Arithmetic fact retrieval deficits in chronic stroke – a deficit of relearning?

Arithmetic fact retrieval deficits in acute stroke patients can arise after the severing ofwhite matter connections within left temporo-parietal areas (Smaczny et al., 2023). Thecurrent study examined white matter disconnections in multiplication, subtraction, andaddition in patients in the chronic stage of stroke. The strongest effects were found inmultiplication, where the disconnection of long-term memory parahippocampal areaswas strongly associated with lower multiplication scores. Lower subtraction scoreswere related to interhemispheric thalamus disconnections and weakly withdisconnections within the left hemisphere language network. The results for additionproblems were equivocal, yet they were in line with the literature, stating that additioncan be solved by either fact retrieval or magnitude processing. The multiplicationresults are in line with the view that the neuroanatomical correlates of arithmetic factretrieval deficits in chronic stroke point at a relearning deficit, the subtraction results arein line with bilateral redundancy of the magnitude processing network, and all resultstogether suggest that number operations are more in line with strategy-dependentprocessing than operation-dependent processing.