Talking hands: tongue motor excitability during observation of hand gestures associated with words.

Perception of speech and gestures engage common brain areas. Neural regions involved in speech perception overlap with those involved in speech production in an articulator-specific manner. Yet, it is unclear whether motor cortex also has a role in processing communicative actions like gesture and sign language. We asked whether the mere observation of hand gestures, paired and not paired with words, may result in changes in the excitability of the hand and tongue areas of motor cortex. Using single-pulse transcranial magnetic stimulation (TMS), we measured the motor excitability in tongue and hand areas of left primary motor cortex, while participants viewed video sequences of bimanual hand movements associated or not-associated with nouns. We found higher motor excitability in the tongue area during the presentation of meaningful gestures (noun-associated) as opposed to meaningless ones, while the excitability of hand motor area was not differentially affected by gesture observation. Our results let us argue that the observation of gestures associated with a word results in activation of articulatory motor network accompanying speech production

Speech prosody, reward, and the corticobulbar system: An integrative perspective

Speech prosody is essential for verbal communication. In this commentary I provide an integrative overview, arguing that speech prosody is subserved by the same anatomical and neurochemical mechanisms involved in the processing of reward/affective outcomes

“Grounding sports in the motor cortex”

SENSE OF BODY, BOLOGNA 16-21 GIUGNO, POSTER PRESENTATIO

Competing Mechanisms for Mapping Action-Related Categorical Knowledge and Observed Actions

Responses to pictures of famous tennis and soccer athletes are slower when the responding effector is a hand or foot, respectively, indicating that visual recognition of individuals characterized by skilled motor behavior interferes with the motor reactivity of nonproficient observers. By contrast, directly viewing actions induces motor facilitation, suggesting that actions are mapped in the observers' motor system. Here, we used single-pulse Transcranial Magnetic Stimulation to determine 1) whether observing and recognizing the identity of famous tennis and soccer athletes selectively reduce the corticospinal excitability of arm and leg representations (categorization), 2) whether any athlete-related inhibition effect contrasts the facilitation associated with direct action observation (categorization + action), and 3) whether the classic action observation-related facilitation effect is found when viewing "in action" nonathlete models (action). In 3 experiments, we found that amplitude of motor evoked potentials (MEPs) recorded from leg and arm muscles gradually shifted from reduction to facilitation, moving from the categorization to the action observation tasks. Thus, semantic derivation of motor skills is reflected in limb-specific reduction of MEP amplitude, indicating that even abstract action knowledge is embodied in the motor system and that mapping others' actions on the basis of categorization or of their direct observation relies on competing functional mechanisms

Anodal transcranial direct current stimulation over the ventromedial prefrontal cortex enhances fear extinction in healthy humans: A single blind sham-controlled study

Anxiety disorders are among the most common mental disorders [1,2]. Fear extinction is considered essential to promote successful treatment of several anxiety disorders. Neuroscience research has provided evidence for the contribution of the ventromedial prefrontal cortex (vmPFC) in extinction learning and recall [3,4]. Its role in fear extinction has been investigated via transcranial direct current stimulation (tDCS) in a recent sham-controlled study involving healthy participants. In that study [5], 5 minutes of 2 mA anodal stimulation over the left vmPFC during fear extinction reduced the physiological expression of fear (reduction of Skin conductance response - SCR) induced via Pavlovian conditioning. However, no effects were reported for the recall session. We extended this study by applying tDCS for 10 minutes over the vmPFC during fear extinction, and hypothesized that this intensified stimulation enhances tDCS efficacy. Thirty-two participants with an age mean of 24.15 years were recruited. They were randomly assigned to one of two sub-groups: anodal (n = 16, 5 males) or sham (n = 16, 5 males) stimulation. Overall, tDCS over the left vmPFC appears to reduce the sympathetic component of fear reactions in extinction in participants that acquired fear responses during fear acquisition. Therefore, tDCS had a facilitatory effect on consolidation of extinction, as compared to initial extinction learning. In conclusion, our results corroborate and also extend those provided by van \u2018t Wout et al. [5], as we showed that prolonged tDCS, as compared to the former protocol, facilitates fear extinction consolidation

Supplementary Material for: Interoceptive and affective alterations in Body Integrity Dysphoria: An online self-reporting study

Introduction: Body Integrity Dysphoria (BID) is a rare condition in which individuals experience a long-lasting desire to achieve a specific physical disability. In this study, we tested the hypothesis of interoceptive and affective abnormalities in BID, in line with the evidence of structural and functional alteration of the interoceptive-affective neural system in these individuals. Method: Our study involved 68 participants with BID (mean age 35.6, SD 16.4). Among these participants, 47 expressed a desire for amputation, 14 desired paralysis, 3 sought sensory deprivation, and 3 desired a combination of these forms. For comparisons, we recruited a control group of 79 participants (mean age 35.2, SD 15.8). We administered assessment measures to investigate alexithymia level (TAS-20), disgust sensitivity (DS-R), interoceptive awareness (MAIA-2), and (affective and cognitive) empathy (QCAE). We also administered the Short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) to identify psychiatric comorbidities. Subgroups with Low O-LIFE scores (BID=31; Controls=43) and subgroups with High O-LIFE scores (BID=37; Controls=36) were derived through a median-split procedure. Results: Within the BID Low O-LIFE group, we found reduced interoceptive sensibility, reduced disgust sensitivity, and increased difficulty in identifying feelings, which refers to a dimension of the alexithymia trait. Within the BID High O-LIFE group, we observed a reduced disgust sensitivity and interoceptive sensibility, accompanied by a diminished score in cognitive empathy. Conclusion: Our study suggests that BID can be associated with altered interoceptive and affective processing

Transcranial direct current stimulation in ADHD: A systematic review of efficacy, safety, and protocol-induced electrical field modeling results

Contains fulltext : 219423.pdf (Publisher’s version ) (Closed access)Transcranial direct current stimulation (tDCS) is a promising method for altering cortical excitability with clinical implications. It has been increasingly used in neurodevelopmental disorders, especially attention-deficit hyperactivity disorder (ADHD), but its efficacy (based on effect size calculations), safety, and stimulation parameters have not been systematically examined. In this systematic review, we aimed to (1) explore the effectiveness of tDCS on the clinical symptoms and neuropsychological deficits of ADHD patients, (2) evaluate the safety of tDCS application, especially in children with ADHD, (3) model the electrical field intensity in the target regions based on the commonly-applied and effective versus less-effective protocols, and (4) discuss and propose advanced tDCS parameters. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach, a literature search identified 14 empirical experiments investigating tDCS effects in ADHD. Partial improving effects of tDCS on cognitive deficits (response inhibition, working memory, attention, and cognitive flexibility) or clinical symptoms (e.g., impulsivity and inattention) are reported in 10 studies. No serious adverse effects are reported in 747 sessions of tDCS. The left and right dorsolateral prefrontal cortex are the regions most often targeted, and anodal tDCS the protocol most often applied. An intensity of 2 mA induced stronger electrical fields than 1 mA in adults with ADHD and was associated with significant behavioral changes. In ADHD children, however, the electrical field induced by 1 mA, which is likely larger than the electrical field induced by 1 mA in adults due to the smaller head size of children, was sufficient to result in significant behavioral change. Overall, tDCS seems to be a promising method for improving ADHD deficits. However, the clinical utility of tDCS in ADHD cannot yet be concluded and requires further systematic investigation in larger sample sizes. Cortical regions involved in ADHD pathophysiology, stimulation parameters (e.g. intensity, duration, polarity, and electrode size), and types of symptom/deficit are potential determinants of tDCS efficacy in ADHD. Developmental aspects of tDCS in childhood ADHD should be considered as well.22 p