Chapter 4 - Animal studies of deviance detection along the auditory pathway

Abstract

This chapter presents animal studies on deviance detection using MMN in nonhuman primates, cats, and rodents. It appears that stimulus-specific adaptation (SSA) is strongest in the nonlemniscal (nontonotopic) pathway, clearly demonstrated in inferior colliculus and thalamus. In auditory cortex one finds that the nonlemniscal posterior auditory field is more engaged in context-dependent processing underlying deviance detection than the other auditory cortex fields. Animal studies allow detailed investigation of the role of neurotransmitters and neuromodulators of SSA. Results demonstrate that GABAergic, glutamatergic, and cholinergic receptors play different and complementary roles on shaping SSA. Inhibition modulates the strength and dynamics of SSA, but does not generate it. Using optogenetic inactivation of the auditory cortico-collicular feedback in awake mice showed that this led to a decrease in prediction error in inferior colliculus. Repetition suppression was unaffected by cortico-collicular inactivation, suggesting that this metric may reflect adaptation of bottom-up sensory inputs rather than predictive processing.