The Semantics of Natural Objects and Tools in the Brain: A Combined Behavioral and MEG Study

Abstract

Current literature supports the notion that the recognition of objects, when visually presented, is sub-served by neural structures different from those responsible for the semantic processing of their nouns. However, embodiment foresees that processing observed objects and their verbal labels should share similar neural mechanisms. In a combined behavioral and MEG study, we compared the modulation of motor responses and cortical rhythms during the processing of graspable natural objects and tools, either verbally or pictorially presented. Our findings demonstrate that conveying meaning to an observed object or processing its noun similarly modulates both motor responses and cortical rhythms; being natural graspable objects and tools differently represented in the brain, they affect in a different manner both behavioral and MEG findings, independent of presentation modality. These results provide experimental evidence that neural substrates responsible for conveying meaning to objects overlap with those where the object is represented, thus supporting an embodied view of semantic processing.

Grounding abstract concepts and beliefs into experience: The embodied perspective

“…The embodied perspective on language is now supported by several studies showing that activation of neural substrates processing the sensory and motor aspects of the world is not only associated with the processing of language referring to concrete aspects of the world (Buccino et al, 2005;Tettamanti et al, 2005;Gough et al, 2012Gough et al, , 2013Marino et al, 2013Marino et al, , 2014Visani et al, 2022) but is also causal to the understanding of concrete language (e.g., Bak et al, 2006;Sato et al, 2008;Kemmerer et al, 2012;Tremblay et al, 2012;Cardona et al, 2013;Fernandino et al, 2013;Desai et al, 2015;Klepp et al, 2015;Buccino et al, 2018; for review Buccino et al, 2016).…”

Hand constraint reduces brain activity and affects the speed of verbal responses on semantic tasks

“…We therefore defined the regions of interest (ROIs) for this study as the anterior (AIP) and posterior (CIP) areas of the LIPS and the anterior (SMG) and posterior (AG) areas of the LIPL. Viewing hand-manipulable objects activates the precentral cortex 27 , 48 , 49 ; such activity might be altered by hand constraint. Therefore, it would be beneficial to simultaneously record the LIPL and premotor cortex.…”

Grasping the semantic of actions: a combined behavioral and MEG study

“…In humans, the neural structures implicated in the execution and understanding of observed actions also appear involved in the understanding and processing of action-related language (Vigliocco et al, 2011 ; Marino et al, 2014 ; Borghi and Riggio, 2015 ; Buccino et al, 2016 , 2018 ; García and Ibáñez, 2016 ; Sakreida et al, 2016 ; Zhang et al, 2016 ; Horoufchin et al, 2018 ; Garofalo et al, 2022 ; Visani et al, 2022 ). In this respect, accumulating empirical evidence suggested that the sensorimotor and even emotional systems involved in experiencing the content expressed by verbal material are causally involved in understanding the content of that linguistic stuff (Pulvermüller, 2002 , 2010 ; Barsalou, 2008 ; Fischer and Zwaan, 2008 ; Gallese, 2008 ; Jirak et al, 2010 ; Buccino et al, 2016 ).…”

“…In support of this interpretation, Transcranial Magnetic Stimulation (TMS) studies showed a decrease in Motor-Evoked Potentials (MEPs) during verb listening (Buccino et al, 2005 ). Furthermore, a weaker suppression of Beta band oscillations was found when motor responses are given with the same body part normally used to perform the action expressed by the verb (Klepp et al, 2015 ; Visani et al, 2022 ). Beta band oscillations are the main rhythm deriving from the motor cortex, and it is characterized by a pattern of suppression and rebound during movement (Pfurtscheller and Lopes da Silva, 1999 ).…”

“…Beta suppression, or event-related desynchronization (ERD), starts several 100 ms before the start of the movement (both when the movement is internally or externally triggered) and becomes maximal around the time of movement. Hence, due to these features, the ERD is frequently used to investigate the brain correlates of action-related processes, such as action observation (Hari and Kujala, 2009 ; Moreno and de Vega, 2013 ), motor imagery (Schnitzler et al, 1997 ; de Lange and Roelofs, 2008 ; Brinkman et al, 2014 ), and the processing of action-related language (Weiss and Mueller, 2012 ; Klepp et al, 2015 ; Visani et al, 2022 ). In general terms, a weaker suppression (minor decrease of ERD) of Beta rhythm indicates that the motor system is less ready for generating a motor output, while an increased suppression (greater decrease of ERD) indicates that the motor system is more ready to generate a motor response.…”