Mouse vocal communication system: are ultrasounds learned or innate?

Mouse ultrasonic vocalizations (USVs) are often used as behavioral readouts of internal states, to measure effects of social and pharmacological manipulations, and for behavioral phenotyping of mouse models for neuropsychiatric and neurodegenerative disorders. However, little is known about the neurobiological mechanisms of rodent USV production. Here we discuss the available data to assess whether male mouse song behavior and the supporting brain circuits resemble those of known vocal non-learning or vocal learning species. Recent neurobiology studies have demonstrated that the mouse USV brain system includes motor cortex and striatal regions, and that the vocal motor cortex sends a direct sparse projection to the brainstem vocal motor nucleus ambiguous, a projection previously thought be unique to humans among mammals. Recent behavioral studies have reported opposing conclusions on mouse vocal plasticity, including vocal ontogeny changes in USVs over early development that might not be explained by innate maturation processes, evidence for and against a role for auditory feedback in developing and maintaining normal mouse USVs, and evidence for and against limited vocal imitation of song pitch. To reconcile these findings, we suggest that the trait of vocal learning may not be dichotomous but encompass a broad spectrum of behavioral and neural traits we call the continuum hypothesis, and that mice possess some of the traits associated with a capacity for limited vocal learning.

Psicologia evolucionista e a seleção sexual: o caso da linguagem

Na tentativa de entender o caráter adaptativo e a história evolucionária dos processos cognitivos subjacentes ao comportamento lingüístico, uma série de mecanismos e conceitos advindos da teoria evolucionária tem tido, recentemente, sua potencial relevância aferida em uma série de estudos, entre eles, o chamado "Efeito Baldwin" e a teoria da seleção inclusiva (Kin Selection Theory). No presente trabalho, é oferecida, além de uma breve revisão do conceito de seleção sexual e do seu uso e status na Psicologia Evolucionista, uma crítica de uma proposta particular acerca do papel que o processo de seleção sexual possa ter tido no desenvolvimento da capacidade de linguagem na linhagem do Homo sapiens sapiens. Além de pontos específicos à hipótese sujeita à análise, são levantados também problemas e questões de natureza mais ampla e relevante para pesquisas posteriores.

Language evolution and an emergent property

Much debate has been stimulated by the recent hypothesis that human language consists of a faculty that is shared with non-human animals (faculty of language in a broad sense; FLB) and a faculty that is specific to human language (faculty of language in a narrow sense; FLN). This hypothesis has encouraged a tendency to emphasize one component of FLN: the cognitive operation of recursion. In consequence, non-syntactical, yet unique, aspects of human language have been neglected. One of these properties consists of vocal learning that enables an abundance of learned syllables. I suggest that FLN is not an independent faculty, but an 'emergent' property, arising from interactions between several other non-syntactical subfaculties of FLB, including vocal learning ability.