One motor cortex, two different views


To the editorHere we refute claims by Todorov1 and Scott7 that the importance of target direction as an explanatory factor for cortical activity in a regression analysis we performed5 is an 'artifact' of a square-root transformation of neural discharge rates. Specifically, it was touted by Scott7 that "squaring [sic] the discharge rate of neurons in order to stabilize the variance … causes a dramatic increase in the percentage of neurons that appear to represent movement direction (from 17% [sic] to 43% in Todorov's model)."