scholarly journals Prior knowledge promotes hippocampal separation but cortical assimilation in the left inferior frontal gyrus

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Oded Bein ◽  
Niv Reggev ◽  
Anat Maril
Keyword(s):  
Prior Knowledge ◽  
Inferior Frontal Gyrus ◽  
Activity Patterns ◽  
Neural Representation ◽  
The Novel ◽  
Left Inferior Frontal Gyrus ◽  
Specific Direction ◽  
Before And After ◽  
Novel Associations ◽  
Striking Contrast

Abstract An adaptive memory system rarely learns information tabula rasa, but rather builds on prior knowledge to facilitate learning. How prior knowledge influences the neural representation of novel associations remains unknown. Here, participants associated pairs of faces in two conditions: a famous, highly familiar face with a novel face or two novel faces while undergoing fMRI. We examine multivoxel activity patterns corresponding to individual faces before and after learning. The activity patterns representing members of famous-novel pairs becomes separated in the hippocampus, that is, more distinct from one another through learning, in striking contrast to paired novel faces that become similar. In the left inferior frontal gyrus, however, prior knowledge leads to integration, and in a specific direction: the representation of the novel face becomes similar to that of the famous face after learning, suggesting assimilation of new into old memories. We propose that hippocampal separation might resolve interference between existing and newly learned information, allowing cortical assimilation. Thus, associative learning with versus without prior knowledge relies on radically different computations.

scholarly journals The direction of associations: prior knowledge promotes hippocampal separation, but cortical assimilation

2019 ◽  
Author(s):  
Oded Bein ◽  
Niv Reggev ◽  
Anat Maril
Keyword(s):  
Prior Knowledge ◽  
Internal State ◽  
Activity Patterns ◽  
The Novel ◽  
Familiar Face ◽  
New Information ◽  
Specific Direction ◽  
Before And After ◽  
New Association ◽  
Striking Contrast

SummaryWhat does it mean to say, “a new association is learned”? And how is this learning different when adding new information to already-existing knowledge? Here, participants associated pairs of faces while undergoing fMRI, under two different conditions: a famous, highly-familiar face with a novel face or two novel faces. We examined multivoxel activity patterns corresponding to individual faces before and after learning. In the hippocampus, paired novel faces became more similar to one another through learning. In striking contrast, members of famous-novel pairs became distinct. In the cortex, prior knowledge led to integration, but in a specific direction: the representation of the novel face became similar to that of the famous face before learning, but less so vice versa, suggesting assimilation of new into old memories. We propose that hippocampal separation might resolve interference between existing and newly learned information, allowing cortical assimilation. Associations are formed through divergent but specific neural codes, that are adaptively shaped by the internal state of the system – its prior knowledge.

scholarly journals Computational mechanisms for neural representation of words

2021 ◽  
Author(s):  
Ze Fu ◽  
Xiaosha Wang ◽  
Xiaoying Wang ◽  
Huichao Yang ◽  
Jiahuan Wang ◽  
...  
Keyword(s):  
Neural Network ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Activity Patterns ◽  
Explanatory Power ◽  
Word Meaning ◽  
Brain Regions ◽  
Neural Representation ◽  
Space Representation ◽  
Neural Representations

A critical way for humans to acquire, represent and communicate information is through language, yet the underlying computation mechanisms through which language contributes to our word meaning representations are poorly understood. We compared three major types of word computation mechanisms from large language corpus (simple co-occurrence, graph-space relations and neural-network-vector-embedding relations) in terms of the association of words’ brain activity patterns, measured by two functional magnetic resonance imaging (fMRI) experiments. Word relations derived from a graph-space representation, and not neural-network-vector-embedding, had unique explanatory power for the neural activity patterns in brain regions that have been shown to be particularly sensitive to language processes, including the anterior temporal lobe (capturing graph-common-neighbors), inferior frontal gyrus, and posterior middle/inferior temporal gyrus (capturing graph-shortest-path). These results were robust across different window sizes and graph sizes and were relatively specific to language inputs. These findings highlight the role of cumulative language inputs in organizing word meaning neural representations and provide a mathematical model to explain how different brain regions capture different types of language-derived information.

The Neural Representation of Events Is Dominated by Elements that Are Most Reliably Present

2021 ◽  
pp. 1-15
Author(s):  
Konstantinos Bromis ◽  
Petar P. Raykov ◽  
Leah Wickens ◽  
Warrick Roseboom ◽  
Chris M. Bird
Keyword(s):  
Episodic Memory ◽  
Specific Activity ◽  
Activity Patterns ◽  
Neural Representation ◽  
The Novel ◽  
Experimental Paradigm ◽  
Multiple Events ◽  
The People ◽  
The Brain ◽  
Posterior Midline

Abstract An episodic memory is specific to an event that occurred at a particular time and place. However, the elements that comprise the event—the location, the people present, and their actions and goals—might be shared with numerous other similar events. Does the brain preferentially represent certain elements of a remembered event? If so, which elements dominate its neural representation: those that are shared across similar events, or the novel elements that define a specific event? We addressed these questions by using a novel experimental paradigm combined with fMRI. Multiple events were created involving conversations between two individuals using the format of a television chat show. Chat show “hosts” occurred repeatedly across multiple events, whereas the “guests” were unique to only one event. Before learning the conversations, participants were scanned while viewing images or names of the (famous) individuals to be used in the study to obtain person-specific activity patterns. After learning all the conversations over a week, participants were scanned for a second time while they recalled each event multiple times. We found that during recall, person-specific activity patterns within the posterior midline network were reinstated for the hosts of the shows but not the guests, and that reinstatement of the hosts was significantly stronger than the reinstatement of the guests. These findings demonstrate that it is the more generic, familiar, and predictable elements of an event that dominate its neural representation compared with the more idiosyncratic, event-defining, elements.

scholarly journals Can the Executive Control Network be Used to Diagnose Parkinson’s Disease and as an Efficacy Indicator of Deep Brain Stimulation?

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Wenwen Dong ◽  
Chang Qiu ◽  
Xu Jiang ◽  
Bo Shen ◽  
Li Zhang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Inferior Frontal Gyrus ◽  
Imaging Biomarker ◽  
Posterior Lobe ◽  
Left Inferior Frontal Gyrus ◽  
Before And After ◽  
Deep Brain

Objective. The aim of this work was to investigate whether there are differences in the executive control network (ECN) between patients with Parkinson’s disease (PD) before and after deep brain stimulation (DBS) surgery and to explore how deep brain stimulation (DBS) surgery affects ECN connectivity in patients with PD. Methods. Resting-state magnetic resonance imaging (MRI) data were obtained from 23 patients with Parkinson’s disease preoperatively (pre-PD) and postoperatively (post-PD) and 14 normal controls (CN). The right dorsolateral prefrontal cortex (DLPFC) was used as the seed region of interest (ROI) to study the characteristics of the functional connectivity of the ECN in these subjects. Results. There were differences in the ECN among PD patients before and after surgery and between the CN. Compared with the CN group, the pre-PD patients showed significantly reduced functional connectivity (FC) between the DLPFC and the left inferior frontal gyrus, left precuneus, left cerebellum posterior lobe, right middle frontal gyrus, right inferior parietal gyrus, right posterior central gyrus, right precuneus, and right inferior frontal gyrus. Compared to the CN group, the post-PD patients showed significantly reduced FC between the DLPFC and left inferior frontal gyrus, left precuneus, left cerebellum posterior lobe, right middle frontal gyrus, right inferior frontal gyrus, and right parietal lobule. There is no difference in the ECN between the pre-PD patients and the post-PD patients. Conclusions. The FC of ECN in PD patients was different from that in normal controls, but the FC of the ECN in patients with PD may not be altered by DBS. This suggests that the ECN may be considered an imaging biomarker for the identification of PD but may not be a good imaging biomarker for the evaluation of DBS efficacy.

More Alike Than Unalike: Cross-language Similarity Influences Novel Word Lexicalization in Bilingual Individuals

2020 ◽  
Author(s):  
Pauline Palma ◽  
Marie-France Marin ◽  
k onishi ◽  
Debra Titone
Keyword(s):  
Lexical Decision ◽  
Lexical Decision Task ◽  
Decision Task ◽  
The Novel ◽  
Lexical Representations ◽  
Before And After ◽  
Word Forms ◽  
Explicit Recognition ◽  
Novel Word Learning ◽  
Cross Language

Although several studies have focused on novel word learning and consolidation in native (presumably monolingual) speakers, less is know about how bilinguals add novel words to their mental lexicon. Here, we trained 33 English-French bilinguals on novel word-forms that were neighbors to “hermit” English words (i.e., words with no existing neighbors). Importantly, these English words varied in terms of orthographic overlap with their French translation equivalent (i.e., cognates vs. noncognates). We measured explicit recognition of the novel neighbors and the interaction between novel neighbors and English words through a lexical decision task, both before and after a sleep interval. In the lexical decision task, we found evidence of immediate facilitation for English words with novel neighbors, and evidence of competition after a sleep interval for cognate words only. These results suggest that higher quality of existing lexical representations predicts an earlier onset for novel word lexicalization.

A CRITICAL ASSESSMENT OF THE NOVEL «ASSEMBLY HALL» BY HERMANN KANT IN THE REUNIFIED GERMANY (AFTER 1991)

2020 ◽  
pp. 144-152
Author(s):  
Rimma Gurevich
Keyword(s):  
Critical Assessment ◽  
The Novel ◽  
Aesthetic Appreciation ◽  
Party Position ◽  
Creative Personality ◽  
Before And After

H. Kant’s novel received a high literary and aesthetic appreciation in criticism and wide recognition by readers. Criticism (before and after the unification of Germany) concerns mainly one aspect viz. authenticity of the events depicted in the novel and the charcters’ images. Opponents argue that Kant’s ideological views, his consistent socialist and party position have prompt him to embellish reality, create simulacra, and the idyllic world of socialist Biedermeyer. The article shows that these assessments ignore the nature of his talent, especially his creative personality peculiarities such as journalistic orientation of the motivated «political» person and writer.

scholarly journals Syntactic Complexity and Frequency in the Neurocognitive Language System

2017 ◽  
Vol 29 (9) ◽  
pp. 1605-1620 ◽  
Author(s):  
Yun-Hsuan Yang ◽  
William D. Marslen-Wilson ◽  
Mirjana Bozic
Keyword(s):  
Language Comprehension ◽  
Multivariate Analyses ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Frequency Effect ◽  
Syntactic Complexity ◽  
Left Inferior Frontal Gyrus ◽  
Fmri Study ◽  
Key Factor ◽  
Frequent Items

Prominent neurobiological models of language follow the widely accepted assumption that language comprehension requires two principal mechanisms: a lexicon storing the sound-to-meaning mapping of words, primarily involving bilateral temporal regions, and a combinatorial processor for syntactically structured items, such as phrases and sentences, localized in a left-lateralized network linking left inferior frontal gyrus (LIFG) and posterior temporal areas. However, recent research showing that the processing of simple phrasal sequences may engage only bilateral temporal areas, together with the claims of distributional approaches to grammar, raise the question of whether frequent phrases are stored alongside individual words in temporal areas. In this fMRI study, we varied the frequency of words and of short and long phrases in English. If frequent phrases are indeed stored, then only less frequent items should generate selective left frontotemporal activation, because memory traces for such items would be weaker or not available in temporal cortex. Complementary univariate and multivariate analyses revealed that, overall, simple words (verbs) and long phrases engaged LIFG and temporal areas, whereas short phrases engaged bilateral temporal areas, suggesting that syntactic complexity is a key factor for LIFG activation. Although we found a robust frequency effect for words in temporal areas, no frequency effects were found for the two phrasal conditions. These findings support the conclusion that long and short phrases are analyzed, respectively, in the left frontal network and in a bilateral temporal network but are not retrieved from memory in the same way as simple words during spoken language comprehension.

Syntactic Dependencies as Memorized Sequences in the Brain

2005 ◽  
Vol 50 (1-4) ◽  
pp. 241-266 ◽  
Author(s):  
Yosef Grodzinsky
Keyword(s):  
Working Memory ◽  
Inferior Frontal Gyrus ◽  
Functional Neuroanatomy ◽  
Left Inferior Frontal Gyrus ◽  
Broca’S Region ◽  
Syntactic Representation ◽  
Syntactic Approach ◽  
Syntactic Relations ◽  
Syntactic Dependencies ◽  
The Brain

AbstractThe prospects of a cognitive neuroscience of syntax are considered with respect to functional neuroanatomy of two seemingly independent systems: Working Memory and syntactic representation and processing. It is proposed that these two systems are more closely related than previously supposed. In particular, it is claimed that a sentence with anaphoric dependencies involves several Working Memories, each entrusted with a different linguistic function. Components of Working Memory reside in the Left Inferior Frontal Gyrus, which is associated with Broca’s region. When lesioned, this area manifests comprehension disruptions in the ability to analyze intra-sentential dependencies, suggesting that Working Memory spans over syntactic computations. The unification of considerations regarding Working Memory with a purely syntactic approach to Broca’s regions leads to the conclusion that mechanisms that compute transformations—and no other syntactic relations—reside in this area.

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.

Sign in / Sign up

Export Citation Format

Share Document