Original Articles Standard body-space relationships: Fingers hold spatial information Daniele Romano a,b , Francesco Marini a,c , Angelo Maravita a,b,⇑ a University of Milano Bicocca, Department of Psychology, piazza Ateneo Nuovo 1, 20126 Milan, Italy b NeuroMi – Milan Center for Neuroscience, Milan, Italy c Department of Psychology, University of Nevada, Reno, NV 89557, USA article info Article history: Received 7 November 2016 Revised 10 May 2017 Accepted 12 May 2017 Keywords: Embodied cognition Body representation Body schema Body image Posture Tactile processing abstract The representation of the body in the brain is constantly updated to allow optimal sensorimotor interac- tions with the external world. In addition to dynamic features, body representation holds stable features that are still largely unknown. In the present work we explored the hypothesis that body parts have pref- erential associations with relative spatial locations. Specifically, in three experiments, we found consis- tent preferential associations between the index finger and the top position, and between the thumb and the bottom position. This association was found in a tactile sensory discrimination task, which was conducted both with and without vision, as well as at the implicit conceptual association level. These findings show that body parts and spatial locations are stably associated. Therefore, not only are body segments dynamically mapped in space for perception and action, but they also hold intrinsic spatial information that contributes to somatosensory spatial processing. Ó 2017 Elsevier B.V. All rights reserved. 1. Introduction The idea that everyone has a mental representation of his/her own body has received wide support in the multidisciplinary field of research at the intersection of philosophy, experimental psychol- ogy, and cognitive neuroscience that focuses on how mind and body interact. This representation is thought to help localizing the bodily self and interacting with the external world (Blanke & Metzinger, 2009; de Vignemont, 2010). Different sub-components of body rep- resentations (BR) have been distinguished since its first description (e.g. Head & Holmes, 1911). On the one hand, a dynamic represen- tation of the body oriented to action, namely the body schema (Cardinali, Frassinetti et al., 2009; Coslett, 1998; Kammers, Kootker, Hogendoorn, & Dijkerman, 2009; Maravita, Spence, & Driver, 2003), allows processing of information necessary to plan actions in space (Cardinali, Brozzoli, & Farnè, 2009; de Vignemont, 2010; Holmes & Spence, 2004; Kammers, van der Ham, & Dijkerman, 2006; Tsakiris & Fotopoulou, 2008). On the other hand, BR also includes more stable aspects about semantic and structural aspects of one’s own body, whose nature is still debated (de Vignemont, 2010; Dijkerman & de Haan, 2007; Gallagher, 2005; Gandevia & Phegan, 1999; Ionta, Perruchoud, Draganski, & Blanke, 2012; Kammers, Mulder, de Vignemont, & Dijkerman, 2009; Longo, Azañón, & Haggard, 2010; Melzack & Bromage, 1973; Moseley, 2005; Tsakiris & Fotopoulou, 2008). The characterization of different components of BR is of para- mount importance because both dynamic and stable features of BR continuously affect our everyday interactions with the external world. Considering a critical aspect of behavior, i.e. the interaction between the body and external objects, there is evidence that body posture may affect the spatial processing of sensory stimuli (Azañón & Soto-Faraco, 2008; Ionta, Fourkas, Fiorio, & Aglioti, 2007; Parsons, 1987a, 1987b; Reed & Farah, 1995). Even in a simple tactile tempo- ral order judgment task, the relative position of limbs in space can affect performance by automatically referring skin stimulations to the egocentric spatial coordinates (Yamamoto & Kitazawa, 2001a, 2001b), although the early stage of the processing is coded in a somatotopic frame of reference (Azañón & Soto-Faraco, 2008). This suggests the existence of a continuous comparison process between visual, somatosensory, and proprioceptive information, in which contingent bodily and visuospatial representations influence each other. Alternatively, spatial information might be deeply embedded in BR and invariantly modulate performance independent of ongo- ing postural changes. This intriguing possibility implies the exis- tence of a standard representation of the relationship between body and space that potentially modulates all body-space interac- tions regardless of any potential postural change. We sought out the existence of standard associations between spatial locations and body parts focusing on the fingers because http://dx.doi.org/10.1016/j.cognition.2017.05.014 0010-0277/Ó 2017 Elsevier B.V. All rights reserved. ⇑ Corresponding author at: University of Milano Bicocca, Department of Psychol- ogy, piazza Ateneo Nuovo 1, 20126 Milan, Italy. E-mail addresses: daniele.romano@unimib.it (D. Romano), francesco.pd@gmail. com (F. Marini), angelo.maravita@unimib.it (A. Maravita). Cognition 165 (2017) 105–112 Contents lists available at ScienceDirect Cognition journal homepage: www.elsevier.com/locate/COGNIT