Biology subjects

Zanini, A.

Publications and source records attributed to Zanini, A..

5 recordsLinked to original sources

bioRxiv2023

A vocalization-processing network in marmosets

Vocalizations play an important role in the daily life of primates and likely form the basis of human language. Functional imaging studies have demonstrated that listening to language or reading activates a left-lateralized fronto-temporal language network in human participants. Here we acquired whole-brain ultrahigh field (9.4 Tesla) fMRI in awake marmosets (Callithrix jacchus) and demonstrate that these highly vocal small New World primates possess a similar fronto-temporal network, including subcortical regions, that is activated by the presentation of conspecific vocalizations. The findings suggest that the human language network has evolved from an ancestral vocalization network that predates the separation of New and Old World primates.

neuroscience↗

bioRxiv2023

Gaze patterns and brain activations in humans and marmosets in the Frith-Happe; theory-of-mind animation task

Theory of Mind (ToM) refers to the ability to ascribe mental states to other individuals. This process is so strong that it extends even to the attribution of mental states to animations depicting interacting simple geometric shapes, such as in the Frith-Happe animations in which two triangles move either purposelessly (Random condition), or as if one triangle is reacting to the other triangles mental state (ToM condition). Currently, there is no evidence that nonhuman primates attribute mental states to moving abstract shapes. Here we investigated whether highly social marmosets (Callithrix jacchus) process ToM and Random Frith-Happe animations differently. Our results show that marmosets and humans (1) follow more closely one of the triangles during the observation of ToM compared to Random animations, and (2) activate large and comparable brain networks when viewing ToM compared to Random animations. These findings indicate that marmosets, like humans, process ToM animations differently from Random animations.

neuroscience↗

bioRxiv2022

Perception of dynamic facial expressions activates a cortico-subcortico-cerebellar network in marmosets

The perception and identification of faces and facial emotional expressions are critical for social communication in the daily life of all primates. Here, we investigated the neural network activated by dynamic facial expressions in awake New World common marmosets with ultra-high field fMRI at 9.4T. Our results show that dynamic facial expressions activate several areas along the occipitotemporal axis (V2/V3, V4/TEO, FST, caudal TE, rostral TE, TPO), frontal cortex (areas 45/47, 13, 8a and orbital cortex), amygdala, motion-sensitive areas, premotor area, and in the posterior lobe of the cerebellum. Negative faces increased the monkeys respiration rates and elicited stronger responses along the occipitotemporal cortical axis, in the amygdala and in the hypothalamus. This cortico-subcortico-cerebellar network may play an important role in the perception of behaviorally relevant facial expressions that are vital for social communication in marmosets. Significance StatementRecent research has highlighted the importance of emotional content of faces in social communication in humans and non-human primates. The current study focuses on the neural responses to dynamic emotional facial expressions in the common marmoset (Callithrix jacchus), a New World primate species sharing several similarities of social behavior with humans. Using ultra-high-field fMRI, we show that negative facial expressions activate a cortico-subcortico-cerebellar network and, critically, negative faces increase the level of arousal of marmosets, possibly relayed through a modulation of the activity in the autonomic nervous system via stress-integrative brain centres in the hypothalamus. Our results reveal the existence of specific neural and physiological responses to negative emotional faces suggesting that behaviorally relevant facial expressions are vital for social communication in New World marmosets.

neuroscience↗

bioRxiv2022

An action-observation network in the common marmoset identified by ultra-high field fMRI

The observation of others actions activates a network of temporal, parietal and premotor/prefrontal areas in macaque monkeys and humans. This action-observation network (AON) has been shown to play important roles in understanding the actions of others, learning by imitation, and social cognition in both species. It is unclear whether a similar network exists in New World primates, which separated from Old Word Primates [~] 35 million years ago. Here we used ultra-high field fMRI at 9.4T in awake common marmosets (Callithrix jacchus) while they watched videos depicting the upper-limb of conspecifics performing goal-directed (grasping food) or non-goal-directed actions. We found that the observation of goal-directed actions, compared to non-goal directed ones, activated a temporo-parieto-frontal network, including areas 6 and 45 in premotor and prefrontal cortices, areas PGa-IPa, FST and the TE complex in occipito-temporal region and areas V6A, MIP, LIP and PG in the occipito-parietal cortex. These results show remarkable overlap with the AON observed in humans and macaques. These results demonstrate the existence of an evolutionarily conserved AON that likely predates the separation of Old and New World primates.

neuroscience↗

bioRxiv2020

Patterns of multisensory facilitation distinguish peripersonal from reaching space

Peripersonal space (PPS) is a multisensory representation of the space near body parts facilitating interactions with the close environment. Studies on non-human and human primates converge in showing that PPS is a body-part-centred representation that guides actions. Because of these characteristics, growing confusion conflates peripersonal and arm-reaching space (ARS), that is the space ones arm can reach. Despite neuroanatomical evidence favors their distinction, no study has contrasted directly their respective extent and behavioral features. Here, in five experiments (N=140) we found that PPS differs from ARS, as evidenced both by participants spatial and temporal performance and its modeling. We mapped PPS and ARS using both their respective gold standard tasks and a novel multisensory facilitation paradigm. Results show that 1) PPS is smaller than ARS; 2) multivariate analyses of spatial patterns of multisensory facilitation predict participants hand locations within ARS; 3) the multisensory facilitation map shifts isomorphically following hand positions, revealing hand-centred coding of PPS, therefore pointing to a functional similarity to the receptive fields of monkeys multisensory neurons. A control experiment further corroborated these results and additionally ruled out the orienting of attention as driving mechanism for the increased multisensory facilitation near the hand. In sharp contrast, ARS mapping results in a larger spatial extent, with undistinguishable patterns across hand positions, cross-validating the conclusion that PPS and ARS are distinct spatial representations. These findings urge for a refinement of theoretical models of PPS, which is relevant to constructs as diverse as self-representation, social interpersonal distance, and motor control.

neuroscience↗