Working memory related brain activity and networks in typically developing children and young adults

Ping Jiang

Tutkimustuotos: OpinnäyteVäitöskirjaArtikkelikokoelma

Abstrakti

The high-level cognitive abilities such as attention and working memory develop throughout childhood and adolescence. Neuroimaging studies have shown that several brain regions including areas in the prefrontal (PFC) and parietal cortices play an important role in cognitive control. The prolonged maturation of the PFC and related networks may underlie the immature cognitive control abilities in children. In this thesis, functional magnetic resonance imaging and 1-back WM tasks were used to investigate 1) top-down modulation of brain activity in cortical areas related to visual information processing and 2) functional connectivity of resting state and task-related brain networks in healthy 7-11-year-old children and young adults. The tasks required the subjects to attend to either face or scene stimuli and to ignore distracting scene or face images, respectively. Studies I and II of this thesis found weaker or otherwise immature top-down modulation of the face processing-related visual association cortices that could partially be explained by the observed weaker functional connectivity between the PFC and the visual association cortex in the typically developing 7–11-year-old children compared to the young adults. Moreover, there were age-dependent differences in the recruitment of the PFC during visual working memory tasks. These age-dependent differences between the two groups are in line with the observed differences in the performance of the working memory tasks that was poorer in children than young adults. Study III showed that the 7-11-year-old children have already established an adult-like pattern of resting state networks, but especially during task performance, the functional connectivity within and between these networks differed from that in young adults. The group differences observed in the brain activation and functional connectivity are likely partly related to the morphological developmental state of the grey- and white matter in the 7–11-year-old children (i.e., the ongoing synaptic pruning and myelination of axons that continue up to young adulthood). The findings of this thesis conform to the suggestion that during development, the function of brain regions, especially the PFC, and the functional connectivity of brain networks, undergo dynamic changes, and that the same cognitive function may rely on different brain networks at different ages.
Alkuperäiskielienglanti
JulkaisupaikkaHelsinki
Kustantaja
Painoksen ISBN978-951-51-3495-0
Sähköinen ISBN978-951-51-3496-7
TilaJulkaistu - 2017
OKM-julkaisutyyppiG5 Tohtorinväitöskirja (artikkeli)

Tieteenalat

  • Adult
  • Attention
  • +physiology
  • Brain Mapping
  • Cerebral Cortex
  • Child
  • Child Development
  • Magnetic Resonance Imaging
  • Memory, Short-Term
  • Nerve Net
  • Neural Pathways
  • +growth & development
  • Neuronal Plasticity
  • Occipital Lobe
  • Parahippocampal Gyrus
  • Pattern Recognition, Visual
  • Prefrontal Cortex
  • Temporal Lobe
  • Visual Cortex
  • 3112 Neurotieteet
  • 3111 Biolääketieteet
  • 1184 Genetiikka, kehitysbiologia, fysiologia

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