Mapping cortical change across the human life span

Abstract

We used magnetic resonance imaging and cortical matching algorithms to map gray matter density (GMD) in 176 normal individuals ranging in age from 7 to 87 years. We found a significant, nonlinear decline in GMD with age, which was most rapid between 7 and about 60 years, over dorsal frontal and parietal association cortices on both the lateral and interhemispheric surfaces. Age effects were inverted in the left posterior temporal region, where GMD gain continued up to age 30 and then rapidly declined. The trajectory of maturational and aging effects varied considerably over the cortex. Visual, auditory and limbic cortices, which are known to myelinate early, showed a more linear pattern of aging than the frontal and parietal neocortices, which continue myelination into adulthood. Our findings also indicate that the posterior temporal cortices, primarily in the left hemisphere, which typically support language functions, have a more protracted course of maturation than any other cortical region.

Motion‐related artifacts in structural brain images revealed with independent estimates of in‐scanner head motion

“…Of note, T1w scans flagged by a combination of $\overline{\mathit{F}\mathit{D}}$ and QC ratings: (1) increased with increasing age, and (2) exhibited considerably reduced global and regional estimates of gray matter volume and thickness. Reductions in gray matter volume and thickness are well documented as a hallmark of healthy aging and cognitive decline [DeKosky and Scheff, 1990; Dickerson et al, 2008, 2012; Sowell et al, 2003]. We suggest that these effects may in some cases be overestimated, particularly in certain brain locations, by the inclusion of biased estimates from T1w structural scans with motion artifacts.…”

EEG gamma-band synchronization in visual coding from childhood to old age: Evidence from evoked power and inter-trial phase locking

“…In the present study, all the participants in the group of older adults were at least 70 years of age. Therefore, first signs of senescent reductions in neuronal mass (Sowell et al, 2003), and in neurotransmitter availability are likely (Backman and Farde, 2005;Backman et al, 2006;Li et al, 2001), even in early visual processing areas, which are known to be well preserved in aging (Raz et al, 2005). Furthermore, It has been shown that gamma-band activity is modulated by genetic polymorphisms (Demiralp et al, 2007) and psychiatric disorders (Gallinat et al, 2004;Herrmann and Demiralp, 2005) affecting dopaminergic neu-romodulation.…”

“…During child development and aging, the structure and function of the human brain undergo major changes (Sowell et al, 2003;Raz et al, 2005; for reviews, see Baltes et al, 2006;Cabeza et al, 2005;Li, 2003;Lindenberger et al, 2006). Results from post-mortem studies of the brain, magnetic resonance imaging (MRI), functional MRI, as well as electrophysiological studies indicate that human brain development can be characterized as non-linear and heterochronous, with different parts of the brain follow different developmental time courses (Gogtay et al, 2004;Sowell et al, 2003;Thatcher, 1992;Thatcher et al, 1986).…”

“…Results from post-mortem studies of the brain, magnetic resonance imaging (MRI), functional MRI, as well as electrophysiological studies indicate that human brain development can be characterized as non-linear and heterochronous, with different parts of the brain follow different developmental time courses (Gogtay et al, 2004;Sowell et al, 2003;Thatcher, 1992;Thatcher et al, 1986). Besides lifespan changes in brain structure and connectivity, the availability and expression of neurotransmitters (especially dopamine) also changes and affects cognitive functioning (for reviews, see Backman et al, 2006;Li et al, 2006).…”

“…After a phase of synaptic overproduction and pruning (e.g., Huttenlocher and de Courten, 1987), occipital areas show relatively little senescence-related changes compared to, for example, prefrontal regions (Sowell et al, 2003;Raz et al, 2005), and provide the main input for higher order cognitive processes requiring visual information (Tobimatsu and Celesia, 2006). Therefore, we chose gamma-band synchronization in early visual perception as a target mechanism.…”