The "thalamocortical loop" is the functional loop between these two structures. The loop consists of projections from thalamus to cortex (feedforward and driving inputs) and from cortex back to thalamus. These projections usually remain within the same sensory or motor nuclei and cortex areas. The loops are involved in the production of sleep spindles, absence seizures, and the control of the propagation of sensory information.
Computational neuroscientists are particularly interested in thalamocortical loops because they represent a structure that is dispoportionally larger in humans than other mammals (when body size is taken into account) and thus may make a significant contribution to humans' special cognitive abilities.