Age-related decline in differentiated neural responses to rare target versus frequent standard stimuli

Abstract

One mechanism hypothesized to contribute to cognitive aging is the failure to recruit specialized neural modules and generate differentiated neural responses to various classes of stimuli. Here, ERPs were used to examine the extent to which target and standard stimulus types were processed differently by well-matched adults ages 19–99. Subjects responded to designated visual target letters under low and high load conditions. Temporospatial PCA was used to parse the P3b component, an index of categorization/memory updating. The P3b amplitude difference between targets and standards decreased substantially as a function of age. Dedifferentiation began in middle age, and continued into old-old age. The reduced differentiation of neural responses was driven by an age-related decline in the size of the P3b to targets and an age-related increase in the P3b to standards. Larger P3b amplitude to standards among older subjects was associated with higher executive capacity and better task performance. In summary, dedifferentiation begins relatively early in adulthood and progresses in a linear fashion throughout the lifespan. The age-related augmentation of the P3b to standards appears to reflect a compensatory mechanism that helps maintain task performance.

Testing a novel method for improving wayfinding by means of a P3b Virtual Reality Visual Paradigm in normal aging

“…An age-related decline in the ability to differentiate targeted from standard stimuli was previously observed, and even normal aging may be characterized by a failure to recruit specialized neural modules and generate differentiated neural responses to various classes of stimuli responses (Mott et al 2014 ). So far, old people may have the need to be facilitated in the wayfinding of a very simple target place to produce a P3b response comparable to young subjects.…”

“…In normal aging, visual recognition of daily life stimuli is impaired with respect to young people, depending upon the intrinsic characteristics of the object and the context in which this is embedded (Mateus et al 2013 ; Rémy et al 2013 ; Mott et al 2014 ). Special recognition is a fundamental element to achieve a good orientation in different environments, like a house, hospitals, and health facilities, in order to facilitate activities in daily living.…”

Investigating age-related changes in anterior and posterior neural activity throughout the information processing stream

“…Additionally, we found positive correlations between the amplitude of several anterior and posterior factors, such that the larger the components anteriorly, the larger the components posteriorly (Supplemental Tables 1 and 2). This finding may reflect an internal consistency in the amount of resources an individual appropriates to carry out a task (Mott, Alperin, Holcomb, & Daffner, 2014). Of note, our results did not include an analysis of early sensory processing in posterior visual regions because this ERP activity explained very little of the overall variance in the principal component analysis.…”

Are Older Adults Less Embodied? A Review of Age Effects through the Lens of Embodied Cognition

“…Degradation in the internal action model may also explain the characteristic dedifferentiated brain response in older adults. If embodied cognitive effects in young adults reflect the efficient integration of sensory, cognitive, and motor systems, the older adult brain is characterized by the failure to recruit specialized neuronal modules and the adoption of a more diffuse cortical response ( Mott et al, 2014 ; Roski et al, 2014 ). Research indicates that the older adult motor system is affected by dedifferentiation ( Bernard and Seidler, 2012 ; Koppelmans et al, 2015 ; Reuter et al, 2015 ).…”