Looking at ancillary systems for verb recovery: Evidence from non-invasive brain stimulation

• Published in: Brain and cognition 2020-03, Vol.139, p.105515-105515, Article 105515
• Main Authors: Pisano, F., Marangolo, P.
• Format: Article
• Language: English
• Subjects: Aphasia rehabilitation; Broca's area; Cerebellum; Cognition; Cortex (motor); Embodied cognition; Frontal lobe; Language; Neuroimaging; Non-invasive brain stimulation; Sensorimotor system; Spinal cord; Verb recovery
• ISSN: 0278-2626; 1090-2147
• DOI: 10.1016/j.bandc.2019.105515

•We report non invasive brain stimulation (NIBS) evidence on verb processing.•NIBS over the Broca’s area enhances verb production in healthy and aphasic patients.•NIBS is efficacious for verb recovery also when applied over motor structures.•Indeed, cerebellar and spinal stimulation improve verb production.•The sensorimotor structures might work as ancillary systems for verb processing. Several behavioural and neuroimaging studies have suggested that the language function is not restricted into the left areas but it involves regions not predicted by the classical language model. Accordingly, the Embodied Cognition theory postulates a close interaction between the language and the motor system. Indeed, it has been shown that non-invasive brain stimulation (NIBS) is effective for language recovery also when applied over sensorimotor regions, such as the motor cortex, the cerebellum and the spinal cord. We will review a series of NIBS studies in post-stroke aphasic people aimed to assess the impact of NIBS on verb recovery. We first present results which, following the classical assumption of the Broca’s area as the key region for verb processing, have shown that the modulation over this area is efficacious for verb improvement. Then, we will present experiments which, according to Embodied Cognition, have directly investigated through NIBS the role of different sensorimotor regions in enhancing verb production. Since verbs play a crucial role for sentence construction which are most often impaired in the aphasic population, we believe that these results have important clinical implications. Indeed, they address the possibility that different structures might support verb processing.