scholarly journals Parcellation of the Hippocampus According to Its Connection Probability with Prefrontal Cortex Subdivisions in a Malaysian Malay Population: Preliminary Findings

2021 ◽  
Vol 28 (3) ◽  
pp. 65-76
Author(s):  
Aimi Nadhiah Abdullah ◽  
Asma Hayati Ahmad ◽  
Rahimah Zakaria ◽  
Sofina Tamam ◽  
Jafri Malin Abdullah
Keyword(s):  
Prefrontal Cortex ◽  
Diffusion Magnetic Resonance Imaging ◽  
Spatial Information ◽  
Structural Connectivity ◽  
Resonance Imaging ◽  
Malaysian Population ◽  
Connection Probability ◽  
Malay Population ◽  
Lesion Studies ◽  
The Brain

Background: Lesion studies have shown distinct roles for the hippocampus, with the dorsal subregion being involved in processing of spatial information and memory, and the ventral aspect coding for emotion and motivational behaviour. However, its structural connectivity with the subdivisions of the prefrontal cortex (PFC), the executive area of the brain that also has various distinct functions, has not been fully explored, especially in the Malaysian population. Methods: We performed diffusion magnetic resonance imaging with probabilistic tractography on four Malay males to parcellate the hippocampus according to its relative connection probability to the six subdivisions of the PFC. Results: Our findings revealed that each hippocampus showed putative connectivity to all the subdivisions of PFC, with the highest connectivity to the orbitofrontal cortex (OFC). Parcellation of the hippocampus according to its connection probability to the six PFC subdivisions showed variability in the pattern of the connection distribution and no clear distinction between the hippocampal subregions. Conclusion: Hippocampus displayed highest connectivity to the OFC as compared to other PFC subdivisions. We did not find a unifying pattern of distribution based on the connectivity- based parcellation of the hippocampus.

scholarly journals Miswiring of Frontostriatal Projections in Schizophrenia

2020 ◽  
Vol 46 (4) ◽  
pp. 990-998 ◽  
Author(s):  
James J Levitt ◽  
Paul G Nestor ◽  
Marek Kubicki ◽  
Amanda E Lyall ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Magnetic Resonance Imaging ◽  
Right Hemisphere ◽  
Structural Connectivity ◽  
Chronic Schizophrenia ◽  
Input Pattern ◽  
Healthy Controls ◽  
Resonance Imaging ◽  
Circuit Integration ◽  
Projection Zone

Abstract We investigated brain wiring in chronic schizophrenia and healthy controls in frontostriatal circuits using diffusion magnetic resonance imaging tractography in a novel way. We extracted diffusion streamlines in 27 chronic schizophrenia and 26 healthy controls connecting 4 frontal subregions to the striatum. We labeled the projection zone striatal surface voxels into 2 subtypes: dominant-input from a single cortical subregion, and, functionally integrative, with mixed-input from diverse cortical subregions. We showed: 1) a group difference for total striatal surface voxel number (P = .045) driven by fewer mixed-input voxels in the left (P  = .007), but not right, hemisphere; 2) a group by hemisphere interaction for the ratio quotient between voxel subtypes (P  = .04) with a left (P  = .006), but not right, hemisphere increase in schizophrenia, also reflecting fewer mixed-input voxels; and 3) fewer mixed-input voxel counts in schizophrenia (P  = .045) driven by differences in left hemisphere limbic (P  = .007) and associative (P  = .01), but not sensorimotor, striatum. These results demonstrate a less integrative pattern of frontostriatal structural connectivity in chronic schizophrenia. A diminished integrative pattern yields a less complex input pattern to the striatum from the cortex with less circuit integration at the level of the striatum. Further, as brain wiring occurs during early development, aberrant brain wiring could serve as a developmental biomarker for schizophrenia.

scholarly journals Adaptive brain activity changes during tongue movement with palatal coverage from fMRI data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuka Inamochi ◽  
Kenji Fueki ◽  
Nobuo Usui ◽  
Masato Taira ◽  
Noriyuki Wakabayashi
Keyword(s):  
Spatial Information ◽  
Brain Activity ◽  
Motor Impairment ◽  
Angular Gyrus ◽  
Tongue Movement ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Oral Environment ◽  
Motor Dexterity ◽  
The Brain

AbstractSuccessful adaptation to wearing dentures with palatal coverage may be associated with cortical activity changes related to tongue motor control. The purpose was to investigate the brain activity changes during tongue movement in response to a new oral environment. Twenty-eight fully dentate subjects (mean age: 28.6-years-old) who had no experience with removable dentures wore experimental palatal plates for 7 days. We measured tongue motor dexterity, difficulty with tongue movement, and brain activity using functional magnetic resonance imaging during tongue movement at pre-insertion (Day 0), as well as immediately (Day 1), 3 days (Day 3), and 7 days (Day 7) post-insertion. Difficulty with tongue movement was significantly higher on Day 1 than on Days 0, 3, and 7. In the subtraction analysis of brain activity across each day, activations in the angular gyrus and right precuneus on Day 1 were significantly higher than on Day 7. Tongue motor impairment induced activation of the angular gyrus, which was associated with monitoring of the tongue’s spatial information, as well as the activation of the precuneus, which was associated with constructing the tongue motor imagery. As the tongue regained the smoothness in its motor functions, the activation of the angular gyrus and precuneus decreased.

scholarly journals Structural connectivity of the human anterior temporal lobe: A diffusion magnetic resonance imaging study

2016 ◽  
Vol 37 (6) ◽  
pp. 2210-2222 ◽  
Author(s):  
Nico Papinutto ◽  
Sebastiano Galantucci ◽  
Maria Luisa Mandelli ◽  
Benno Gesierich ◽  
Jorge Jovicich ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Temporal Lobe ◽  
Diffusion Magnetic Resonance Imaging ◽  
Structural Connectivity ◽  
Imaging Study ◽  
Magnetic Resonance Imaging Study ◽  
Resonance Imaging ◽  
Anterior Temporal Lobe

scholarly journals Medial prefrontal cortex represents the object-based cognitive map when remembering an egocentric target location

2019 ◽  
Author(s):  
Bo Zhang ◽  
Yuji Naya
Keyword(s):  
Prefrontal Cortex ◽  
Social Interactions ◽  
Medial Prefrontal Cortex ◽  
Spatial Information ◽  
Target Location ◽  
Neural Substrates ◽  
Cognitive Map ◽  
Object Based ◽  
Constituent Elements ◽  
The Brain

AbstractA cognitive map, representing an environment around oneself, is necessary for spatial navigation. However, compared with its constituent elements such as individual landmarks, neural substrates of coherent spatial information remain largely unknown. The present study investigated how the brain codes map-like representations in a virtual environment specified by the relative positions of three objects. Representational similarity analysis revealed an object-based spatial representation in the hippocampus (HPC) when participants located themselves within the environment, while the medial prefrontal cortex (mPFC) represented it when they recollected a target object’s location relative to their self-body. During recollection, task-dependent functional connectivity increased between the two areas implying exchange of self- and target-location signals between the HPC and mPFC. Together, the coherent cognitive map, which could be formed by objects, may be recruited in the HPC and mPFC for complementary functions during navigation, which may generalize to other aspects of cognition, such as navigating social interactions.

Is There a Common Network for Processing Reward and Aversion in the Brain?

2016 ◽  
Author(s):  
Jiameng Xu
Keyword(s):  
Magnetic Resonance Imaging ◽  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Meta Analysis ◽  
Anterior Cingulate ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Aversive Stimuli ◽  
Midcingulate Cortex ◽  
The Brain

How do our brains process and attach positive and negative value to the objects around us, the sensations we feel, and the experiences that we have? One method of examining these questions is to detect, using functional magnetic resonance imaging (fMRI), which areas of the human brain are activated when subjects are exposed to rewarding and aversive stimuli. Although many fMRI studies have concentrated on identifying a network of areas that become active in processing either reward or aversion, there is evidence of significant overlap between the “reward” and “aversion” networks, suggesting that the brain might process rewarding and aversive stimuli in a similar manner regardless of valence. Thus, a meta-analysis of fMRI studies involving rewarding and aversive stimuli was undertaken to determine the areas of the brain that are commonly and differentially activated by reward and aversion. The preliminary results indicate that regions of the prefrontal cortex, anterior cingulate cortex, amygdala, nucleus accumbens, hippocampus, and basal ganglia were commonly activated by rewarding and aversive stimuli, while areas including the insula, midcingulate cortex, and parts of the hippocampus were differentially activated. Locating such commonalities and differences might help in our understanding of how the brain ascribes value to our environment.  

scholarly journals Medial Prefrontal Cortex Represents the Object-Based Cognitive Map When Remembering an Egocentric Target Location

2020 ◽  
Vol 30 (10) ◽  
pp. 5356-5371 ◽  
Author(s):  
Bo Zhang ◽  
Yuji Naya
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Spatial Information ◽  
Target Location ◽  
Neural Substrates ◽  
Cognitive Map ◽  
Object Based ◽  
The Individual ◽  
Constituent Elements ◽  
The Brain

Abstract A cognitive map, representing an environment around oneself, is necessary for spatial navigation. However, compared with its constituent elements such as individual landmarks, neural substrates of coherent spatial information, which consists in a relationship among the individual elements, remain largely unknown. The present study investigated how the brain codes map-like representations in a virtual environment specified by the relative positions of three objects. Representational similarity analysis revealed an object-based spatial representation in the hippocampus (HPC) when participants located themselves within the environment, while the medial prefrontal cortex (mPFC) represented it when they recollected a target object’s location relative to their self-body. During recollection, task-dependent functional connectivity increased between the two areas implying exchange of self-location and target location signals between the HPC and mPFC. Together, the object-based cognitive map, whose coherent spatial information could be formed by objects, may be recruited in the HPC and mPFC for complementary functions during navigation, which may generalize to other aspects of cognition, such as navigating social interactions.

scholarly journals The Impact of Undiagnosed Synaesthesia on the Interpretation of Structural and Functional MRI Images Connectivity Maps and Resulting Diagnoses

2016 ◽  
Vol 15 (11) ◽  
pp. 7227-7234
Author(s):  
Nourhan Zayed
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Sensory Modality ◽  
Structural Connectivity ◽  
Brain Regions ◽  
Resonance Imaging ◽  
Functional Connections ◽  
The Impact ◽  
The Brain

Synathesia is a condition in which stimulation of a sensory modality triggers another sensation in the alike or an unalike sensory modality. Currently, synaesthesia is deemed a neurological condition that engages unwanted transfer of signals between brain regions from one sense to another “crosstalk activation”. The probability that undiagnosed synaesthesia may impact the results of structural magnetic resonance imaging (MRI), Diffusion Tensor imaging (DTI), functional magnetic resonance imaging (fMRI) and resting state connectivity studies is high, given the multiple anatomical and functional connections within the brain. In this paper, the currently available literature to mark which sensations adjured by synaesthesia and how could this impact MRI different modalities. Our study found that synaesthesia can have an opaque impact on fMRI studies of sensory, memory and cognitive functions, and there is testimony to suggest structural connections in the brain are also mutated DTI measurements especially, it shows enhanced structural connectivity for synesthetes between brain regions, higher Fractional anisotropy (FA), as well as increased in the white matter integrity between some regions.. Given the low dispersal of synaesthesia, the likelihood of synaesthesia being a perplexing factor in DTI, fMRI studies of patient groups is small; however, determining the existence of synaesthesia is paramount for investigating individual patients especially Shizoherenia, and autistic patients.

scholarly journals Political neuroscience: Understanding how the brain makes political decisions

2020 ◽  
Author(s):  
Ingrid Johnsen Haas ◽  
Clarisse Warren ◽  
Samantha J. Lauf
Keyword(s):  
Magnetic Resonance Imaging ◽  
Decision Making ◽  
Prefrontal Cortex ◽  
Magnetic Resonance ◽  
Political Psychology ◽  
Reward Processing ◽  
Anterior Cingulate ◽  
Resonance Imaging ◽  
The Brain ◽  
Political Cognition

Recent research in political psychology and biopolitics has begun to incorporate theory and methods from cognitive neuroscience. The emerging interdisciplinary field of political neuroscience (or neuropolitics) is focused on understanding the neural mechanisms underlying political information processing and decision making. Most of the existing work in this area has utilized structural magnetic resonance imaging, functional magnetic resonance imaging, or electroencephalography, and focused on understanding areas of the brain commonly implicated in social and affective neuroscience more generally. This includes brain regions involved in affective and evaluative processing, such as the amygdala, insula, anterior cingulate, and orbitofrontal cortex, as well as regions involved in social cognition (e.g., medial prefrontal cortex), decision making (e.g., dorsolateral prefrontal cortex), and reward processing (e.g., ventral striatum). Existing research in political neuroscience has largely focused on understanding candidate evaluation, political participation, and ideological differences. Early work in the field focused simply on examining neural responses to political stimuli, whereas more recent work has begun to examine more nuanced hypotheses about how the brain engages in political cognition and decision making. While the field is still relatively new, this work has begun to improve our understanding of how people engage in motivated reasoning about political candidates and elected officials and the extent to which these processes may be automatic versus relatively more controlled. Other work has focused on understanding how brain differences are related to differences in political opinion, showing both structural and functional variation between political liberals and political conservatives. Neuroscientific methods are best used as part of a larger, multimethod research program to help inform theoretical questions about mechanisms underlying political cognition. This work can then be triangulated with experimental laboratory studies, psychophysiology, and traditional survey approaches and help to constrain and ensure that theory in political psychology and political behavior is biologically plausible given what we know about underlying neural architecture. This field will continue to grow, as interest and expertise expand and new technologies become available.

Sign in / Sign up

Export Citation Format

Share Document