 50 ms time lead over older observers. Conclusion: Using a component-free ERP analysis that provides a precise timing of the visual system sensitivity to image structure, the current study demonstrates that older observers accumulate face information more slowly than younger subjects. Additionally, the N170 appears to be less face-sensitive in older observers.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Pernet, Dr Cyril and Rousselet, Dr Guillaume and Gaspar, Dr Carl
Authors: Rousselet, G., Husk, J., Pernet, C., Gaspar, C., Bennett, P., and Sekuler, A.
Subjects:B Philosophy. Psychology. Religion > BF Psychology
College/School:College of Science and Engineering > School of Psychology
College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
Journal Name:BMC Neuroscience
Publisher:Biomed Central
ISSN:1471-2202
First Published:First published in BMC Neuroscience
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
489271A new EEG technique to access object visual processing speed in younger and older adultsGuillaume RousseletEconomic & Social Research Council (ESRC)ES/G023093/1Cognitive Neuroimaging & Neuroengineering Technologies