Contents lists available at ScienceDirect Brain and Cognition journal homepage: www.elsevier.com/locate/b&c Imagine squeezing a cactus: Cortical activation during affective motor imagery measured by functional near-infrared spectroscopy Selina C. Wriessnegger a,b, ⁎ , Günther Bauernfeind d,e , Eva-Maria Kurz c , Philipp Raggam a , Gernot R. Müller-Putz a,b a Institute of Neural Engineering, Graz University of Technology, Graz, Austria b BioTechMed-Graz, Graz, Austria c University of Tuebingen, Department of Paediatric and Juvenile Psychiatry and Psychotherapy, Tuebingen, Germany d Department of Otolaryngology, Hannover Medical School, Carl Neuberg Str. 1, 30625 Hannover, Germany e Cluster of Excellence “Hearing4all”, Hannover, Germany ABSTRACT The activation of different brain areas during kinaesthetic and visual motor imagery has been extensively studied, whereas little is known about affective motor imagery, i.e. the imagery of pleasant/unpleasant movements. In the present neuroimaging study we investigated cortical activation of kinaesthetic motor imagery (KMI) based on emotional stimulus content by means of functional near infrared spectroscopy (fNIRS). Twenty healthy adult participants were instructed to imagine affective, and neutral motor tasks while multichannel fNIRS was recorded simultaneously. In the affective MI condition they had to imagine e.g. squeezing a cactus with their right hand several times, eliciting an unpleasant emotion. In the neutral condition their task was to imagine squeezing a ball. Significant differences in oxy- hemoglobin [oxy-Hb] concentration changes during KMI including affective objects in different brain regions were found. Specifically activation in left parietal and frontal regions was increased during the imagery of squeezing a cactus which induced a painful feeling. Both areas are also involved in the perception of pain and commonly labelled as parts of the “pain matrix”. Our study provides novel insights in cortical activation patterns during affective motor imagery and its psychological and cognitive mechanisms underlying pain experience. 1. Introduction Motor imagery (MI) is a dynamic cognitive state during which the representation of a specific motor action is internally created without any muscular activity. Furthermore it requires the activation of brain regions that are also involved in movement preparation and execution, accompanied by a voluntary inhibition of the actual movement (Jeannerod, 1995; Lotze & Cohen, 2006; Porro et al., 1996). There is increasing evidence that mental representations of motor events involve to a large extent the same cortical areas that are activated during actual motor preparation and execution (Decety, 1996; Jeannerod & Decety, 1995; Jeannerod & Frak, 1999; Kimberley et al., 2006). Concretely, motor imagery corresponds to a type of motor preparation process where motor programs are recruited to simulate motor performance without executing the movements. This so called “simulation hypoth- esis” has been established by psychophysiological (Danckert et al., 2002; Decety, Jeannerod, & Prablanc, 1989) and neuroimaging evi- dence in human subjects (Ehrsson, Geyer, & Naito, 2003; Lotze, Montoya, Erb, & Hülsmann, 1999; Naito, Roland, & Ehrsson, 2002; Neuper & Pfurtscheller, 2001; Pfurtscheller & Neuper, 1997; Solodkin, Hlustik, Chen, & Small, 2004). Several imaging studies showed the involvement of the premotor, supplementary motor, cingulate and parietal cortical areas, the basal ganglia, and the cerebellum, not only during the actual execution of a movement but also during the imagi- nation of a movement (Dechent, Merboldt, & Frahm, 2004; Hanakawa et al., 2003). Ehrsson et al. (2003) for example showed that imagery of finger, tongue and toe movements is somatotopically organized, meaning that imagery of finger movement activated the finger area, imagery of toe movements activated the centrally located foot area of the supplementary motor area and the primary motor cortex and ima- gery of tongue movements activated the tongue region of the primary motor cortex. These data suggest that the imagined body part is re- flected more or less directly in the pattern of cortical activation. Some studies using fMRI also found activation in the primary motor cortex (Gerarding et al., 2000; Porro et al., 1996; Porro, Cettolo, Francescato, & Baraldi, 2000; Roth et al., 1996, see also Sharma, Pomeroy, & Baron, 2006), however others reported the absence of primary motor cortex activity (Blefari, Sulzer, Hepp-Reymond, Kollias, & Gassert, 2015; Hanakawa et al., 2003; Lange, Hagoort, & Toni, 2005; Parsons et al., 1995; Tomasino & Gremese, 2016) so that the degree of involvement of the primary motor cortex is still a matter of discussion (see also De Vries & Mulder, 2007, Hétu et al., 2013). There is a lot of evidence that MI is https://doi.org/10.1016/j.bandc.2018.07.006 Received 19 June 2018; Received in revised form 17 July 2018; Accepted 17 July 2018 ⁎ Corresponding author at: Institute of Neural Engineering, Graz University of Technology, Stremayrgasse 16/IV, 8010 Graz, Austria. E-mail address: s.wriessnegger@tugraz.at (S.C. Wriessnegger). Brain and Cognition 126 (2018) 13–22 0278-2626/ © 2018 Elsevier Inc. All rights reserved. T