title: Are mirror neurons the basis of speech perception? Evidence from five cases with damage to the purported human mirror system.
abstract: The discovery of mirror neurons in macaque has led to a resurrection of motor theories of speech perception. Although the majority of lesion and functional imaging studies have associated perception with the temporal lobes, it has also been proposed that the 'human mirror system', which prominently includes Broca's area, is the neurophysiological substrate of speech perception. Although numerous studies have demonstrated a tight link between sensory and motor speech processes, few have directly assessed the critical prediction of mirror neuron theories of speech perception, namely that damage to the human mirror system should cause severe deficits in speech perception. The present study measured speech perception abilities of patients with lesions involving motor regions in the left posterior frontal lobe and/or inferior parietal lobule (i.e., the proposed human 'mirror system'). Performance was at or near ceiling in patients with fronto-parietal lesions. It is only when the lesion encroaches on auditory regions in the temporal lobe that perceptual deficits are evident. This suggests that 'mirror system' damage does not disrupt speech perception, but rather that auditory systems are the primary substrate for speech perception.
authors.affiliation: Dana and David Dornsife Cognitive Neuroscience Imaging Center, Brain & Creativity Institute, University of Southern California, Los Angeles, USA.
authors.forename: Corianne
authors.initials: C
authors.lastname: Rogalsky
authors.forename: Tracy
authors.initials: T
authors.lastname: Love
authors.forename: David
authors.initials: D
authors.lastname: Driscoll
authors.forename: Steven W
authors.initials: SW
authors.lastname: Anderson
authors.forename: Gregory
authors.initials: G
authors.lastname: Hickok
mesh_terms: D000328:Adult; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology* / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000473:pathology* / Q000502:physiology; D013067:Speech Perception / Q000502:physiology*