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The overlap between motor and cognitive signs resulting from posterior parietal cortex (PPC) and cerebellar lesions can mask their relative contribution in the sensorimotor integration process. This study aimed to identify distinguishing motor and cognitive features to disentangle PPC and cerebellar involvement in two sensorimotor-related functions: gait and body schema representation. Thirty healthy volunteers were enrolled and randomly assigned to PPC or cerebellar stimulation. Sham stimulation and 1 Hz-repetitive-Transcranial-Magnetic-Stimulation were delivered over P3 or cerebellum before a balance and a walking distance estimation task. Each trial was repeated with eyes open (EO) and closed (EC). Eight inertial measurement units recorded spatiotemporal and kinematic variables of gait. Instability increased in both groups after real stimulation: PPC inhibition resulted in increased instability in EC conditions, as evidenced by increased ellipse area and range of movement in medio-lateral and anterior-posterior (ROMap) directions. Cerebellar inhibition affected both EC (increased ROMap) and EO stability (greater displacement of the center of mass). Inhibitory stimulation (EC vs. EO) affected also gait spatiotemporal variability, with a high variability of ankle and knee angles plus different patterns in the two groups (cerebellar vs parietal). Lastly, PPC group overestimates distances after real stimulation (EC condition) compared to the cerebellar group. Stability, gait variability, and distance estimation parameters may be useful clinical parameters to disentangle cerebellar and PPC sensorimotor integration deficits. Clinical differential diagnosis efficiency can benefit from this methodological approach.

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Objective:To explor the effects of mentalization-based family therapy (MBFT) on the emotions of anxiety and depression, reflective functions, and related brain regions of adolescents with depression.Methods:Thirty-two adolescent patients with depression were selected in Beijing Huilongguan Hospital.Among them, fifteen patients treated with conventional drugs were defined as the control group, the other seventeen patients served as the observation group.On the basis of routine drug treatment, patients in the observation group were treated with 1.5 h MBFT once a week, for a total of 3 months.Among them, 10 patients underwent resting functional magnetic resonance imaging(rs-fMRI) scans before and after the intervention.SPSS 23.0 was used for statistical analysis of scale evaluation data by using chi-square test and repeated-measure analysis of variance, and pairwise Pearson correlation was used to construct a brain network matrix for the MRI results.The patient's brain network matrix was put into Gretna to calculate, and then use repeated measures analysis of variance and t test for judgment. Results:(1)Repeated measurement analysis of variance showed, over time and group, before and after intervention, the group×time interactions of patients' reflective function, anxiety, depression were statistically significant ( F=5.113, 9.350, 5.264, all P<0.05). Further simple effect analysis showed, in the observation group, there were statistically significant differences in patients' anxiety ((55.09±14.35) vs (30.58±3.62)), depression ((61.58±16.81) vs (31.00±3.48)) before and after intervention (all P<0.01). There was no significant difference in reflective function ((8.71±0.51) vs (8.87±0.50) ) in the observation group before and after intervention( P> 0.05). The reflective function((8.92±0.33) vs (8.73±0.35)) and anxiety((50.67±13.88) vs (45.78±12.89)) scores of the control group were not statistically significant different before and after intervention(all P>0.05), and the depression scores of the control group before and after inter-vention((69.33±9.11) vs (50.94±7.99)) were statistically significant different( P<0.01). (2)rs-fMRI showed that, using the posterior parietal lobe and the medial prefrontal lobe as seed points, the group×time interactions with right inferior frontal gyrus, right fusiform gyrus, right superior temporal gyrus, left middle temporal gyrus and right superior frontal gyrus were statistically significant ( F=29.56, 20.63, 8.69, 9.49, 8.62, all P<0.05). The further simple effect analysis showed in the observation group, the pre-test was less than the post-test, and the difference was statistically significant( P<0.05). In the control group, there were not statistically significant differences in the functional connection strength before and after the test(all P>0.05). (3)The brain network analysis of 264 regions of interest (ROIs) in the whole brain showed that the number of modules in the observation group was less than that in the control group, and the difference was statistically significant ( t=-2.64, P=0.046). Conclusion:MBFT can improve the anxiety and depression of adolescent patients with depression.It enhances the functional link between mentalization related brain regions and the whole brain, and enhances the activity of the whole brain link to become more integrated.

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Lexical competence includes both the ability to relate words to the external world as accessed through (mainly) visual perception (referential competence) and the ability to relate words to other words (inferential competence). We investigated the role of visual imagery in lexical inferential competence by using an auditory version of an inferential naming-to-definition task, in which visual imageability of both definitions and target words was manipulated. A visual imageability-related brain activity (bilateral posterior-parietal lobe and ventrotemporal cortex, including fusiform gyrus) was found during a "pure" inferential performance. The definition effect in high vs. low imageability contrast suggests that a visual-imagery strategy is spontaneously activated during the retrieval of a word from a high imageable definition; such an effect appears to be independent of whether the target word is high or low imageable. This contributes to the understanding of the neural correlates of semantic processing and the differential role of spontaneous visual imagery, depending on the semantic properties of the processed stimuli.

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The digit span is one of the most widely used memory tests in clinical and experimental neuropsychology for reliably measuring short-term memory capacity. In the forward version, sequences of digits of increasing length have to be reproduced in the order in which they are presented, whereas in the backward version items must be reproduced in the reversed order. Here, we assessed whether transcranial alternating current stimulation (tACS) increases the memory span for digits of young and midlife adults. Imperceptibly weak electrical currents in the alpha (10 Hz), beta (20 Hz), theta (5 Hz), and gamma (40 Hz) range, as well as a sham stimulation, were delivered over the left posterior parietal cortex, a cortical region thought to sustain maintenance processes in short-term memory through oscillatory brain activity in the beta range. We showed a frequency-specific effect of beta-tACS that robustly increased the forward memory span of young, but not middle-aged, healthy individuals. The effect correlated with age: the younger the subjects, the greater the benefit arising from parietal beta stimulation. Our results provide evidence of a short-term memory capacity improvement in young adults by online frequency-specific tACS application.

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Verbs denote relations between entities acting a role in an event. Thematic roles are essential to the correct use of verbs and involve both semantic and syntactic aspects. We used repetitive Transcranial Magnetic Stimulation (rTMS) to study the involvement of three different left parietal sites in the understanding of thematic roles. In a sentence-to-picture matching task, twelve participants were asked to judge whether or not a given picture matched with a written sentence. Pictures represented simple reversible actions, and sentences were in the active or passive diathesis. Whereas both active and passive sentences require the correct encoding of thematic roles, passives also imply thematic reanalysis, as the canonical order of thematic roles is systematically reversed. The experiment was divided in three sessions. In each session a different parietal site (anterior, middle, posterior) was stimulated at 5 Hz in an event-related fashion, time-locked to the presentation of visual stimuli. Results showed increased accuracy for passive sentences following posterior parietal stimulation. The effect appeared to be (a) TMS-related, as no effect was observed in a control, no-TMS experiment with eighteen new participants; (b) independent from semantic processes involved in word-picture association, as no TMS-related effects were observed in a picture-word matching task. We interpret the results as showing that the posterior parietal site is specifically involved in the assignment of thematic roles, in particular when the correct interpretation of a sentence requires reanalysis of temporarily encoded thematic roles, as in passive reversible sentences.

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Adaptation to optical prisms displacing the visual scene laterally is a widely investigated instance of visuo-motor plasticity, also because prism adaptation (PA) has been extensively used as a treatment for right-brain-damaged patients suffering from left spatial neglect. The lateral visual displacement brought about by prisms, as indexed by a pointing error in the direction of the displacement, is progressively corrected through repeated pointings: after prism removal, a shift in the direction opposite to the prism-induced deviation occurs in visual, proprioceptive, and visuo-proprioceptive straight-ahead tasks (aftereffects, AEs). The cerebellum and the posterior parietal cortex (PPC) are key components of the bilateral cerebral network subserving the AEs, and the reduction of the pointing error during prism exposure in PA. We report the experimental study of a patient with bilateral occipital and left cerebellar damage, who showed a preserved reduction of the pointing errors to rightward displacing prisms, but not the leftward AEs in the proprioceptive straight-ahead task; instead, visual-proprioceptive and visual AEs were preserved. Anodal transcranial Direct Current Stimulation (tDCS) over the left PPC restored the leftward proprioceptive AEs, and anodal tDCS over the left cerebellum abolished the rightward deviation. Conversely, stimulation over the right PPC or the right cerebellum was ineffective. These results provide novel evidence for neuromodulatory effects of tDCS on defective AEs, through the stimulation over dedicated cortical regions.

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