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Dynamic functional reorganizations and relationship with working memory performance in healthy aging.

Sala-Llonch R, Arenaza-Urquijo EM, Valls-Pedret C, Vidal-Piñeiro D, Bargalló N, Junqué C, Bartrés-Faz D - Front Hum Neurosci (2012)

Bottom Line: Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks.We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks.We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging.

View Article: PubMed Central - PubMed

Affiliation: Departament de Psiquiatria i Psicobiologia Clinica, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain.

ABSTRACT
In recent years, several theories have been proposed in attempts to identify the neural mechanisms underlying successful cognitive aging. Old subjects show increased neural activity during the performance of tasks, mainly in prefrontal areas, which is interpreted as a compensatory mechanism linked to functional brain efficiency. Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks. We used functional MRI during resting-state and a verbal n-back task with different levels of memory load in a cohort of young and old healthy adults to identify patterns of networks associated with working memory and brain default mode. We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks. Moreover, elders who were able to activate additional areas and to recruit a more bilateral frontal pattern within the task-related network achieved successful performance on the task. We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging. This observation allows the integration of several theories that have been proposed to date regarding the aging brain.

No MeSH data available.


Results of the task-performance during the different working memory loads. (A) Mean and SD values of d prime index, and (B) Mean and SD values of average response time (RT), in seconds. *Indicates p < 0.05 in the ANOVA post hoc analysis of between-group differences. 0B, 0-back; 1B, 1-back, 2B, 2-back, 3B, 3-back, YA, young adults; high-HE, high-performing healthy elders; low-HE, low-performing healthy elders.
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Figure 2: Results of the task-performance during the different working memory loads. (A) Mean and SD values of d prime index, and (B) Mean and SD values of average response time (RT), in seconds. *Indicates p < 0.05 in the ANOVA post hoc analysis of between-group differences. 0B, 0-back; 1B, 1-back, 2B, 2-back, 3B, 3-back, YA, young adults; high-HE, high-performing healthy elders; low-HE, low-performing healthy elders.

Mentions: Low-HE and high-HE groups differed in task-performance, but there were no significant differences in the performance of the 3-back task between YA and high-HE subjects. Mean RT was higher in elders than in young subjects for all the conditions, but there were no differences between high-HE and low-HE. Across the two groups of elders, age, gender, and MMSE were comparable, but high-HE had significantly higher education levels (Table 1; Figure 2).


Dynamic functional reorganizations and relationship with working memory performance in healthy aging.

Sala-Llonch R, Arenaza-Urquijo EM, Valls-Pedret C, Vidal-Piñeiro D, Bargalló N, Junqué C, Bartrés-Faz D - Front Hum Neurosci (2012)

Results of the task-performance during the different working memory loads. (A) Mean and SD values of d prime index, and (B) Mean and SD values of average response time (RT), in seconds. *Indicates p < 0.05 in the ANOVA post hoc analysis of between-group differences. 0B, 0-back; 1B, 1-back, 2B, 2-back, 3B, 3-back, YA, young adults; high-HE, high-performing healthy elders; low-HE, low-performing healthy elders.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369258&req=5

Figure 2: Results of the task-performance during the different working memory loads. (A) Mean and SD values of d prime index, and (B) Mean and SD values of average response time (RT), in seconds. *Indicates p < 0.05 in the ANOVA post hoc analysis of between-group differences. 0B, 0-back; 1B, 1-back, 2B, 2-back, 3B, 3-back, YA, young adults; high-HE, high-performing healthy elders; low-HE, low-performing healthy elders.
Mentions: Low-HE and high-HE groups differed in task-performance, but there were no significant differences in the performance of the 3-back task between YA and high-HE subjects. Mean RT was higher in elders than in young subjects for all the conditions, but there were no differences between high-HE and low-HE. Across the two groups of elders, age, gender, and MMSE were comparable, but high-HE had significantly higher education levels (Table 1; Figure 2).

Bottom Line: Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks.We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks.We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging.

View Article: PubMed Central - PubMed

Affiliation: Departament de Psiquiatria i Psicobiologia Clinica, Facultat de Medicina, Universitat de Barcelona Barcelona, Spain.

ABSTRACT
In recent years, several theories have been proposed in attempts to identify the neural mechanisms underlying successful cognitive aging. Old subjects show increased neural activity during the performance of tasks, mainly in prefrontal areas, which is interpreted as a compensatory mechanism linked to functional brain efficiency. Moreover, resting-state studies have concluded that elders show disconnection or disruption of large-scale functional networks. We used functional MRI during resting-state and a verbal n-back task with different levels of memory load in a cohort of young and old healthy adults to identify patterns of networks associated with working memory and brain default mode. We found that the disruption of resting-state networks in the elderly coexists with task-related overactivations of certain brain areas and with reorganizations within these functional networks. Moreover, elders who were able to activate additional areas and to recruit a more bilateral frontal pattern within the task-related network achieved successful performance on the task. We concluded that the balanced and plastic reorganization of brain networks underlies successful cognitive aging. This observation allows the integration of several theories that have been proposed to date regarding the aging brain.

No MeSH data available.