Age-related differences in enhancement and suppression of neural activity underlying selective attention in matched young and old adults

A.E Haring,T.Y Zhuravleva,B.R Alperin,D.M Rentz,P.J Holcomb,K.R Daffner

doi:10.1016/j.brainres.2013.01.003

A.E Haring, T.Y Zhuravleva + Show 4 more

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https://doi.org/10.1016/j.brainres.2013.01.003

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Abstract

Selective attention reflects the top-down control of sensory processing that is mediated by enhancement or inhibition of neural activity. ERPs were used to investigate age-related differences in neural activity in an experiment examining selective attention to color under Attend and Ignore conditions, as well as under a Neutral condition in which color was task-irrelevant. We sought to determine whether differences in neural activity between old and young adult subjects were due to differences in age rather than executive capacity. Old subjects were matched to two groups of young subjects on the basis of neuropsychological test performance: one using age-appropriate norms and the other using test scores not adjusted for age. We found that old and young subject groups did not differ in the overall modulation of selective attention between Attend and Ignore conditions, as indexed by the size of the anterior Selection Positivity. However, in contrast to either young adult group, old subjects did not exhibit reduced neural activity under the Ignore relative to Neutral condition, but showed enhanced activity under the Attend condition. The onset and peak of the Selection Positivity occurred later for old than young subjects. In summary, older adults execute selective attention less efficiently than matched younger subjects, with slowed processing and failed suppression under Ignore. Increased enhancement under Attend may serve as a compensatory mechanism.

Highlights

Visual selective attention reflects top-down control of information processing based on task demands and is hypothesized to be primarily mediated by the executive control component of working memory (Desimone and Duncan, 1995; Lavie et al, 2004; Rutman et al, 2010)
Do the age groups differ in the degree to which they rely on enhancement of neural activity when attending to stimuli, or suppression of neural activity when ignoring stimuli, or both? it is unclear whether differences in neural activity that have been found between old and young subject groups are due to the aging process itself, or differences in executive capacity or task performance in the particular groups investigated
The three groups did not differ in number of years of education or estimated intelligence quotient (IQ) according to the American National Adult Reading Test (AMNART) (Ryan and Paolo, 1992)

Summary

Introduction

Visual selective attention reflects top-down control of information processing based on task demands and is hypothesized to be primarily mediated by the executive control component of working memory (Desimone and Duncan, 1995; Lavie et al, 2004; Rutman et al, 2010). Most studies in the literature have not explicitly addressed the challenge of minimizing group differences in cognitive abilities and task performance in order to interpret changes in neural activity that are due to age. Without accounting for these issues, observed differences between groups in neural activity may not be the result of age, but other factors (Daffner et al, 2011; Daselaar and Cabeza, 2005; Riis et al, 2008).

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