The neuropsychology of basal ganglia.

Basal ganglia are subcortical structures specialized at very early age, functionally different according to the right or left side. They are part of complex distributed network composed by parallel segregated loops where specific information are processed and open loops where different information are integrated. These loops are connected to specialized cortical areas thus entering into distributed processing of higher order cognitive functions and behaviours. Lesion or malfunction of basal ganglia nuclei cause deficits in different neuropsychological functions and neurobehavioural diseases, such Autism Spectrum Disorder, Attention Deficit/Hyperactivity Disorder, Tourette syndrome, etc., for the reciprocal connections from and to the limbic system and the frontal system. Basal ganglia have a computational functioning, working by activation and inhibition sequences, coded in time and space and regulated by inhibitory and excitatory mechanisms, with such accuracy to guarantee an effective and elegant product.