Table 4.
Brain connectivity results reported in the studies included in the review, listed in chronological order.
| ROI/seed | Results in older adults relative to young adults | |
|---|---|---|
| Daselaar et al. (2006) | Hippocampus Rhinal cortex |
↓ Hippocampus—Retrosplenial cortex, left parietotemporal cortex ↑ Rhinal cortex—PFC |
| Dennis et al. (2008) | Left hippocampus |
↓Occipitotemporal cortex, parahippocampal gyrus, superior parietal, thalamus, hypothalamus, posterior cingulate ↑ Ventrolateral PFC, superior PFC, mid-dorsolateral PFC, orbitofrontal cortex, cingulate gyrus |
| St Jacques et al. (2009) | Amygdala |
↓ Ventrolateral PFC, left hippocampus ↑ Dorsolateral PFC, fusiform gyrus, posterior parietal cortex |
| Tsukiura et al. (2011) | ↓ Hippocampus—left anterior temporal lobe | |
| Dew et al. (2012) | Left hippocampus | ↓ Red nucleus ↑ Superior temporal gyrus, inferior frontal gyrus, anterior cingulate, precentral gyrus |
| Matthäus et al. (2012) | ↓ Small-worldness, left—right occipital lobes, left—right parietal lobes, hippocampus—amygdala | |
| ↑ Density and size network, left parietal—left frontal regions | ||
| St Jacques et al. (2012) | Hippocampus, ventrolateral PFC | ↓ Modulation ventrolateral PFC → hippocampus |
| Waring et al. (2013) | Several ROIs | ↑Positive orbitofrontal ↔ dorsolateral PFC, positive orbitofrontal ↔ amygdala, negative amygdala ↔ fusiform, positive fusiform ↔ superior parietal lobe |
| Fandakova et al. (2015) | Left anterior PFC | ↑ Right postcentral, parahippocampal and middle temporal gyri in older adults whose activation patterns deviate less from that of young adults |
| Grady et al. (2015) | Inferior frontal operculum and anterior insula | = No significant task-related connectivity differences between young and older adults in episodic memory |
| Legon et al. (2016) | Right hippocampus, visual association area, right inferior frontal gyrus | ↓ Modulation of the inferior frontal gyrus → visual association area ↑ Modulation of the inferior frontal gyrus → hippocampus |
| Cansino et al. (2017) | Superior occipital gyrus, hippocampus, orbitofrontal cortex | ↑ Modulation superior occipital gyrus ↔ hippocampus ↔ orbitofrontal cortex ↔ superior occipital gyrus during successful encoding and retrieval ↓ Negative driving input of the occipital cortex during successful encoding |
| King et al. (2018) | Left angular gyrus, medial PFC, left hippocampus, left middle temporal gyrus, posterior cingulate cortex | ↓ Average correlations between pairs of anatomical brain regions, except for hippocampus; average correlations between pairs of functional brain regions, except for medial PFC; average connectivity change across all seed and target pairs that exhibited a main effect of age group |
| Monge et al. (2018) | ↑ Widespread functional connections at the medial temporal lobe nodes in the source memory task | |
| Ankudowich et al. (2019) | Right dorsolateral PFC, left hippocampus | ↑ Positive hippocampus—bilateral dorsolateral PFC, superior parietal cortex, precuneus, ventral occipital cortex, left inferior parietal cortex, cingulate cortex, negative related to retrieval accuracy |
| Stark et al. (2020) | Six hippocampal segmentations, parahippocampal cortex, perirhinal cortex, entorhinal cortex | ↓ Hippocampus—parahippocampal cortex; three anterior hippocampus regions—parahippocampal cortex |
| Varangis et al. (2021) | = No significant connectivity metric differences noted between young and older adults in episodic memory |
|
| Deng et al. (2021) | ↑ Functional integration of PFC with the remainder of the brain network, that was associated with better performance; reconfiguration of connectivity patterns in PFC ↓ Reconfiguration in medial temporal lobe |
|
| Tsuruha and Tsukiura (2021) | Right hippocampus, right anterior temporal lobe | ↓ Hippocampus, anterior temporal lobe—posterior superior temporal sulcus for words encoded by a person from a different age group |
| Ness et al. (2022) | Left hippocampus, putamen, caudate | ↓ Hippocampus—putamen, caudate for durable memories (six days retention) ↑ Hippocampus—caudate associated with higher durable memory performance |
When more than one ROI or seed was used, the specific ROI or seed showing significant results is indicated in the result column.
PFC, prefrontal cortex, ↑ increased, ↓ decreased, or = no change in connectivity or other parameters in older adults relative to young adults,—no direction, → forward, backward, or ↔ bidirectional connectivity.