Progressive modulation of resting‑state brain activity during neurofeedback of positive‑social emotion regulation networks

Neurofeedback allows for the self-regulation of brain circuits implicated in specific maladaptive behaviors, leading to persistent changes in brain activity and connectivity. Positive-social emotion regulation neurofeedback enhances emotion regulation capabilities, which is critical for reducing the severity of various psychiatric disorders. Training dorsomedial prefrontal cortex (dmPFC) to exert a top-down influence on bilateral amygdala during positive-social emotion regulation progressively (linearly) modulates connectivity within the trained network and induces positive mood. However, the processes during rest that interleave the neurofeedback training remain poorly understood. We hypothesized that short resting periods at the end of training sessions of positive-social emotion regulation neurofeedback would show alterations within emotion regulation and neurofeedback learning networks. We used complementary model-based and data-driven approaches to assess how resting-state connectivity relates to neurofeedback changes at the end of training sessions. In the experimental group, we found lower progressive dmPFC self-inhibition and an increase of connectivity in networks engaged in emotion regulation, neurofeedback learning, visuospatial processing, and memory. Our findings highlight a large-scale synergy between neurofeedback and resting-state brain activity and connectivity changes within the target network and beyond. This work contributes to our understanding of concomitant learning mechanisms post training and facilitates development of efficient neurofeedback training.publishedVersio

Does phonological overlap of cognate words modulate cognate acquisition and processing in developing and skilled readers?

Very few studies exist on the role of cross-language similarities in cognate word acquisition. Here we sought to explore, for the first time, the interplay of orthography (O) and phonology (P) during the early stages of cognate word acquisition, looking at children and adults with the same level of foreign language proficiency, and by using two variants of the word-association learning paradigm (auditory learning method vs. auditory + written method). Eighty participants (forty children and forty adults, native speakers of European Portuguese [EP]), learned a set of EP-Catalan cognate words and non-cognate words. Among the cognate words, the degree of orthographic and phonological similarity was manipulated. Half of the children and adult participants learned the new words via an L2 auditory and written-L1 word association method, while the other half learned the same words only through an L2 auditoryL1 word association method. Both groups were tested in an auditory recognition task and a go/no-go lexical decision task. Results revealed a disadvantage for children in comparison to adults, which was reduced in the auditory learning method. Furthermore, there was an advantage for cognates relative to non-cognates regardless of the age of participants. Importantly, there were modulations in cognate word processing as a function of the degree of O and P overlap which were restricted to children. The findings are discussed in light of the most relevant bilingual models of word recognition.This research was conducted at the Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and was funded by the FCT (Foundation for Science and Technology) through the state budget, with reference IF / 00784/2013 / CP1158 / CT0013. The study has also been partially supported by the FCT and the EP Ministry of Science, Technology and Higher Education through national funds, and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). It has also been partially supported by the Spanish Ministry of Economy and Competitiveness (PCIN-2015-165-C02-02).info:eu-repo/semantics/publishedVersio

Neural networks underlying language processing in same script bilinguals: an investigation of functional specificity in the visual word form area

A small area in the inferior occipito-temporal cortex of the brain named the Visual Word Form Area (VWFA) was shown to be involved in recognition of written words. This area becomes more active when participants view written words as compared to other kinds of visual stimuli, such as checkerboard patterns (e.g., Cohen et al., 2000; 2002), digits (Polk et al., 2002), or geometric shapes (Gros et al., 2001). This dissertation research examined how functional specialization to written words emerges in the VWFA as a function of language experience and how the response in this area may rapidly adapt to the constraints imposed by the characteristics of the visual input. VWFA activity was measured with fMRI in two samples of same-script bilingual speakers, who varied in the level of proficiency across two languages. In Experiments 1 and 2, activity for first and second language words was contrasted with checkerboard pattern baseline. Both overlapping and distinct areas of activation within VWFA were found for each language. The extent of activation overlap for first and second language was related to participants' language proficiency and age of acquisition. This result was confirmed by univariate (Experiment 1) and multivariate (Experiment 2) analyses. In Experiment 3, repetition suppression was observed in the VWFA for word-pairs with similar orthography (homographs), but not for word-pairs with similar orthography and meaning (cognates), indicating that the VWFA is sensitive to semantic information. In addition, graphical connectivity analyses revealed that the more proficient language activated a ventral route from the VWFA to the prefrontal areas, and the less proficient language activated a dorsal route. Experiment 4 tested whether neural activity in the VWFA increases when target words are semantically congruent with the rest of the words in a sentence. The results showed that while the VWFA activity is buffered against repetition suppression by semantic similarity between single words, the VWFA is not sensitive to sentence level congruency. Collectively, the results suggest that the VWFA supports abstract orthographic processing, with similar mechanisms employed for early-acquired same-script languages, and that it participates in the integration of incoming visual information with single word semantics.Ph. D.Includes bibliographical referencesIncludes vitaby Olga Boukrin

Neural Mechanisms of Prism Adaptation in Healthy Adults and Individuals with Spatial Neglect after Unilateral Stroke: A Review of fMRI Studies

Functional disability due to spatial neglect hinders recovery in up to 30% of stroke survivors. Prism adaptation treatment (PAT) may alleviate the disabling consequences of spatial neglect, but we do not yet know why some individuals show much better outcomes following PAT than others. The goal of this scoping review and meta-analysis was to investigate the neural mechanisms underlying prism adaptation (PA). We conducted both quantitative and qualitative analyses across fMRI studies investigating brain activity before, during, and after PA, in healthy individuals and patients with right or left brain damage (RBD or LBD) due to stroke. In healthy adults, PA was linked with activity in posterior parietal and cerebellar clusters, reduced bilateral parieto-frontal connectivity, and increased fronto-limbic and sensorimotor network connectivity. In contrast, RBD individuals with spatial neglect relied on different circuits, including an activity cluster in the intact left occipital cortex. This finding is consistent with a shift in hemispheric dominance in spatial processing to the left hemisphere. However, more studies are needed to clarify the contribution of lesion location and load on the circuits involved in PA after unilateral brain damage. Future studies are also needed to clarify the relationship of decreasing resting state functional connectivity (rsFC) to visuomotor function

Learning Relational Categories by Comparison of Paired Examples

Our central question is whether comparison of co-presented instances promotes category learning. We report results of four experiments testing acquisition of relational categories under conditions of Comparison learning versus traditional Single item learning. In order to control for frequency of exposure, the Single group received twice as many learning trials. Experiment 1 showed more accurate single-item classification at test for both old and new items by the Comparison group relative to the Single group. Experiment 2 used only withincategory pairs in the Comparison condition (rather than both types of pairs), but no accuracy advantage was found. Experiment 3 repeated this design using a reduced training set and showed a learning effect of comparison and a marginal advantage in transfer to new items. In Experiment 4, a novel paradigm revealed further evidence of a facilitative effect for within-category comparison. The power of comparison to promote learning and transfer is discussed in terms of mechanisms of encoding and knowledge change