Altered prefrontal function with aging: insights into age-associated performance decline.
We examined the effects of aging on visuo-spatial attention. Participants performed a bi-field visual selective attention task consisting of infrequent target and task-irrelevant novel stimuli randomly embedded among repeated standards in either attended or unattended visual fields. Blood oxygenation level dependent (BOLD) responses to the different classes of stimuli were measured using functional magnetic resonance imaging. The older group had slower reaction times to targets, and committed more false alarms but had comparable detection accuracy to young controls. Attended target and novel stimuli activated comparable widely distributed attention networks, including anterior and posterior association cortex, in both groups. The older group had reduced spatial extent of activation in several regions, including prefrontal, basal ganglia, and visual processing areas. In particular, the anterior cingulate and superior frontal gyrus showed more restricted activation in older compared with young adults across all attentional conditions and stimulus categories. The spatial extent of activations correlated with task performance in both age groups, but the regional pattern of association between hemodynamic responses and behavior differed between the groups. Whereas the young subjects relied on posterior regions, the older subjects engaged frontal areas. The results indicate that aging alters the functioning of neural networks subserving visual attention, and that these changes are related to cognitive performance.
Solbakk
Anne-Kristin
AK
Department of Psychology and the Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. anne-kristin.solbakk@rikshospitalet.no
Fuhrmann Alpert
Galit
G
Furst
Ansgar J
AJ
Hale
Laura A
LA
Oga
Tatsuhide
T
Chetty
Sundari
S
Pickard
Natasha
N
Knight
Robert T
RT
D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D001288:Attention / Q000502:physiology; D001519:Behavior / Q000502:physiology; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000254:growth & development / Q000502:physiology; D017397:Prefrontal Cortex / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D011795:Surveys and Questionnaires; D055815:Young Adult