Birdsong as a window into language origins and evolutionary neuroscience

Abstract

Humans and songbirds share the key trait of vocal learning, manifested in speech and song, respectively. Striking analogies between these behaviours include that both are acquired during developmental critical periods when the brain's ability for vocal learning peaks. Both behaviours show similarities in the overall architecture of their underlying brain areas, characterized by cortico-striato-thalamic loops and direct projections from cortical neurons onto brainstem motor neurons that control the vocal organs. These neural analogies extend to the molecular level, with certain song control regions sharing convergent transcriptional profiles with speech-related regions in the human brain. This evolutionary convergence offers an unprecedented opportunity to decipher the shared neurogenetic underpinnings of vocal learning. A key strength of the songbird model is that it allows for the delineation of activity-dependent transcriptional changes in the brain that are driven by learned vocal behaviour. To capitalize on this advantage, we used previously published datasets from our laboratory that correlate gene co-expression networks to features of learned vocalization within and after critical period closure to probe the functional relevance of genes implicated in language. We interrogate specific genes and cellular processes through converging lines of evidence: human-specific evolutionary changes, intelligence-related phenotypes and relevance to vocal learning gene co-expression in songbirds. This article is part of the theme issue ‘What can animal communication teach us about human language?’

Can Cognitive Ability Give Invasive Species the Means to Succeed? A Review of the Evidence

“…Moreover, analyses are hampered because the relationship between brain size and body size is not linear in all taxa [e.g., Fitzpatrick et al (2012) cited by Montgomery et al (2013), Logan et al (2018) cited by Logan et al (2018)] and often, brain measures used in comparative studies are based on a few individuals (Logan et al, 2018). Results of such comparative studies using brain size are, therefore, better used as a starting point for more detailed investigations looking at how individual differences in cognitive ability translate to brain anatomy within species (e.g., Audet et al, 2018) followed by investigations into differences between closely related species (e.g., Aamodt et al, 2020) to better understand how changes in brain size and structure are related to cognition and behavior (Logan et al, 2018).…”

Evidence for Teaching in an Australian Songbird

“…Although the processes that guide song development can overlap ( Nottebohm, 1969 ) and the time span varies widely, song acquisition by and large transpires in the first year of life during a critical sensitive period ( Marler, 1970a ; Nelson et al, 1995 ). Striking parallels exist between human speech and birdsong in their developmental stages ( Darwin, 1871/1981 ; Marler, 1970b ; Doupe and Kuhl, 1999 ; Hauser et al, 2002 ; Goldstein et al, 2003 ; Jarvis, 2004 ; Fitch, 2005 ; Merker and Okanoya, 2007 ; Bolhuis et al, 2010 ; Bolhuis and Everaert, 2016 ; Aamodt et al, 2020 ). Some songbirds retain vocal plasticity into adulthood; these open-ended learners may routinely learn new repertoire, re-open seasonally, or deliver previously unused song phrases ( Yasukawa et al, 1980 ; Marler, 1981 , 1990 ; Nottebohm et al, 1986 ; Brown et al, 1988 ; McGregor and Krebs, 1989 ; Nottebohm, 1989 , 1993 ; Trainer, 1989 ; Adret-Hausberger et al, 1990 ; Chaiken et al, 1994 ; Mountjoy and Lemon, 1995 ; Payne, 1996 ; Baptista and Gaunt, 1997 ; Doupe and Kuhl, 1999 ; Adret, 2004 ; Taylor, 2017 ).…”

What can animal communication teach us about human language?

“…Seminal recent work by Jarvis and colleagues [21] revealed the evolutionary convergence of vocal learning at the level of gene expression in birds and humans. Here, Aamodt et al [22] explore the genetic landscape of this convergence, analysing thousands of genes in avian song production to provide insights into the neurogenetic underpinnings of human communication disorders. They review shared genes in humans and songbirds related to vocal learning, including genes encoding a linked reward system that are also implicated in human communication disorders.…”