What is the exact rule for cell activation in a column?

When a column is activated, as determined by the spatial pooler, one of two things can happen with regard to the cells inside the column. If there are no cells in the column that are in a slightly depolarized “predicted” state, all the cells within the column become active together (bursting). There have been observations in biological experiments that cell firing activity becomes more dense in the presence of unpredictable patterns versus repetitive, predictable patterns. Alternatively, if there are any combination of cells in the column that are in a predicted state, that subset of cells become active first and inhibit all of their neighbors in the column.