Semantic Repetition Priming for Verbal and Pictorial Knowledge: A Functional MRI Study of Left Inferior Prefrontal Cortex

1997 ◽  
Vol 9 (6) ◽  
pp. 714-726 ◽  
Author(s):  
Anthony D. Wagner ◽  
John E. Desmond ◽  
Jonathan B. Demb ◽  
Gary H. Glover ◽  
John D. E. Gabrieli
Keyword(s):  
Prefrontal Cortex ◽  
Repetition Priming ◽  
Conceptual Knowledge ◽  
Word Processing ◽  
Semantic Processing ◽  
Semantic Analysis ◽  
Functional Neuroimaging ◽  
Cortical Activation ◽  
Prefrontal Cortical ◽  
Mri Study

Functional neuroimaging studies of single-word processing have demonstrated decreased activation in left inferior prefrontal cortex (LIPC) during repeated semantic processing relative to initial semantic processing. This item-specific memory effect occurs under implicit test instructions and represents word-toword semantic repetition priming. The present study examined the stimulus generality of LIPC function by measuring prefrontal cortical activation during repeated relative to initial semantic processing of words (word-to-word semantic repetition priming) and of pictures (picture-to-picture semantic repetition priming). For both words and pictures, LIPC activation decreased with repetition, suggesting that this area subserves semantic analysis of stimuli regardless of perceptual form. Decreased activation was greater in extent for words than for pictures. The LIPC area may act as a semantic executive system that mediates on-line retrieval of long-term conceptual knowledge necessary for guiding task performance.

The Constraints Functional Neuroimaging Places on Classical Models of Auditory Word Processing

2001 ◽  
Vol 13 (6) ◽  
pp. 754-765 ◽  
Author(s):  
A. L. Giraud ◽  
C. J. Price
Keyword(s):  
Word Processing ◽  
Semantic Processing ◽  
Functional Neuroimaging ◽  
Functional Integration ◽  
Temporal Cortex ◽  
Superior Temporal Gyrus ◽  
Inferior Temporal Cortex ◽  
Auditory Presentation ◽  
Classical Models ◽  
Auditory Noise

Several previous functional imaging experiments have demonstrated that auditory presentation of speech, relative to tones or scrambled speech, activate the superior temporal sulci (STS) bilaterally. In this study, we attempted to segregate the neural responses to phonological, lexical, and semantic input by contrasting activation elicited by heard words, meaningless syllables, and environmental sounds. Inevitable differences between the duration and amplitude of each stimulus type were controlled with auditory noise bursts matched to each activation stimulus. Half the subjects were instructed to say “okay” in response to presentation of all stimuli. The other half repeated back the words and syllables, named the source of the sounds, and said “okay” to the control stimuli (noise bursts). We looked for stimulus effects that were consistent across task. The results revealed that central regions in the STS were equally responsive to speech (words and syllables) and familiar sounds, whereas the posterior and anterior regions of the left superior temporal gyrus were more active for speech. The effect of semantic input was small but revealed more activation in the inferior temporal cortex for words and familiar sounds than syllables and noise. In addition, words (relative to syllables, sounds, and noise) enhanced activation in the temporo-parietal areas that have previously been linked to modality independent semantic processing. Thus, in cognitive terms, we dissociate phono-logical (speech) and semantic responses and propose that word specificity arises from functional integration among shared phonological and semantic areas.

Lexical Processing as Revealed by Lateralized Event-Related Brain Potentials

2019 ◽  
Vol 33 (3) ◽  
pp. 148-164 ◽  
Author(s):  
Judith Koppehele-Gossel ◽  
Robert Schnuerch ◽  
Henning Gibbons
Keyword(s):  
Word Processing ◽  
Semantic Processing ◽  
Semantic Analysis ◽  
Lexical Processing ◽  
Word Reading ◽  
Recognition Task ◽  
Time Range ◽  
Processing Negativity ◽  
Written Word ◽  
Single Word Reading

Abstract. Neurocognitive models of written-word processing from low-level perceptual up to semantic analysis include the notion of a strongly left-lateralized posterior-to-anterior stream of activation. Two left-lateralized components in the event-related brain potential (ERP), N170 and temporo-parietal PSA (posterior semantic asymmetry; peak at 300 ms), have been suggested to reflect sublexical analysis and semantic processing, respectively. However, for intermediate processing steps, such as lexical access, no posterior left-lateralized ERP signature has yet been observed under single-word reading conditions. In combination with a recognition task, lexicality and depth of processing were varied. Left-minus-right difference ERPs optimally suited to accentuate left-lateralized language processes revealed an occipito-temporal processing negativity (210–270 ms) for all stimuli except alphanumerical strings. This asymmetry showed greater sensitivity to the combined effects of attention and lexicality than other ERPs in this time range (i.e., N170, P1, and P2). It is therefore introduced as “lexical asymmetry.”

Distinct Brain Systems for Processing Concrete and Abstract Concepts

2005 ◽  
Vol 17 (6) ◽  
pp. 905-917 ◽  
Author(s):  
J. R. Binder ◽  
C. F. Westbury ◽  
K. A. McKiernan ◽  
E. T. Possing ◽  
D. A. Medler
Keyword(s):  
Conceptual Knowledge ◽  
Word Processing ◽  
Semantic Processing ◽  
Verbal Working Memory ◽  
Concrete Word ◽  
Angular Gyrus ◽  
Abstract Concepts ◽  
Central Interest ◽  
Abstract Words ◽  
Concrete Words

Behavioral and neurophysiological effects of word imageability and concreteness remain a topic of central interest in cognitive neuroscience and could provide essential clues for understanding how the brain processes conceptual knowledge. We examined these effects using event-related functional magnetic resonance imaging while participants identified concrete and abstract words. Relative to nonwords, concrete and abstract words both activated a left-lateralized network of multimodal association areas previously linked with verbal semantic processing. Areas in the left lateral temporal lobe were equally activated by both word types, whereas bilateral regions including the angular gyrus and the dorsal prefrontal cortex were more strongly engaged by concrete words. Relative to concrete words, abstract words activated left inferior frontal regions previously linked with phonological and verbal working memory processes. The results show overlapping but partly distinct neural systems for processing concrete and abstract concepts, with greater involvement of bilateral association areas during concrete word processing, and processing of abstract concepts almost exclusively by the left hemisphere.

The prefrontal landscape: implications of functional architecture for understanding human mentation and the central executive

1996 ◽  
Vol 351 (1346) ◽  
pp. 1445-1453 ◽  
Keyword(s):  
Prefrontal Cortex ◽  
Semantic Processing ◽  
Central Executive ◽  
Functional Architecture ◽  
Domain Specific ◽  
Prefrontal Cortical ◽  
Long Term Storage ◽  
The One ◽  
Object Cognition

The functional architecture of prefrontal cortex is central to our understanding of human mentation and cognitive prowess. This region of the brain is often treated as an undifferentiated structure, on the one hand, or as a mosaic of psychological faculties, on the other. This paper focuses on the working memory processor as a specialization of prefrontal cortex and argues that the different areas within prefrontal cortex represent iterations of this function for different information domains, including spatial cognition, object cognition and additionally, in humans, semantic processing. According to this parallel processing architecture, the ‘central executive’ could be considered an emergent property of multiple domain-specific processors operating interactively. These processors are specializations of different prefrontal cortical areas, each interconnected both with the domain-relevant long-term storage sites in posterior regions of the cortex and with appropriate output pathways.

scholarly journals The Role of Primate Prefrontal Cortex in Bias and Shift Between Visual Dimensions

2019 ◽  
Vol 30 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Farshad A Mansouri ◽  
Mark J Buckley ◽  
Daniel J Fehring ◽  
Keiji Tanaka
Keyword(s):  
Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Top Down ◽  
Attentional Processes ◽  
Prefrontal Cortical ◽  
Frontopolar Cortex ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Visual Cortical ◽  
Bilateral Lesions

Abstract Imaging and neural activity recording studies have shown activation in the primate prefrontal cortex when shifting attention between visual dimensions is necessary to achieve goals. A fundamental unanswered question is whether representations of these dimensions emerge from top-down attentional processes mediated by prefrontal regions or from bottom-up processes within visual cortical regions. We hypothesized a causative link between prefrontal cortical regions and dimension-based behavior. In large cohorts of humans and macaque monkeys, performing the same attention shifting task, we found that both species successfully shifted between visual dimensions, but both species also showed a significant behavioral advantage/bias to a particular dimension; however, these biases were in opposite directions in humans (bias to color) versus monkeys (bias to shape). Monkeys’ bias remained after selective bilateral lesions within the anterior cingulate cortex (ACC), frontopolar cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), or superior, lateral prefrontal cortex. However, lesions within certain regions (ACC, DLPFC, or OFC) impaired monkeys’ ability to shift between these dimensions. We conclude that goal-directed processing of a particular dimension for the executive control of behavior depends on the integrity of prefrontal cortex; however, representation of competing dimensions and bias toward them does not depend on top-down prefrontal-mediated processes.

scholarly journals Brain Activation During Reading in Deep Dyslexia: An MEG Study

2000 ◽  
Vol 12 (4) ◽  
pp. 622-634 ◽  
Author(s):  
Matti Laine ◽  
Riitta Salmelin ◽  
Päivi Helenius ◽  
Reijo Marttila
Keyword(s):  
Semantic Processing ◽  
Semantic Analysis ◽  
Right Hemisphere ◽  
Word Reading ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Single Word ◽  
Lexical Semantic ◽  
Deep Dyslexia ◽  
Single Word Reading

Magnetoencephalographic (MEG) changes in cortical activity were studied in a chronic Finnish-speaking deep dyslexic patient during single-word and sentence reading. It has been hypothesized that in deep dyslexia, written word recognition and its lexical-semantic analysis are subserved by the intact right hemisphere. However, in our patient, as well as in most nonimpaired readers, lexical-semantic processing as measured by sentence-final semantic-incongruency detection was related to the left superior-temporal cortex activation. Activations around this same cortical area could be identified in single-word reading as well. Another factor relevant to deep dyslexic reading, the morphological complexity of the presented words, was also studied. The effect of morphology was observed only during the preparation for oral output. By performing repeated recordings 1 year apart, we were able to document significant variability in both the spontaneous activity and the evoked responses in the lesioned left hemisphere even though at the behavioural level, the patient's performance was stable. The observed variability emphasizes the importance of estimating consistency of brain activity both within and between measurements in brain-damaged individuals.

scholarly journals Sentence Reading: A Functional MRI Study at 4 Tesla

1997 ◽  
Vol 9 (5) ◽  
pp. 664-686 ◽  
Author(s):  
D. Bavelier ◽  
D. Corina ◽  
P. Jezzard ◽  
S. Padmanabhan ◽  
V. P. Clark ◽  
...  
Keyword(s):  
Language Processing ◽  
Word Processing ◽  
Blood Oxygenation ◽  
Anterior Portion ◽  
Individual Subject ◽  
Sentence Reading ◽  
Wernicke’S Area ◽  
Classical Language ◽  
Mri Study ◽  
Language Areas

In this study, changes in blood oxygenation and volume were monitored while monolingual right-handed subjects read English sentences. Our results confirm the role of the left peri-sylvian cortex in language processing. Interestingly, individual subject analyses reveal a pattern of activation characterized by several small, limited patches rather than a few large, anatomically well-circumscribed centers. Between-subject analyses confirm a lateralized pattern of activation and reveal active classical language areas including Broca's area, Wernicke's area, and the angular gyms. In addition they point to areas only more recently considered as language-relevant including the anterior portion of the superior temporal sulcus. This area has not been reliably observed in imaging studies of isolated word processing. This raises the hypothesis that activation in this area is dependent on processes specific to sentence reading.

scholarly journals Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Amanda G. Jaimes-Bautista ◽  
Mario Rodríguez-Camacho ◽  
Iris E. Martínez-Juárez ◽  
Yaneth Rodríguez-Agudelo
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Semantic Processing ◽  
Functional Neuroimaging ◽  
Declarative Memory ◽  
Semantic Networks ◽  
N400 Effect ◽  
Functional Reorganization ◽  
Electrophysiological Studies

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.

Prefrontal Cortex Acetylcholine Release, EEG Slow Waves, and Spindles Are Modulated by M2 Autoreceptors in C57BL/6J Mouse

2002 ◽  
Vol 87 (6) ◽  
pp. 2817-2822 ◽  
Author(s):  
Christopher L. Douglas ◽  
Helen A. Baghdoyan ◽  
Ralph Lydic
Keyword(s):  
Prefrontal Cortex ◽  
Slow Wave ◽  
Cortical Activation ◽  
Mouse Strains ◽  
Potential Contribution ◽  
Ach Release ◽  
Power Spectral ◽  
Eeg Data ◽  
Muscarinic Cholinergic ◽  
Eeg Power

Recent evidence suggests that muscarinic cholinergic receptors of the M2 subtype serve as autoreceptors modulating acetylcholine (ACh) release in prefrontal cortex. The potential contribution of M2 autoreceptors to excitability control of prefrontal cortex has not been investigated. The present study tested the hypothesis that M2 autoreceptors contribute to activation of the cortical electroencephalogram (EEG) in C57BL/6J (B6) mouse. This hypothesis was evaluated using microdialysis delivery of the muscarinic antagonist AF-DX116 (3 nM) while simultaneously quantifying ACh release in prefrontal cortex, number of 7- to 14-Hz EEG spindles, and EEG power spectral density. Mean ACh release in prefrontal cortex was significantly increased ( P < 0.0002) by AF-DX116. The number of 7- to 14-Hz EEG spindles caused by halothane anesthesia was significantly decreased ( P < 0.0001) by dialysis delivery of AF-DX116 to prefrontal cortex. The cholinergically induced cortical activation was characterized by a significant ( P < 0.05) decrease in slow-wave EEG power. Together, these neurochemical and EEG data support the conclusion that M2 autoreceptor enhancement of ACh release in prefrontal cortex activates EEG in contralateral prefrontal cortex of B6 mouse. EEG slow-wave activity varies across mouse strains, and the results encourage comparative phenotyping of cortical ACh release and EEG in additional mouse models.

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