Short review A "voice patch" system in the primate brain for processing vocal information?

International audienceWe review behavioural and neural evidence for the processing of information contained in conspecific vocalizations (CVs) in three primate species: humans, macaques and marmosets. We focus on abilities that are present and ecologically relevant in all three species: the detection and sensitivity to CVs; and the processing of identity cues in CVs. Current evidence, although fragmentary, supports the notion of a "voice patch system" in the primate brain analogous to the face patch system of visual cortex: a series of discrete, interconnected cortical areas supporting increasingly abstract representations of the vocal input. A central question concerns the degree to which the voice patch system is conserved in evolution. We outline challenges that arise and suggesting potential avenues for comparing the organization of the voice patch system across primate brains

Functional imaging studies of visual-auditory integration in man.

This thesis investigates the central nervous system's ability to integrate visual and auditory information from the sensory environment into unified conscious perception. It develops the possibility that the principle of functional specialisation may be applicable in the multisensory domain. The first aim was to establish the neuroanatomical location at which visual and auditory stimuli are integrated in sensory perception. The second was to investigate the neural correlates of visual-auditory synchronicity, which would be expected to play a vital role in establishing which visual and auditory stimuli should be perceptually integrated. Four functional Magnetic Resonance Imaging studies identified brain areas specialised for: the integration of dynamic visual and auditory cues derived from the same everyday environmental events (Experiment 1), discriminating relative synchronicity between dynamic, cyclic, abstract visual and auditory stimuli (Experiment 2 & 3) and the aesthetic evaluation of visually and acoustically perceived art (Experiment 4). Experiment 1 provided evidence to suggest that the posterior temporo-parietal junction may be an important site of crossmodal integration. Experiment 2 revealed for the first time significant activation of the right anterior frontal operculum (aFO) when visual and auditory stimuli cycled asynchronously. Experiment 3 confirmed and developed this observation as the right aFO was activated only during crossmodal (visual-auditory), but not intramodal (visual-visual, auditory-auditory) asynchrony. Experiment 3 also demonstrated activation of the amygdala bilaterally during crossmodal synchrony. Experiment 4 revealed the neural correlates of supramodal, contemplative, aesthetic evaluation within the medial fronto-polar cortex. Activity at this locus varied parametrically according to the degree of subjective aesthetic beauty, for both visual art and musical extracts. The most robust finding of this thesis is that activity in the right aFO increases when concurrently perceived visual and auditory sensory stimuli deviate from crossmodal synchrony, which may veto the crossmodal integration of unrelated stimuli into unified conscious perception

A Relationship Between Auditory Evoked Responses to Speech Sounds Recorded at Birth and Vocabulary Size as Measured by the Peabody Picture Vocabulary Test Administered at Three Years of Age

The role of biological components as related to language processes has received increased attention in recent years. Evidence from a variety of different methodologies has indicated the presence of early hemisphere differences in young infants. Yet the relationship between such early differences and later language development has remained unclear although several recent reports suggest a marked relationship between the two. The present paper examined the relationship between such lateralized responses in young infants and performance on the Peabody Picture Vocabulary test at three years of age

Maturing Temporal Bones as Non-Neural Sites for Transforming the Speech Signal during Language Development

Developmental events in the temporal bones shift the pattern of a given speech sounds acoustic profile through the time children are mapping linguistic sound systems. Before age 5 years, frequency information in vowels is differentially accessible through the years children are acquiring the sound systems of their native language(s). To model the acoustic effects caused by developing temporal bones, data collected to elicit steady-state vowels from adult native speakers of English and Diné were modified to reflect the form of children\u27s hearing sensitivities at different ages based on patterns established in the psychoacoustic literature. It was assumed, based on the work of psychacousticians (e.g., Werner, Fay & Popper 2012; and Werner & Marean 1996), that the effects caused by immature temporal bones were conductive immaturities, and the age-sensitive filters were constructed based on psychoacoustic research into the hearing of infants and children. Data were partitioned by language, sex, and individual vowels and compared for points of similarity and difference in the way information in vowels is filtered because of the constraints imposed by the immaturity of the temporal bones. Results show that the early formant pattern becomes successively modified in a constrained pattern reflecting maturational processes. Results also suggest that children may well be switching strategies for processing vowels, using a more adult-like process after 18 months. Future research should explore if early hearing not only affects individual speech sounds but their relationships to one another in the vowel space as well. Additionally, there is an interesting artifact in the observed gradual progression to full adult hearing which may be the effect of the foramen of Huschke contributing to the filters at 1 year and 18 months. Given that immature temporal bones reflect brain expansion and rotational birth in hominids, these results contribute to the discussion of the biological underpinnings of the evolution of language.\u2

Precis of neuroconstructivism: how the brain constructs cognition

Neuroconstructivism: How the Brain Constructs Cognition proposes a unifying framework for the study of cognitive development that brings together (1) constructivism (which views development as the progressive elaboration of increasingly complex structures), (2) cognitive neuroscience (which aims to understand the neural mechanisms underlying behavior), and (3) computational modeling (which proposes formal and explicit specifications of information processing). The guiding principle of our approach is context dependence, within and (in contrast to Marr [1982]) between levels of organization. We propose that three mechanisms guide the emergence of representations: competition, cooperation, and chronotopy; which themselves allow for two central processes: proactivity and progressive specialization. We suggest that the main outcome of development is partial representations, distributed across distinct functional circuits. This framework is derived by examining development at the level of single neurons, brain systems, and whole organisms. We use the terms encellment, embrainment, and embodiment to describe the higher-level contextual influences that act at each of these levels of organization. To illustrate these mechanisms in operation we provide case studies in early visual perception, infant habituation, phonological development, and object representations in infancy. Three further case studies are concerned with interactions between levels of explanation: social development, atypical development and within that, developmental dyslexia. We conclude that cognitive development arises from a dynamic, contextual change in embodied neural structures leading to partial representations across multiple brain regions and timescales, in response to proactively specified physical and social environment

Individual auditory categorization abilities are shaped by intrinsic and experience-driven neural factors

Individual auditory categorization abilities are shaped by intrinsic and experience-driven neural factor

Hardwiring: Innateness in the Age of the Brain

“Hardwired” is a term commonly used to describe the properties of certain behaviors or brain regions. As its usage has increased exponentially in the past 50 years, both in popular media and the scholarly literature, the concept appears to have gained a cloak of respectability in scientific discourse. However, its specific meaning is difficult to pinpoint. In this paper, I examine how “hardwired” has been used in the psychological and neuroscientific literature. The analysis reveals two major themes: one centers on certain purported characteristics of behaviors or brain regions, such as fixedness; the other places these and other characteristics within an evolutionary framework. Overall, the analysis reveals a degree of overlap between “hardwiring” and the folk biology concept of innateness. Various complications arise from such overlap, casting doubts on the usefulness and legitimacy of “hardwired” in scientific discourse