Similar behaviour, different brain patterns: Age-related changes in neural signatures of ignoring

Abstract

We measured behavioural performance and fMRI activity whilst old and young adults performed a temporal segmentation task ('preview search'). Being able to select parts of the visual world to be attended or ignored is a critical visual skill. Both old and young adults were able to improve their performance on a difficult search task when some of the distracter items were presented earlier than the remainder. Comparisons of brain activity and functional connectivity, however, suggested that the underlying mechanisms are quite different for the two age groups. Older adults' activation patterns do not correspond to those predicted by simple increased involvement of frontal regions reflecting higher demand with age but seem to suggest that changes in brain activation patterns propagate throughout the cortex.

Functional modular architecture underlying attentional control in aging

“…Furthermore, these findings extend previous univariate activation studies showing that older (vs. younger) adults exhibit greater frontoparietal activity in service of visual search target detection (e.g., Allen and Payne, 2012; Madden et al, 2005a), by demonstrating that in middle-aged and older adults, frontoparietal regions become central to the network by exhibiting more between-module connections. We also improve upon limitations of past studies examining the functional modular topology of the aging brain (e.g., Chan et al, 2014; Gallen et al, 2016; Grady et al, 2016; Schlesinger et al, 2017) by demonstrating that (a) functional modular properties during task undergo changes at approximately 42 years of age, (b) these changes are reflected in middle aged and older adults becoming more reliant on between-module connections in service of cognition, and (c) functional modular properties are associated with visual attention in aging.…”

“…Regarding aging, it appears that the previously described preservation of top-down attentional processes in older adults is often associated with increased activation in dorsal frontoparietal regions (Allen and Payne, 2012; Eyler et al, 2011; Madden et al, 2005a; Spreng et al, 2010), but how bottom-up attentional processes may influence dorsal frontoparietal functional properties in aging is largely unknown. Madden et al (2017) recently explored this issue using the conjunction visual search task adapted from Proulx (2007), and found, in the examination of brain-behavior relations, that individuals 35 years of age and older (vs. relatively younger adults) exhibited greater engagement of the left frontal eye field (FEF) in service of the size singleton effect (i.e., increased bottom-up guidance).…”

“…To investigate this question, for each of the modules that significantly predicted either the drift rate/nondecision time (size singleton or target detection effects), we conducted linear regressions to examine if Age × Module Centrality interactions could predict the drift rate/nondecision time size singleton or target detection effects. Based on evidence demonstrating increased frontoparietal activation in older adults in service of visual attention (e.g., Allen and Payne, 2012; Madden et al, 2005a), particularly during bottom-up processing (Madden et al, 2017), we predicted that increased frontoparietal centrality may become more prominent with increasing age, particularly with regard to bottom-up attentional guidance and associated effects in the RT component measures.…”

The ups and downs of global motion perception: a paradoxical advantage for smaller stimuli in the aging visual system

“…Location-selective selective attention mechanisms operate early in visual processing (Cave and Bichot, 1999) and differences in attentional strategy and ability between older and younger adults are commonly found (e.g., Allen and Payne, 2012). Older adults are less able than their younger counterparts to extract information from a cluttered visual scene (Sekuler et al, 2000), show longer search times and larger set size effects than younger adults on visual search tasks (e.g., Madden, 2007).…”

Age-related differences in selection by visual saliency

“…There is substantial evidence that the lack of impact of the initial distractors is dependent, at least in part, on a process of active distractor suppression of its location (Allen, Humphreys, & Matthews, 2008;Humphreys et al, 2004;Watson & Humphreys, 2000) and features (Olivers & Humphreys, 2003). As in studies of negative priming, it has been shown that older participants recruit distinctly different functional mechanisms (Allen & Payne, 2011) and can show a selective reduction in the efficiency of preview search, particularly under conditions where distractor inhibition is challenged (e.g., with moving distractors; Watson & Maylor, 2002). This is consistent with reduced inhibition of distractor locations and/or features in older adults, relative to young adults.…”