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Borderline personality disorder (BPD) is a severe psychiatric disorder accompanied by multiple comorbidities. Neuroimaging studies have identified structural abnormalities in BPD with most findings pointing to gray matter volume reductions in the fronto-limbic network, although results remain inconsistent. Similar alterations were found in posttraumatic stress disorder (PTSD), a common comorbidity of BPD. Only a small number of studies have investigated structural differences in BPD patients regarding comorbid PTSD specifically and studies conducting additional surface analyses are scarce. We investigated structural differences in women with BPD with and without PTSD and non-patient controls. Automated voxel-based and region-based volumetric analyses were applied. Additionally, four surface-based measures were analyzed: cortical thickness, gyrification index, fractal dimension, and sulcus depth. Analyses did not identify cortical volume alterations in the fronto-limbic network. Instead, hypergyrification was detected in the right superior parietal cortex in BPD patients compared to non-patient controls. No distinction was revealed between BPD patients with and without PTSD. These findings underline the importance of a holistic investigation examining volumetric and surface measures as these might enhance the understanding of structural alterations in BPD.

Although the neural bases of numerical processing and memory have been extensively studied, much remains to be elucidated concerning the spectral and temporal dynamics surrounding these important cognitive processes. To further this understanding, we employed a novel numerical working memory paradigm in 28 young, healthy adults who underwent magnetoencephalography (MEG). The resulting data were examined in the time‐frequency domain prior to image reconstruction using a beamformer. Whole‐brain, spectrally‐constrained coherence was also employed to determine network connectivity. In response to the numerical task, participants exhibited robust alpha/beta oscillations in the bilateral parietal cortices. Whole‐brain statistical comparisons examining the effect of numerical manipulation during memory‐item maintenance revealed a difference centered in the right superior parietal cortex, such that oscillatory responses during numerical manipulation were significantly stronger than when no manipulation was necessary. Additionally, there was significantly reduced cortico‐cortical coherence between the right and left superior parietal regions during the manipulation compared to the maintenance trials, indicating that these regions were functioning more independently when the numerical information had to be actively processed. In sum, these results support previous studies that have implicated the importance of parietal regions in numerical processing, but also provide new knowledge on the spectral, temporal, and network dynamics that serve this critical cognitive function during active working memory maintenance., Using magnetoencephalography and a novel numerical working memory task, we examined the oscillatory neural dynamics supporting numerical working memory. Active mental manipulation of a number set during working memory maintenance preferentially desynchronized alpha oscillations in the right superior parietal cortex (SPC), and whole‐brain coherence imaging showed that this region decoupled from its left homologue during the same time window. These results suggest that numerical working memory requires specialized processing by the right SPC, which is distinct from the left SPC.

Brain imaging studies in children with prenatal methamphetamine exposure (PME) suggest structural and functional alterations of striatal, frontal, parietal, and limbic regions. However, no longitudinal studies have investigated changes in structural connectivity during the first 2 years of formal schooling. The aim of this study was to explore the effects of PME on structural connectivity of brain networks in children over the critical first 2 years of formal schooling when foundational learning takes place. Networks are expected to gradually increase in global connectedness while segregating into defined systems. Graph theoretical analysis was used to investigate changes in structural connectivity at age 6 and 8 years in children with and without PME. While healthy control children showed increased connectivity in frontal and limbic hubs over time, children with PME showed increased connectivity in the superior parietal cortex and striatum in their global network. Furthermore, compared to control children, those with PME were characterized by less change in segregation of structural networks over time. These findings are consistent with previous work on regions implicated in children with PME, but they additionally demonstrate alterations in structural connectivity between regions that underlie primary cognitive, behavioral, and emotional development. Understanding patterns of network development during critical periods in at-risk children may inform strategies for supporting this group of children in these developmental tasks important for lifelong brain health and development.

Selective attention is relevant for goal directed behavior as it allows people to attend to task-relevant target stimuli and to ignore task-irrelevant distractors. Attentional focus at encoding affects subsequent memory for target and distractor stimuli. Remembering selectively more targets than distractors represents memory selectivity. Brain imaging studies suggest that the superior parietal cortex is associated with the dorsal attentional network supporting top-down control of selective attention while the inferior parietal cortex is associated with the ventral attentional network supporting bottom-up attentional orienting. To investigate the roles of the dorsal and ventral networks in the effect of selective attention during encoding on long-term memory, we stimulated the left superior and the right inferior parietal cortex. Building on previous work, we applied transcranial direct current stimulation (tDCS) during a study phase where pictures and words were presented simultaneously and participants had to switch between a picture and a word decision. A subsequent recognition test assessed memory for target and distractor pictures and words. We hypothesized that a relative increase in activity in the dorsal network would boost selective attention while increased activity in the ventral network would impair selective attention. We also expected to find corresponding effects on memory. Enhanced selective attention should lead to higher memory selectivity, while impaired selective attention should lead to lower memory selectivity. Our results replicated that task switching reduced memory selectivity. However, we found no significant effects of tDCS. Thus, the present study questions the effectiveness of the present tDCS protocol for modulating attention during task switching and subsequent memory.

L'objectiu principal d'aquest treball és estudiar la relació del còrtex parietal superior (CPS) amb l'aparició de l'art, per explorar el potencial de l'art com a eina educativa i terapèutica a la infància. Per això s'ha dut a terme una revisió sistemàtica a diverses bases de dades com Pubmed, TripDataBase, Science Direct i Google Scholar. L'estratègia de cerca es va basar en explorar les paraules clau següents: Art, Brain, Evolution, Superior Parietal Cortex, Symbolism, Cognition. Mitjançant l'estratègia d'exploració bibliogràfica es van trobar en total 420 estudis, dels quals una vegada aplicats els criteris d'inclusió i exclusió només se'n van incloure 20 en aquest article. En aquesta selecció, es va observar que les categories tractades més explorades a l'hora d'abordar la relació entre art i cervell van ser: la mida cerebral i l'encefalització (27,27%), els efectes de la cuina i la dieta (22,73 %), el còrtex parietal superior (22,73%) i la cognició simbòlica (18,18%). Després de la revisió exhaustiva de la literatura científica, cal destacar que la varietat d'investigacions en matèria de neurociència, evolució anatòmica i desenvolupament cognitiu no són suficients per establir una relació directa entre l'increment del còrtex parietal superior i l'origen de l'art. Tot i així, l'aparició de l'art durant el procés d'encefalització de l'espècie humana ens porta a preguntar-nos si l'art pot ser un potenciador del desenvolupament cognitiu i no només una conseqüència de l'encefalització humana. Si fos així, una major inclusió de l'art a les aules i de la teràpia artística als Centres de Desenvolupament Infantil i Atenció Precoç (CDIAP) podria guardar relació amb la configuració cognitiva futura. The main objective of this work is to study the relationship of the superior parietal cortex (CPS) with the appearance of art, to explore the potential of art as an educational and therapeutic tool in childhood. A systematic review has been carried out in databases such as Pubmed, TripDataBase, Science Direct and Google Scholar. The search strategy was based on exploring the following keywords: Art, Brain, Evolution, Superior Parietal Cortex, Symbolism, Cognition. Through the literature exploration strategy, a total of 420 studies were found. After inclusion and exclusion criteria were applied, only 20 were included in the present article. In this selection, it was observed that the most explored categories treated when addressing the relationship between art and brain were brain size and encephalization (27.27%), the effects of cooking and diet (22.73 %), the superior parietal cortex (22.73%) and symbolic cognition (18.18%). After an exhaustive review of the scientific literature, it should be noted that the variety of investigations in neuroscience, anatomical evolution and cognitive development are not enough to establish a direct relationship between the increase in the superior parietal cortex and the origin of art. Even so, the appearance of art during the encephalization process of the human species leads us to wonder if it is possible that art can be an enhancer of cognitive development and not just a consequence of human encephalization. If so, a greater inclusion of art in the classroom and of art therapy in the Centers for Child Development and Early Attention (CDIAP in Catalonia) could be related to the future cognitive configuration. El principal objetivo de este trabajo es estudiar la relación del córtex parietal superior (CPS) con la aparición del arte, para explorar el potencial del arte como herramienta educativa y terapéutica en la infancia. Para ello se he llevado a cabo una revisión sistemática en diversas bases de datos como Pubmed, TripDataBase, Science Direct i Google Scholar. La estrategia de búsqueda se basó en explorar las siguientes palabras claves: Arte, Brain, Evolution, Superior Parietal Cortex, Symbolism, Cognition. Mediante la estrategia de exploración bibliográfica fueron hallados en total 420 estudios, de los cuales una vez aplicados los criterios de inclusión y exclusión sólo se incluyeron 20 en el presente artículo. En esta selección, se observó que las categorías tratadas más exploradas a la hora de abordar la relación entre arte y cerebro fueron: el tamaño cerebral y la encefalización (27,27%), los efectos de la cocina y la dieta (22,73%), el córtex parietal superior (22,73%) y la cognición simbólica (18,18%). Tras la revisión exhaustiva de la literatura científica cabe destacar que la variedad de investigaciones en materia de neurociencia, evolución anatómica y desarrollo cognitivo no son suficientes para establecer una relación directa entre el incremento del córtex parietal superior y el origen del arte. Aun así, la aparición del arte durante el proceso de encefalización de la especie humana nos lleva a preguntarnos si es posible que el arte pueda ser un potenciador del desarrollo cognitivo y no sólo una consecuencia de la encefalización humana. De ser así, una mayor inclusión del arte en las aulas y de la terapia artística en los Centros de Desarrollo Infantil y Atención Precoz (CDIAP) podría guardar relación con la configuración cognitiva futura. &nbsp

AIM OF THE STUDY Previous studies have shown that several cortical regions are involved in temporal tasks in multiple timescales. However, the hemispheric predominance of the dorsolateral prefrontal cortex (DLPFC) during time reproduction after repetitive low-frequency transcranial magnetic stimulation (rTMS) is relatively unexplored. Here, we study the effects of 1 Hz rTMS and sham stimulation applied medially over the superior parietal cortex (SPC) on the DLPFC alpha and beta band asymmetry and on time reproduction. MATERIALS AND METHODS For this purpose, we have combined rTMS with electroencephalography in 20 healthy subjects who performed the time reproduction task in two conditions (sham and 1 Hz). RESULTS The worst performance was observed in sham and 1Hz conditions for longer time intervals (p

Introduction Prior Go/NoGo studies have localized specific regions and EEG spectra for which traditional approaches have distinguished between Go and NoGo conditions. A more detailed characterization of the spatial distribution and timing of the synchronization of frequency bands would contribute substantially to the clarification of neural mechanisms that underlie performance of the Go/NoGo task. Methods The present study used a machine learning approach to learn the features that distinguish between ERSPs involved in selection and inhibition in a Go/NoGo task. A single‐layer neural network classifier was used to predict task conditions for each subject to characterize ERSPs associated with Go versus NoGo trials. Results The final classifier accurately identified individual task conditions at an overall rate of 92%, estimated by fivefold cross‐validation. The detailed accounting of EEG time–frequency patterns localized to brain regions (i.e., thalamus, pre‐SMA, orbitofrontal cortex, and superior parietal cortex) corroborates and also elaborates upon previous findings from fMRI and EEG studies, and expands the information about EEG power changes in multiple frequency bands (i.e., primarily theta power increase, alpha decreases, and beta increases and decreases) within these regions underlying the selection and inhibition processes engaged in the Go and NoGo trials. Conclusion This time–frequency‐based classifier extends previous spatiotemporal findings and provides information about neural mechanisms underlying selection and inhibition processes engaged in Go and NoGo trials, respectively. This neural network classifier can be used to assess time–frequency patterns from an individual subject and thus may offer insight into therapeutic uses of neuromodulation in neural dysfunction., We used a relatively large dataset of EEG time–frequency measures for the Go/NoGo task to develop a machine learning based classifier of successful selection and inhibition trials. This neural network classifier accurately identified individual task conditions at an overall rate of 92%, estimated by fivefold cross‐validation. The signatures of the classifier not only replicated the previous main findings of the Neural Hybrid model for selection and inhibition processes in location and time–frequency correlates, but extended these findings with additional signatures not previously isolated.

Kraepelinian theory posits that schizophrenia (SZ) is a degenerative disorder that worsens throughout the lifespan. Behavioral studies of cognition have since challenged that viewpoint, particularly in the early phases of illness. Nonetheless, the extent to which cognition remains functionally stable during the early course of illness is unclear, particularly with regard to task-associated connectivity in cognition-related brain networks. In this study, we examined the 1-year stability of the frontoparietal control network during the AX-Continuous Performance Task (AX-CPT) from a new baseline sample of 153 participants scanned at 3T, of which 29 recent onset individuals with SZ and 42 healthy control (HC) participants had follow-up data available for analysis. Among individuals that had both baseline and follow-up data, reduced functional connectivity in SZ was observed between the dorsolateral prefrontal cortex (DLPFC) and superior parietal cortex (SPC) during the high control (B cue) condition. Furthermore, this deficit was stable over time, as no significant time × diagnosis interaction or effects of time were observed and intraclass correlation coefficients were greater than 0.6 in HCs and SZ. Previous 1.5T findings showing stable deficits with no evidence of degeneration in performance or DLPFC activation in an independent SZ sample were replicated. Overall, these results suggest that the neuronal circuitry supporting cognitive control is stably impaired during the early course of illness in SZ across multiple levels of analysis with no evidence of functional decline.

Conflicts at various stages of cognition can cause interference effects on behavior. Two well-studied forms of cognitive interference are stimulus–stimulus (e.g., Flanker), where the conflict arises from incongruence between the task-relevant stimulus and simultaneously presented irrelevant stimulus information, and stimulus-response (e.g., Simon), where interference is the result of an incompatibility between the spatial location of the task-relevant stimulus and a prepotent motor mapping of the expected response. Despite substantial interest in the neural and behavioral underpinnings of cognitive interference, it remains uncertain how differing sources of cognitive conflict might interact, and the spectrally specific neural dynamics that index this phenomenon are poorly understood. Herein, we used an adapted version of the multisource interference task and magnetoencephalography to investigate the spectral, temporal, and spatial dynamics of conflict processing in healthy adults (N = 23). We found a double-dissociation such that, in isolation, stimulus–stimulus interference was indexed by alpha (8–14 Hz), but not gamma-frequency (64–76 Hz) oscillations in the lateral occipital regions, while stimulus–response interference was indexed by gamma oscillations in nearby cortices, but not by alpha oscillations. Surprisingly, we also observed a superadditive effect of simultaneously presented interference types (multisource) on task performance and gamma oscillations in superior parietal cortex.

Publicado (Open access) en: https://doi.org/10.1080/13546783.2018.1481144 The neural basis of developmental changes in transitive reasoning in parietal regions was examined, using voxel-based morphometry. Young adolescents and adults performed a transitive reasoning task, subsequent to undergoing anatomical magnetic resonance imaging (MRI) brain scans. Behaviorally, adults reasoned more accurately than did the young adolescents. Neural results showed (i) less grey matter density in superior parietal cortex in the adults than in the young adolescents, possibly due to a developmental period of synaptic pruning; (ii) improved performance in the reasoning task was negatively correlated with grey matter density in superior parietal cortex in the adolescents, but not in the adult group; and (iii) the latter results were driven by the more difficult trials, requiring greater spatial manipulation. Taken together, the results support the idea that during development, regions in superior parietal cortex are fine-tuned, to support more robust spatial manipulation, resulting in greater accuracy and efficiency in transitive reasoning.

Persistent postural perceptual dizziness (PPPD) is a common functional vestibular disorder that is triggered and sustained by a complex interaction between physiological and psychological factors affecting spatial orientation and postural control. Past functional neuroimaging research and one recent structural (i.e., voxel-based morphometry-VBM) study have identified alterations in vestibular, visuo-spatial, and limbic brain regions in patients with PPPD and anxiety-prone normal individuals. However, no-one thus far has employed surface based morphometry (SBM) to explore whether cortical morphology in patients with PPPD differs from that of healthy people. We calculated SBM measures from structural MR images in 15 patients with PPPD and compared them to those from 15 healthy controls matched for demographics, personality traits known to confer risk for PPPD as well as anxiety and depressive symptoms that are commonly comorbid with PPPD. We tested for associations between SBM measures and dizziness severity in patients with PPPD. Relative to controls, PPPD patients showed significantly decreased local gyrification index (LGI) in multi-modal vestibular regions bilaterally, specifically the posterior insular cortices, supra-marginal gyri, and posterior superior temporal gyri (p

Multisensory stimuli create behavioral flexibility, e.g. by allowing us to derive a weighted combination of the information received by different senses. They also allow perception to adapt to discrepancies in the sensory world, e.g. by biasing the judgement of unisensory cues based on preceding multisensory evidence. While both facets of multisensory perception are central for behavior, it remains unknown whether they arise from a common neural substrate. In fact, very little is known about the neural mechanisms underlying multisensory perceptual recalibration. To reveal these, we measured whole-brain activity using MEG while human participants performed an audio-visual ventriloquist paradigm designed to reveal multisensory integration within a trial, and the (trial-by-trial) recalibration of subsequent unisensory judgements. Using single trial classification and behavioral modelling, we localized the encoding of sensory information within and between trials, and determined the behavioral relevance of candidate neural representations. While we found neural signatures of perceptual integration within temporal and parietal regions, of these, only medial superior parietal activity retained multisensory information between trials and combined this with current evidence to mediate perceptual recalibration. These results suggest a common neural substrate of sensory integration and trial-by-trial perceptual recalibration, and expose the medial superior parietal cortex as a flexible hub that links present and previous evidence within and between senses to guide behavior.

Transcranial magnetic stimulation (TMS) was developed 30 years ago, in part to decrease the peripheral side-effects associated with transcranial electrical stimulation (Barker, 1991). TMS has been effective in that aim, and great advances have been made over the past 30 years. TMS can still be uncomfortable and painful, however, as it stimulates excitable superficial tissue including scalp muscles and peripheral nerves (Maizey et al., 2013). This causes annoyance, pain, and muscle twitches (i.e., discomfort) that vary systematically across the scalp (Meteyard and Holmes, 2018). While superior and posterior scalp locations are associated with almost no discomfort, inferior frontal and temporal locations are associated with significant discomfort. This discomfort can include sharp pain and strong contractions of scalp, head, and neck muscles. In protocols where TMS and a behavioral task are separated by time (“off-line”), these peripheral side-effects of brain stimulation may not affect subsequent task performance. But, in protocols where TMS is applied simultaneously with the behavioral task (“on-line”), these side-effects of TMS might interfere significantly with performance.

The current study investigates a new neurobiological model of human hand choice: The Posterior Parietal Interhemispheric Competition (PPIC) model. The model specifies that neural populations in bilateral posterior intraparietal and superior parietal cortex (pIP-SPC) encode actions in hand-specific terms, and compete for selection across and within hemispheres. Actions with both hands are encoded bilaterally, but the contralateral hand is overrepresented. We use a novel fMRI paradigm to test the PPIC model. Participants reach to visible targets while in the scanner, and conditions involving free choice of which hand to use (Choice) are compared with when hand-use is instructed. Consistent with the PPIC model, bilateral pIP-SPC is preferentially responsive for the Choice condition, and for actions made with the contralateral hand. In the right pIP-SPC, these effects include anterior intraparietal and superior parieto-occipital cortex. Left dorsal premotor cortex, and an area in the right lateral occipitotemporal cortex show the same response pattern, while the left inferior parietal lobule is preferentially responsive for the Choice condition and when using the ipsilateral hand. Behaviourally, hand choice is biased by target location – for targets near the left/right edges of the display, the hand in ipsilateral hemispace is favoured. Moreover, consistent with a competitive process, response times are prolonged for choices to more ambiguous targets, where hand choice is relatively unbiased, and fMRI responses in bilateral pIP-SPC parallel this pattern. Our data provide support for the PPIC model, and reveal a selective network of brain areas involved in free hand choice, including bilateral posterior parietal cortex, left-lateralized inferior parietal and dorsal premotor cortices, and the right lateral occipitotemporal cortex.

Background: The functional mechanism behind autism spectrum disorder (ASD) is not clear, but it is related to a brain connectivity disorder. Previous studies have found that functional brain connectivity of ASD is linked to both increased connections and weakened connections, and the inconsistencies in functional brain connectivity may be related to age. The functional connectivity in adolescents and adults with ASD is generally less than in age-matched controls; functional connectivity in younger children with the disorder appears to be higher. As the basis of the functional network, the structural network is less studied. This study intends to further study the pathogenesis of ASD by analyzing the white matter network of ASD preschool children. Materials and Methods: In this study, Diffusion Tensor Imaging (DTI) was used to scan preschool children (aged 2-6 years, 39 children with ASD, 19 children as controls), and graph theory was used for analysis. Result: Enhanced topological network efficiency was found in the preschool children with ASD. A higher nodal efficiency was found in the left precuneus, thalamus, and bilateral superior parietal cortex, and the nodal efficiency of the left precuneus was positively associated with the severity of ASD. Conclusion: Our research shows the white matter network efficiency of preschoolers with ASD. It supports the theory of excessive early brain growth in ASD, and it shows left brain lateralization. It opens the way for new research perspectives of children with ASD.

Although research shows that working memory improves during early childhood, it remains unclear how the fronto-parietal network of cortical regions, known to support this ability in adults, relates to changes in young children. Measures of cortical thickness may be useful in investigating this association as they reflect age-related differences in gray matter and have been proposed to support age-related improvements in other cognitive abilities, but have only sparingly been tested empirically in early childhood. The present study sought to investigate relations between cortical thickness and performance on a digit span task in 200 4- to 8-year-old children using both a priori defined regions of interest related to working memory (superior frontal cortex, middle frontal cortex, anterior cingulate cortex, superior parietal cortex) and whole brain analyses. Results indicated a significant association between cortical thickness in each a priori defined fronto-parietal region and performance on digit span, such that those with a thinner cortex recalled more items than those with a thicker cortex. Similar regions emerged from the whole brain analyses, as did several other regions not typically included in the fronto-parietal network. Results of a mediation analysis indicated that age-related differences in behavior were partially explained by variations in thickness of anterior cingulate cortex, suggesting a potentially important role for this structure during early childhood. Overall, these results suggest that in children as young as 4 years of age there are associations between working memory abilities and thickness in cortical areas known to support working memory in adults.

Theoretical accounts of the visual number sense (VNS), i.e., an ability to discriminate approximate numerosities, remain controversial. A proposal that the VNS represents a process of numerosity extraction, leading to an abstract number representation in the brain, has been challenged by the view that the VNS is non-numerical in its essence and amounts to a weighted integration of continuous magnitude features that typically change with numerosity. In the present study, using two-alternative forced-choice paradigm, we aimed to distinguish between these proposals by probing brain areas implicated in the VSN with transcranial random noise stimulation (tRNS). We generated predictions for the stimulation-related changes in behavioural performance which would be compatible with alternative mechanisms proposed for the VSN. First, we investigated whether the superior parietal (SP) area hosts a numerosity code or whether its function is to modulate weighting of continuous stimulus features. We predicted that stimulation may affect the VNS precision if the SP role is representational, and that it may affect decision threshold if its role is modulatory. Second, we investigated whether the intra-parietal (IP) area hosts a numerosity code independently of codes for continuous stimulus features, or whether their representations overlap. If the numerosity code is independent, we predicted that IP stimulation may improve the VNS but not continuous magnitude judgements. Our results were consistent with the hypotheses of a modulatory role of the SP and of the independence of the numerosity code in the IP, whereby suggesting that VNS is an emergent abstract property based on continuous magnitude statistics.

Spatial working memory has been extensively investigated with different tasks, treatments, and analysis tools. Several studies suggest that low frequency of the repetitive transcranial magnetic stimulation (rTMS) applied to the parietal cortex may influence spatial working memory (SWM). However, it is not yet known if after low-frequency rTMS applied to the superior parietal cortex, according to Pz electroencephalography (EEG) electrode, would change the orientation interpretation about the vertical and horizontal axes coordinates in an SWM task. The current study aims at filling this gap and obtains a better understanding of the low-frequency rTMS effect in SWM. In this crossover study, we select 20 healthy subjects in two conditions (control and 1-Hz rTMS). The subjects performed an SWM task with two random coordinates. Our results presented that low-frequency rTMS applied over the superior parietal cortex may influence the SWM to lead to a larger distance of axes interception point (p

We examined the effects of aging and cognitive fatigue on working memory (WM) related brain activation using functional magnetic resonance imaging. Age-related differences were investigated in 13 young and 16 middle-aged male school teachers. Cognitive fatigue was induced by sustained performance on cognitively demanding tasks (compared to a control condition). Results showed a main effect of age on left dorsolateral prefrontal and superior parietal cortex activation during WM encoding; greater activation was evident in middle-aged than young adults regardless of WM load or fatigue condition. An interaction effect was found in the dorsomedial prefrontal cortex (DMPFC); WM load-dependent activation was elevated in middle-aged compared to young in the control condition, but did not differ in the fatigue condition due to a reduction in activation in middle-aged in contrast to an increase in activation in the young group. These findings demonstrate age-related activation differences and differential effects of fatigue on activation in young and middle-aged adults. © 2013 Elsevier B.V.

Psychopathy is a personality disorder associated with a profound lack of empathy. Neuroscientists have associated empathy and its interindividual variation with how strongly participants activate brain regions involved in their own actions, emotions and sensations while viewing those of others. Here we compared brain activity of 18 psychopathic offenders with 26 control subjects while viewing video clips of emotional hand interactions and while experiencing similar interactions. Brain regions involved in experiencing these interactions were not spontaneously activated as strongly in the patient group while viewing the video clips. However, this group difference was markedly reduced when we specifically instructed participants to feel with the actors in the videos. Our results suggest that psychopathy is not a simple incapacity for vicarious activations but rather reduced spontaneous vicarious activations co-existing with relatively normal deliberate counterparts.

Music performance requires control of two sequential structures: the ordering of pitches and the temporal intervals between successive pitches. Whether pitch and temporal structures are processed as separate or integrated features remains unclear. A repetition suppression paradigm compared neural and behavioral correlates of mapping pitch sequences and temporal sequences to motor movements in music performance. Fourteen pianists listened to and performed novel melodies on an MR-compatible piano keyboard during fMRI scanning. The pitch or temporal patterns in the melodies either changed or repeated (remained the same) across consecutive trials. We expected decreased neural response to the patterns (pitch or temporal) that repeated across trials relative to patterns that changed. Pitch and temporal accuracy were high, and pitch accuracy improved when either pitch or temporal sequences repeated over trials. Repetition of either pitch or temporal sequences was associated with linear BOLD decrease in frontal–parietal brain regions including dorsal and ventral premotor cortex, pre-SMA, and superior parietal cortex. Pitch sequence repetition (in contrast to temporal sequence repetition) was associated with linear BOLD decrease in the intraparietal sulcus (IPS) while pianists listened to melodies they were about to perform. Decreased BOLD response in IPS also predicted increase in pitch accuracy only when pitch sequences repeated. Thus, behavioral performance and neural response in sensorimotor mapping networks were sensitive to both pitch and temporal structure, suggesting that pitch and temporal structure are largely integrated in auditory–motor transformations. IPS may be involved in transforming pitch sequences into spatial coordinates for accurate piano performance.

Prospective memory (PM) is the ability to remember to carry out an intention when the appropriate cue occurs. This study aimed to investigate whether the superior parietal cortex is causally involved in PM and, if so, what is its functional role. We applied repetitive transcranial magnetic stimulation (rTMS) to the left and right superior parietal cortex, and we evaluated the TMS effects on two different PM tasks that required to direct the attention towards either the external stimuli ('Monitoring-load' task) or the intention in memory ('Retrospective-load' task). rTMS of left parietal cortex produced a facilitation of PM performance in both tasks. This was coupled by slower responses to the ongoing activity, for left and right parietal stimulation, but selectively in the 'Retrospective-load' condition. The present results suggest that superior parietal cortex is causally involved in biasing top-down attentional resources between the external, ongoing stimuli and the internal, PM intentions. The possible physiological mechanisms underlying the TMS-related improvement in PM performance are discussed.

Response selection is foundational to adaptive behavior, and considerable attention has been devoted to investigating this behavior under conditions in which the mapping between stimuli and responses is fixed. Results from prior studies implicate the left supramarginal gyrus (SMg), premotor and prefrontal cortices, as well as the cerebellum in this essential function. Yet, many goal-directed motor behaviors have multiple solutions with flexible mappings between stimuli and responses whose solutions are believed to involve prospective planning. Studies of selection under conditions of flexible mappings also reveal involvement of the left SMg, as well as bilateral premotor, superior parietal cortex (SPL) and pre-supplementary motor (pre-SMA) cortices, along with the cerebellum. This evidence is, however, limited by exclusive reliance on tasks that involve selection in the absence of overt action execution and without complete control of possible confounding effects related to differences in stimulus and response processing demands. Here, we address this limitation through use of a novel fMRI repetition suppression (FMRI-RS) paradigm. In our prime-probe design, participants select and overtly pantomime manual object rotation actions when the relationship between stimuli and responses is either flexible (experimental condition) or fixed (control condition). When trials were repeated in prime-probe pairs of the experimental condition, we detected improvements in performance accompanied by a significant suppression of blood oxygen-level dependent (BOLD) responses in: left SMg extending into and along the length of the intraparietal sulcus (IPS), right IPS, bilateral caudal superior parietal lobule (cSPL), dorsal premotor cortex (dPMC), pre-SMA, and in the lateral cerebellum. Further, region-of-interest analyses revealed interaction effects of fMRI-RS in the experimental versus control condition within left SMg and cerebellum, as well as in bilateral caudal SPL. These efficiency effects cannot be attributed to the repetition of stimulus or response processing, but instead are planning-specific and generally consistent with earlier findings from conventional fMRI investigations. We conclude that repetition-related increases in the efficiency of planning-based selection appears to be associated with parieto-cerebellar networks.

Little is known about how the human brain keeps track of body parts in the visual field. Here we show that unattended images of right/left hands elicit a mismatch response when they violate a regularity established by repeated visual presentations of the other hand. In a visual oddball experiment we found mismatch responses to hands with unexpected laterality (e.g. left versus predicted right hand) in the periphery of the visual field. Unexpected left hands were processed predominantly in the contralateral superior parietal cortex, whereas unexpected right hands evoked differential activity in the contralateral superior parietal, ventral premotor, prefrontal and temporal areas, indicating a more elaborate automatic processing of the dominant hand. The amplitude of the differential activity to the right hand correlated with handedness test scores. Our results reveal the continuous monitoring of the left or right identity of hands, which is prerequisite to the ability to automatically transform observed actions into the observer's ego-centric spatial reference frame.

The insular cortex of macaques has a wide spectrum of anatomical connections whose distribution is related to its heterogeneous cytoarchitecture. Although there is evidence of a similar cytoarchitectural arrangement in humans, the anatomical connectivity of the insula in the human brain has not yet been investigated in vivo. In the present work, we used in vivo probabilistic white-matter tractography and Laplacian eigenmaps (LE) to study the variation of connectivity patterns across insular territories in humans. In each subject and hemisphere, we recovered a rostrocaudal trajectory of connectivity variation ranging from the anterior dorsal and ventral insula to the dorsal caudal part of the long insular gyri. LE suggested that regional transitions among tractography patterns in the insula occur more gradually than in other brain regions. In particular, the change in tractography patterns was more gradual in the insula than in the medial premotor region, where a sharp transition between different tractography patterns was found. The recovered trajectory of connectivity variation in the insula suggests a relation between connectivity and cytoarchitecture in humans resembling that previously found in macaques: tractography seeds from the anterior insula were mainly found in limbic and paralimbic regions and in anterior parts of the inferior frontal gyrus, while seeds from caudal insular territories mostly reached parietal and posterior temporal cortices. Regions in the putative dysgranular insula displayed more heterogeneous connectivity patterns, with regional differences related to the proximity with either putative granular or agranular regions. Hum Brain Mapp 33:20052034, 2012. (c) 2011 Wiley Periodicals, Inc.