Developmental dyscalculia is related to visuo-spatial memory and inhibition impairment

Developmental dyscalculia is thought to be a specific impairment of mathematics ability. Currently dominant cognitive neuroscience theories of developmental dyscalculia suggest that it originates from the impairment of the magnitude representation of the human brain, residing in the intraparietal sulcus, or from impaired connections between number symbols and the magnitude representation. However, behavioral research offers several alternative theories for developmental dyscalculia and neuro-imaging also suggests that impairments in developmental dyscalculia may be linked to disruptions of other functions of the intraparietal sulcus than the magnitude representation. Strikingly, the magnitude representation theory has never been explicitly contrasted with a range of alternatives in a systematic fashion. Here we have filled this gap by directly contrasting five alternative theories (magnitude representation, working memory, inhibition, attention and spatial processing) of developmental dyscalculia in 9–10-year-old primary school children. Participants were selected from a pool of 1004 children and took part in 16 tests and nine experiments. The dominant features of developmental dyscalculia are visuo-spatial working memory, visuo-spatial short-term memory and inhibitory function (interference suppression) impairment. We hypothesize that inhibition impairment is related to the disruption of central executive memory function. Potential problems of visuo-spatial processing and attentional function in developmental dyscalculia probably depend on short-term memory/working memory and inhibition impairments. The magnitude representation theory of developmental dyscalculia was not supported.     

Isolation and characterization of polymorphic microsatellite loci from the golden mouse (Ochrotomys nuttalli)

Thirteen polymorphic microsatellite loci were developed for golden mouse using an enrichment protocol. The markers were tested on 37 golden mouse specimens collected from southern Illinois. Numbers of alleles ranged from 3 to 11 with observed heterozygosities ranging from 0.29 to 0.92. Three of the loci exhibit nominally significant excesses of homozygosity, but none were significant following a correction for multiple tests. None of the loci appear to be linked. Although golden mouse is not considered at risk in the core of its range, peripheral populations in several states are considered threatened or otherwise at risk due to low population densities. Because of the evolutionary distinctiveness of Ochrotomys, species-specific primers are needed to identify patterns of gene flow among core and peripheral populations.     

Letter to the editor for a published article titled “The effect of online versus hospital warfarin management on patient outcomes: a systematic review and meta-analysis”

International Journal of Clinical Pharmacy -