Table 3.
Study | Design | Sample | Intervention conditions | fMRI protocol cognitive measure | Post-intervention fMRI comparisons | Direction of FMRI | fMRI results after intervention | fMRI and cognitive tasks |
---|---|---|---|---|---|---|---|---|
Rosen et al. [14] | RCT double-blind | 12 MCIs | Auditory processing training Computer-based activities | Auditory verbal task RBANS | COT MCI | Increasing | L hippocampus | L hippocampus activation correlated with changes in memory performance on RBANS (r = 0.49) |
CCI MCI | Decreased | L hippocampus | ||||||
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Belleville et al. [17] | CGT single-blind | 15 HC 15 MCI | Mnemonic strategy training | Word list memory encoding and retrieval and word list recall test | ENCODING HC | Decreased | R/L basal ganglia, R/L cingulate gyrus, R inferior frontal gyrus, R inferior and superior parietal cortex, R inferior, medial and superior frontal gyrus, L prefrontal cortex, L precentral gyrus, and R hippocampus | HC performance on immediate word recall was correlated with activation in L inferior frontal gyrus during retrieval (r = 0.521) |
MCI | Increased | L superior temporal gyrus, L thalamus, putamen and globus pallidus, R inferior parietal cortex, R superior frontal gyrus, and R cerebellum | ||||||
RETRIEVAL HC | Increased | R middle temporal gyrus, thalamus, R superior temporal gyrus, R putamen, R/L precuneus, L superior temporal gyrus, L inferior frontal gyrus, and R hippocampus | ||||||
MCI | Increased | L postcentral gyrus, L inferior parietal lobule, L inferior and supramarginal gyrus, R/L posterior cingulate, R/L superior temporal gyrus, R insula, and L middle frontal gyrus | MCI performance on delayed word recall was correlated with activation in R inferior parietal lobule during encoding (r = 0.538) | |||||
COT MCI post > pre encoding | Cingulate and medial frontal gyri (p < 0.001) and R inferior parietal lobule (p < 0.01) | |||||||
Retrieval | L middle frontal gyrus (p < 0.01) R superior Parietal lobule (p < 0.05) | |||||||
| ||||||||
Hampstead et al. [18] | Case control | 6 MCI | Face name associative training | Face name Associative encoding and off-scan recognition task | TS > US | Increased | R/L medial frontal cortex; medial parietal cortex, precuneus, medial occipital cortex, L frontal operculum, L temporoparietal junction, and L temporal cortex | |
U S > TS | Increased | L middle occipital gyrus | ||||||
U S > RS | Increased | L occipital cortex, L inferior frontal cortex and R/L inferior parietal cortex. The activations on inferior frontal gyrus, inferior frontal sulcus, superior middle occipital gyrus and fusiform area could be related to attempts to generalize the trained strategies | ||||||
Connectivity analysis | Effective connectivity on L middle temporal gyrus | |||||||
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Hampstead et al. [20] | RCT single-blind | 16 HC 18 MCI | Object location Associative training Stimuli exposition |
Object location associative encoding and retrieval task | ENCODING COT MCI | Increased | L hippocampal body (TS + US) | |
RETRIEVAL COT HC | Increased | L hippocampal tail and R hippocampal head (US) | ||||||
COT MCI | Increased | R/L hippocampal body and tail (TS) | ||||||
Increased | L hippocampal body and tail (US) | |||||||
COT HC + CCI MCI | Decreased | R hippocampal body (TS) | ||||||
COT MCI > CCI MCI | Increased | L hippocampal body and R hippocampus (TS) | ||||||
Increased | R hippocampal body (US) | |||||||
| ||||||||
Balardin et al. [21] | CGT Single Blind | 17 MCI 18 HC | Semantic encoding strategy orientation | SR and UR Word Lists memory encoding with off-scan free recall | HC | Increased | L middle frontal gyrus, inferior frontal gyrus, dorsal premotor cortex, posterior parietal cortex, angular gyrus within intraparietal sulcus borders | Performance on encoding the SR list was correlated with activations in orbitofrontal cortex, medial prefrontal cortex, and anterior cingulate HC - higher performance correlated with greater decrease on activations (r = −0.734) MCI - higher performance correlated with greater increase on activations (r = 0.339) |
Decreased | R superior frontal gyrus, vmPFC, L inferior Parietal Cortex, infero-lateral Temporal cortex, posterior cingulate and precuneus | |||||||
MCI | Increased | L middle frontal gyrus, inferior frontal gyrus, dorsal premotor cortex, posterior parietal cortex, angular gyrus within intraparietal sulcus borders | ||||||
Decreased | Parietooccipital cortex | |||||||
Changes on activations HC | Decreased | L middle frontal gyrus | ||||||
Decreased | R superior frontal gyrus | |||||||
MCI | Increased | R superior frontal gyrus | ||||||
| ||||||||
Lin et al. [15] | RCT | 21 MCI | Visual | Resting | Connectivity | Improvement | ||
Single-blind | Speed of processing and attention training Computer-based activities |
State | Analysis COT MCI | of connectivity on CEN (p = 0.02) | ||||
CCI MCI | Trend to poor connectivity strength in DMN (p = 0.07) | |||||||
COT MCI > CCI MCI | COT MCI showed increased connectivity in DMN compared to CCI MCI (p = 0.004, η2 = 0.62) | |||||||
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De Marco et al. [16] | RCT single-blind | 23 MCI | Cognitive training Social engagement | Resting state and CCRI | DMN connectivity analysis COT MCI | Increased in DMN connectivity on precuneus - cuneus and increased connectivity on R/L parietal cortices | Connectivity on parietal DMN were associated with the CCRI (r = 0.409) | |
CCI MCI | Decreased connectivity in R/L parietal cortices |
RCT: randomized controlled trial; CGT: controlled group trial; COT: cognitive oriented treatment; CCI: control condition intervention; MCI: mild cognitive impairment; HC: healthy controls; fMRI: functional magnetic resonance imaging; TS: trained stimulus; US: untrained stimulus; SR: semantic related; UR: unrelated; R: right; L: left; vmPFC: ventromedial prefrontal cortex; r: Pearson correlation coefficient; CCRI: cognitive change ratio index; DMN: default mode network.