The studies cited by Dijkerman & de Haan (D&dH) stress the distinction between perception and action within the somatosensory system but provide little information about memory functions. Recent findings by our group and by others show that the dorsal stream is also activated during short-term memory maintenance and long-term memory retrieval of haptic information. These data complement and extend the proposed model.

Evidence for the contribution of the neocortex to memory is overwhelming. However, the theory proposed by Ruchkin et al. does not only ignore subcortical contributions, but also introduces an unnecessary and empirically unsupported division between the posterior cortex, assumed to represent information, and the prefrontal cortex, assumed to control activation. We argue instead that the representational power of the neocortex is not restricted to its posterior part.

The identity of working-memory and long-term memory representations follows from many lines of evidence. However, the data provided by Ruchkin et al. are hardly compelling, as they make unproved assumptions about hypothetical generators. We cite studies from our lab in which congruent slow-wave topographies were found for short-term and long-term memory tasks, strongly suggesting that both activate identical cell assemblies.