scholarly journals Conceptual Representations of Action in the Lateral Temporal Cortex

2005 ◽  
Vol 17 (12) ◽  
pp. 1855-1870 ◽  
Author(s):  
Joseph W. Kable ◽  
Irene P. Kan ◽  
Ashley Wilson ◽  
Sharon L. Thompson-Schill ◽  
Anjan Chatterjee
Keyword(s):  
Semantic Information ◽  
Temporal Cortex ◽  
Human Motion ◽  
Middle Temporal Gyrus ◽  
Conceptual Information ◽  
Middle Temporal ◽  
Conceptual Representations ◽  
Additional Support ◽  
Left Middle ◽  
Manipulable Object

Retrieval of conceptual information from action pictures causes greater activation than from object pictures bilaterally in human motion areas (MT/MST) and nearby temporal regions. By contrast, retrieval of conceptual information from action words causes greater activation in left middle and superior temporal gyri, anterior and dorsal to the MT/MST. We performed two fMRI experiments to replicate and extend these findings regarding action words. In the first experiment, subjects performed conceptual judgments of action and object words under conditions that stressed visual semantic information. Under these conditions, action words again activated posterior temporal regions close to, but not identical with, the MT/MST. In the second experiment, we included conceptual judgments of manipulable object words in addition to judgments of action and animal words. Both action and manipulable object judgments caused greater activity than animal judgments in the posterior middle temporal gyrus. Both of these experiments support the hypothesis that middle temporal gyrus activation is related to accessing conceptual information about motion attributes, rather than alternative accounts on the basis of lexical or grammatical factors. Furthermore, these experiments provide additional support for the notion of a concrete to abstract gradient of motion representations with the lateral occipito-temporal cortex, extending anterior and dorsal from the MT/MST towards the peri-sylvian cortex.

Neural Circuits Subserving the Retrieval and Maintenance of Abstract Rules

2003 ◽  
Vol 90 (5) ◽  
pp. 3419-3428 ◽  
Author(s):  
Silvia A. Bunge ◽  
Itamar Kahn ◽  
Jonathan D. Wallis ◽  
Earl K. Miller ◽  
Anthony D. Wagner
Keyword(s):  
Parietal Cortex ◽  
Semantic Information ◽  
Temporal Cortex ◽  
Delay Period ◽  
Specific Response ◽  
Middle Temporal ◽  
Rule Type ◽  
Abstract Rule ◽  
Left Middle ◽  
Rule Representation

Behavior is often governed by abstract rules or instructions for behavior that can be abstracted from one context and applied to another. Prefrontal cortex (PFC) is thought to be important for representing rules, although the contributions of ventrolateral (VLPFC) and dorsolateral (DLPFC) regions remain under-specified. In the present study, event-related fMRI was used to examine abstract rule representation in humans. Prior to scanning, subjects learned to associate unfamiliar shapes and nonwords with particular rules. During each fMRI trial, presentation of one of these cues was followed by a delay and then by sample and probe stimuli. Match and non-match rules required subjects to indicate whether or not the sample and probe matched; go rules required subjects to make a response that was not contingent on the sample/probe relation. Left VLPFC, parietal cortex, and pre-SMA exhibited sensitivity to rule type during the cue and delay periods. Delay-period activation in these regions, but not DLPFC, was greater when subjects had to maintain response contingencies (match, non-match) relative to when the cue signaled a specific response (go). In contrast, left middle temporal cortex exhibited rule sensitivity during the cue but not delay period. These results support the hypothesis that VLPFC interacts with temporal cortex to retrieve semantic information associated with a cue and with parietal cortex to retrieve and maintain relevant response contingencies across delays. Future investigations of cross-regional interactions will enable full assessment of this account. Collectively, these results demonstrate that multiple, neurally separable processes are recruited during abstract rule representation.

scholarly journals Neural Basis of Depression Related to a Dominant Right Hemisphere: A Resting-State fMRI Study

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mi Li ◽  
Hongpei Xu ◽  
Shengfu Lu
Keyword(s):  
Right Hemisphere ◽  
Inferior Frontal Gyrus ◽  
Middle Temporal Gyrus ◽  
Neural Basis ◽  
Middle Temporal ◽  
Middle Occipital Gyrus ◽  
The Right ◽  
Depressive Patients ◽  
The Brain ◽  
Left Middle

Background. In the past, studies on the lateralization of the left and right hemispheres of the brain suggested that depression is dominated by the right hemisphere of the brain, but the neural basis of this theory remains unclear. Method. Functional magnetic resonance imaging of the brain was performed in 22 depressive patients and 15 healthy controls. The differences in the mean values of the regional homogeneity (ReHo) of two groups were compared, and the low-frequency amplitudes of these differential brain regions were compared. Results. The results show that compared with healthy subjects, depressive patients had increased ReHo values in the right superior temporal gyrus, right middle temporal gyrus, left inferior temporal gyrus, left middle temporal gyrus, right middle frontal gyrus, triangular part of the right inferior frontal gyrus, orbital part of the right inferior frontal gyrus, right superior occipital gyrus, right middle occipital gyrus, bilateral anterior cingulate, and paracingulate gyri; reduced ReHo values were seen in the right fusiform gyrus, left middle occipital gyrus, left lingual gyrus, and left inferior parietal except in the supramarginal and angular gyri. Conclusions. The results show that regional homogeneity mainly occurs in the right brain, and the overall performance of the brain is such that right hemisphere synchronization is enhanced while left hemisphere synchronization is weakened. ReHo abnormalities in the resting state can predict abnormalities in individual neurological activities that reflect changes in the structure and function of the brain; abnormalities shown with this indicator are the neuronal basis for the phenomenon that the right hemisphere of the brain has a dominant effect on depression.

scholarly journals Disrupted Topological Organization of Functional Networks in Asymptomatic Carotid Plaque Without Significant Carotid Stenosis: A Resting-State fMRI Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Jia Tuo ◽  
Wei He ◽  
Shuai Yang ◽  
Lihui Liu ◽  
Xiaojuan Liu ◽  
...  
Keyword(s):  
Resting State ◽  
Carotid Plaque ◽  
Functional Network ◽  
Middle Temporal Gyrus ◽  
Functional Networks ◽  
Middle Temporal ◽  
Brain Functional Network ◽  
Asymptomatic Patients ◽  
The Brain ◽  
Left Middle

Purpose: Previous studies have found that there are significant changes in functional network properties for patients with moderate to severe carotid artery stenosis. Our study aimed to explore the topology properties of brain functional network in asymptomatic patients with carotid plaque without significant stenosis.Methods: A total of 61 asymptomatic patients with carotid plaque (mean age 61.79 ± 7.35 years) and 25 healthy control subjects (HC; 58.12 ± 6.79 years) were recruited. General data collection, carotid ultrasound examination and resting state functional magnetic resonance imaging were performed on all subjects. Graph-theory was applied to examine the differences in the brain functional network topological properties between two groups.Results: In the plaque group, Eloc(P = 0.03), γ (P = 0.01), and σ (P = 0.01) were significantly higher than in the HC group. The degree centrality of left middle frontal gyrus and the nodal efficiency of left middle frontal gyrus and right inferior parietal angular gyrus were significantly higher in the plaque group than in HC. The degree centrality and betweenness centrality of right middle temporal gyrus, as well as the nodal efficiency of right middle temporal gyrus, were significantly lower in the plaque group than in HC.Conclusions: The brain functional networks of patients with carotid plaques differ from those of healthy controls. Asymptomatic patients with carotid plaques exhibit increased local and global connectivity, which may reflect subtle reorganizations in response to early brain damage.

scholarly journals Abnormal functional connectivity density in patients with dysthyroid optic neuropathy

2020 ◽  
Author(s):  
Yunhai Tu ◽  
Pingping Huang ◽  
Chuanwan Mao ◽  
Xiaozheng Liu ◽  
Jianlu Gao
Keyword(s):  
Visual Field ◽  
Functional Connectivity ◽  
Optic Neuropathy ◽  
Middle Temporal Gyrus ◽  
Functional Connectivity Density ◽  
Dysthyroid Optic Neuropathy ◽  
Middle Temporal ◽  
The Right ◽  
Left Middle Temporal Gyrus ◽  
Left Middle

[Objective] Functional connectivity density (FCD) mapping was used to investigate abnormalities and factors related to brain functional connectivity (F.C.) in cortical regions of patients with dysthyroid optic neuropathy (DON) and to analyze the pathogenesis of DON further. [Methods] Patients diagnosed with thyroid-associated ophthalmopathy (TAO) in the Eye Hospital were enrolled. All patients underwent comprehensive eye examinations and best-corrected visual acuity, visual field(V.F.) test. MRI data collection and analysis were completed in the 2nd Affiliated Hospital of Wenzhou Medical University. The patients were divided into two groups: the DON group, with an average visual field, mean deviation (M.D.) of both eyes < -5 dB, and the non-DON group (nDON group), with an average visual field M.D. of both eyes ≥ -2 dB. [Results] A total of 30 TAO patients (14 men, 16 women) with complete data who met the experimental requirements were enrolled. The average age was 48.79 (40~ 57) years. There were 16 patients in the DON group and 14 patients in the nDON group. No significant differences in age, gender, education level, and the maximum horizontal diameter of either medial rectus muscle were found between the two groups. The difference of brain FCD between the two groups showed significant abnormal connectivity in the right orbital gyri of the frontal lobe (Frontal_Inf_Orb_R) and the left precuneus in the DON group compared with the nDON group. As demonstrated by decreased FCD values in the right inferior frontal gyrus/orbital part, the relevant brain regions were the left middle temporal gyrus, left precuneus, left middle frontal gyrus, right postcentral gyrus, and brain gyri (excluding the supramarginal gyrus and angular gyrus) below the left parietal bone. The FCD associated with the left precuneus was increased, and the relevant brain areas were the left middle temporal gyrus, right cuneus, superior occipital gyrus, and right fusiform gyrus. A significant correlation was identified between the MD. of the binocular visual field and brain FCD. [Conclusion] The abnormal FCD in the cortex of DON patients suggests that a central nervous system mechanism may be related to the pathogenesis of the DON.

scholarly journals Aberrant functional connectivity density in patients with treatment-refractory obsessive-compulsive disorder: a pilot study

2019 ◽  
Vol 47 (6) ◽  
pp. 2434-2445
Author(s):  
Pei Wei Shan ◽  
Wei Liu ◽  
Caixing Liu ◽  
Yunyi Han ◽  
Lina Wang ◽  
...  
Keyword(s):  
Middle Temporal Gyrus ◽  
Obsessive Compulsive ◽  
Middle Temporal ◽  
Compulsive Disorder ◽  
Functional Connections ◽  
Processing Ability ◽  
Treatment Refractory ◽  
Left Middle Temporal Gyrus ◽  
Processing Circuit ◽  
Left Middle

Objective Functional connectivity (FC) is altered in patients with obsessive-compulsive disorder (OCD). Most previous studies have focused on the strength of FC in patients with OCD; few have examined the number of functional connections in these patients. The number of functional connections is an important index for assessing aberrant FC. In the present study, we used FC density (FCD) mapping to explore alterations in the number of functional connections in patients with treatment-refractory OCD (TROCD) using the FCD index. Methods Twenty patients with TROCD and 20 patients with OCD in clinical remission were enrolled in the study. Global FCD (gFCD) was adopted to compare the differences between the two groups of patients. Results The gFCD in the left middle temporal gyrus was lower in the patients with TROCD than in those with remitted OCD, suggesting that decreased information processing ability may play a significant role in TROCD. Conclusion The left middle temporal gyrus is a key component of the emotional processing circuit and attentional processing circuit. Decreased information processing ability in this brain region may play a significant role in TROCD; however, further well-designed follow-up studies are needed to support this hypothesis.

scholarly journals Lexical Influences on Categorical Speech Perception Are Driven by a Temporoparietal Circuit

2021 ◽  
pp. 1-13
Author(s):  
Gavin M. Bidelman ◽  
Claire Pearson ◽  
Ashleigh Harrison
Keyword(s):  
Parietal Lobe ◽  
Middle Temporal Gyrus ◽  
Brain Areas ◽  
Lexical Status ◽  
Inferior Parietal Lobe ◽  
Middle Temporal ◽  
Phonetic Perception ◽  
Speech Categorization ◽  
Left Middle Temporal Gyrus ◽  
Left Middle

Categorical judgments of otherwise identical phonemes are biased toward hearing words (i.e., “Ganong effect”) suggesting lexical context influences perception of even basic speech primitives. Lexical biasing could manifest via late stage postperceptual mechanisms related to decision or, alternatively, top–down linguistic inference that acts on early perceptual coding. Here, we exploited the temporal sensitivity of EEG to resolve the spatiotemporal dynamics of these context-related influences on speech categorization. Listeners rapidly classified sounds from a /gɪ/-/kɪ/ gradient presented in opposing word–nonword contexts ( GIFT–kift vs. giss–KISS), designed to bias perception toward lexical items. Phonetic perception shifted toward the direction of words, establishing a robust Ganong effect behaviorally. ERPs revealed a neural analog of lexical biasing emerging within ~200 msec. Source analyses uncovered a distributed neural network supporting the Ganong including middle temporal gyrus, inferior parietal lobe, and middle frontal cortex. Yet, among Ganong-sensitive regions, only left middle temporal gyrus and inferior parietal lobe predicted behavioral susceptibility to lexical influence. Our findings confirm lexical status rapidly constrains sublexical categorical representations for speech within several hundred milliseconds but likely does so outside the purview of canonical auditory-sensory brain areas.

scholarly journals Lexical selection with competing distractors: Evidence from left temporal lobe lesions

2016 ◽  
Author(s):  
Vitória Piai ◽  
Robert T. Knight
Keyword(s):  
Interference Effect ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Lexical Selection ◽  
Semantic Interference ◽  
Middle Temporal ◽  
Relative Contribution ◽  
Unrelated Condition

AbstractAccording to the competition account of lexical selection in word production, conceptually driven word retrieval involves the activation of a set of candidate words in left temporal cortex, and competitive selection of the intended word from this set, regulated by frontal cortical mechanisms. However, the relative contribution of these brain regions to competitive lexical selection is uncertain. In the present study, five patients with left prefrontal cortex lesions (overlapping in ventral and dorsal lateral cortex), eight patients with left lateral temporal cortex lesions (overlapping in middle temporal gyrus), and 13 matched controls performed a picture-word interference task. Distractor words were semantically related or unrelated to the picture, or the name of the picture (congruent condition). Semantic interference (related vs unrelated), tapping into competitive lexical selection, was examined. An overall semantic interference effect was observed for the control and left-temporal groups separately. The left-frontal patients did not show a reliable semantic interference effect as a group. The left-temporal patients had increased semantic interference in the error rates relative to controls. Error distribution analyses indicated that these patients had more hesitant responses for the related than for the unrelated condition. We propose that left middle temporal lesions affect the lexical activation component, making lexical selection more susceptible to errors.

scholarly journals Fronto-temporal Interactions during Overt Verbal Initiation and Suppression

2008 ◽  
Vol 20 (9) ◽  
pp. 1656-1669 ◽  
Author(s):  
Paul Allen ◽  
Andrea Mechelli ◽  
Klaas E. Stephan ◽  
Fern Day ◽  
Jeffery Dalton ◽  
...  
Keyword(s):  
Effective Connectivity ◽  
Causal Modeling ◽  
Sentence Completion ◽  
Middle Temporal Gyrus ◽  
Response Suppression ◽  
Lexical Information ◽  
Response Initiation ◽  
Middle Temporal ◽  
Temporal Language ◽  
Left Middle

The Hayling Sentence Completion Task (HSCT) is known to activate left hemisphere frontal and temporal language regions. However, the effective connectivity between frontal and temporal language regions associated with the task has yet to be examined. The aims of the study were to examine activation and effective connectivity during the HSCT using a functional magnetic resonance imaging (fMRI) paradigm in which participants made overt verbal responses. We predicted that producing an incongruent response (response suppression), compared to a congruent one (response initiation), would be associated with greater activation in the left prefrontal cortex and an increase in the effective connectivity between temporal and frontal regions. Fifteen participants were scanned while completing 80 sentence stems. The congruency and constraint of sentences varied across trials. Dynamic Causal Modeling (DCM) and Bayesian Model Selection (BMS) were used to compare a set of alternative DCMs of fronto-temporal connectivity. The HSCT activated regions in the left temporal and prefrontal cortices, and the cuneus. Response suppression was associated with greater activation in the left middle and orbital frontal gyri and the bilateral precuneus than response initiation. Left middle temporal and frontal regions identified by the conventional fMRI analyses were entered into the DCM analysis. Using a systematic BMS procedure, the optimal DCM showed that the connection from the left middle temporal gyrus, which was driven by verbal stimuli per se, was significantly increased in strength during response suppression compared to initiation. Greater effective connectivity between left temporal and prefrontal regions during response suppression may reflect the transfer of information from posterior temporal regions where semantic and lexical information is stored to prefrontal regions where it is manipulated in preparation for an appropriate response.

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