Neural correlates of cognitively controlled vocalizations in a corvid songbird

Exploring Anatomical Links Between the Crow’s Nidopallium Caudolaterale and its Song System

“…Therefore, it is highly likely that the carrion crow's song system is involved in producing vocalizations in response to visual or auditory cues (Brecht et al, 2019;Liao et al, 2024). However, functional neural data supporting this hypothesis is currently lacking, as neuronal recordings in vocalizing crows have thus far only been obtained from their NCL (Brecht et al, 2023), a highly integrative multimodal nidopallial area (Kroner and Gunturkun, 1999;Nieder, 2015, 2017;Kersten et al, 2024). These recordings have shown that the firing rates of single NCL neurons can predict the onset of crow vocalizations following a visual go-cue but not the onset of un-cued vocalizations, suggesting that this premotor activity may be a driver of volitional calls (Brecht et al, 2023).…”

“…However, functional neural data supporting this hypothesis is currently lacking, as neuronal recordings in vocalizing crows have thus far only been obtained from their NCL (Brecht et al, 2023), a highly integrative multimodal nidopallial area (Kroner and Gunturkun, 1999;Nieder, 2015, 2017;Kersten et al, 2024). These recordings have shown that the firing rates of single NCL neurons can predict the onset of crow vocalizations following a visual go-cue but not the onset of un-cued vocalizations, suggesting that this premotor activity may be a driver of volitional calls (Brecht et al, 2023). Beyond vocalizations, NCL neurons are also involved in various higher cognitive functions (Rose and Colombo, 2005;Veit and Nieder, 2013;Veit et al, 2014;Hahn and Rose, 2023), of which the representation of magnitudes is a particularly interesting example (Moll and Nieder, 2014;Nieder, 2015, 2020;Kirschhock and Nieder, 2022;Wagener and Nieder, 2023) given the crows' ability to flexibly control the number of their calls (Liao et al, 2024).…”

Crows “count” the number of self-generated vocalizations

“…However, a species could significantly enhance goal-directed communication if it could integrate numerical proficiency with voluntary control over vocalizations. We hypothesized that carrion crows, one of the few bird species ( 8 , 9 ) that possess not only numerical competency ( 10 – 12 ) but also volitional vocal control ( 13 , 14 ), can deliberately control the number of produced vocalizations.…”

“…Our results demonstrate that crows can flexibly and deliberately produce an instructed number of vocalizations by using the “approximate number system” ( 21 ), a nonsymbolic number estimation system shared by humans and animals ( 15 ). This ability is especially impressive given that volitional vocalizations are more difficult to produce and require much longer reaction times (~1 to 2 s) for crows ( 13 , 14 ) and monkeys ( 22 ) as compared with instructed pecks or head movements in crows ( 12 , 23 ) or hand movements in monkeys ( 22 , 24 ), which show reaction times of only a few hundreds of milliseconds. The crows’ cognitive vocal control opens the possibility that some bird species may deliberately use the number of vocalizations to convey ecologically relevant information ( 3 , 25 ).…”

“…Neuronal representations of variable numbers of repeat syllables in song have been found in certain song nuclei ( 27 ) and manipulations of song nuclei can influence the number of repeats produced ( 28 ). Moreover, neurons selective to the number of objects and self-generated actions ( 11 , 12 ), and neurons signaling volitional vocal initiation ( 14 ), are present in the telencephalic nidopallium caudolaterale, a brain area representing executive functions in birds. Notably, better vocal learning in songbirds correlates with enhanced problem solving ( 29 ).…”