scholarly journals Feature overlap modulates rapid semantic but not lexical integration of novel associations by means of fast mapping

2019 ◽  
Author(s):  
Ann-Kathrin Zaiser ◽  
Patric Meyer ◽  
Regine Bader
Keyword(s):  
Semantic Integration ◽  
List Type ◽  
Fast Mapping ◽  
Lexical Competition ◽  
Cortical Networks ◽  
Learning Procedure ◽  
Item Level ◽  
Feature Overlap ◽  
Novel Associations ◽  
Shed Light

AbstractThere is evidence that rapid integration of novel associations into cortical networks is possible if associations are acquired through a learning procedure called fast mapping (FM). FM requires precise visual discrimination of sometimes highly similar pictures of a previously unknown and a known item, and linking an unfamiliar label to the unknown item. In order to shed light on the mechanisms underlying learning through FM, we manipulated feature overlap between the two items as potential modulating factor. In Experiment 1, we found that labels of the unknown items generally evoked instantaneous lexical competition when encoded through FM, indicating rapid integration into lexical networks. In Experiment 2, we observed semantic priming immediately after FM encoding but only if the items shared many features. This indicates that whereas feature overlap leaves item-level lexical integration unaffected, it might mediate semantic integration of arbitrary picture-label associations, which could explain contradictory findings in the literature.HighlightsWe examined cortical integration of associations using implicit memory measures.Fast mapping enables immediate integration of associations into cortical networks.Semantic integration requires the discrimination between items sharing many features.Item-level lexical integration is unaffected by feature overlap.

scholarly journals High feature overlap reveals the importance of anterior and medial temporal lobe structures for learning by means of fast mapping

2020 ◽  
Author(s):  
Ann-Kathrin Zaiser ◽  
Regine Bader ◽  
Patric Meyer
Keyword(s):  
Medial Temporal Lobe ◽  
Declarative Memory ◽  
Perirhinal Cortex ◽  
Semantic Integration ◽  
The Novel ◽  
Fast Mapping ◽  
Learning Procedure ◽  
Feature Overlap ◽  
High Degree ◽  
Novel Associations

AbstractContrary to traditional theories of declarative memory, it has recently been shown that novel, arbitrary associations can be rapidly and directly integrated into cortical memory networks by means of a learning procedure called fast mapping (FM), possibly bypassing time-consuming hippocampal-neocortical consolidation processes. In the typical FM paradigm, a picture of a previously unknown item is presented next to a picture of a previously known item and participants answer a question referring to an unfamiliar label. It is assumed that they thereby incidentally create associations between the unknown item and the label. However, contradictory findings have been reported and factors moderating rapid cortical integration through FM yet need to be identified. In the context of previous behavioral results showing rapid semantic integration through FM especially if the unknown and the known item shared many features, we propose that due to its computational mechanisms during the processing of complex and particularly highly similar objects, the perirhinal cortex might be especially qualified to support the rapid incorporation of these associations into cortical memory networks within the FM paradigm. We therefore expected that a high degree of feature overlap between the unknown and the known item would trigger strong engagement of the perirhinal cortex at encoding, which in turn might enhance rapid cortical integration of the novel picture-label associations. Within an fMRI experiment, we observed stronger activation for subsequent hits than misses during encoding in the perirhinal cortex and an associated anterior temporal network if the items shared many features than if they shared few features, indicating that the perirhinal cortex indeed contributes to the acquisition of novel associations by means of FM if feature overlap is high.

scholarly journals Decoding the Formation of New Semantics: MVPA Investigation of Rapid Neocortical Plasticity during Associative Encoding through Fast Mapping

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Tali Atir-Sharon ◽  
Asaf Gilboa ◽  
Hananel Hazan ◽  
Ester Koilis ◽  
Larry M. Manevitz
Keyword(s):  
Temporal Lobe ◽  
Conceptual Knowledge ◽  
Cortical Plasticity ◽  
Declarative Memory ◽  
Memory Performance ◽  
Activity Patterns ◽  
Semantic Networks ◽  
Fast Mapping ◽  
Anterior Temporal Lobe ◽  
Novel Associations

Neocortical structures typically only support slow acquisition of declarative memory; however, learning through fast mapping may facilitate rapid learning-induced cortical plasticity and hippocampal-independent integration of novel associations into existing semantic networks. During fast mapping the meaning of new words and concepts is inferred, and durable novel associations are incidentally formed, a process thought to support early childhood’s exuberant learning. The anterior temporal lobe, a cortical semantic memory hub, may critically support such learning. We investigated encoding of semantic associations through fast mapping using fMRI and multivoxel pattern analysis. Subsequent memory performance following fast mapping was more efficiently predicted using anterior temporal lobe than hippocampal voxels, while standard explicit encoding was best predicted by hippocampal activity. Searchlight algorithms revealed additional activity patterns that predicted successful fast mapping semantic learning located in lateral occipitotemporal and parietotemporal neocortex and ventrolateral prefrontal cortex. By contrast, successful explicit encoding could be classified by activity in medial and dorsolateral prefrontal and parahippocampal cortices. We propose that fast mapping promotes incidental rapid integration of new associations into existing neocortical semantic networks by activating related, nonoverlapping conceptual knowledge. In healthy adults, this is better captured by unique anterior and lateral temporal lobe activity patterns, while hippocampal involvement is less predictive of this kind of learning.

scholarly journals Can evolutionary thinking shed light on gender diversity?

2019 ◽  
Vol 25 (6) ◽  
pp. 351-362 ◽  
Author(s):  
Bernadette Wren ◽  
John Launer ◽  
Michael J. Reiss ◽  
Annie Swanepoel ◽  
Graham Music
Keyword(s):  
Gender Identity ◽  
Gender Diversity ◽  
Medical Intervention ◽  
List Type ◽  
Sex And Gender ◽  
Medical Interventions ◽  
The Core ◽  
Causal Pathways ◽  
And Gender ◽  
Shed Light

SUMMARYIssues of sexual reproduction lie at the core of evolutionary thinking, which often places an emphasis on how individuals attempt to maximise the number of successful offspring that they can produce. At first sight, it may therefore appear that individuals who opt for gender-affirming medical interventions are acting in ways that are evolutionarily disadvantageous. However, there are persuasive hypotheses that might make sense of such choices in evolutionary terms and we explore these here. It is premature to claim knowledge of the extent to which evolutionary arguments can usefully be applied to issues of gender identity, although worth reflecting on the extent to which nature tends towards diversity in matters of sex and gender. The importance of acknowledging and respecting different views in this domain, as well as recognising both the uncertainty and likely multiplicity of causal pathways, has implications for clinicians. We make some suggestions about how clinicians might best respond when faced with requests from patients in this area.LEARNING OBJECTIVESAfter reading this article you will be able to:•understand evolutionary arguments about diversity in human gender identity•identify strengths and weaknesses in evolutionary arguments applied to transgender issues•appreciate the range and diversity of gender experience and gender expression among people who present to specialist gender services, as well as the likely complexities of their reasons for requesting medical intervention.

scholarly journals Revealing the neural networks that extract conceptual gestalts from continuously evolving or changing semantic contexts

2019 ◽  
Author(s):  
Francesca M. Branzi ◽  
Gina F. Humphreys ◽  
Paul Hoffman ◽  
Matthew A. Lambon Ralph
Keyword(s):  
Right Hemisphere ◽  
Internal Representation ◽  
Semantic Integration ◽  
Multivariate Techniques ◽  
List Type ◽  
Semantic Cognition ◽  
Narrative Processing ◽  
Time Space ◽  
Context Integration ◽  
Meaningful Stimuli

AbstractReading a book, understanding the news reports or any other behaviour involving the processing of meaningful stimuli requires the semantic system to have two main features: being active during an extended period of time and flexibly adapting the internal representation according to the changing environment. Despite being key features of many everyday tasks, formation and updating of the semantic “gestalt” are still poorly understood. In this fMRI study we used naturalistic stimuli and task manipulations to identify the neural network that forms and updates conceptual gestalts during time-extended integration of meaningful stimuli. Univariate and multivariate techniques allowed at drawing a distinction between networks that are crucial for the formation of a semantic gestalt (meaning integration) and those that instead are important for linking incoming cues about the current context (e.g., time, space cues) into a schema representation. Specifically, we revealed that time-extended formation of the conceptual gestalt was reflected in the neurocomputations of the anterior temporal lobe accompanied by multi-demand areas and hippocampus, with a key role of brain structures in the right hemisphere. This “semantic gestalt network” was strongly recruited when an update of the current semantic representation was required during narrative processing. A distinct fronto-parietal network, instead, was recruited for context integration, independently from the meaning associations between words (semantic coherence). Finally, in contrast with accounts positing that the default-mode-network (DMN) may have a crucial role in semantic cognition, our findings revealed that DMN activity was sensitive to task difficulty, but not to semantic integration. The implications of these findings for neurocognitive models of semantic cognition and the literature on narrative processing are discussed.HighlightsfMRI revealed areas and networks for semantic integration during narrative readingATL has a key role in the formation of the conceptual gestaltIFG, pMTG and dAG reflect the update of the conceptual gestaltLeft AG (Mid-PGp) has a key role in context integration

scholarly journals Cortical networks for encoding near and far space in the non-human primate

2018 ◽  
Author(s):  
Justine Cléry ◽  
Olivier Guipponi ◽  
Soline Odouard ◽  
Claire Wardak ◽  
Suliann Ben Hamed
Keyword(s):  
Personal Space ◽  
Peripersonal Space ◽  
The Body ◽  
The Other ◽  
Space Representation ◽  
List Type ◽  
Cortical Networks ◽  
Near Space ◽  
Space Processing ◽  
Human Primate

AbstractWhile extra-personal space is often erroneously considered as a unique entity, early neuropsychological studies report a dissociation between near and far space processing both in humans and in monkeys. Here, we use functional MRI in a naturalistic 3D environment to describe the non-human primate near and far space cortical networks. We describe the co-occurrence of two extended functional networks respectively dedicated to near and far space processing. Specifically, far space processing involves occipital, temporal, parietal, posterior cingulate as well as orbitofrontal regions not activated by near space, possibly subserving the processing of the shape and identity of objects. In contrast, near space processing involves temporal, parietal and prefrontal regions not activated by far space, possibly subserving the preparation of an arm/hand mediated action in this proximal space. Interestingly, this network also involves somatosensory regions, suggesting a cross-modal anticipation of touch by a nearby object. Last, we also describe cortical regions that process both far and near space with a preference for one or the other. This suggests a continuous encoding of relative distance to the body, in the form of a far-to-near gradient. We propose that these cortical gradients in space representation subserve the physically delineable peripersonal spaces described in numerous psychology and psychophysics studies.HighlightsNear space processing involves temporal, parietal and prefrontal regions.Far space activates occipital, temporal, parietal, cingulate & orbitofrontal areas.Most regions process both far & near space, with a preference for one or the other.Far-to-near gradient may subserve behavioral changes in peripersonal space size.

scholarly journals Symptoms of Autism Spectrum Disorder in Individuals with Down Syndrome

2021 ◽  
Vol 11 (10) ◽  
pp. 1278
Author(s):  
Amanda Dimachkie Nunnally ◽  
Vivian Nguyen ◽  
Claudine Anglo ◽  
Audra Sterling ◽  
Jamie Edgin ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Expressive Language ◽  
Autism Diagnostic Observation Schedule ◽  
Autism Spectrum ◽  
Language Abilities ◽  
The Social ◽  
Item Level ◽  
Spectrum Disorders ◽  
Shed Light ◽  
Autism Diagnostic Observation

There is a growing body of evidence to suggest that individuals with Down syndrome (DS) are diagnosed with autism spectrum disorders (ASD) at a higher rate than individuals in the general population. Nonetheless, little is known regarding the unique presentation of ASD symptoms in DS. The current study aims to explore the prevalence and profiles of ASD symptoms in a sample of individuals with DS (n = 83), aged between 6 and 23 years. Analysis of this sample (MAge = 15.13) revealed that approximately 37% of the sample met the classification cut-off for ASD using the Autism Diagnostic Observation Schedule 2 (ADOS-2) Calibrated Severity Score (CSS), an indicator of the participants’ severity of ASD-related symptoms. Item-level analyses revealed that multiple items on Module 2 and Module 3 of the ADOS-2, mostly in the Social Affect (SA) subdomain, differentiated the children with DS who did not meet ASD classification (DS-only) from those who did (DS + ASD). Lastly, comparisons of individuals with DS-only and those with DS + ASD differed significantly on the syntactic complexity of their expressive language. These findings shed light on the unique presentation of ASD symptoms in a sample of individuals with DS and suggest that expressive language abilities may play a pivotal role in the presentation of ASD symptoms in DS.

scholarly journals Lexical Competition in Nonnative Speech Comprehension

2010 ◽  
Vol 22 (6) ◽  
pp. 1165-1178 ◽  
Author(s):  
Ian FitzPatrick ◽  
Peter Indefrey
Keyword(s):  
Language Comprehension ◽  
First Language ◽  
Semantic Integration ◽  
Sentence Completion ◽  
Speech Comprehension ◽  
Lexical Competition ◽  
Final Word ◽  
N400 Effect ◽  
Translation Equivalent ◽  
Electrophysiological Studies

Electrophysiological studies consistently find N400 effects of semantic incongruity in nonnative (L2) language comprehension. These N400 effects are often delayed compared with native (L1) comprehension, suggesting that semantic integration in one's second language occurs later than in one's first language. In this study, we investigated whether such a delay could be attributed to (1) intralingual lexical competition and/or (2) interlingual lexical competition. We recorded EEG from Dutch–English bilinguals who listened to English (L2) sentences in which the sentence-final word was (a) semantically fitting and (b) semantically incongruent or semantically incongruent but initially congruent due to sharing initial phonemes with (c) the most probable sentence completion within the L2 or (d) the L1 translation equivalent of the most probable sentence completion. We found an N400 effect in each of the semantically incongruent conditions. This N400 effect was significantly delayed to L2 words but not to L1 translation equivalents that were initially congruent with the sentence context. Taken together, these findings firstly demonstrate that semantic integration in nonnative listening can start based on word initial phonemes (i.e., before a single lexical candidate could have been selected based on the input) and secondly suggest that spuriously elicited L1 lexical candidates are not available for semantic integration in L2 speech comprehension.

scholarly journals Human alveolar Type 2 epithelium transdifferentiates into metaplastic KRT5+ basal cells during alveolar repair

2020 ◽  
Author(s):  
Jaymin J. Kathiriya ◽  
Chaoqun Wang ◽  
Alexis Brumwell ◽  
Monica Cassandras ◽  
Claude Le Saux ◽  
...  
Keyword(s):  
Alveolar Type ◽  
List Type ◽  
Basal Cells ◽  
Cell Transdifferentiation ◽  
Primary Fibroblasts ◽  
Intermediate Cells ◽  
Deficient Mice ◽  
Adult Human Lung ◽  
Shed Light

SUMMARYUnderstanding differential lineage potential of orthologous stem cells across species can shed light on human disease. Here, utilizing 3D organoids, single cell RNAseq, and xenotransplants, we demonstrate that human alveolar type 2 cells (hAEC2s), unlike murine AEC2s, are multipotent and able to transdifferentiate into KRT5+ basal cells when co-cultured with primary fibroblasts in 3D organoids. Trajectory analyses and immunophenotyping of epithelial progenitors in idiopathic pulmonary fibrosis (IPF) indicate that hAEC2s transdifferentiate into metaplastic basal cells through alveolar-basal intermediate (ABI) cells that we also identify in hAEC2-derived organoids. Modulating hAEC2-intrinsic and niche factors dysregulated in IPF can attenuate metaplastic basal cell transdifferentiation and preserve hAEC2 identity. Finally, hAEC2s transplanted into fibrotic immune-deficient murine lungs engraft as either hAEC2s or differentiated KRT5+ basal cells. Our study indicates that hAEC2s-loss and expansion of alveolar metaplastic basal cells in IPF are causally connected, which would not have been revealed utilizing murine AEC2s as a model.HighlightsHuman AEC2s transdifferentiate into KRT5+ basal cells when accompanied by primary adult human lung mesenchyme in 3D organoid culture.Alterations of hAEC2-intrinsic and niche factors dysregulated in IPF can modify metaplastic hAEC2 transdifferentiation.hAEC2s engraft into fibrotic lungs of immune-deficient mice and transdifferentiate into metaplastic basal cells.Transcriptional trajectory analysis suggests that hAEC2s in IPF gives rise to metaplastic basal cells via alveolar-basal intermediate cells.

scholarly journals A plant-like mechanism coupling m6A reading to polyadenylation safeguards transcriptome integrity and developmental genes partitioning in Toxoplasma

2021 ◽  
Author(s):  
Dayana C. Farhat ◽  
Matthew Bowler ◽  
Guillaume Communie ◽  
Dominique Pontier ◽  
Lucid Belmudes ◽  
...  
Keyword(s):  
High Resolution ◽  
Regulatory Mechanism ◽  
List Type ◽  
Regulatory Requirements ◽  
Apicomplexan Parasites ◽  
Transcriptional Termination ◽  
C Terminus ◽  
Cleavage And Polyadenylation ◽  
Host Life ◽  
Shed Light

AbstractCorrect 3’end processing of mRNAs is regarded as one of the regulatory cornerstones of gene expression. In a parasite that must answer to the high regulatory requirements of its multi-host life style, there is a great need to adopt additional means to partition the distinct transcriptional signatures of the closely and tandemly-arranged stage specific genes. In this study, we report on our findings in T. gondii of an m6A-dependent 3’end polyadenylation serving as a transcriptional barrier at these loci. We identify the core polyadenylation complex within T. gondii and establish CPSF4 as a reader for m6A-modified mRNAs, via a YTH domain within its C-terminus, a feature which is shared with plants. We bring evidence of the specificity of this interaction both biochemically, and by determining the crystal structure at high resolution of the T. gondii CPSF4-YTH in complex with an m6A modified RNA. We show that the loss of m6A, both at the level of its deposition or its recognition was associated with an increase in aberrantly elongated chimeric mRNAs emanating from impaired transcriptional termination, a phenotype previously noticed in the plant model Arabidopsis thaliana. We bring Nanopore direct RNA sequencing-based evidence of the occurrence of transcriptional read-through breaching into downstream repressed stage-specific genes, in the absence of either CPSF4 or the m6A RNA methylase components in both T. gondii and A. thaliana. Taken together, our results shed light on an essential regulatory mechanism coupling the pathways of m6A metabolism directly to the cleavage and polyadenylation processes, one that interestingly seem to serve, in both T. gondii and A. thaliana, as a guardian against aberrant transcriptional read-throughs.Highlightsm6A is recognized in apicomplexan and plants by CPSF4, a member of the cleavage and polyadenylation complex machinery.The structural insight behind the specificity of the binding of m6A by the CPSF4 YTH subunit are solved by high resolution crystal structures.The m6A-driven 3’end polyadenylation pathway protects transcriptome integrity by restricting transcriptional read-throughs and RNA chimera formation in apicomplexan parasites and plants.

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