Cortical Regions Associated with Perceiving, Naming, and Knowing about Colors

1999 ◽  
Vol 11 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Linda L. Chao ◽  
Alex Martin
Keyword(s):  
Color Perception ◽  
Brain Regions ◽  
Gray Scale ◽  
Brain Areas ◽  
Low Level ◽  
Positron Emission ◽  
Specific Object ◽  
Cortical Regions ◽  
Object Form ◽  
Parietal Cortices

Positron emission tomography (PET) was used to investigate whether retrieving information about a specific object attribute requires reactivation of brain areas that mediate perception of that attribute. During separate PET scans, subjects passively viewed colored and equiluminant gray-scale Mondrians, named colored and achromatic objects, named the color of colored objects, and generated color names associated with achromatic objects. Color perception was associated with activations in the lingual and fusiform gyri of the occipital lobes, consistent with previous neuroimaging and human lesion studies. Retrieving information about object color (generating color names for achromatic objects relative to naming achromatic objects) activated the left inferior temporal, left frontal, and left posterior parietal cortices, replicating previous findings from this laboratory. When subjects generated color names for achromatic objects relative to the low-level baseline of viewing gray-scale Mondrians, additional activations in the left fusi-form/lateral occipital region were detected. However, these activations were lateral to the occipital regions associated with color perception and identical to occipital regions activated when subjects simply named achromatic objects relative to the same low-level baseline. This suggests that the occipital activa-tions associated with retrieving color information were due to the perception of object form rather than to the top-down influence of brain areas that mediate color perception. Taken together, these results indicate that retrieving previously acquired information about an object's typical color does not require reactivation of brain regions that subserve color perception.

scholarly journals Trans-Synaptic Spread of Amyloid-βin Alzheimer’s Disease: Paths toβ-Amyloidosis

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Annabella Pignataro ◽  
Silvia Middei
Keyword(s):  
Neuronal Activity ◽  
Amyloid Plaques ◽  
Brain Regions ◽  
Amyloid Peptide ◽  
Synaptic Connections ◽  
Brain Areas ◽  
Close Link ◽  
Gradual Accumulation ◽  
Cortical Regions ◽  
Activity Dependent

Neuronal activity has a strong causal role in the production and release of the neurotoxicβ-amyloid peptide (Aβ). Because of this close link, gradual accumulation of Aβinto amyloid plaques has been reported in brain areas with intense neuronal activity, including cortical regions that display elevated activation at resting state. However, the link between Aβand activity is not always linear and recent studies report exceptions to the view of “more activity, more plaques.” Here, we review the literature about the activity-dependent production of Aβin both human cases and AD models and focus on the evidences that brain regions with elevated convergence of synaptic connections (herein referred to as brain nodes) are particularly vulnerable to Aβaccumulation. Next, we will examine data supporting the hypothesis that, since Aβis released from synaptic terminals,β-amyloidosis can spread in AD brain by advancing through synaptically connected regions, which makes brain nodes vulnerable to Aβaccumulation. Finally, we consider possible mechanisms that account forβ-amyloidosis progression through synaptically linked regions.

scholarly journals microRNA profiling uncovers region-specific molecular correlates of threat responses in a marmoset model of anxiety

2021 ◽  
Author(s):  
Natalia Popa ◽  
Angela C Roberts ◽  
Andrea M Santangelo ◽  
Eduardo Gascon
Keyword(s):  
Emotional Regulation ◽  
Brain Regions ◽  
Molecular Heterogeneity ◽  
Depression And Anxiety ◽  
Behavioral Differences ◽  
Brain Areas ◽  
Molecular Changes ◽  
Highly Correlated ◽  
Cortical Regions ◽  
And Behavior

Background: Neuroimaging studies have consistently reported that stress-related disorders such as depression and anxiety impinge on the activity of emotion regulation networks, namely in the ventromedial prefrontal cortex (vmPFC). This circuitry is known to be extensively modulated by serotonin and it has been long shown that genetic polymorphisms in the serotonin transporter gene (SLC6A4) are linked to anxiey and depression. vmPFC encompasses different brain regions in terms of cytoarchitecture, activity and connectivity. However, molecular heterogeneity within the vmPFC and how these differences affect emotional regulation and behavior have not been elucidated. Methods: Here, we took advantage of recently described polymorphisms in marmoset SLC6A4 gene linked to alter threat responses. Using FACS-sorted cells from different brain areas of genotyped marmosets, we tested the hypothesis that specific molecular changes in precise regions of the vmPFC underlie the behavioral differences and can be associated with high anxiety-like trait. Results: miRNA analysis of FACS-sorted cells from marmoset cortex revealed that clear miRNA profiles can be identified for different cell subsets (NeuN+ versus NeuN- cells) or cortical regions (visual cortex versus vmPFC). More importantly, marmosets bearing different SLC6A4 polymorphisms show distinct miRNAs signatures specifically in vmPFC area 32 neurons but not in the closely related vmPFC area 25 neurons. Finally, levels of these miRNAs were highly correlated to the anxiety-like score in a test of uncertain threat. Conclusions: These data demonstrate that molecular changes within area 32 likely underlie the differential anxiety-like responses associated with SLC6A4 polymorphisms.

scholarly journals Network-targeted, multi-site direct cortical stimulation enhances working memory by modulating phase lag of low frequency oscillations

2019 ◽  
Author(s):  
Sankaraleengam Alagapan ◽  
Justin Riddle ◽  
Wei Angel Huang ◽  
Eldad Hadar ◽  
Hae Won Shin ◽  
...  
Keyword(s):  
Working Memory ◽  
Brain Stimulation ◽  
Effective Means ◽  
Low Frequency ◽  
Brain Regions ◽  
Phase Lag ◽  
Frequency Bands ◽  
Alpha Frequency ◽  
Cortical Regions ◽  
Parietal Cortices

AbstractWorking memory, an important component of cognitive control, is supported by the coordinated activation of a network of cortical regions in the frontal and parietal cortices. Oscillations in theta and alpha frequency bands are thought to coordinate these network interactions. Thus, targeting multiple nodes of the network with brain stimulation at the frequency of interaction may be an effective means of modulating working memory. We tested this hypothesis by identifying regions that are functionally connected in theta and alpha frequency bands and intracranially stimulating both regions simultaneously in participants undergoing invasive monitoring. We found that in-phase stimulation resulted in improvement in performance compared to sham stimulation. In contrast, anti-phase stimulation did not affect performance. In-phase stimulation resulted in decreased phase lag between regions within working memory network while anti-phase stimulation resulted in increased phase lag suggesting that shorter phase lag in oscillatory connectivity may lead to better performance. The results support the idea that phase lag may play a key role in information transmission across brain regions. More broadly, brain stimulation strategies that aim to improve cognition may be better served targeting multiple nodes of brain networks.

scholarly journals Alzheimer's Disease: Metabolic Uncoupling of Associative Brain Regions

1986 ◽  
Vol 13 (S4) ◽  
pp. 540-545 ◽  
Author(s):  
Stanley I. Rapoport ◽  
Barry Horwitz ◽  
James V. Haxby ◽  
Cheryl L. Grady
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Parietal Lobe ◽  
Brain Regions ◽  
Metabolic Abnormalities ◽  
Alzheimer Type ◽  
Positron Emission ◽  
Partial Correlations ◽  
Metabolic Uncoupling ◽  
Parietal Cortices

Abstract:Evidence indicates that Alzheimer's disease (AD) causes functional disconnection of neocortical association areas. In mildly demented AD patients without measurable neocortically-mediated cognitive abnormalities, positron emission tomography demonstrates reduced parietal lobe glucose metabolism and left/right metabolic asymmetries in neocortical association areas. Similar metabolic abnormalities occur in moderately demented patients, but are accompanied by appropriate language and visuospatial discrepancies. Left/right metabolic asymmetries correspond with reduced numbers of partial correlations between metabolic rates in homologous right and left regions, and in the frontal and parietal cortices, indicating metabolic uncoupling among these regions. The affected association regions are those which demonstrate Alzheimer-type neuropathology post-mortem.

scholarly journals The Effect of Nimodipine on the Evolution of Human Cerebral Infarction Studied by PET

1989 ◽  
Vol 9 (4) ◽  
pp. 523-534 ◽  
Author(s):  
A. M. Hakim ◽  
A. C. Evans ◽  
L. Berger ◽  
H. Kuwabara ◽  
K. Worsley ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Statistical Significance ◽  
Treated Group ◽  
Brain Regions ◽  
Normal Brain ◽  
Oxygen Extraction Ratio ◽  
Perfusion Measurement ◽  
Positron Emission ◽  
The Difference ◽  
Cortical Regions

Fourteen patients were studied by positron emission tomography (PET) within 48 h of onset of a hemispheric ischemic stroke and again 7 days later. After the first set of PET scans, the patients were randomized to receive either nimodipine (n = 7) or a carrier solution (n = 7) by intravenous infusion. The infusions were maintained until the end of the second PET studies. CBF, cerebral blood volume (CBV), oxygen extraction ratio (OER), CMRO2, and CMRglc were measured each time. These metabolic and perfusion measurements were performed by standard methods. A surface map of each metabolic and perfusion measurement in the cortical mantle was generated by interpolating between the available slices. The various surface maps representing the physiological characteristics determined in the same or subsequent studies were aligned so that all data sets could be analyzed identically using an array of square regions of interest (ROIs). The functional status of each ROI was recorded at the two intervals following the cerebrovascular accident to characterize the evolution of the infarct, penumbra, and normal brain regions. We presumed the ischemic penumbra to be cortical regions in the proximity of the infarct and perfused at CBF values between 12 and 18 ml/100 g/min on the first PET scan, while densely ischemic regions had CBF of <12 nl/100 g/min and normally perfused brain >18 ml/100 g/min. In the densely ischemic zone, CBF increased more in the nimodipine-treated group than in the carrier group. As well, in this region nimodipine reversed the decline in CMRO2 noted in the carrier group, the difference in the changes being significant. In the penumbra zone, comparable trends were noted in OER and CMRO2 but the difference in the changes between the two groups did not reach statistical significance. Changes in CMRglc and CBV were comparable between the two groups in both cortical regions.

scholarly journals Detection of Remote Neuronal Reactions in the Thalamus and Hippocampus Induced by Rat Glioma Using the PET Tracer Cis-4-[18F]Fluoro-D-Proline

2013 ◽  
Vol 33 (5) ◽  
pp. 724-731 ◽  
Author(s):  
Stefanie Geisler ◽  
Antje Willuweit ◽  
Michael Schroeter ◽  
Karl Zilles ◽  
Kurt Hamacher ◽  
...  
Keyword(s):  
Ex Vivo ◽  
High Sensitivity ◽  
Brain Regions ◽  
Tracer Uptake ◽  
Thalamic Nuclei ◽  
Brain Areas ◽  
Rat Glioma ◽  
F98 Rat Glioma ◽  
Pet Tracer ◽  
Positron Emission

After cerebral ischemia or trauma, secondary neurodegeneration may occur in brain regions remote from the lesion. Little is known about the capacity of cerebral gliomas to induce secondary neurodegeneration. A previous study showed that cis-4-[18F]fluoro-D-proline (D- cis-[18F]FPro) detects secondary reactions of thalamic nuclei after cortical infarction with high sensitivity. Here we investigated the potential of D- cis-[18F]FPro to detect neuronal reactions in remote brain areas in the F98 rat glioma model using ex vivo autoradiography. Although the tumor tissue of F98 gliomas showed no significant D- cis-[18F]FPro uptake, we observed prominent tracer uptake in 7 of 10 animals in the nuclei of the ipsilateral thalamus, which varied with the specific connectivity with the cortical areas affected by the tumor. In addition, strong D- cis-[18F]FPro accumulation was noted in the hippocampal area CA1 in two animals with ipsilateral F98 gliomas involving hippocampal subarea CA3 rostral to that area. Furthermore, focal D- cis-[18F]FPro uptake was present in the necrotic center of the tumors. Cis-4-[18F]fluoro-D-proline uptake was accompanied by microglial activation in the thalamus, in the hippocampus, and in the necrotic center of the tumors. The data suggest that brain tumors induce secondary neuronal reactions in remote brain areas, which may be detected by positron emission tomography (PET) using D- cis-[18F]FPro.

Pain Intensity Processing Within the Human Brain: A Bilateral, Distributed Mechanism

1999 ◽  
Vol 82 (4) ◽  
pp. 1934-1943 ◽  
Author(s):  
Robert C. Coghill ◽  
Christine N. Sang ◽  
Jose Ma. Maisog ◽  
Michael J. Iadarola
Keyword(s):  
Pain Intensity ◽  
Somatosensory Cortex ◽  
Functional Organization ◽  
Human Subjects ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Pain Processing ◽  
Brain Areas ◽  
Secondary Somatosensory Cortex ◽  
Positron Emission

Functional imaging studies of human subjects have identified a diverse assortment of brain areas that are engaged in the processing of pain. Although many of these brain areas are highly interconnected and are engaged in multiple processing roles, each area has been typically considered in isolation. Accordingly, little attention has been given to the global functional organization of brain mechanisms mediating pain processing. In the present investigation, we have combined positron emission tomography with psychophysical assessment of graded painful stimuli to better characterize the multiregional organization of supraspinal pain processing mechanisms and to identify a brain mechanism subserving the processing of pain intensity. Multiple regression analysis revealed statistically reliable relationships between perceived pain intensity and activation of a functionally diverse group of brain regions, including those important in sensation, motor control, affect, and attention. Pain intensity–related activation occurred bilaterally in the cerebellum, putamen, thalamus, insula, anterior cingulate cortex, and secondary somatosensory cortex, contralaterally in the primary somatosensory cortex and supplementary motor area, and ipsilaterally in the ventral premotor area. These results confirm the existence of a highly distributed, bilateral supraspinal mechanism engaged in the processing of pain intensity. The conservation of pain intensity information across multiple, functionally distinct brain areas contrasts sharply with traditional views that sensory-discriminative processing of pain is confined within the somatosensory cortex and can account for the preservation of conscious awareness of pain intensity after extensive cerebral cortical lesions.

scholarly journals Different perceptual tasks performed with the same visual stimulus attribute activate different regions of the human brain: a positron emission tomography study

1993 ◽  
Vol 90 (23) ◽  
pp. 10927-10931 ◽  
Author(s):  
P Dupont ◽  
G A Orban ◽  
R Vogels ◽  
G Bormans ◽  
J Nuyts ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Human Brain ◽  
Brain Regions ◽  
Detection Task ◽  
Emission Tomography ◽  
Orientation Discrimination ◽  
Positron Emission ◽  
Passive Viewing ◽  
Cortical Regions ◽  
Visual Cortical

To investigate the processing of visual form in human cerebral cortex, we used the PET (positron emission tomography) activation technique to compare the human brain regions that are involved in a visual detection task and two orientation discrimination tasks: the temporal same-different (TSD) task, which includes a short-term memory component, and the identification (ID) task, which is without this component. As a control task we used passive viewing. Stimuli were identical in all four tasks. Subtraction of passive viewing from detection showed that the detection task activates early visual cortical regions (areas 17/18) as well as several motor brain regions, while decreasing activity in several higher order frontal, temporal, and parietal regions. Comparing the ID task to the detection task revealed no further visual cortical activation, while comparison of the TSD task to the detection task revealed an activation of several right visual cortical regions, one of which remained significant after the subtraction of ID from TSD (right area 19). These experiments demonstrate the task dependence of visual processing, even for very closely related tasks, and the localization of the temporal comparison component involved in orientation discrimination in human area 19.

Modulation of Motor Excitability during Speech Perception: The Role of Broca's Area

2004 ◽  
Vol 16 (6) ◽  
pp. 978-987 ◽  
Author(s):  
Kate Watkins ◽  
Tomáš Paus
Keyword(s):  
Speech Perception ◽  
Motor System ◽  
Inferior Frontal Gyrus ◽  
Posterior Part ◽  
Brain Regions ◽  
Broca’S Area ◽  
Broca's Area ◽  
Auditory Speech ◽  
Positron Emission ◽  
Cortical Regions

Studies in both human and nonhuman primates indicate that motor and premotor cortical regions participate in auditory and visual perception of actions. Previous studies, using transcranial magnetic stimulation (TMS), showed that perceiving visual and auditory speech increased the excitability of the orofacial motor system during speech perception. Such studies, however, cannot tell us which brain regions mediate this effect. In this study, we used the technique of combining positron emission tomography with TMS to identify the brain regions that modulate the excitability of the motor system during speech perception. Our results show that during auditory speech perception, there is increased excitability of motor system underlying speech production and that this increase is significantly correlated with activity in the posterior part of the left inferior frontal gyrus (Broca's area). We propose that this area “primes” the motor system in response to heard speech even when no speech output is required and, as such, operates at the interface of perception and action.

Engaging regularly with fiction influences connectivity in cortical areas for language and mentalizing

2017 ◽  
Author(s):  
Roel M. Willems ◽  
Franziska Hartung
Keyword(s):  
Functional Connectivity ◽  
Time Course ◽  
Language Skills ◽  
Brain Regions ◽  
Brain Areas ◽  
Daily Lives ◽  
Cortical Areas ◽  
Social Abilities ◽  
Behavioral Evidence ◽  
Amount Of Reading

Behavioral evidence suggests that engaging with fiction is positively correlated with social abilities. The rationale behind this link is that engaging with fictional narratives offers a ‘training modus’ for mentalizing and empathizing. We investigated the influence of the amount of reading that participants report doing in their daily lives, on connections between brain areas while they listened to literary narratives. Participants (N=57) listened to two literary narratives while brain activation was measured with fMRI. We computed time-course correlations between brain regions, and compared the correlation values from listening to narratives to listening to reversed speech. The between-region correlations were then related to the amount of fiction that participants read in their daily lives. Our results show that amount of fiction reading is related to functional connectivity in areas known to be involved in language and mentalizing. This suggests that reading fiction influences social cognition as well as language skills.

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