Macaque claustrum, pulvinar and putative dorsolateral amygdala support the cross-modal association of social audio-visual stimuli based on meaning
Social communication draws on several cognitive functions such as perception, emotion recognition and attention. The association of audio-visual information is essential to the processing of species-specific communication signals. In this study, we use functional magnetic resonance imaging in order to identify the subcortical areas involved in the cross-modal association of visual and auditory information based on their common social meaning. We identified three subcortical regions involved in audio-visual processing of species-specific communicative signals: the dorsolateral amygdala, the claustrum and the pulvinar. These regions responded to visual, auditory congruent and audio-visual stimulations. However, none of them was significantly activated when the auditory stimuli were semantically incongruent with the visual context, thus showing an influence of visual context on auditory processing. For example, positive vocalization (coos) activated the three subcortical regions when presented in the context of positive facial expression (lipsmacks) but not when presented in the context of negative facial expression (aggressive faces). In addition, the medial pulvinar and the amygdala presented multisensory integration such that audiovisual stimuli resulted in activations that were significantly higher than those observed for the highest unimodal response. Last, the pulvinar responded in a task-dependent manner, along a specific spatial sensory gradient. We propose that the dorsolateral amygdala, the claustrum and the pulvinar belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context.
Socially meaningful visual context either enhances or inhibits vocalisation processing in the macaque brain
Social interactions rely on the interpretation of semantic and emotional information, often from multiple sensory modalities. Nonhuman primates send and receive auditory and visual communicative signals. However, the neural mechanisms underlying the association of visual and auditory information based on their common social meaning are unknown. Using heart rate estimates and functional neuroimaging, we show that in the lateral and superior temporal sulcus of the macaque monkey, neural responses are enhanced in response to species-specific vocalisations paired with a matching visual context, or when vocalisations follow, in time, visual information, but inhibited when vocalisation are incongruent with the visual context. For example, responses to affiliative vocalisations are enhanced when paired with affiliative contexts but inhibited when paired with aggressive or escape contexts.
The Universal Generative Faculty: The source of our expressive power in language, mathematics, morality, and music
Many have argued that the expressive power of human thought comes from language. Language plays this role, so the argument goes, because its generative computations construct hierarchically structured, abstract representations, covering virtually any content and communicated in linguistic expressions. However, language is not the only domain to implement generative computations and abstract representations, and linguistic communication is not the only medium of expression. Mathematics, morality, and music are three others. These similarities are not, we argue, accidental. Rather, we suggest they derive from a common computational system that we call the Universal Generative Faculty or UGF. UGF is, at its core, a suite of contentless generative procedures that interface with different domains of knowledge to create contentful expressions in thought and action.
The faculty of language: what is it, who has it, and how did it evolve?
We argue that an understanding of the faculty of language requires substantial interdisciplinary cooperation. We suggest how current developments in linguistics can be profitably wedded to work in evolutionary biology, anthropology, psychology, and neuroscience. We submit that a distinction should be made between the faculty of language in the broad sense (FLB) and in the narrow sense (FLN). FLB includes a sensory-motor system, a conceptual-intentional system, and the computational mechanisms for recursion, providing the capacity to generate an infinite range of expressions from a finite set of elements. We hypothesize that FLN only includes recursion and is the only uniquely human component of the faculty of language. We further argue that FLN may have evolved for reasons other than language, hence comparative studies might look for evidence of such computations outside of the domain of …
The evolution of communication
Bound to become a classic and to stimulate debate and research, The Evolution of Communication looks at species in their natural environments as a way to begin to understand what the real units of analysis of communicating systems are, using arguments about design and function to illuminate both the origin and subsequent evolution of each system. It lights the way for a research program that seriously addresses the problem of how communication systems, including language, have been designed over the course of evolution.