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 Lexical Access in Naming and Reading: Spatiotemporal Localization of Semantic Facilitation and Interference Using MEG

2020 ◽  
Vol 1 (2) ◽  
pp. 185-207 ◽  
Author(s):  
Julien Dirani ◽  
Liina Pylkkänen
Keyword(s):  
Lexical Access ◽  
Interference Effect ◽  
Language Production ◽  
Temporal Cortex ◽  
Angular Gyrus ◽  
Long Term Memory ◽  
Lexical Selection ◽  
Semantic Interference ◽  
Processing Level ◽  
Spatiotemporal Localization

Naming an object involves quick retrieval of a target word from long-term memory. Research using the semantic interference paradigm has shown that objects take longer to name when they are preceded by primes in the same semantic category. This has been interpreted as reflecting either competition during lexical selection or as an interference effect at a later, postlexical level. Since the behavioral finding has been a core argument for the existence of competition during lexical selection in naming, understanding its processing level is important for models of language production. We used MEG to determine the spatiotemporal localization of the interference effect. We also compared its neural signature to the effect of semantic relatedness in reading, in which relatedness is expected to speed up behavioral responses and reduce activity in the left superior temporal cortex at around 200–300 ms. This is exactly what we found. However, in naming, we observed a more complex pattern for our semantically related targets. First, the angular gyrus showed a facilitory pattern at 300–400 ms, likely reflecting aspects of lexical access. This was followed by a broadly distributed and sustained interference pattern that lasted until articulatory stages. More transient interference effects were also observed at 395–485 ms in the left STG and at ∼100–200 ms before articulation in the parietal cortex. Thus, our findings suggest that the semantic interference effect originates from both early and late sources, which may explain its varying localizations in previous literature.

scholarly journals Effects of orthography in the picture-word task: Evidence from Japanese scripts

2021 ◽  
Author(s):  
Alexandra S. Dylman ◽  
Mariko Kikutani ◽  
Miho Sasaki ◽  
Christopher Barry
Keyword(s):  
Speech Production ◽  
Interference Effect ◽  
Distractor Word ◽  
Response Patterns ◽  
Lexical Selection ◽  
Semantic Interference ◽  
Facilitation Effect ◽  
Word Combination ◽  
Word Task ◽  
Different Populations

AbstractThe picture-word task presents participants with a number of pictured objects together with a written distractor word superimposed upon each picture, and their task is to name the depicted object while ignoring the distractor word. Depending on the specific picture and word combination, various effects, including the identity facilitation effect (e.g., DOG + dog) and the semantic interference effect (e.g., GOAT + cow), are often observed. The response patterns of the picture-word task in terms of naming latencies reflect the mechanisms underlying lexical selection in speech production. Research using this method, however, has typically focused on alphabetic languages, or involved bilingual populations, making it difficult to specifically investigate orthographic effects in isolation. In this paper, we report five experiments investigating the role of orthography in the picture-word task by varying distractor script (using the multiscriptal language Japanese, and pseudohomophonic spellings in English) across three different populations (Japanese monolinguals, Japanese-English bilinguals, and English monolinguals), investigating both the identity facilitation effect and the semantic interference effect. The results generally show that the magnitude of facilitation is affected by orthography even within a single language. The findings and specific patterns of results are discussed in relation to current theories on speech production.

scholarly journals IN VIVO ASSESSMENT OF AMYLOID AND GLUCOSE SIGNATURES IN SUBJECTIVE COGNITIVE DECLINE SUBJECTS

2021 ◽  
pp. 2140018
Author(s):  
XIAOFENG YU ◽  
ZHILONG ZHU ◽  
SHUZHAN ZHENG ◽  
JIAN JIANG ◽  
JUANJUAN JIANG ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Characteristic Curve ◽  
Standardized Uptake Value ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Subjective Cognitive Decline ◽  
Middle Temporal ◽  
Main Effect ◽  
Heschl Gyrus

Subjective cognitive decline (SCD), characterized by self-perceived subtle cognitive impairment ahead of the appearance of explicit and measurable cognitive deficits, is regarded as the preclinical manifestation of the pathological change continuum of Alzheimer’s disease (AD). We were committed to exploring the amyloid and glucose metabolic signatures related to imminent brain metabolic changes in SCD subjects. This study included 39 subjects (mean age = 71.9 years; 14 males and 25 females) diagnosed with SCD disease and 39 gender-matched healthy controls (HCs) (mean age = 75.2; 16 males and 23 females) with brain [18F] fluorodeoxyglucose positron emission tomography (PET) images and [18F] florbetapir PET images. The standardized uptake value ratios (SUVRs) of PET images within the regions of interest (ROIs) were calculated. Inter-group SUVR differences were assessed by two-sample [Formula: see text]-testing and receiver operating characteristic curve (ROC) analyses. A generalized linear model (GLM) was employed to evaluate the correlations between amyloid and FDG uptake. Compared with HCs, SCD subjects showed significantly increased amyloid SUVR, as well as significantly increased glucose SUVR in the olfactory, amygdala, thalamus, heschl gyrus, superior and middle temporal gyrus and temporal pole (all [Formula: see text]). The amyloid SUVR of thalamus was found to have a better ROC result (area under the curve (AUC): 0.77, 95% confidence interval (CI): 0.66–0.86) in the HC group, as was the case with the glucose SUVR of the middle temporal gyrus (AUC: 0.83, 95% CI: 0.73–0.91). There were significant positive correlations between amyloid and glucose SUVRs ([Formula: see text]). The amyloid SUVR of the thalamus showed a significantly better main effect (odd ratio [Formula: see text] 2.91, 95% CI: 1.44–6.7, [Formula: see text]), and the glucose SUVR of the heschl gyrus indicated an enhanced main effect (odd ratio [Formula: see text] 5.08, 95% CI: 1.86–18.15, [Formula: see text]). SCD subjects demonstrated significant amyloid accumulation and glucose hypermetabolism in specific brain regions, and amyloid pathology overlapped with regions of glucose abnormality. These findings may advance the understanding of imminent pathological changes in the SCD stage and help to provide clinical guidelines for interventional management.

scholarly journals Imagining Sounds and Images: Decoding the Contribution of Unimodal and Transmodal Brain Regions to Semantic Retrieval in the Absence of Meaningful Input

2019 ◽  
Vol 31 (11) ◽  
pp. 1599-1616 ◽  
Author(s):  
Charlotte Murphy ◽  
Shirley-Ann Rueschemeyer ◽  
Jonathan Smallwood ◽  
Elizabeth Jefferies
Keyword(s):  
Sensory Information ◽  
Brain Regions ◽  
External Input ◽  
Neural Systems ◽  
Middle Temporal Gyrus ◽  
Connectivity Analysis ◽  
Semantic Retrieval ◽  
Middle Temporal ◽  
Auditory Features

In the absence of sensory information, we can generate meaningful images and sounds from representations in memory. However, it remains unclear which neural systems underpin this process and whether tasks requiring the top–down generation of different kinds of features recruit similar or different neural networks. We asked people to internally generate the visual and auditory features of objects, either in isolation (car, dog) or in specific and complex meaning-based contexts (car/dog race). Using an fMRI decoding approach, in conjunction with functional connectivity analysis, we examined the role of auditory/visual cortex and transmodal brain regions. Conceptual retrieval in the absence of external input recruited sensory and transmodal cortex. The response in transmodal regions—including anterior middle temporal gyrus—was of equal magnitude for visual and auditory features yet nevertheless captured modality information in the pattern of response across voxels. In contrast, sensory regions showed greater activation for modality-relevant features in imagination (even when external inputs did not differ). These data are consistent with the view that transmodal regions support internally generated experiences and that they play a role in integrating perceptual features encoded in memory.

scholarly journals Transient perturbation of the left temporal cortex evokes plasticity-related reconfiguration of the lexical network

2019 ◽  
Author(s):  
Jana Klaus ◽  
Dennis J.L.G. Schutter ◽  
Vitória Piai
Keyword(s):  
Language Impairment ◽  
Language Production ◽  
Semantic Network ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Naming Task ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Lexical Retrieval ◽  
Control Mechanisms

Language impairment is common after left-hemisphere damage. However, the involvement of perilesional and homologous contralateral regions in compensating for left-sided lesions remains poorly understood. The aim of this study was to examine acute organizational changes in brain activity related to conceptual and lexical retrieval in unimpaired language production following transient disruption of the left middle temporal gyrus (MTG). In a randomized singleblind within-subject experiment, we recorded the electroencephalogram from sixteen healthy participants during a context-driven picture-naming task. Prior to the task, the left MTG was perturbed with real neuronavigated continuous theta-burst stimulation (cTBS) or sham stimulation. During the task, participants read lead-in sentences that created a constraining (e.g. “The farmer milks the”) or non-constraining context (e.g. “The farmer buys the”). The last word was shown as a picture that participants had to name (e.g. “cow”). Replicating behavioral studies, participants were overall faster in naming pictures following a constraining relative to a non-constraining context, but this effect did not differ between real and sham cTBS. Real cTBS, however, increased overall error rates compared to sham cTBS. In line with previous studies, we observed a decrease in alpha-beta (8-24 Hz) oscillatory power for constraining relative to non-constraining contexts over left temporal-parietal cortex after participants received sham cTBS. However, following real cTBS, this decrease extended towards left prefrontal regions associated with both domain-general and domain-specific control mechanisms. Our findings provide evidence that immediately after the disruption of the left MTG, the lexical-semantic network is able to quickly reconfigure, also recruiting domain-general regions.

scholarly journals The Shape of Things to Come in Speech Production: A Functional Magnetic Resonance Imaging Study of Visual Form Interference during Lexical Access

2019 ◽  
Vol 31 (6) ◽  
pp. 913-921 ◽  
Author(s):  
Hanna S. Gauvin ◽  
Katie L. McMahon ◽  
Marcus Meinzer ◽  
Greig I. de Zubicaray
Keyword(s):  
Speech Production ◽  
Language Production ◽  
Context Effects ◽  
Inferior Frontal Gyrus ◽  
Imaging Study ◽  
Middle Temporal Gyrus ◽  
Distractor Word ◽  
Lexical Selection ◽  
Middle Temporal ◽  
Visual Form

Studies of context effects in speech production have shown that semantic feature overlap produces interference in naming of categorically related objects. In neuroimaging studies, this semantic interference effect is consistently associated with involvement of left superior and middle temporal gyri. However, at least part of this effect has recently been shown to be attributable to visual form similarity, as categorically related objects typically share visual features. This fMRI study examined interference produced by visual form overlap in the absence of a category relation in a picture–word interference paradigm. Both visually similar and visually dissimilar distractors led to increased BOLD responses in the left inferior frontal gyrus compared with the congruent condition. Naming pictures in context with a distractor word denoting an object visually similar in form slowed RTs compared with unrelated words and was associated with reduced activity in the left posterior middle temporal gyrus. This area is reliably observed in lexical level processing during language production tasks. No significant differential activity was observed in areas typically engaged by early perceptual or conceptual feature level processing or in areas proposed to be engaged by postlexical language processes, suggesting that visual form interference does not arise from uncertainty or confusion during perceptual or conceptual identification or after lexical processing. We conclude that visual form interference has a lexical locus, consistent with the predictions of competitive lexical selection models.

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.

scholarly journals Dynamic semantic cognition: Characterising coherent and controlled conceptual retrieval through time using magnetoencephalography and chronometric transcranial magnetic stimulation

2017 ◽  
Author(s):  
Catarina Teige ◽  
Giovanna Mollo ◽  
Rebecca Millman ◽  
Nicola Savill ◽  
Jonathan Smallwood ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Temporal Lobe ◽  
Magnetic Stimulation ◽  
Temporal Dynamics ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Semantic Retrieval ◽  
Current Task ◽  
Stimulation Of

AbstractDistinct neural processes are thought to support the retrieval of semantic information that is (i) coherent with strongly-encoded aspects of knowledge, and (ii) non-dominant yet relevant for the current task or context. While the brain regions that support coherent and controlled patterns of semantic retrieval are relatively well-characterised, the temporal dynamics of these processes are not well-understood. This study used magnetoencephalography (MEG) and dual-pulse chronometric transcranial magnetic stimulation (cTMS) in two separate experiments to examine temporal dynamics within the temporal lobe during the retrieval of strong and weak associations. MEG results revealed a dissociation within left temporal cortex: anterior temporal lobe (ATL) showed greater oscillatory response for strong than weak associations, while posterior middle temporal gyrus (pMTG) showed the reverse pattern. In the cTMS experiment, stimulation of ATL at ~150ms disrupted the efficient retrieval of strong associations, indicating a necessary role for ATL in coherent conceptual activations. Stimulation of pMTG at the onset of the second word disrupted the retrieval of weak associations, suggesting this site may maintain information about semantic context from the first word, allowing engagement of semantic control. Together these studies provide converging evidence for a functional dissociation within the temporal lobe, across both tasks and time.

scholarly journals Independent Representations of Verbs and Actions in Left Lateral Temporal Cortex

2012 ◽  
Vol 24 (10) ◽  
pp. 2096-2107 ◽  
Author(s):  
Marius V. Peelen ◽  
Domenica Romagno ◽  
Alfonso Caramazza
Keyword(s):  
Functional Neuroimaging ◽  
Group Analysis ◽  
Temporal Cortex ◽  
Memory Task ◽  
Middle Temporal Gyrus ◽  
Semantic Features ◽  
Middle Temporal ◽  
Left Posterior ◽  
Action Verbs ◽  
Action Representations

Verbs and nouns differ not only on formal linguistic grounds but also in what they typically refer to: Verbs typically refer to actions, whereas nouns typically refer to objects. Prior neuroimaging studies have revealed that regions in the left lateral temporal cortex (LTC), including the left posterior middle temporal gyrus (pMTG), respond selectively to action verbs relative to object nouns. Other studies have implicated the left pMTG in action knowledge, raising the possibility that verb selectivity in LTC may primarily reflect action-specific semantic features. Here, using functional neuroimaging, we test this hypothesis. Participants performed a simple memory task on visually presented verbs and nouns that described either events (e.g., “he eats” and “the conversation”) or states (e.g., “he exists” and “the value”). Verb-selective regions in the left pMTG and the left STS were defined in individual participants by an independent localizer contrast between action verbs and object nouns. Both regions showed equally strong selectivity for event and state verbs relative to semantically matched nouns. The left STS responded more to states than events, whereas there was no difference between states and events in the left pMTG. Finally, whole-brain group analysis revealed that action verbs, relative to state verbs, activated a cluster in pMTG that was located posterior to the verb-selective pMTG clusters. Together, these results indicate that verb selectivity in LTC is independent of action representations. We consider other differences between verbs and nouns that may underlie verb selectivity in LTC, including the verb property of predication.

Functional Double Dissociation Between Two Inferior Temporal Cortical Areas: Perirhinal Cortex Versus Middle Temporal Gyrus

1997 ◽  
Vol 77 (2) ◽  
pp. 587-598 ◽  
Author(s):  
M. J. Buckley ◽  
D. Gaffan ◽  
E. A. Murray
Keyword(s):  
Performance Test ◽  
Temporal Cortex ◽  
Color Discrimination ◽  
Perirhinal Cortex ◽  
Inferior Temporal Cortex ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Postoperative Performance ◽  
Double Dissociation ◽  
Cortical Areas

Buckley, M. J., D. Gaffan, and E. A. Murray. Functional double dissociation between two inferior temporal cortical areas: perirhinal cortex versus middle temporal gyrus. J. Neurophysiol. 77: 587–598, 1997. There is both anatomic and cytoarchitectural evidence for dorsal-ventral subdivisions of the inferior temporal cortex. Despite this, there has been only limited evidence of corresponding functional subdivisions and no evidence that two adjacent cortical areas within the inferior temporal cortex, namely area TE and the perirhinal cortex, have distinctly different roles in vision and memory. We assessed the color discrimination abilities of cynomolgus monkeys with either bilateral ablation of the perirhinal cortex or bilateral ablation of the middle temporal gyrus. The stimuli were isoluminant colored squares presented on a touch screen. In each trial the subject had to learn to discriminate and select the correct choice (green) from among a maximum of eight other foils, each varying in either hue or saturation. Relative to unoperated controls, monkeys with middle temporal gyrus lesions were severely impaired in the color discrimination task, whereas monkeys with perirhinal lesions were unimpaired on this task. We also assessed the visual recognition abilities, as measured by a basic delayed nonmatching-to-sample task with trial-unique objects presented in a Wisconsin General Test Apparatus, of rhesus monkeys with bilateral middle temporal gyrus lesions. We then tested the monkeys' postoperative performance on a delayed nonmatching-to-sample task with delays and extended list lengths. The results from this experiment were compared with those from two other groups of rhesus monkeys, an unoperated control group and a group with bilateral perirhinal cortex lesions, both of which had performed the identical tasks in a previous experiment. Relative to unoperated controls, monkeys with perirhinal cortex lesions were severely impaired both in relearning the basic delayed nonmatching-to-sample task and on the postoperative performance test. In contrast, monkeys with middle temporal gyrus lesions were only mildly affected in relearning the basic nonmatching task and were unimpaired on the postoperative performance test. Thus our data demonstrate a clear functional double dissociation between the perirhinal cortex and the middle temporal gyrus. This result gives strong support to the hypothesis that the perirhinal cortex and the adjacent area TE have distinctly different roles in visual learning and memory.

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