scholarly journals Timecourse and convergence of abstract and concrete knowledge in the anterior temporal lobe

2020 ◽  
Author(s):  
L. Vignali ◽  
Y. Xu ◽  
J. Turini ◽  
O. Collignon ◽  
D. Crepaldi ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Conceptual Knowledge ◽  
Word Processing ◽  
Semantic Information ◽  
Anterior Temporal Lobe ◽  
Conceptual Processing ◽  
Feature Spaces ◽  
Semantic Hub ◽  
Late Stages ◽  
The Brain

AbstractHow is conceptual knowledge organized and retrieved by the brain? Recent evidence points to the anterior temporal lobe (ATL) as a crucial semantic hub integrating both abstract and concrete conceptual features according to a dorsal-to-medial gradient. It is however unclear when this conceptual gradient emerges and how semantic information reaches the ATL during conceptual retrieval. Here we used a multiple regression approach to magnetoencephalography signals of spoken words, combined with dimensionality reduction in concrete and abstract semantic feature spaces. Results showed that the dorsal-to-medial abstract-to-concrete ATL gradient emerges only in late stages of word processing: Abstract and concrete semantic information are initially encoded in posterior temporal regions and travel along separate cortical pathways eventually converging in the ATL. The present finding sheds light on the neural dynamics of conceptual processing that shape the organization of knowledge in the anterior temporal lobe.

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.

The Word Processing Deficit in Semantic Dementia: All Categories Are Equal, but Some Categories Are More Equal than Others

2010 ◽  
Vol 22 (9) ◽  
pp. 2027-2041 ◽  
Author(s):  
Friedemann Pulvermüller ◽  
Elisa Cooper-Pye ◽  
Clare Dine ◽  
Olaf Hauk ◽  
Peter J. Nestor ◽  
...  
Keyword(s):  
Speech Acts ◽  
Conceptual Knowledge ◽  
Word Processing ◽  
Case Series ◽  
Specific Pattern ◽  
Semantic Dementia ◽  
Semantic Features ◽  
Topography Model ◽  
Semantic Hub ◽  
Action Verbs

It has been claimed that semantic dementia (SD), the temporal variant of fronto-temporal dementia, is characterized by an across-the-board deficit affecting all types of conceptual knowledge. We here confirm this generalized deficit but also report differential degrees of impairment in processing specific semantic word categories in a case series of SD patients (N = 11). Within the domain of words with strong visually grounded meaning, the patients' lexical decision accuracy was more impaired for color-related than for form-related words. Likewise, within the domain of action verbs, the patients' performance was worse for words referring to face movements and speech acts than for words semantically linked to actions performed with the hand and arm. Psycholinguistic properties were matched between the stimulus groups entering these contrasts; an explanation for the differential degrees of impairment must therefore involve semantic features of the words in the different conditions. Furthermore, this specific pattern of deficits cannot be captured by classic category distinctions such as nouns versus verbs or living versus nonliving things. Evidence from previous neuroimaging research indicates that color- and face/speech-related words, respectively, draw most heavily on anterior-temporal and inferior-frontal areas, the structures most affected in SD. Our account combines (a) the notion of an anterior-temporal amodal semantic “hub” to explain the profound across-the-board deficit in SD word processing, with (b) a semantic topography model of category-specific circuits whose cortical distributions reflect semantic features of the words and concepts represented.

scholarly journals The anterior temporal artery: an underutilized but robust donor for revascularization of the distal middle cerebral artery

2017 ◽  
Vol 127 (4) ◽  
pp. 740-747 ◽  
Author(s):  
Ali Tayebi Meybodi ◽  
Michael T. Lawton ◽  
Dylan Griswold ◽  
Pooneh Mokhtari ◽  
Andre Payman ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Temporal Lobe ◽  
Cerebral Artery ◽  
Insular Cortex ◽  
Temporal Artery ◽  
Loss Of Function ◽  
Anterior Temporal Lobe ◽  
Work Supports ◽  
The Brain ◽  
Distal Middle Cerebral Artery

OBJECTIVEThe anterior temporal artery (ATA) supplies an area of the brain that, if sacrificed, does not cause a noticeable loss of function. Therefore, the ATA may be used as a donor in intracranial-intracranial (IC-IC) bypass procedures. The capacities of the ATA as a donor have not been studied previously. In this study, the authors assessed the feasibility of using the ATA as a donor for revascularization of different segments of the distal middle cerebral artery (MCA).METHODSThe ATA was studied in 15 cadaveric specimens (8 heads, excluding 1 side). First, the cisternal segment of the artery was untethered from arachnoid adhesions and small branches feeding the anterior temporal lobe and insular cortex, to evaluate its capacity for a side-to-side bypass to insular, opercular, and cortical segments of the MCA. Any branch entering the anterior perforated substance was preserved. Then, the ATA was cut at the opercular-cortical junction and the capacity for an end-to-side bypass was assessed.RESULTSFrom a total of 17 ATAs, 4 (23.5%) arose as an early MCA branch. The anterior insular zone and the frontal parasylvian cortical arteries were the best targets (in terms of mobility and caliber match) for a side-to-side bypass. Most of the insula was accessible for end-to-side bypass, but anterior zones of the insula were more accessible than posterior zones. End-to-side bypass was feasible for most recipient cortical arteries along the opercula, except for posterior temporal and parietal regions. Early ATAs reached significantly farther on the insular MCA recipients than non-early ATAs for both side-to-side and end-to-side bypasses.CONCLUSIONSThe ATA is a robust arterial donor for IC-IC bypass procedures, including side-to-side and end-to-side techniques. The evidence provided in this work supports the use of the ATA as a donor for distal MCA revascularization in well-selected patients.

scholarly journals Anterior Temporal Lobe Tracks the Formation of Prejudice

2017 ◽  
Vol 29 (3) ◽  
pp. 530-544 ◽  
Author(s):  
Hugo J. Spiers ◽  
Bradley C. Love ◽  
Mike E. Le Pelley ◽  
Charlotte E. Gibb ◽  
Robin A. Murphy
Keyword(s):  
Temporal Lobe ◽  
Minority Groups ◽  
Social Groups ◽  
Temporal Cortex ◽  
Brain Structures ◽  
Brain Regions ◽  
Prediction Errors ◽  
Anterior Temporal Lobe ◽  
Majority Groups ◽  
The Brain

Despite advances in understanding the brain structures involved in the expression of stereotypes and prejudice, little is known about the brain structures involved in their acquisition. Here, we combined fMRI, a task involving learning the valence of different social groups, and modeling of the learning process involved in the development of biases in thinking about social groups that support prejudice. Participants read descriptions of valenced behaviors performed by members of novel social groups, with majority groups being more frequently encountered during learning than minority groups. A model-based fMRI analysis revealed that the anterior temporal lobe tracked the trial-by-trial changes in the valence associated with each group encountered in the task. Descriptions of behavior by group members that deviated from the group average (i.e., prediction errors) were associated with activity in the left lateral PFC, dorsomedial PFC, and lateral anterior temporal cortex. Minority social groups were associated with slower acquisition rates and more activity in the ventral striatum and ACC/dorsomedial PFC compared with majority groups. These findings provide new insights into the brain regions that (a) support the acquisition of prejudice and (b) detect situations in which an individual's behavior deviates from the prejudicial attitude held toward their group.

scholarly journals Distinctive responses in anterior temporal lobe and ventrolateral prefrontal cortex during categorization of semantic information

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atsushi Matsumoto ◽  
Takahiro Soshi ◽  
Norio Fujimaki ◽  
Aya S. Ihara
Keyword(s):  
Prefrontal Cortex ◽  
Temporal Lobe ◽  
Marine Mammals ◽  
Semantic Information ◽  
Category Membership ◽  
Neural Basis ◽  
Anterior Temporal Lobe ◽  
Ventrolateral Prefrontal Cortex ◽  
Semantic Categorization ◽  
Target Words

AbstractSemantic categorization is a fundamental ability in language as well as in interaction with the environment. However, it is unclear what cognitive and neural basis generates this flexible and context dependent categorization of semantic information. We performed behavioral and fMRI experiments with a semantic priming paradigm to clarify this. Participants conducted semantic decision tasks in which a prime word preceded target words, using names of animals (mammals, birds, or fish). We focused on the categorization of unique marine mammals, having characteristics of both mammals and fish. Behavioral experiments indicated that marine mammals were semantically closer to fish than terrestrial mammals, inconsistent with the category membership. The fMRI results showed that the left anterior temporal lobe was sensitive to the semantic distance between prime and target words rather than category membership, while the left ventrolateral prefrontal cortex was sensitive to the consistency of category membership of word pairs. We interpreted these results as evidence of existence of dual processes for semantic categorization. The combination of bottom-up processing based on semantic characteristics in the left anterior temporal lobe and top-down processing based on task and/or context specific information in the left ventrolateral prefrontal cortex is required for the flexible categorization of semantic information.

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