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. 2026 Feb 2;17:1644741. doi: 10.3389/fnagi.2025.1644741

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Copyright © 2026 Hwang, Liu, Winesett, Fettow, Shah, Chatterjee, Manini, Hass, Seidler, Ferris, Roy, Reuter-Lorenz and Clark.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

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Graphs A and B display changes in prefrontal ΔO2Hb levels across different cognitive tasks. Graph A with a long interstimulus interval (ISI) of 1500 milliseconds shows distinct patterns for younger, older high functioning (HF), and older low functioning (LF) groups across 0-back to 3-back tasks. Graph B with a short ISI of 500 milliseconds presents similar comparisons. Error bars indicate variability, and different symbols represent each group. — Task-related prefrontal cortical activity in long ISI 1,500-ms (A) and short ISI 500-ms (B) n-back tasks. Data represents the mean ± Standard error. ISI denotes inter-stimulus interval. ① Indicates significance compared to 1-back, and ② indicates significance compared to 2-back across all pooled groups. HF refers to high physical function, and LF refers to low physical function.