scholarly journals Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps

2016 ◽  
Author(s):  
Mariam R Sood ◽  
Martin I Sereno
Keyword(s):  
Reading Comprehension ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Occipital Lobe ◽  
Cortical Activation ◽  
Cortical Mapping ◽  
Sensory Motor ◽  
Motor Maps ◽  
Mapping Techniques ◽  
Classical Language

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe completely overlaps visual maps, whereas most of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to dorsolateral frontal cortex.

Semantic Cortical Activation in Dyslexic Readers

1999 ◽  
Vol 11 (5) ◽  
pp. 535-550 ◽  
Author(s):  
Päivi Helenius ◽  
Riitta Salmelin ◽  
Elisabet Service ◽  
John F. Connolly
Keyword(s):  
Reading Comprehension ◽  
Word Recognition ◽  
Semantic Processing ◽  
Right Hemisphere ◽  
Temporal Cortex ◽  
Sentence Context ◽  
Cortical Activation ◽  
Neural Population ◽  
Brain Areas ◽  
Control Subjects

The combined temporal and spatial resolution of MEG (magnetoencephalography) was used to study whether the same brain areas are similarly engaged in reading comprehension in normal and developmentally dyslexic adults. To extract a semantically sensitive stage of brain activation we manipulated the appropriateness of sentence-ending words to the preceding sentence context. Sentences, presented visually one word at a time, either ended with a word that was (1) expected, (2) semantically appropriate but unexpected, (3) semantically anomalous but sharing the initial letters with the expected word, or (4) both semantically and orthographically inappropriate to the sentence context. In both subject groups all but the highly expected sentence endings evoked strong cortical responses, localized most consistently in the left superior temporal cortex, although additional sources were occasionally found in more posterior parietal and temporal areas and in the right hemisphere. Thus, no significant differences were found in the spatial distribution of brain areas involved in semantic processing between fluent and dyslexic readers. However, both timing and strength of activation clearly differed between the two groups. First, activation sensitivity to word meaning within a sentence context began about 100 msec later in dyslexic than in control subjects. This is likely to result from affected presemantic processing stages in dyslexic readers. Second, the neural responses were significantly weaker in dyslexic than in control subjects, indicating involvement of a smaller or less-synchronous neural population in reading comprehension. Third, in contrast to control subjects, the dyslexic readers showed significantly weaker activation to semantically inappropriate words that began with the same letters as the most expected word than to both orthographically and semantically inappropriate sentence-ending words. Thus, word recognition by the dyslexic group seemed to be qualitatively different: Whereas control subjects perceived words as wholes, dyslexic subjects may have relied on sublexical word recognition and occasionally mistook a correctly beginning word for the one they had expected.

Visual Processing of Faces in Temporal Cortex: Physiological Evidence for a Modular Organization and Possible Anatomical Correlates

1991 ◽  
Vol 3 (1) ◽  
pp. 9-24 ◽  
Author(s):  
M. H. Harries ◽  
D. I. Perrett
Keyword(s):  
Parietal Cortex ◽  
Face Processing ◽  
Visual Processing ◽  
Fluorescent Dyes ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Superior Temporal Sulcus ◽  
Modular Organization ◽  
Spatial Awareness ◽  
Inferior Parietal Lobe

Physiological recordings along the length of the upper bank of the superior temporal sulcus (STS) revealed cells each of which was selectively responsive to a particular view of the head and body. Such cells were grouped in large patches 3-4 mm across. The patches were separated by regions of cortex containing cells responsive to other stimuli. The distribution of cells projecting from temporal cortex to the posterior regions of the inferior parietal lobe was studied with retrogradely transported fluorescent dyes. A strong temporoparietal projection was found originating from the upper bank of the STS. Cells projecting to the parietal cortex occurred in large patches or bands. The size and periodicity of modules defined through anatomical connections matched the functional subdivisions of the STS cortex involved in face processing evident in physiological recordings. It is speculated that the temporoparietal projections could provide a route through which temporal lobe analysis of facial signals about the direction of others' attention can be passed to parietal systems concerned with spatial awareness.

scholarly journals Development of a Modelling to Correlate Site and Diameter of Brain Metastases with Hippocampal Sparing Using Volumetric Modulated Arc Therapy

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Silvia Chiesa ◽  
Mario Balducci ◽  
Luigi Azario ◽  
Simona Gaudino ◽  
Francesco Cellini ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Parietal Lobe ◽  
Volumetric Modulated Arc Therapy ◽  
Occipital Lobe ◽  
Brain Structures ◽  
Hippocampal Volume ◽  
Brain Lesions ◽  
Whole Brain ◽  
Hippocampal Sparing ◽  
The Mean

Purpose. To correlate site and diameter of brain metastases with hippocampal sparing in patients treated by RapidArc (RA) technique on whole brain with simultaneously integrated boost (SIB).Methods and Materials. An RA plan was calculated for brain metastases of 1-2-3 cm of diameter. The whole brain dose was 32.25 Gy (15 fractions), and SIB doses to brain metastases were 63 Gy (2 and 3 cm) or 70.8 Gy (1 cm). Plans were optimized and evaluated for conformity, target coverage, prescription isodose to target volume, homogeneity index, and hippocampal sparing.Results. Fifteen brain lesions and RA plan were generated. Hippocampal volume was 4.09 cm3, and hippocampal avoidance volume was 17.50 cm3. Related to site of metastases, the mean hippocampal dose was 9.68 Gy2for occipital lobe, 10.56 Gy2for frontal lobe, 10.56 Gy2for parietal lobe, 10.94 Gy2for deep brain structures, and 40.44 Gy2for temporal lobe. The mean hippocampal dose was 9.45 Gy2, 10.15 Gy2, and 11.70 Gy2for diameter’s metastases of 1.2 and 3 cm, respectively, excluding results relative to temporal brain lesions.Conclusions. Location more than size of metastases can adversely influence the hippocampus sparing. Further investigation is necessary to meet definitive considerations.

scholarly journals Brain Mechanisms of Arithmetic: A Crucial Role for Ventral Temporal Cortex

2018 ◽  
Vol 30 (12) ◽  
pp. 1757-1772 ◽  
Author(s):  
Pedro Pinheiro-Chagas ◽  
Amy Daitch ◽  
Josef Parvizi ◽  
Stanislas Dehaene
Keyword(s):  
Numerical Cognition ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Classical Problem ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Problem Size ◽  
Ventral Temporal Cortex ◽  
Intracranial Electroencephalography ◽  
Problem Size Effect

Elementary arithmetic requires a complex interplay between several brain regions. The classical view, arising from fMRI, is that the intraparietal sulcus (IPS) and the superior parietal lobe (SPL) are the main hubs for arithmetic calculations. However, recent studies using intracranial electroencephalography have discovered a specific site, within the posterior inferior temporal cortex (pITG), that activates during visual perception of numerals, with widespread adjacent responses when numerals are used in calculation. Here, we reexamined the contribution of the IPS, SPL, and pITG to arithmetic by recording intracranial electroencephalography signals while participants solved addition problems. Behavioral results showed a classical problem size effect: RTs increased with the size of the operands. We then examined how high-frequency broadband (HFB) activity is modulated by problem size. As expected from previous fMRI findings, we showed that the total HFB activity in IPS and SPL sites increased with problem size. More surprisingly, pITG sites showed an initial burst of HFB activity that decreased as the operands got larger, yet with a constant integral over the whole trial, thus making these signals invisible to slow fMRI. Although parietal sites appear to have a more sustained function in arithmetic computations, the pITG may have a role of early identification of the problem difficulty, beyond merely digit recognition. Our results ask for a reevaluation of the current models of numerical cognition and reveal that the ventral temporal cortex contains regions specifically engaged in mathematical processing.

scholarly journals Genetically predicted complement component 4A expression: effects on memory function and middle temporal lobe activation

2018 ◽  
Vol 48 (10) ◽  
pp. 1608-1615 ◽  
Author(s):  
G. Donohoe ◽  
J. Holland ◽  
D. Mothersill ◽  
S. McCarthy-Jones ◽  
D. Cosgrove ◽  
...  
Keyword(s):  
Visual Processing ◽  
Structural Variation ◽  
Memory Performance ◽  
Memory Function ◽  
Temporal Cortex ◽  
Complement Component ◽  
Cortical Activation ◽  
Rna Expression ◽  
Middle Temporal ◽  
Healthy Participants

AbstractBackgroundThe longstanding association between the major histocompatibility complex (MHC) locus and schizophrenia (SZ) risk has recently been accounted for, partially, by structural variation at the complement component 4 (C4) gene. This structural variation generates varying levels ofC4RNA expression, and genetic information from the MHC region can now be used to predictC4RNA expression in the brain. Increased predictedC4ARNA expression is associated with the risk of SZ, andC4is reported to influence synaptic pruning in animal models.MethodsBased on our previous studies associating MHC SZ risk variants with poorer memory performance, we tested whether increased predictedC4ARNA expression was associated with reduced memory function in a large (n= 1238) dataset of psychosis cases and healthy participants, and with altered task-dependent cortical activation in a subset of these samples.ResultsWe observed that increased predictedC4ARNA expression predicted poorer performance on measures of memory recall (p= 0.016, corrected). Furthermore, in healthy participants, we found that increased predictedC4ARNA expression was associated with a pattern of reduced cortical activity in middle temporal cortex during a measure of visual processing (p< 0.05, corrected).ConclusionsThese data suggest that the effects ofC4on cognition were observable at both a cortical and behavioural level, and may represent one mechanism by which illness risk is mediated. As such, deficits in learning and memory may represent a therapeutic target for new molecular developments aimed at alteringC4’s developmental role.

Post-Stimulation Effect of Electroacupuncture at Yintang (EX-HN3) and GV20 on cerebral functional regions in healthy volunteers: A resting functional MRI study

2012 ◽  
Vol 30 (4) ◽  
pp. 307-315 ◽  
Author(s):  
Yu Zheng ◽  
Shanshan Qu ◽  
Na Wang ◽  
Limin Liu ◽  
Guanzhong Zhang ◽  
...  
Keyword(s):  
Frontal Lobe ◽  
Temporal Lobe ◽  
Parietal Lobe ◽  
Occipital Lobe ◽  
Cingulate Gyrus ◽  
Left Frontal Lobe ◽  
Posterior Cingulate Gyrus ◽  
Functional Regions ◽  
Limbic Lobe ◽  
The Right

Objective The aim of the present work was to observe the activation/deactivation of cerebral functional regions after electroacupuncture (EA) at Yintang (EX-HN3) and GV20 by functional MRI (fMRI). Design A total of 12 healthy volunteers were stimulated by EA at Yintang and GV20 for 30 min. Resting-state fMRI scans were performed before EA, and at 5 and 15 min after needle removal. Statistical parametric mapping was used to preprocess initial data, and regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) were analysed. Results ReHo at 5 min post stimulation showed increases in the left temporal lobe and cerebellum and decreases in the left parietal lobe, occipital lobe and right precuneus. At 15 min post stimulation, ReHo showed increases in the left fusiform gyrus; lingual gyrus; middle temporal gyrus; postcentral gyrus; limbic lobe; cingulate gyrus; paracentral lobule; cerebellum, posterior lobe, declive; right cuneus and cerebellum, anterior lobe, culmen. It also showed decreases in the left frontal lobe, parietal lobe, right temporal lobe, frontal lobe, parietal lobe and right cingulate gyrus. ALFF at 5 min post stimulation showed increases in the right temporal lobe, but decreases in the right limbic lobe and posterior cingulate gyrus. At 15 min post stimulation ALFF showed increases in the left frontal lobe, parietal lobe, occipital lobe, right temporal lobe, parietal lobe, occipital lobe and cerebellum, but decreases in the left frontal lobe, anterior cingulate gyrus, right frontal lobe and posterior cingulate gyrus. Conclusions After EA stimulation at Yintang and GV20, which are associated with psychiatric disorder treatments, changes were localised in the frontal lobe, cingulate gyrus and cerebellum. Changes were higher in number and intensity at 15 min than at 5 min after needle removal, demonstrating lasting and strong after-effects of EA on cerebral functional regions.

The influence of dynamic response and brain deformation metrics on the occurrence of subdural hematoma in different regions of the brain

2014 ◽  
Vol 120 (2) ◽  
pp. 453-461 ◽  
Author(s):  
Andrew Post ◽  
T. Blaine Hoshizaki ◽  
Michael D. Gilchrist ◽  
Susan Brien ◽  
Michael D. Cusimano ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Subdural Hematoma ◽  
Parietal Lobe ◽  
Linear Acceleration ◽  
Occipital Lobe ◽  
Von Mises Stress ◽  
Rotational Acceleration ◽  
Brain Deformation ◽  
Strain And Strain Rate ◽  
The Brain

Object The purpose of this study was to examine how the dynamic response and brain deformation of the head and brain—representing a series of injury reconstructions of which subdural hematoma (SDH) was the outcome—influence the location of the lesion in the lobes of the brain. Methods Sixteen cases of falls in which SDH was the outcome were reconstructed using a monorail drop rig and Hybrid III headform. The location of the SDH in 1 of the 4 lobes of the brain (frontal, parietal, temporal, and occipital) was confirmed by CT/MR scan examined by a neurosurgeon. Results The results indicated that there were minimal differences between locations of the SDH for linear acceleration. The peak resultant rotational acceleration and x-axis component were larger for the parietal lobe than for other lobes. There were also some differences between the parietal lobe and the other lobes in the z-axis component. Maximum principal strain, von Mises stress, shear strain, and product of strain and strain rate all had differences in magnitude depending on the lobe in which SDH was present. The parietal lobe consistently had the largest-magnitude response, followed by the frontal lobe and the occipital lobe. Conclusions The results indicated that there are differences in magnitude for rotational acceleration and brain deformation metrics that may identify the location of SDH in the brain.

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