Vol.:(0123456789) 1 3 Psychological Research https://doi.org/10.1007/s00426-019-01242-x ORIGINAL ARTICLE Peripersonal space in social context is modulated by action reward, but diferently in males and females Maria Francesca Gigliotti 1  · Patrícia Soares Coelho 1,2  · Joana Coutinho 2  · Yann Coello 1 Received: 20 April 2019 / Accepted: 25 August 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The peripersonal space (PPS) is a multisensory representation of the near-body region of space where objects appear at hand. It also represents a bufer zone protecting the body from external threats and as such it contributes to the organization of social interactions. However, how the combination of embodied objects processing and constraints inherent to social interactions contributes to PPS representation remains an open issue. By using a cooperative task where two male (N = 22) or female (N = 18) participants, sharing the same action space, were requested to select a number of stimuli on a touch-screen table, we investigated the efect of non-uniform distribution of reward-yielding stimuli on selection strategy and perceptual judgments of reachability, used as a proxy of PPS representation. The probability to select a reward-yielding stimulus (50% of the stimuli) was 75% in the proximal space of one of the two confederates. Results showed that participants initially prioritized stimuli in their proximal space and were progressively infuenced by the spatial distribution of reward-yielding stimuli, thus invading their confederate’s action space when associated with higher probability of reward. The distribution of reward-yielding stimuli led to an increase of reachability threshold, but only when biased towards the participants’ distal space. Although the invasion of others’ PPS was more pronounced in male participants, the biased distribution of reward- yielding stimuli altered the reachability threshold similarly in males and females. As a whole, the data revealed that reward expectations in relation to motor actions infuence both PPS exploration and representation in social context, but diferently in males and females. Introduction In everyday life, the way we interact with the environ- ment relies on a series of computations performed by the brain, based on the integration of information related to the body and the space in which it is embedded. This implies that the brain retains a functional representation of the environment which depends on the current sensory- motor state as well as the outcome of previous interactions with the physical and social context (Grusser, 1983; Hall, 1966; Previc, 1998). Within this functional representa- tion, the peripersonal space (PPS) specifes the limited space around the body dedicated to the interaction with objects located at hand-reachable distance (Bufacchi & Iannetti, 2018; Coello & Iachini, 2016; de Vignemont & Iannetti, 2015; di Pellegrino & Làdavas, 2015; Rizzolatti, Scandolara, Matelli, & Gentilucci, 1981). In relation to the linkage between PPS and action, object processing in PPS involves multisensory integration supported by a large subcortical and cortical brain fronto-parietal network implying the motor system (Brozzoli, Makin, Cardinali, Holmes, & Farné, 2011; Cléry, Guipponi, Wardak, & Hamed, 2015; Graziano, Yap, & Gross, 1994; Holmes & Spence 2004; Makin, Holmes, & Zohary, 2007; Serino, Canzoneri, & Avenanti, 2011). In line with this view, Gra- ziano (2017) described multimodal neurons in the pre- motor cortex that discharge predominantly not only for stimuli near the body but also for more distant stimuli, so * Yann Coello yann.coello@univ-lille.fr Maria Francesca Gigliotti maria-francesca.gigliotti@univ-lille.fr Patrícia Soares Coelho patricia.a.soares.coelho@gmail.com Joana Coutinho joanafcp@gmail.com 1 UMR CNRS 9193 - SCALab - Sciences Cognitives et Sciences Afectives, University of Lille, 59650 Villeneuve-d’Ascq CEDEX, Francia 2 Psychological Neuroscience Laboratory, University of Minho, 4710-057 Braga, Portugal