Published online by Cambridge University Press: 17 December 2014
In this response to commentaries, we revisit the two main arguments of our target article. Based on data drawn from a variety of research areas – vocal behavior in nonhuman primates, speech physiology and pathology, neurobiology of basal ganglia functions, motor skill learning, paleoanthropological concepts – the target article, first, suggests a two-stage model of the evolution of the crucial motor prerequisites of spoken language within the hominin lineage: (1) monosynaptic refinement of the projections of motor cortex to brainstem nuclei steering laryngeal muscles, and (2) subsequent “vocal-laryngeal elaboration” of cortico-basal ganglia circuits, driven by human-specific FOXP2 mutations. Second, as concerns the ontogenetic development of verbal communication, age-dependent interactions between the basal ganglia and their cortical targets are assumed to contribute to the time course of the acquisition of articulate speech. Whereas such a phylogenetic reorganization of cortico-striatal circuits must be considered a necessary prerequisite for ontogenetic speech acquisition, the 30 commentaries – addressing the whole range of data sources referred to – point at several further aspects of acoustic communication which have to be added to or integrated with the presented model. For example, the relationships between vocal tract movement sequencing – the focus of the target article – and rhythmical structures of movement organization, the connections between speech motor control and the central-auditory and central-visual systems, the impact of social factors upon the development of vocal behavior (in nonhuman primates and in our species), and the interactions of ontogenetic speech acquisition – based upon FOXP2-driven structural changes at the level of the basal ganglia – with preceding subvocal stages of acoustic communication as well as higher-order (cognitive) dimensions of phonological development. Most importantly, thus, several promising future research directions unfold from these contributions – accessible to clinical studies and functional imaging in our species as well as experimental investigations in nonhuman primates.
Target article
Brain mechanisms of acoustic communication in humans and nonhuman primates: An evolutionary perspective
Related commentaries (30)
Beyond cry and laugh: Toward a multilevel model of language production
Comparative analyses of speech and language converge on birds
Contribution of the basal ganglia to spoken language: Is speech production like the other motor skills?
Differences in auditory timing between human and nonhuman primates
Does it talk the talk? On the role of basal ganglia in emotive speech processing
Early human communication helps in understanding language evolution
En route to disentangle the impact and neurobiological substrates of early vocalizations: Learning from Rett syndrome
Environments organize the verbal brain
Evolution of affective and linguistic disambiguation under social eavesdropping pressures
Functional neuroimaging of human vocalizations and affective speech
Functions of the cortico-basal ganglia circuits for spoken language may extend beyond emotional-affective modulation in adults
Modification of spectral features by nonhuman primates
Neanderthals did speak, but FOXP2 doesn't prove it
Perceptual elements in brain mechanisms of acoustic communication in humans and nonhuman primates
Phonation takes precedence over articulation in development as well as evolution of language
Physical mechanisms may be as important as brain mechanisms in evolution of speech
Speech as a breakthrough signaling resource in the cognitive evolution of biological complex adaptive systems
Speech prosody, reward, and the corticobulbar system: An integrative perspective
Speech, vocal production learning, and the comparative method
The basal ganglia within a cognitive system in birds and mammals
The evolution of coordinated vocalizations before language
The forgotten role of consonant-like calls in theories of speech evolution
The sensorimotor and social sides of the architecture of speech
The sound of one hand clapping: Overdetermination and the pansensory nature of communication
Very young infants' responses to human and nonhuman primate vocalizations
Vocal communication is multi-sensorimotor coordination within and between individuals
Vocal learning, prosody, and basal ganglia: Don't underestimate their complexity1
Voluntary and involuntary processes affect the production of verbal and non-verbal signals by the human voice
Why vocal production of atypical sounds in apes and its cerebral correlates have a lot to say about the origin of language
Why we can talk, debate, and change our minds: Neural circuits, basal ganglia operations, and transcriptional factors
Author response
Phylogenetic reorganization of the basal ganglia: A necessary, but not the only, bridge over a primate Rubicon of acoustic communication