Decreased stimulus-driven connectivity of the primary visual cortex during visual motion stimulation in amnestic mild cognitive impairment: An fMRI study.

Motion perceptual deficits are common in Alzheimer's disease (AD). Although the posterior parietal cortex is thought to play a critical role in these deficits, it is currently unclear whether the primary visual cortex (V1) contributes to these deficits in AD. To elucidate this issue, we investigated the net activity or connectivity within V1 in 17 amnestic mild cognitive impairment (aMCI) patients, 17 AD patients and 17 normal controls (NC) using functional magnetic resonance imaging (fMRI).

Radiation Effects on Cognitive Function Among Atomic Bomb Survivors Exposed at or After Adolescence.

Background: The objective of this study was to investigate radiation effects on longitudinal pre-dementia cognitive decline among participants who developed dementia as well as on those who did not develop dementia during follow-up.

Methods: Measuring cognitive function with the Cognitive Abilities Screening Instrument approximately every 2 years, we followed 1844 atomic bomb survivors participating in the Adult Health Study of the Radiation Effects Research Foundation from 1992 to 2011. Participants were adolescents or older when exposed to between 0 and 4 Gy.

Trajectories of cognitive function in dementia-free subjects: Radiation Effects Research Foundation Adult Health Study.

Objectives: To investigate associations between age, sex, education, and birth cohort and global cognitive decline among a population that would most likely not progress to dementia.

Methods: A total of 1538 dementia-free subjects aged 60 to 80years in 1992 were followed up through 2011 without dementia occurrence. We assessed cognitive function using the Cognitive Ability Screening Instrument (CASI).

Relevance of in vivo neurophysiological biomarkers for mild cognitive impairment and Alzheimer's disease.

Visuospatial dysfunction including defects in motion perception in Alzheimer's disease (AD) and mild cognitive impairment (MCI) are clues to search for potential in vivo biomarkers. In this review, we focus on the clinical relevance of non-invasive neurophysiological findings in event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) to assess visual dysfunction in AD and MCI. We first summarize the current concept of the parallel visual pathways in primates and humans.