Single‐value scores of memory‐related brain activity reflect dissociable neuropsychological and anatomical signatures of neurocognitive aging

Abstract

Memory‐related functional magnetic resonance imaging (fMRI) activations show age‐related differences across multiple brain regions that can be captured in summary statistics like single‐value scores. Recently, we described two single‐value scores reflecting deviations from prototypical whole‐brain fMRI activity of young adults during novelty processing and successful encoding. Here, we investigate the brain‐behavior associations of these scores with age‐related neurocognitive changes in 153 healthy middle‐aged and older adults. All scores were associated with episodic recall performance. The memory network scores, but not the novelty network scores, additionally correlated with medial temporal gray matter and other neuropsychological measures including flexibility. Our results thus suggest that novelty‐network‐based fMRI scores show high brain‐behavior associations with episodic memory and that encoding‐network‐based fMRI scores additionally capture individual differences in other aging‐related functions. More generally, our results suggest that single‐value scores of memory‐related fMRI provide a comprehensive measure of individual differences in network dysfunction that may contribute to age‐related cognitive decline.

Openness to experience is associated with neural and performance measures of memory in older adults

“…While the SAME novelty score was significantly different between the age groups (young: -0.08, SD = 0.71; older: M = -0.39, SD = 0.54; t (350) = -4.43, p < 0.001, d = -0.48), there was no significant group difference in the FADE novelty score (young: M = -1.77, SD = 0.66; older: M = -1.89, SD = 0.62; t (350) = -1.73, p = 0.084, d = -0.19). This might be due to differences in the underlying brain networks and their association with aging (e.g., a rather specific association of the FADE novelty score with MTL regions, vs. more widespread associations for all other scores, for illustration see Richter et al, 2023, Figure S2, and for a detailed discussion, see Soch, Richter, Schütze, Kizilirmak, Assmann, Behnisch, et al, 2021).…”

“…FADE and SAME scores were calculated following the protocol of previous studies (Soch, Richter, Schütze, Kizilirmak, Assmann, Behnisch, et al ., 2021; Richter et al ., 2023). First, we generated single-subject contrast images representing effects of novelty processing (contrasting novel with master images) and subsequent memory effects (parametrically modulating the BOLD response to novel images as a function of arcsine-transformed subject’s responses ranging from 1 to 5 in the subsequent recognition memory test).…”

“…FADE and SAME scores were calculated following the protocol of previous studies (Soch, Richter, Schütze, Kizilirmak, Assmann, Behnisch, et al, 2021;Richter et al, 2023). More precisely, let 𝐽 + be the set of voxels showing a positive effect in young subjects at an a priori defined significance level (here: p < 0.05, FWE-corrected, extent threshold k = 10 voxels), and let 𝑡 𝑖𝑗 be the t-value of the 𝑖-th older subject in the 𝑗-th voxel on the same contrast.…”

“…In a recent study, we showed that chronological age is generally better predicted by structural MRI, whereas functional MRI data, and particularly single-value scores, are superior in predicting individual memory performance in older adults (Soch et al ., 2022), possibly due to individual differences in compensatory mechanisms to maintain cognitive abilities (Raz and Lindenberger, 2011; Cabeza, Albert, Belleville, et al ., 2018; Tang et al ., 2018; Bråthen et al ., 2021). As such functional age-related differences are often but not always accompanied by cognitive decline (Cansino, 2009; Wong et al ., 2012; Richter et al ., 2023), they may also reflect adaptive strategies that are employed as a compensatory mechanism (Grady and Craik, 2000; Cabeza et al ., 2002; Stern, 2009; Maillet and Rajah, 2014; Cabeza, Albert, Craik, et al ., 2018). It was proposed that the time point from which on behavioral performance declines during aging strongly relates to an individual’s ability to compensate age-related physiological alterations (e.g., Stern, 2009).…”

“…This holds for dependent measures (i.e. obtained from the same fMRI task; Soch, Richter, Schütze, Kizilirmak, Assmann, Behnisch, et al ., 2021) as well as for independent measures (Richter et al ., 2023) of memory performance. As a reductionist measure, this single-value scores are suitable for investigating correlations with other variables offering a unique possibility to investigate the complex interplay of age-related functional differences, memory decline and personality traits (Allen and DeYoung, 2015; DeYoung and Allen, 2019).…”