• European Marine Science
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Abstract Neuroimaging has tremendous potential for quantifying hemispheric specializations. However, the possibilities remain under-utilized, in part, given some of the complexities in quantifying any differences in a reliable, transparent fashion. A second issue with hemispheric asymmetries is that they are extremely one-sided in most people. This skew limits the generalisability of any findings to those participants with rarer forms of cerebral asymmetry. Here, we demonstrate usefulness of an approach developed by Wilke and Lidzba, (J Neurosci Meth, 163, 2007), which allows for threshold-independent estimates of cerebral asymmetry to be calculated in individual participants. We compared these estimates from two separate runs for three different cerebral asymmetries in the same participants. We circumvented the skewed nature of this type of data in two ways; first, we scanned a large number of non-right handed participants, and second, we included asymmetries that favour the right hemisphere in right handers, which we had reason to believe were less skewed than those related to speech and language. Verbal fluency and two visuoperceptual asymmetries were localized in a sample of 33 right handed and 60 non-right handed participants. Laterality indices (LIs), which quantify the direction and strength of an asymmetry, were calculated for BOLD activity relating to language, face perception, and body perception in each run separately. Run 1 - run 2 correlations were all statistically significant and surprisingly sizeable (r = 0.89 to r = 0.62), considering the relatively short amount of time on task within our particular localizers. This noteworthy success validates a number of useful ways that functional neuroimaging can be used to advance understanding of cerebral asymmetries.

The individual difference in valuing immediate and future outcomes is referred to as consideration of future consequences (CFC, including CFC-Future [CFC-F] and CFC-Immediate [CFC-I]), which significantly influences daily behaviour. Although CFC is believed to be affected by brain features and personalities, the relational model of brain correlates, personalities and CFC has yet to be determined. This study was designed to explore the brain structure related to CFC-F and CFC-I and the mediating role of conscientiousness. We adopted a voxel-based morphometry study and used grey matter density (GMD) as an indication of brain structure. The results showed that GMD in the ventromedial prefrontal cortex (VMPFC) was positively associated with CFC-F; however, we did not find relevant regions affecting CFC-I. Furthermore, conscientiousness was found to mediate the relationship between GMD in the VMPFC and CFC-F. This study provides initial evidence concerning the neural basis of CFC-F and argues that the features of brain structure could be associated with CFC-F through related high-order personality traits. Additionally, the distinction between CFC-F and CFC-I may be based on differences in brain structure.

Dyslexia is characterized by poor reading skills, yet often also difficulties in second-language learning. The differences between native- and second-language speech processing and the establishment of new brain representations for spoken second language in dyslexia are not, however, well understood. We used recordings of the mismatch negativity component of event-related potential to determine possible differences between the activation of long-term memory representations for spoken native- and second-language word forms in Finnish-speaking 9-11-year-old children with or without dyslexia, studying English as their second language in school. In addition, we sought to investigate whether the bottleneck of dyslexic readers' second-language learning lies at the level of word representations or smaller units and whether the amplitude of mismatch negativity is correlated with native-language literacy and related skills. We found that the activation of brain representations for familiar second-language words, but not for second-language speech sounds or native-language words, was weaker in children with dyslexia than in typical readers. Source localization revealed that dyslexia was associated with weak activation of the right temporal cortex, which has been previously linked with word-form learning. Importantly, the amplitude of the mismatch negativity for familiar second-language words correlated with native-language literacy and rapid naming scores, suggesting a close link between second-language processing and these skills. Peer reviewed

Abstract Sensory suppression effects observed in electroencephalography (EEG) index successful predictions of the type and timing of self-generated sensory feedback. However, it is unclear how precise the timing prediction of sensory feedback is, and how temporal delays between an action and its sensory feedback affect perception. The current study investigated how prediction errors induced by delaying tone onset times affect the processing of sensory feedback in audition. Participants listened to self-generated (via button press) or externally generated tones. Self-generated tones were presented either without or with various delays (50, 100, or 250 ms; in 30% of trials). Comparing listening to externally generated and self-generated tones resulted in action-related P50 amplitude suppression to tones presented immediately or 100 ms after the button press. Subsequent ERP responses became more sensitive to the type of delay. Whereas the comparison of actual and predicted sensory feedback (N1) tolerated temporal uncertainty up to 100 ms, P2 suppression was modulated by delay in a graded manner: suppression decreased with an increase in sensory feedback delay. Self-generated tones occurring 250 ms after the button press additionally elicited an enhanced N2 response. These findings suggest functionally dissociable processes within the forward model that are affected by the timing of sensory feedback to self-action: relative tolerance of temporal delay in the P50 and N1, confirming previous results, but increased sensitivity in the P2. Further, they indicate that temporal prediction errors are treated differently by the auditory system: only delays that occurred after a temporal integration window (∼100 ms) impact the conscious detection of altered sensory feedback.

Abstract Reaching toward a target viewed through laterally refracting prisms results in adaptation of both visual and (limb) proprioceptive spatial representations. Common ways to measure adaptation after-effect are to ask a person to point straight ahead with their eyes closed (“manual straight ahead”, MSA), or to a seen target using their unseen hand (“open-loop pointing”, OLP). MSA measures changes in proprioception only, whereas OLP measures the combined visual and proprioceptive shift. The behavioural and neurological mechanisms of prism adaptation have come under scrutiny following reports of reduced hemispatial neglect in patients following this procedure. We present evidence suggesting that shifts in proprioceptive spatial representations induced by prism adaptation are larger following lesions to the intraparietal cortex – a brain region that integrates retinotopic visual signals with signals of eye position in the orbit and that is activated during prism adaptation. Six healthy participants and six patients with unilateral intraparietal cortex lesions underwent prism adaptation. After-effects were measured with OLP and MSA. After-effects of control participants were larger when measured with OLP than with MSA, consistent with previous research and with the additional contribution of visual shift to OLP after-effects. However, patients' OLP shifts were not significantly different to their MSA shifts. We conclude that, for the patients, correction of pointing errors during prism adaptation involved proportionally more changes to arm proprioception than for controls. Since lesions to intraparietal cortex led to enhanced realignment of arm proprioceptive representations, our results indirectly suggest that the intraparietal cortex could be key for visual realignment.

We aimed to identify cognitive signatures (phenotypes) of patients suffering from mesial temporal lobe epilepsy (mTLE) with respect to their epilepsy lateralization (left or right), through the use of SVM (Support Vector Machine) and XGBoost (eXtreme Gradient Boosting) machine learning (ML) algorithms. Specifically, we explored the ability of the two algorithms to identify the most significant scores (features, in ML terms) that segregate the left from the right mTLE patients. We had two versions of our dataset which consisted of neuropsychological test scores: a "reduced and working" version (n ¼ 46 patients) without any missing data, and another one "original" (n ¼ 57) with missing data but useful for testing the robustness of results obtained with the working dataset. The emphasis was placed on a precautionary machine learning (ML) approach for classification, with reproducible and generalizable results. The effects of several clinical medical variables were also studied. We obtained excellent predictive classification performances (>75%) of left and right mTLE with both versions of the dataset. The most segregating features were four language and memory tests, with a remarkable stability close to 100%. Thus, these cognitive tests appear to be highly relevant for neuropsychological assessment of patients. Moreover, clinical variables such as structural asymmetry between hippocampal gyri, the age of patients and the number of anti-epileptic drugs, influenced the cognitive phenotype. This exploratory study represents an in-depth analysis of cognitive scores and allows observing interesting interactions between language and memory performance. We discuss implications of these findings in terms of clinical and theoretical applications and perspectives in the field of neuropsychology. International audience

People tend to describe others' immoral behaviors as intentional and dispositional, and their own as unintentional events. The actor-observer asymmetry might reflect at least true attitudes potentially free from intentional faking. Implicit attitudes - i.e., automatic evaluation of the rightness or wrongness of actions - play a central role in guiding moral decision-making. Yet, little research has investigated how value computations are associated with actor-observer asymmetry of moral decision-making. In this fMRI study, we developed the morally-laden implicit association test (mIAT) to examine the extent to which implicit attitudes are predictive of online neural response when participants mentally simulate or passively observe morally-laden behaviors such as helping or harming others. Results showed that the scores on the mIAT were predictive of actor-observer asymmetry when attributing blame for immoral behavior, associated with neural responses in the orbitofrontal cortex and temporal pole. The asymmetry between first-hand experiencing and passive viewing moral behavior recruited the activity in the dorsolateral prefrontal cortex and right temporoparietal junction. These findings indicate that implicit moral attitudes can predict moral evaluation and neural responses to asymmetry between experiencing and observing injustice. They provide important knowledge regarding the individual differences involved in the computational mechanisms underlying how implicit attitudes guide moral decision-making.

Unlike taking, which can be redescribed in non-social and object-directed terms, acts of giving are invariably expressed across languages in a three-argument structure relating agent, patient, and object. Developmental evidence suggests this difference in the syntactic entailment of the patient role to be rooted in a prelinguistic understanding of giving as a patient-directed, hence obligatorily social, action. We hypothesized that minimal cues of possession transfer, known to induce this interpretation in preverbal infants, should similarly encourage adults to perceive the patient of giving, but not taking, actions as integral participant of the observed event, even without cues of overt involvement in the transfer. To test this hypothesis, we measured a known electrophysiological correlate of action understanding (the suppression of alpha-band oscillations) during the observation of giving and taking events, under the assumption that the functional grouping of agent and patient should have induced greater suppression that the representation of individual object-directed actions. As predicted, the observation of giving produced stronger lower alpha suppression than superficially similar acts of object disposal, whereas no difference emerged between taking from an animate patient or an inanimate target. These results suggest that the participants spontaneously represented giving, but not kinematically identical taking actions, as social interactions, and crucially restricted this interpretation to transfer events featuring animate patients. This evidence gives empirical traction to the idea that such asymmetry, rather than being an interpretive propensity circumscribed to the first year of life, is attributable to an ontogenetically stable system dedicated to the efficient identification of interactions based on active transfer.