Getting ahead: forward models and their place in cognitive architecture

• Describes the key mechanisms that distinguish leading accounts of forward models in motor control.
• Relates these models to accounts of understanding, and coordinating with, other agents.
• Considers challenges to the need for efference copies and explicit inverse models in motor control.
• Suggests empirical tests to discriminate accounts of forward models.

The use of forward models (mechanisms that predict the future state of a system) is well established in cognitive and computational neuroscience. We compare and contrast two recent, but interestingly divergent, accounts of the place of forward models in the human cognitive architecture. On the Auxiliary Forward Model (AFM) account, forward models are special-purpose prediction mechanisms implemented by additional circuitry distinct from core mechanisms of perception and action. On the Integral Forward Model (IFM) account, forward models lie at the heart of all forms of perception and action. We compare these neighbouring but importantly different visions and consider their implications for the cognitive sciences. We end by asking what kinds of empirical research might offer evidence favouring one or the other of these approaches.