scholarly journals Prefrontal Cortical Response to Conflict during Semantic and Phonological Tasks

2007 ◽  
Vol 19 (5) ◽  
pp. 761-775 ◽  
Author(s):  
Hannah R. Snyder ◽  
Keith Feigenson ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Phonological Processing ◽  
Functional Organization ◽  
Inferior Frontal Gyrus ◽  
General Function ◽  
Left Inferior Frontal Gyrus ◽  
Domain Specific ◽  
Prefrontal Cortical ◽  
Specific Effects

Debates about the function of the prefrontal cortex are as old as the field of neuropsychology—often dated to Paul Broca's seminal work. Theories of the functional organization of the prefrontal cortex can be roughly divided into those that describe organization by process and those that describe organization by material. Recent studies of the function of the posterior, left inferior frontal gyrus (pLIFG) have yielded two quite different interpretations: One hypothesis holds that the pLIFG plays a domain-specific role in phonological processing, whereas another hypothesis describes a more general function of the pLIFG in cognitive control. In the current study, we distinguish effects of increasing cognitive control demands from effects of phonological processing. The results support the hypothesized role for the pLIFG in cognitive control, and more task-specific roles for posterior areas in phonology and semantics. Thus, these results suggest an alternative explanation of previously reported phonology-specific effects in the pLIFG.

Contemporary model of language organization: an overview for neurosurgeons

2015 ◽  
Vol 122 (2) ◽  
pp. 250-261 ◽  
Author(s):  
Edward F. Chang ◽  
Kunal P. Raygor ◽  
Mitchel S. Berger
Keyword(s):  
Speech Processing ◽  
Phonological Processing ◽  
Semantic Processing ◽  
Functional Organization ◽  
Inferior Frontal Gyrus ◽  
Superior Temporal Gyrus ◽  
Functional Neuroanatomy ◽  
Additional Information ◽  
Dorsal Pathway ◽  
Subcortical Mapping

Classic models of language organization posited that separate motor and sensory language foci existed in the inferior frontal gyrus (Broca's area) and superior temporal gyrus (Wernicke's area), respectively, and that connections between these sites (arcuate fasciculus) allowed for auditory-motor interaction. These theories have predominated for more than a century, but advances in neuroimaging and stimulation mapping have provided a more detailed description of the functional neuroanatomy of language. New insights have shaped modern network-based models of speech processing composed of parallel and interconnected streams involving both cortical and subcortical areas. Recent models emphasize processing in “dorsal” and “ventral” pathways, mediating phonological and semantic processing, respectively. Phonological processing occurs along a dorsal pathway, from the posterosuperior temporal to the inferior frontal cortices. On the other hand, semantic information is carried in a ventral pathway that runs from the temporal pole to the basal occipitotemporal cortex, with anterior connections. Functional MRI has poor positive predictive value in determining critical language sites and should only be used as an adjunct for preoperative planning. Cortical and subcortical mapping should be used to define functional resection boundaries in eloquent areas and remains the clinical gold standard. In tracing the historical advancements in our understanding of speech processing, the authors hope to not only provide practicing neurosurgeons with additional information that will aid in surgical planning and prevent postoperative morbidity, but also underscore the fact that neurosurgeons are in a unique position to further advance our understanding of the anatomy and functional organization of language.

scholarly journals Who Comes First? The Role of the Prefrontal and Parietal Cortex in Cognitive Control

2005 ◽  
Vol 17 (9) ◽  
pp. 1367-1375 ◽  
Author(s):  
Marcel Brass ◽  
Markus Ullsperger ◽  
Thomas R. Knoesche ◽  
D. Yves von Cramon ◽  
Natalie A. Phillips
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Parietal Cortex ◽  
Inferior Frontal Gyrus ◽  
Event Related Potentials ◽  
Brain Regions ◽  
High Temporal Resolution ◽  
Cortical Region ◽  
Task Set ◽  
Related Potentials

Cognitive control processes enable us to adjust our behavior to changing environmental demands. Although neuropsychological studies suggest that the critical cortical region for cognitive control is the prefrontal cortex, neuro-imaging studies have emphasized the interplay of prefrontal and parietal cortices. This raises the fundamental question about the different contributions of prefrontal and parietal areas in cognitive control. It was assumed that the prefrontal cortex biases processing in posterior brain regions. This assumption leads to the hypothesis that neural activity in the prefrontal cortex should precede parietal activity in cognitive control. The present study tested this assumption by combining results from functional magnetic resonance imaging (fMRI) providing high spatial resolution and event-related potentials (ERPs) to gain high temporal resolution. We collected ERP data using a modified task-switching paradigm. In this paradigm, a situation where the same task was indicated by two different cues was compared with a situation where two cues indicated different tasks. Only the latter condition required updating of the task set. Task-set updating was associated with a midline negative ERP deflection peaking around 470 msec. We placed dipoles in regions activated in a previous fMRI study that used the same paradigm (left inferior frontal junction, right inferior frontal gyrus, right parietal cortex) and fitted their directions and magnitudes to the ERP effect. The frontal dipoles contributed to the ERP effect earlier than the parietal dipole, providing support for the view that the prefrontal cortex is involved in updating of general task representations and biases relevant stimulus-response associations in the parietal cortex.

The Regulation of Cognitive Control following Rostral Anterior Cingulate Cortex Lesion in Humans

2007 ◽  
Vol 19 (2) ◽  
pp. 275-286 ◽  
Author(s):  
Giuseppe di Pellegrino ◽  
Elisa Ciaramelli ◽  
Elisabetta Làdavas
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Anterior Cingulate Cortex ◽  
Medial Prefrontal Cortex ◽  
Functional Organization ◽  
Cingulate Cortex ◽  
Preceding Trial ◽  
Response Conflict ◽  
Anterior Cingulate ◽  
Psychological Review

The contribution of the medial prefrontal cortex, particularly the anterior cingulate cortex (ACC), to cognitive control remains controversial. Here, we examined whether the rostral ACC is necessary for reactive adjustments in cognitive control following the occurrence of response conflict [Botvinick, M. M., Braver, T. S., Barch, D. M., Carter, C. S., & Cohen, J. D. Conflict monitoring and cognitive control. Psychological Review, 108, 624–652, 2001]. To this end, we assessed 8 patients with focal lesions involving the rostral sector of the ACC (rACC patients), 6 patients with lesions outside the frontal cortex (non-FC patients), and 11 healthy subjects on a variant of the Simon task in which levels of conflict were manipulated on a trial-by-trial basis. More specifically, we compared Simon effects (i.e., the difference in performance between congruent and incongruent trials) on trials that were preceded by high-conflict (i.e., incongruent) trials with those on trials that were preceded by low-conflict (i.e., congruent) trials. Normal controls and non-FC patients showed a reduction of the Simon effect when the preceding trial was incongruent, suggestive of an increase in cognitive control in response to the occurrence of response conflict. In contrast, rACC patients attained comparable Simon effects following congruent and incongruent events, indicating a failure to modulate their performance depending on the conflict level generated by the preceding trial. Furthermore, damage to the rostral ACC impaired the posterror slowing, a further behavioral phenomenon indicating reactive adjustments in cognitive control. These results provide insights into the functional organization of the medial prefrontal cortex in humans and its role in the dynamic regulation of cognitive control.

scholarly journals Decomposing Components of Task Preparation with Functional Magnetic Resonance Imaging

2004 ◽  
Vol 16 (4) ◽  
pp. 609-620 ◽  
Author(s):  
Marcel Brass ◽  
D. Yves von Cramon
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Cognitive Control ◽  
Functional Magnetic Resonance Imaging ◽  
Inferior Frontal Gyrus ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Task Preparation ◽  
The Right

It is widely acknowledged that the prefrontal cortex plays a major role in cognitive control processes. One important experimental paradigm for investigating such higher order cognitive control is the task-switching paradigm. This paradigm investigates the ability to switch flexibly between different task situations. In this context, it has been found that participants are able to anticipatorily prepare an upcoming task. This ability has been assumed to reflect endogenous cognitive control. However, it is difficult to isolate task preparation process from task execution using functional magnetic resonance imaging (fMRI). In the present study, we introduce a new experimental manipulation to investigate task preparation with fMRI. By manipulating the number of times a task was prepared, we could demonstrate that the left inferior frontal junction (IFJ) area (near the junction of inferior frontal sulcus and inferior precentral sulcus), the right inferior frontal gyrus, and the right intraparietal sulcus are involved in task preparation. By manipulating the cue-task mapping, we could further show that this activation is not related to cue encoding but to the updating of the relevant task representation. Based on these and previous results, we assume that the IFJ area constitutes a functionally separable division of the lateral prefrontal cortex. Finally, our data suggest that task preparation does not differ for switch and repetition trials in paradigms with a high proportion of switch trials, casting doubt on the assumption that an independent task set reconfiguration process takes place in the preparation interval.

scholarly journals Modality- and Task-specific Brain Regions Involved in Chinese Lexical Processing

2009 ◽  
Vol 21 (8) ◽  
pp. 1473-1487 ◽  
Author(s):  
Li Liu ◽  
Xiaoxiang Deng ◽  
Danling Peng ◽  
Fan Cao ◽  
Guosheng Ding ◽  
...  
Keyword(s):  
Phonological Processing ◽  
Lexical Processing ◽  
Inferior Frontal Gyrus ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Chinese Speakers ◽  
Specific Effects ◽  
Left Middle ◽  
And Task

fMRI was used to examine lexical processing in native adult Chinese speakers. A 2 task (semantics and phonology) × 2 modality (visual and auditory) within-subject design was adopted. The semantic task involved a meaning association judgment and the phonological task involved a rhyming judgment to two sequentially presented words. The overall effect across tasks and modalities was used to identify seven ROIs, including the left fusiform gyrus (FG), the left superior temporal gyrus (STG), the left ventral inferior frontal gyrus (VIFG), the left middle temporal gyrus (MTG), the left dorsal inferior frontal gyrus (DIFG), the left inferior parietal lobule (IPL), and the left middle frontal gyrus (MFG). ROI analyses revealed two modality-specific areas, FG for visual and STG for auditory, and three task-specific areas, IPL and DIFG for phonology and VIFG for semantics. Greater DIFG activation was associated with conflicting tonal information between words for the auditory rhyming task, suggesting this region's role in strategic phonological processing, and greater VIFG activation was correlated with lower association between words for both the auditory and the visual meaning task, suggesting this region's role in retrieval and selection of semantic representations. The modality- and task-specific effects in Chinese revealed by this study are similar to those found in alphabetical languages. Unlike English, we found that MFG was both modality- and task-specific, suggesting that MFG may be responsible for the visuospatial analysis of Chinese characters and orthography-to-phonology integration at a syllabic level.

scholarly journals Frontostriatal Maturation Predicts Cognitive Control Failure to Appetitive Cues in Adolescents

2011 ◽  
Vol 23 (9) ◽  
pp. 2123-2134 ◽  
Author(s):  
Leah H. Somerville ◽  
Todd Hare ◽  
B. J. Casey
Keyword(s):  
Cognitive Control ◽  
Risk Taking ◽  
Impulse Control ◽  
Inferior Frontal Gyrus ◽  
Dorsal Striatum ◽  
Public Health Issue ◽  
Prefrontal Cortical ◽  
Enhanced Sensitivity ◽  
Adolescent Risk ◽  
Appetitive Cues

Adolescent risk-taking is a public health issue that increases the odds of poor lifetime outcomes. One factor thought to influence adolescents' propensity for risk-taking is an enhanced sensitivity to appetitive cues, relative to an immature capacity to exert sufficient cognitive control. We tested this hypothesis by characterizing interactions among ventral striatal, dorsal striatal, and prefrontal cortical regions with varying appetitive load using fMRI scanning. Child, teen, and adult participants performed a go/no-go task with appetitive (happy faces) and neutral cues (calm faces). Impulse control to neutral cues showed linear improvement with age, whereas teens showed a nonlinear reduction in impulse control to appetitive cues. This performance decrement in teens was paralleled by enhanced activity in the ventral striatum. Prefrontal cortical recruitment correlated with overall accuracy and showed a linear response with age for no-go versus go trials. Connectivity analyses identified a ventral frontostriatal circuit including the inferior frontal gyrus and dorsal striatum during no-go versus go trials. Examining recruitment developmentally showed that teens had greater between-subject ventral-dorsal striatal coactivation relative to children and adults for happy no-go versus go trials. These findings implicate exaggerated ventral striatal representation of appetitive cues in adolescents relative to an intermediary cognitive control response. Connectivity and coactivity data suggest these systems communicate at the level of the dorsal striatum differentially across development. Biased responding in this system is one possible mechanism underlying heightened risk-taking during adolescence.

scholarly journals Dissociating semantic and phonological contributions of the left inferior frontal gyrus to language production

2019 ◽  
Author(s):  
Jana Klaus ◽  
Gesa Hartwigsen
Keyword(s):  
Phonological Processing ◽  
Language Production ◽  
Semantic Processing ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Inferior Frontal Gyrus ◽  
Control Site ◽  
Generation Task ◽  
Left Inferior Frontal Gyrus ◽  
Functional Relevance ◽  
Naming Latencies

While the involvement of the left inferior frontal gyrus (IFG) in language production is undisputed, the role of specific subregions at different representational levels remains unclear. Some studies suggest a division of anterior and posterior regions for semantic and phonological processing, respectively. Crucially, evidence thus far only comes from correlative neuroimaging studies, but the functional relevance of the involvement of these subregions during a given task remains elusive. We applied repetitive transcranial magnetic stimulation (rTMS) over anterior and posterior IFG (aIFG/pIFG), and vertex as a control site, while participants performed a category member and a rhyme generation task. We found a functional-anatomical double dissociation between tasks and subregions. Naming latencies were significantly delayed in the semantic task when rTMS was applied to aIFG (relative to pIFG and vertex). In contrast, we observed a facilitation of naming latencies in the phonological task when rTMS was applied to pIFG (relative to aIFG and vertex). The results provide first causal evidence for the notion that anterior portions of the IFG are selectively recruited for semantic processing while posterior regions are functionally specific for phonological processing during word production. These findings shed light on the functional parcellation of the left IFG in language production.

scholarly journals A rostro-caudal gradient of structured sequence processing in the left inferior frontal gyrus

2012 ◽  
Vol 367 (1598) ◽  
pp. 2023-2032 ◽  
Author(s):  
Julia Uddén ◽  
Jörg Bahlmann
Keyword(s):  
Functional Organization ◽  
Inferior Frontal Gyrus ◽  
Functional Magnetic Resonance ◽  
Left Inferior Frontal Gyrus ◽  
Cognitive Domains ◽  
Sequence Processing ◽  
Sequential Processing ◽  
Artificial Grammars ◽  
Stimulus Features ◽  
General Organization

In this paper, we present two novel perspectives on the function of the left inferior frontal gyrus (LIFG). First, a structured sequence processing perspective facilitates the search for functional segregation within the LIFG and provides a way to express common aspects across cognitive domains including language, music and action. Converging evidence from functional magnetic resonance imaging and transcranial magnetic stimulation studies suggests that the LIFG is engaged in sequential processing in artificial grammar learning, independently of particular stimulus features of the elements (whether letters, syllables or shapes are used to build up sequences). The LIFG has been repeatedly linked to processing of artificial grammars across all different grammars tested, whether they include non-adjacent dependencies or mere adjacent dependencies. Second, we apply the sequence processing perspective to understand how the functional segregation of semantics, syntax and phonology in the LIFG can be integrated in the general organization of the lateral prefrontal cortex (PFC). Recently, it was proposed that the functional organization of the lateral PFC follows a rostro-caudal gradient, such that more abstract processing in cognitive control is subserved by more rostral regions of the lateral PFC. We explore the literature from the viewpoint that functional segregation within the LIFG can be embedded in a general rostro-caudal abstraction gradient in the lateral PFC. If the lateral PFC follows a rostro-caudal abstraction gradient, then this predicts that the LIFG follows the same principles, but this prediction has not yet been tested or explored in the LIFG literature. Integration might provide further insights into the functional architecture of the LIFG and the lateral PFC.

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.

Models of Functional Organization of the Lateral Prefrontal Cortex in Verbal Working Memory: Evidence in Favor of the Process Model

2002 ◽  
Vol 14 (7) ◽  
pp. 1054-1063 ◽  
Author(s):  
Laura H. F. Barde ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Phonological Processing ◽  
Process Model ◽  
Functional Organization ◽  
Verbal Working Memory ◽  
Delay Period ◽  
Process Models ◽  
Delayed Response ◽  
Lateral Prefrontal Cortex

Research on the functional organization of the lateral prefrontal cortex (PFC) in working memory continues to be fairly equivocal between two major frameworks: organization-by-process or organization-by-material. Although there is fairly strong evidence for organization-by-process models from event-related fMRI studies, some investigators argue that the nature of the stimulus material better defines the functional organization of the lateral PFC, particularly in more ventral regions (BA 47/45/44). Specifically, the anterior region of the ventrolateral PFC (BA 47/45) is hypothesized to subserve semantic processing while the posterior region (BA 44) may subserve phonological processing. In the current event-related fMRI study, we directly compared process-related versus material-related organizational principles in a verbal working memory task. Subjects performed a modified delayed response task in which they (1) retained a list of five words or five nonwords during the delay period (“maintenance”), or (2) performed a semantic (size reordering) or phonological (alphabetical reordering) task on the word or nonword lists, respectively (“manipulation”). We did not find evidence during the delay period of our task to support claims of anterior-posterior specializations in the ventrolateral PFC for semantic versus phonological processing. Subjects did, however, display greater neuronal activity during the delay period of manipulation trials than maintenance trials in both the dorsolateral PFC and posterior ventrolateral regions. These data are more consistent with the process model of the organization of lateral PFC in verbal working memory.

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