The forebrain controls many functions, including smelling. The largest part of the brain, the forebrain processes cognitive, auditory, visual and sensory information.Located in the forebrain, the hippocampus and amygdala are parts of the limbic system.he two main sections of the forebrain, however, are the telencephalon and the diencephalon. The telecephalon includes the cerebral cortex, the subcortical structures, and the corpus callosum, while the diencephalon includes the thalamus and the hypothalamus.