The major occipital sulci, particularly the parieto-occipital, the calcarine, the inferior lateral occipital and the anterior occipital sulci, as well as two points of their intersections (cuneal point and intersection of the transverse occipital and superior occipital sulcus) may be used as reliable anatomical landmarks for the location of architectonically and functionally defined human visual areas (V1, V2, V3, V3A, V5/MT+, LO1 and LO2) and during less invasive neurosurgical procedures in the cases of focal lesions within the occipital lobe. 
These brain regions constituted an occipito-tempro-frontal circuitry involved in visual information processing and eye movement control, including the left calcarine cortex [ Brodmann area (BA) 17], the left cuneus (BA 18), the left superior occipital cortex (BA 18/19), the left superior frontal gyrus (BA 6), the left cerebellum, the right lingual cortex (BA 17/18), the right middle occipital cortex (BA19), the right inferior temporal cortex (BA 37), the right dorsolateral prefrontal cortex (BA 46) and bilateral precentral gyri (BA 6) extending to the frontal eye fields (FEF, BA 8).
Millisecond-by-millisecond analyses of VEPs and distributed source estimations revealed a main effect of grating orientation beginning at 65ms post-stimulus onset within the calcarine sulcus that was followed by a main effect of IC presence beginning at 85ms post-stimulus onset within the LOC.
RESULTS: Focal age-related CBF decreases were detected in the parietal cortex, cuneus and caudate, whereas increases were seen in the lateral and medial temporal lobe such as hippocampus, the calcarine gyrus and the thalamus.
Stimulus duration modulated the BOLD signal and the γ-ERSP in the peri-calcarine and fusiform cortices, whereas there was no such modulation of either physiological signal in the lateral temporal-occipital cortex.
PS training was associated with (1) significant or substantial improvement in the performance of PS measures, (2) changes in the gray matter structures of the left superior temporal gyrus and the bilateral regions around the occipitotemporal junction, (3) changes in functional activity that are related to simple cognitive processes (but not those of WM) in the left perisylvian region, and (4) increased resting-FC between the left perisylvian area and the area that extends to the lingual gyrus and calcarine cortex.
calcarine sulcal cortex possibly contributes to semantic recognition memory in early blind (EB).
For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field.
Ipsilateral fibres seeded in Heschl's region projected to the superior temporal sulcus, the supramarginal gyrus and intraparietal sulcus and the occipital cortex including the calcarine sulcus.
Before therapy, pictures of boys elicited activation in the left calcarine fissure, left insula, anterior cingulate cortex, and left cerebellar vermis.
Volume change based on the sequential method revealed that total supratentorial and CSF volumes increased, while cortical gray matter volumes declined significantly (p<0.01) in anterior (lateral and medial frontal, anterior cingulate, precuneus, and parietal) but not posterior (occipital, calcarine) cortical regions.
Compared with survivors without PTSD, survivors with PTSD had significantly decreased gray matter volume and density in left anterior hippocampus, left parahippocampal gyrus, and bilateral calcarine cortex. The CAPS score correlated negatively with the gray matter density in bilateral calcarine cortex and left hippocampus in coal mine disaster survivors. PTSD symptom severity was associated with gray matter density in calcarine cortex and hippocampus..
Gray matter loss along the posterior and middle portions of the calcarine sulcus is also correlated with scotoma size, indicating that indeed the lack of functional input provokes the gray matter alterations.
Contrasting the two groups, the sighted listeners preferentially activated bilateral parietal plus medial and lateral frontal networks, whereas the blind listeners preferentially activated left anterior insula plus bilateral anterior calcarine and medial occipital regions, including what would otherwise have been visual-related cortex.
A 24-year-old woman with left hemianopsia underwent fMRI and DTI in a 1.5-tesla machine both in the acute phase and 1 month after an ischaemic stroke involving the right calcarine cortex.
Neuroimaging studies revealed intracranial hemorrhages in the medial temporal lobes bilaterally, extending back to the occipital cortex, but sparing the calcarine cortex.
Across three experiments the results showed increased coupling between the pulvinar and the ipsilateral superior frontal gyrus, contralateral temporal-parietal junction (TPJ) and calcarine sulcus when a visual search distracter matched the item held in memory.
Whole brain analyses with multiple comparison correction revealed reduced activation within the left lingual/calcarine gyrus during orthographic processing in children with reading impairment compared to typical readers.
Medial area 10 received additional projections from retrosplenial, rostral calcarine, and parahippocampal areas, while lateral area 10 received small projections from the ventral somatosensory and premotor areas.
To investigate whether these deficits are coupled with atrophy of memory-related brain regions, T(1)-weighted magnetic resonance images were acquired and volumes of the cerebrum, ventricles, prefrontal cortex (PFC), calcarine cortex, hippocampus, and striatum were quantified in young and aged rhesus monkeys.
The scalp point that was extended from the calcarine fissure was identified using magnetic resonance imaging scans of 200 subjects. The position of the calcarine fissure relative to the inion was significantly lower than the value reported for Caucasians.
Using amyloid-β immunostaining, CAA severity was graded in 5 regions (midfrontal, inferior temporal, angular, calcarine, and hippocampal cortices), as 0 = none, 1 = mild, 2 = moderate, 3 = severe, and 4 = very severe.
Regardless of task context, synchronous signals increased activations bilaterally in (1) calcarine sulcus (CaS) extending into ventral occipitotemporal cortex and (2) Heschl's gyrus extending into planum temporale (HG/PT) compared with asynchronous signals.
The subtraction between the bimodal condition and the sum of the unimodal ones showed that categorizing face/voice associations according to their gender produced unimodal activations of the visual (right calcarine sulcus) and auditory regions (bilateral superior temporal gyri), and specific supramodal activations of the left superior parietal gyrus and the right inferior frontal gyrus.
In one patient, fetal calcarine arteries were identified arising from the internal carotid arteries bilaterally with no calcarine branches arising from the posterior circulation and the basilar artery giving rise to terminal parieto-occipital arteries. A second patient demonstrated anomalous origins of the calcarine and parietal occipital branches from the supraclinoid left internal carotid artery.
Regions corresponding to the calcarine sulcus, central sulcus, and Sylvian fissure in both the hemispheres were manually labeled on T1-weighted structural magnetic resonance images from 31 children ranging in age from 4.2 to 11.2years old.
In the primary visual cortex (calcarine fissure) the activations to visual stimuli started at 43 ms and to auditory stimuli at 53 ms.
To establish normal reference ranges for the depth of the insula and Sylvian (SF), parieto-occipital (POF) and calcarine (CF) fissures on prenatal ultrasound between 19 and 30 weeks of gestation..
Auditory responses were also found in the Precuneus, suggesting that it might be a new auditory area responsive to pure tone stimuli, and serving as one end of a novel sensory preference gradient stretching across POG to the calcarine sulcus.
This predictive effect was restricted in time, frequency and space: It started only around 200 ms before the behaviorally relevant stimulus change, was present only between 50 and 80 Hz, and was significant only in bilateral middle occipital gyrus, while the peak of overall visually induced gamma-band activity was found in the calcarine sulcus.
PTSD patients presented relatively diminished activity (P<0.005) in: cingulate gyri, precuneus, insula, hippocampus; frontal, pre-frontal and post-central regions; lingual, calcarine, occipital medial and superior gyri, and verbal and paraverbal areas.
The goal of the present study was to analyze relationships between visual field deficits and the locations of brain tumors compared with optic tracts as visualized by tractography, and compared with the calcarine fissure..
Results: On the top of calcarine infarct, she has pseudoseizures or malingering.
Once known as the hippocampus minor, the structure now known as the calcar avis is an involution of the ventricular wall produced by the calcarine fissure.
Regions of increased cortical thickness were apparent on the banks of the calcarine sulcus, but not in the fundus.
Local field potentials (LFPs) and spiking activity were recorded simultaneously from multiple sites in the opercular and calcarine regions while the monkeys were presented with sequences of single and superimposed components of plaid stimuli.
Right asymmetrical activations of a saccadic/attentional system were observed in the lateral frontal eye fields (FEF), the anterior part of the intraparietal sulcus (aIPS), the posterior third of the superior temporal sulcus (STS), the occipitotemporal junction (MT/V5 area), the middle occipital gyrus, and medially along the calcarine fissure (V1). Only V1 asymmetries were explained for almost 20% of the variance by a difference in the position of the right and left calcarine fissures.
In this study we compared Alzheimer and normative comparison brain samples, from temporal and calcarine cortices, with respect to the interactive correlation between eNOS, iNOS and nNOS isoform positive capillaries and the presence of neurofibrillary tangles (NFTs) and senile plaques (SPs). Cortical samples were taken from the superior temporal and calcarine cortices of 10 confirmed AD and 10 non-demented comparison group (CG) brains.
Here we applied it for the first time to study multisensory integration and identified a network of occipital (LOtv and calcarine sulcus), parietal (aIPS), and prefrontal (precentral sulcus and the insula) areas all showing a clear crossmodal repetition suppression effect.
The left medial frontal cortex, fusiform gyrus, inferior frontal gyrus, calcarine sulcus, right anterior middle temporal gyrus, orbitoinsular junction, and occipito-temporo-parietal junction were commonly activated while monitoring relationships of both types.
Described here are the cases of two pediatric patients who presented with MELAS-like calcarine lesions in addition to novel, bilateral rolandic lesions and epilepsia partialis continua, secondary to MT-ND3 mutations.
Magnetisation transfer ratio (MTR) was measured in the chiasm and in the grey and white matter (CGM and CWM) of the calcarine fissure.
cortical thickness, cortical volume and cortical surface area) in a sample of 48 subjects (24 grapheme-color synesthetes and 24 control subjects), and revealed increased cortical thickness, volume and surface area in the right and left fusiform gyrus and in adjacent regions, such as the lingual gyrus and the calcarine cortex, in grapheme-color synesthetes.
V1 overlap maps showed that the average centres of gravity for the two groups were similarly located near the fundus of the calcarine fissure, approximately 25 mm away from the most posterior aspect of the occipital lobe.
ROIs most prominently associated with these dimensions essentially comprised the medial frontal lobe bilaterally, the inferior frontal gyrus bilaterally, and the left intraparietal sulcus (Dimension 1), and visual areas, including the calcarine sulcus and cuneus bilaterally (Dimension 2).
The main regions that were activated by the alternation learning task included portions of frontal and orbitofrontal cortex as well as the calcarine fissure.
Theta-band (3-7 Hz), MEG signal power was greater for expansion than the other optic flow components in a region concentrated along the calcarine sulcus, indicating an ecologically valid, foveo-fugal bias for unidirectional motion sensors in V1. When the responses to the optic flow components were combined, a decrease in MEG beta-band (17-23 Hz) power was found in regions extending beyond the calcarine sulcus to the posterior parietal lobe (inferior to IPS), indicating the importance of structured motion in this region.
We use diffusion tensor imaging and fiber tractography (DTI-FT) to identify the most likely pathway between the lateral geniculate nucleus (LGN) and the calcarine sulcus in sixteen hemispheres of eight healthy volunteers.
The first responses at 60-80 ms around the calcarine sulcus were similar to all stimuli.
Brain magnetic resonance imaging showed an infarction in the left lower calcarine area over the extrastriate (V2/V3) cortical area and a narrowing of the left middle and posterior cerebral arteries due to severe arteriosclerosis..
Cortical samples from the superior temporal (ST) and calcarine occipital (COC) cortices of ten confirmed AD brains and ten comparison group (CG) brains were examined.
Cortical samples were taken from the superior temporal and calcarine cortices of ten confirmed AD and ten non-demented comparison brains.
Even across the largest amount of size change, accuracy for generalization was still significant in LOC, whereas the same comparison was at chance performance in early visual (calcarine) cortex.
First, we used the geniculo-calcarine system as a validation testbed. When the optic radiations were incorporated, this artifactual association was eliminated and the calcarine cortex was correctly isolated.
Cerebral angiography revealed that the aneurysm originated from the ambient segment of the PCA, and the posterior temporal, calcarine, and parieto-occipital arteries were all branched from the aneurysmal dome. As a result of left occipital lobe infarction due to calcarine artery occlusion, right upper quadrant hemianopsia appeared after surgery, as confirmed by Goldman's perimetry.
ROI analysis showed that galactosaemic patients had significant bilateral decreases in cerebral glucose metabolism in the superior temporal gyrus, medial occipital lobe, parietal lobe, cerebellum, calcarine cortex, superior frontal cortex, and superior parietal cortex when compared with controls.
We tested the effect of sTMS over anterior frontal cortex in facilitating phosphenes from preceding sTMS over calcarine cortex, which alone was rarely effective in eliciting phosphenes.
But Wilbrand not only treated clinical aspects but also supplied evidence for the localization of the optical center in the calcarine fissure of the occipital cortex.
We found that the medial Heschl's gyrus was strongly coupled, in particular, to visual cortex along the anterior banks of the calcarine fissure. fcMRI analysis revealed that although overall coupling between the auditory and visual cortex was significantly reduced when subjects performed a visual perception task, coupling between the anterior calcarine cortex and auditory cortex was not disrupted.
In both patients the calcarine cortex with the primary visual area was bilaterally intact.
We observed that, approximately 200 ms after a covert attentional shift towards the impending visual stimulus, the level of phase-resetting (transient neural coherence) within the calcarine significantly increased for 2-10 Hz activity. We propose that top-down attentional control mechanisms exert their initial effects within the calcarine through a phase-resetting within the 2-10 Hz band, which in turn triggers a suppression of alpha activity, priming early visual areas for incoming information and enhancing behavioral performance..
The lengths of cingulate and calcarine sulci were measured, and the ratios of these lengths to fronto-occipital length were estimated as indices of the size of the "frontoparietal" and "occipital" regions, respectively. The relative length of calcarine sulcus lineally increased between EDs 90 and 130, and the gyri in the "occipital region" generated in a dorso-ventral manner: the gyrus convolutions occurred first in the "phylogenetically older" striate and dorsal extrastriate cortices, and then in the "phylogenetically newer" ventral extrastriate cortex.
Regarding age at examination, patients with frontal spikes were significantly older than patients with spikes on rolandic, parieto-occipital, or calcarine sulci. Occipital spikes were classified into two subgroups, located at the calcarine sulcus and parieto-occipital sulcus. Both calcarine and parieto-occipital localizations were seen in patients around the same age.
Specifically, intraparietal to inferotemporal and precuneus to calcarine connections were stronger for emotionally arousing picture content.
The length, depth, and topology of the calcarine fissure is analyzed in albino, aniridic, and normal subjects. We show that the calcarine fissure, where the primary visual cortex is represented, is abnormally short in those lacking a fovea. Moreover, surface reconstructions of the calcarine fissure revealed marked interhemispheric asymmetries.
Intrinsic (anatomical) connections were strongest from primary cortical regions to unimodal association areas - from Heschl's gyrus to superior temporal gyrus for the auditory spelling task and from calcarine to fusiform gyrus for the visual spelling task. The modulatory (experimental) effect for the visual spelling task from calcarine to superior temporal gyrus was stronger than all other effects from calcarine and this effect showed a developmental increase, suggesting automatic activation of phonology that increased with age.
Detection of activity from the primary visual cortex is a difficult challenge to magneto-encephalography (MEG) source imaging techniques: the geometry of the visual cortex is intricate, with structured visual field maps extending deeper along the calcarine fissure.
Voxelwise group analysis showed that electroacupuncture stimulation at both vision-related acupoints and the NAP produced modest, comparable fMRI signal decreases in the occipital cortex, including the bilateral cuneus, calcarine fissure and surrounding areas, lingual gyrus, and lateral occipital gyrus.
The direct comparison analysis revealed more activation in the right lobule VI of the cerebellum and in the right lingual and calcarine gyri during smooth pursuit than during fixation suppression of OKR.
Furthermore, the amplitude of the BOLD response in the anterior calcarine sulcus of early blind subjects correlated with their discrimination performance on the auditory backward masking task.
Bilateral activation was observed during visual stimulation in the calcarine fissure and the same activation was found medially in the left and right occipital cortex adjacent to the infarcted areas.
The UHDRS-motor score correlated inversely with the atrophy of both caudates, right hippocampus, calcarine fissure, and with the white matter along the fourth and lateral ventricles.
Regression analyses revealed that when participants viewed high calorie foods, Positive Affect correlated significantly with activity within the lingual gyrus and calcarine cortex, whereas Negative Affect was unrelated to visual cortex activity.
We previously reported the results of a magnetoencephalographic study in patients with Panayiotopoulos syndrome manifesting occipital epileptic discharges, in which the equivalent current dipoles of spike discharges were clustered alongside the major cortical sulci, such as parieto-occipital and calcarine.
The retrosplenial cortex is a cytoarchitecturally distinct brain structure located in the posterior cingulate gyrus and bordering the splenium, precuneus, and calcarine fissure.
The distributed MRI-constrained MEG source estimates demonstrated decreased alpha (10 Hz) activity in and around the parieto-occipital sulcus and in the calcarine sulcus of the occipital lobe, following from increased GABA(A)-inhibition by lorazepam.
When auditory and tactile stimuli were presented simultaneously with subjects alternating attention between sensory streams, only the calcarine sulcus continued to respond to stimuli in both modalities.
In the medial occipital region, the calcarine sulcus was the longest and most constant sulcus.
The dipole moments around the calcarine sulcus (CaS) and posterior fusiform gyrus (pFuG) increased at latencies around 70-350 ms.
After flash stimuli applied to the right eye, activations were found in eight cortical areas: the left medial occipital area around the calcarine fissure (primary visual cortex, V1), the left dorsomedial area around the parietooccipital sulcus (DM), the ventral (MOv) and dorsal (MOd) parts of the middle occipital area of bilateral hemispheres, the left temporo-occipito-parietal cortex corresponding to human MT/V5 (hMT), and the ventral surface of the medial occipital area (VO) of the bilateral hemispheres.
In this study, we examined and compared brain tissue from a frequently observed NFT abundant area, the superior temporal cortex (ST), and a comparatively much NFT sparser area, the calcarine cortex (COC), in ten AD and ten normal adult control brain samples. In AD brains, we observed a positive correlation between NFTs and SPs in both regions, and between NFTs and beta-amyloid-positive capillaries and CAA vessels, particularly in the calcarine cortex.
randomised presentations revealed significant increases in the fMRI signal in the bilateral lingual and fusiform gyri as well as in the right calcarine sulcus, in conjunction with a larger amplitude of the posterior P1 component of ERPs, but no modulation of the amplitude of the N1 component.
The primary fissures and sulci that can be examined with prenatal US and MR imaging include the parieto-occipital fissure, calcarine fissure, cingulate sulcus, convexity sulci, and sylvian fissure and insula..
These lesions are found in the calcarine areas of occipital lobes, the pre- and post-central lobes, and the temporal transverse gyri.
Visual cortex dorsal to calcarine projects through a large band that fills much of the inferior half of the splenium, while cortex ventral to calcarine sends projections through a band at the anterior inferior edge of the splenium.
Instead, a reverse effect of area was found in a region of the calcarine sulcus.
Independent component analysis (ICA) and dipolar source modeling confirmed that the neuronal changes we observed originated from within the calcarine cortex. We conclude that attentional shifts affect activity within the human calcarine cortex by altering the amplitude of spontaneous alpha rhythms and that subsequent modulation of visual input with attentional engagement follows as a consequence of these localized changes in oscillatory activity..
The sources of gamma-band activity were in the calcarine sulcus in all subjects.
Probably, unaware of Francesco Gennari's (1750-1797) and Félix Vicq d'Azyr's (1748-1794) observation, Soemmerring in the final years of the eighteenth century saw the broad white line running through the calcarine cortex of the occipital lobe.
Brain magnetic resonance images revealed a well-circumscribed infarction in the ventral portion of the left calcarine fissure that was consistent with the patient's visual field loss.
Notably, the left calcarine fissure demonstrated powerful covariances with functional areas in both hemispheres, suggesting that it serves as a developmental "anchor" for functional areas in the occipital cortex.
The estimated location of the equivalent-current dipole for response at 100-ms latency was in the calcarine sulcus and that of the dipole for the response at 150 ms was in the collateral sulcus in the ventro-occipital area. The average of lags between MEG responses from the calcarine sulcus and ventro-occipital area was 43 ms, which suggests sequential processing of color information across the visual cortices..
Harry Moss Traquair (1875-1954) was one of the founders of neuro-ophthalmology, being concentrated on bitemporal hemianopia, the course of the geniculo-calcarine visual pathway, pituitary tumours, optic nerve diseases (including acute retrobulbar neuritis), tobacco amblyopia and traumatic lesions of the optic tract.
The sources of the responses recorded in condition BDs were mainly localized around calcarine sulci according to the known retinotopic cortical representation.
Campbell used his integrative approach to support the view that vision consisted of a "visuo-sensory" and a "visuo-psychic" stage, combining hodological, cytoarchitectonic, physiological and clinicopathological evidence to locate the former within the calcarine cortex and the latter within the cortical field surrounding it.
Dipole modeling based on a realistic boundary element head model localized the Pd100 to the right calcarine cortex. The results suggest that human calcarine cortex is engaged in early grouping operations defined by proximity, reinforcing the previous fMRI findings.
MR imaging revealed the presence of 2 lipomas, one located within the quadrigeminal cistern and the other in the calcarine fissure.
Using functional magnetic resonance imaging (fMRI), we identified that the calcarine cortex was involved in proximity grouping but not in the grouping process defined by similarity of shape. Moreover, we showed evidence that the neural correlates of proximity grouping in the calcarine cortex were weakened when the elements were of low task relevance and fell outside an attended area of field.
When the high-resolution MRI brain images were analyzed quantitatively with optimized voxel-based morphometry, results indicated that adults and children with amblyopia have decreased gray matter volume in visual cortical regions, including the calcarine sulcus, known to contain primary visual cortex.
Processing of pseudowords and real words activated a highly comparable network of brain regions, including bilateral inferior frontal gyrus, superior, middle temporal gyrus, calcarine and lingual gyrus, and left supramarginal gyrus.
The regions most active in this topography consisted of right hippocampus, posterior insula, thalamus, and right and left operculum; we found concomitant deactivation in right lingual gyrus, inferior parietal lobe and association cortex, left posterior cingulate, and right and left calcarine cortex.
Wiener filter-MEG imaging with upper and lower quadrant field stimulation demonstrated V1 responses differentially distributed respectively in the lower and upper banks of the calcarine sulcus.
Activation was found in regions corresponding to the retinotopic visual areas of sighted humans, including the calcarine sulcus (V1).
To address the extent to which the visual foveal representation is split, we examined a 29-year-old patient with a lower right quadrantanopia following surgical removal of the left occipital cortex above the calcarine sulcus and compared her performance with subjects receiving transcranial magnetic stimulation (TMS) over the occipital lobes.
Cells tested in calcarine V1 at retinal eccentricities larger than 10 degrees , show that horizontal disparity is encoded at least up to 20 degrees around both the horizontal and vertical meridians.
Unique pathologic patterns of disease involving the hippocampal CA2-4 regions and layer 4b of the calcarine cortex were identified. Adjacent regions and lamina, including hippocampal CA1 and calcarine lamina 4a and 4c were spared of pathology, highlighting the specificity of the vulnerability of selective neurons.
In addition, both limb movements and saccades to a detected stimulus produced stronger signals than stimulus detection without motor movements ('covert detection') in the calcarine sulcus and lingual gyrus.
This residual visual response was shown with fMRI to be the result of spared islands of calcarine cortical activity in one of the hemianopes, whereas only lateral occipital activity was documented in the other patient.
Published series were concentrated either on isolated deep PCA territory infarcts or on incomplete calcarine artery territory infarcts.
Other results were unexpected, such as the finding of prominent atrophy in frontal cortex near primary motor cortex and calcarine cortex near primary visual cortex.
In addition, the first principal components of the responses around the vertical meridian were reversed in polarity compared to those around the horizontal meridian, consistent with the region near the vertical meridian lying outside the calcarine fissure.
Activations in the polar visual cortex around the calcarine sulcus (BA 17, BA 18) were larger and more significant during linearvection.
We manipulated the duration of visual checkerboard stimuli across trials and measured stimulus-duration-related changes in ERP and BOLD activity in three brain regions: peri-calcarine cortex, the fusiform gyrus and lateral temporal-occipital (LTO) cortex. Similar BOLD responses were measured in peri-calcarine and fusiform regions, with both showing monotonic but non-linear increases in hemodynamic amplitude with stimulus duration. In sharp contrast, very different ERP responses were observed in these same regions, such that calcarine electrodes exhibited onset potentials, sustained activity over the course of stimulus duration and prominent offset potentials, while fusiform electrodes only exhibited onset potentials that did not vary with stimulus duration.
The major peak of each function occurred at about 120 ms latency and was well modeled by a current dipole near the calcarine sulcus. Independent component analysis (ICA) on the non-averaged data for each observer also revealed one component of calcarine origin, the location of which matched that of the dipolar source determined from the averaged data. Most notably, a sustained increase in alpha-band (7-12 Hz) activity of both calcarine and parieto-occipital origin was evident. In addition, calcarine activity in the range of 13-21 Hz was enhanced, while calcarine activity in the range of 5-6 Hz was reduced. Our results are consistent with the hypothesis that attentional modulation affects neural processing within the calcarine and parieto-occipital cortex by altering the amplitude of alpha-band activity and other natural brain rhythms..
In this anatomic study, we use anterograde tracer injections in parietal (8 monkeys) and auditory (3 monkeys) association areas, and demonstrate direct projections to areas V1 and V2 in the calcarine fissure (i.e.
Our objectives were to test the hypothesis that cortical thinning in patients with schizophrenia (relative to control subjects) is greater in temporal and prefrontal regions of interest (ROIs) than in control ROIs (superior parietal, calcarine, postcentral, central, and precentral cortices), and to obtain an unbiased estimate of the distribution of cortical thinning in patients (relative to controls) by constructing mean and statistical cortical thickness difference maps..
Significantly less signal recovery was associated with identical faces compared to different faces in bilateral mid-fusiform and right prefrontal regions but not in the calcarine and posterior fusiform regions.
VN has a lower right quadranopia following surgical removal of the left occipital cortex above the calcarine sulcus, therefore, there are no remaining islands of intact visual cortex within this area.
The data obtained reveal that: medial face of the visual cortex receives branches from the posterior cerebral artery (throughout its collaterals: calcarine artery 100%, parietooccipital artery 96% and posterior temporal artery 92%; its lateral surface receives cortical branches from the middle cerebral artery (100%) and its inferior surface is irigated from collaterals of the posterior temporal and temporo-occipital arteries (100%).
The earliest ERP component (C1 at 50-90 ms) was unaffected by attention and was localized by dipole modeling to calcarine cortex. A longer latency deflection in the 150-225 ms range that was accounted for by this same calcarine source, however, did show consistent modulation with attention.
Circular checkerboard pattern stimuli with radii from 1.8 to 5.2 degrees were presented at eccentricity of 8 degrees and angular position of 45 degrees in the lower quadrant of the visual field to excite the dorsal part of V1 which is distant from the V1/V2 border and from the fundus of the calcarine sulcus.
Also of paramount importance are the visual and auditory pathways; they are in close relationships with the temporal horn; then they project to the occipital calcarine banks and the temporal operculum, respectively.
VEP are electrical fields that are recorded in the calcarine cortex.
After reviewing the anatomical and functional aspects of the occipital lobe, the authors detail its gyral and sulcal anatomy using MRI in the three planes, with particular attention given to the localization of the calcarine fissure..
Neural sources were localized in the calcarine sulcus (M1) and the posterior fusiform gyrus (M2) of the hemisphere contralateral to the stimuli, the intraparietal sulcus and the posterior superior temporal sulcus (M3) in either of the hemispheres, and the calcarine sulcus (M4) of the same hemisphere in which the early processing (M1 and M2) occurred.
The reduction of individual anatomical variability was judged by the reduction in gray matter (GM) mismatch and by the improvement in overlap frequency between individual calcarine sulci. The HRSN processing significantly reduced the individual anatomical variability: GM mismatch was reduced by a factor of two and the mean calcarine sulcus overlap frequency was improved from 37 to 68%. This is believed to be the variability of individual areas within the calcarine sulcus, and cannot be resolved by sulcal match.
Based on earlier reports and extensive pathological studies on autopsied cases at the Kumamoto University School of Medicine, destructive lesions in the anterior portion of the calcarine cortex and depletion predominantly of granular cells in the cerebellar cortex came to be recognized as the hallmark and diagnostic yardstick of methylmercury poisoning in humans. As the number of autopsy cases of Minamata disease increased, it became apparent that the cerebral lesion was not restricted to the calcarine cortex but was relatively widespread.
We recorded activity of single units in macaque monkey primary visual cortex (V1) to define the retinotopic extent of the visual inputs that drive or modulate V1 neuron responses in parafoveal and peripheral (calcarine) cortex.
The monkey cingulo-parahippocampal isthmus was identified recently in the depths and lateral bank of the anterior calcarine fissure but was not characterized fully.
Additionally, visual imagery of famous faces activated a network of regions composed of bilateral calcarine, hippocampus, precuneus, intraparietal sulcus (IPS), and the inferior frontal gyrus (IFG).
Technical aspects and experimental results are illustrated for the geniculo-calcarine tract with broad projections to visual cortex, occipital and parietal U-fibers, and the temporo-calcarine ventral pathway.
This includes striate cortex (V1), i.e., banks of calcarine sulcus, and several higher visual areas in lingual, fusiform, cuneus, lateral occipital, inferior temporal, and middle temporal gyri.
Using dynamic random dot stereograms, we have tested both HD and VD selectivities in the parafoveal representation of V1 (calcarine V1) and V2 (eccentricities > 10 degrees ) in a behaving monkey.
This decrease was more rostro-dorsal compared to the relative rCBF increase along the calcarine sulcus found during visual stimulation in the awake state.
This stimulus induced responses in areas reaching from calcarine to parieto-occipital and to ventral and lateral temporo-occipital cortex and the anterior insula.
The results indicate that only the striate area, in and near the calcarine fissure, shows significant differences for these stimulation conditions.
Both noisy and silent imagery conditions, as compared to their respective baselines, resulted in activation of a bilateral fronto-parietal network (related to spatial processing), a bilateral inferior temporal area (related to shape processing), and deactivation of anterior calcarine cortex. Among the visual areas, rCBF increased in the most posterior part of the calcarine cortex, but at level just below the statistical threshold. However, blood flow values in the calcarine cortex during the silent imagery condition (but not the noisy imagery condition) were strongly negatively correlated with accuracy; the more challenging subjects found the task, the more strongly the calcarine cortex was activated.
This included foci in peri-calcarine, lingual, cuneus and fusiform cortex, and in the lateral and superior occipital gyri encompassing primary (V1), secondary (V2), and higher tier (VP, V4v, LO and possibly V3A) visual areas previously identified in sighted subjects.
SPM99-processed results showed for both sessions activation in the calcarine sulcus and local activation foci, mainly in the occipito-parietal region. Other studies involving figurative mental imagery using verbal cues, have shown activation in the occipito-temporal area, but none in the calcarine sulcus or in the dorsal route.
Event-related presentation of faces evoked activity in medial calcarine cortex and the fusiform gyrus bilaterally. In both calcarine and fusiform regions, the hemodynamic response to the second face in a pair was of lower amplitude and of increased latency at 1 s IPI, with significant recovery of both amplitude and latency toward single-stimulus values at 6 s IPI. No differences were found across slices in calcarine cortex. There was a significant difference in mean latency to HDR peak between calcarine and fusiform cortex, with the HDR peaking about 400 ms earlier in calcarine cortex.
Neuropathological lesions found in chronic human Minamata disease tend to be localized in the calcarine cortex of occipital lobes, the pre- and postcentral lobuli, and the temporal gyri. To test this hypothesis, we studied common marmosets because the cerebrum of marmosets has 2 distinct deep sulci, the calcarine and Sylvian fissures.
In a young man with bilateral parieto-occipital microgyria extending into the calcarine sulcus, visual stimuli increased ICoh as in normal individuals, but the response was weaker.
In neocortex, 5-HT(2C) mRNA was detected in layer V of all cortical regions examined except in the calcarine sulcus, which was devoid of signal.
All had a relatively large infarction extending from the occipital lobe tip to the posterior part of the calcarine cortex and/or the neighboring subcortical regions.
Activation in the calcarine cortex was associated with task onset, but did not vary with the duration of visual search.
To assess calcarine activation with functional magnetic resonance imaging (fMRI) in patients with anisometropic and strabismic amblyopia..
We used event-related functional magnetic resonance imaging (ER-fMRI) to detect and characterize the activity in the calcarine sulcus (which contains the primary visual cortex) during single instances of mental imagery.
Females had significantly increased grey matter concentration extensively and relatively symmetrically in the cortical mantle, parahippocampal gyri, and in the banks of the cingulate and calcarine sulci.
In horizontal sections, they form a mosaic through the ventral and dorsal calcarine cortex and through the dorso-lateral occipital part of the striate cortex. In frontal sections, their presence is manifest in IVcbeta within the calcarine cortex and they only faintly appear in IVcalpha.
However, the presence of structural changes in the optic radiations and calcarine cortex of these patients is still an unresolved issue. MTR, D and FA values for the white matter of the optic radiations and MTR and D values for the calcarine cortex were obtained using a region of interest (ROI) analysis. Our results suggest that, in patients with LHON, the optic radiations and the calcarine cortex are spared from structural damage, both at a macroscopic and a microscopic level..
Statistical parametric mapping (SPM) revealed a decreased occipital FDG uptake in the patient, particularly at the posterior bank of the parieto-occipital sulcus (putative visual area PO/V6), in the region ventrally bordering V5, and anterolaterally in the calcarine sulcus.
In intra- and extra-calcarine areas of striate cortex a five-banded pattern was distinguished, with layers III and IVc-V showing the highest densities of [ 3H]MDL100,907 labeling.
Activated voxels, identified by correlation with an empirically derived reference waveform, were found for both groups in cortex along the calcarine sulcus and in the fusiform gyrus, with the mean HDR latency in calcarine cortex peaking approximately 300 ms earlier than the HDR evoked in the fusiform gyrus.
Magnetic resonance imaging of the brain revealed a small infarct lesion in the posterior pole of the upper calcarine cortex.
In this study, we compared neuropathological abnormalities in frontal, hippocampal, and calcarine cortices from patients assigned a diagnosis of FTD, normal elderly and Alzheimer's disease (AD). We found that FTD frontal and hippocampal regions exhibited marked neuron loss, abundant ubiquitin-immunoreactive (ir) dystrophic neurites, GFAP-ir astrocytes, and CD68-ir microglia, while calcarine cortex was spared.
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