Biological Basis of Behavior
Mohamed Ahmed Abd El-Hay in Understanding Psychology for Medicine and Nursing, 2019
The occipital cortex is the smallest of the four lobes of the brain. It is located posterior to the temporal lobe and parietal lobes. The occipital cortex is concerned with visual processing and is composed of primary visual cortex (Brodmann area 17), and secondary visual (association) cortex (Brodmann areas 18 and 19). It receives projections from the retina (via the thalamus) from where different groups of neurons separately encode different visual information, such as color, orientation, and motion. Two important pathways of information originate in the occipital lobes: the dorsal and ventral streams. The dorsal stream projects to the parietal lobes and processes where objects are located. The ventral stream projects to structures in the temporal lobes and processes what objects are.
Integrative Synchronization Mechanisms and Models in the Cognitive Neurosciences
Harald Maurer in Cognitive Science, 2021
Recently, the canonical, neuronal, (synchronization) mechanisms of the complex cognitive function of language processing have been increasingly investigated by the German neuropsychologist, Angela D. Friederici and Wolf Singer323: "At the neuronal level, complex cognitive processes appear to be implemented by the integration of a large number of local processes into multidimensional coherent global states or, in other words, by the hierarchical nesting of operations realized at different scales in densely interconnected subnetworks of variable size. These principles appear to hold for all cognitive subsystems (...). Highly stereotyped, automatic processes such as syntactic computation are achieved in devoted subnetworks, as shown by the findings of strictly local processing of the most basic syntactic computations," i.e. the basic operation of "Merge"324 in the dorsal pathway connecting the left Brodmann area (BA) 44 (the pars opercularis Brocas area) and the posterior superior temporal gyrus (pSTG) that constitute the sentence-processing system. This is the neural substrate for the processing of syntactically complex sentences.
Functional Magnetic Resonance Imaging of the Human Motor Cortex
Alexa Riehle, Eilon Vaadia in Motor Cortex in Voluntary Movements, 2004
But what defines an area as charted in an atlas? The set of neuroanatomical criteria range from cyto- and myeloarchitectonic features to densities and laminar distributions of receptors and other neurochemical markers.167 In the case of M1, recent detailed analyses have demonstrated a considerable degree of variability both between different brains and within individual brains, i.e., between hemispheres.168 Moreover, similar methods have rather recently unveiled the fact that, regarding Brodmann area 4, we are actually dealing with two architectonically distinct areas instead of one.169 If form follows function, we must also assume different response properties of these two areas, and we have discussed some of the evidence from functional neuroimaging that this may indeed be the case. However, these conclusions were based on relating functional findings from one or several brains to a database formed from many other and thus different brains. The desideratum at this
Regional estimates of cortical thickness in brain areas involved in control of surgically restored limb movement in patients with tetraplegia
Published in The Journal of Spinal Cord Medicine, 2020
Lina Bunketorp Käll, Jan Fridén, Malin Björnsdotter
Cortical thickness processing and analysis was performed using the Freesurfer image analysis suite, which is documented and freely available for download online (http://surfer.nmr.mgh.harvard.edu/). We examined average cortical thickness measures obtained from individual level surface reconstructions for two types of regions of interest (ROIs). First, we examined the anatomically localized primary motor cortex in the FreeSurfer Brodmann Atlas, i.e. Brodmann Area 4 (posterior and anterior portions combined). Since all participants were right-handed, we restricted the analyses to the left hemisphere. Second, we examined ROIs derived from the functionally defined motor cortex area that had regained control of the pinch grip, as described above.32 Here, we used the reported individual coordinates of the primary motor cortex CoGs. ROIs were created as volumetric spheres with a 5 mm radius centered on these coordinates. The spherical ROIs were then converted into each participants’ native cortical surface space ROIs using FreeSurfer, and the average cortical thickness in each ROIs was extracted.
Fluid–structure interaction analysis of cerebrospinal fluid with a comprehensive head model subject to a rapid acceleration and deceleration
Published in Brain Injury, 2018
Figure 10 shows the cortical areas affected by the SPH impulse intensity at the peak velocity. The diffuse pattern of SPH impulse intensity maxima may represent the cortical areas most affected by a concussion. Brodmann’s areas with at least 10% coverage of maximal SPH impulse intensity include 40 (10.1%), 4 (11.7%), 1, 2, 3 (15.3%) and 52 (21.7%). Brodmann area 40, the left supramarginal gyrus, receives input from multiple sensory modalities and supports complex linguistic processes. Lesions here may result Gerstmann syndrome and fluent aphasia, such as Wernicke’s aphasia. Brodmann area 4 is typically associated with motor functions but also plays a supportive role in sensory perception. Lesions in the primary motor cortex may result in paralysis and decreased somatic sensation. Brodmann areas 1, 2 and 3 comprise the postcentral gyrus in the parietal lobe and are primarily associated with somatosensory perception. Lesions in the postcentral gyrus may result in cortical sensory impairments, including loss of fine touch and proprioception. Brodmann area 52, the parainsular, is the smallest of the mentioned areas and has the high percentage of SPH impulse intensity maxima coverage. It joins the insula and the temporal lobe.
Changes in electroencephalography complexity and functional magnetic resonance imaging connectivity following robotic hand training in chronic stroke
Published in Topics in Stroke Rehabilitation, 2021
Ahsan Khan, Cheng Chen, Kai Yuan, Xin Wang, Prabhav Mehra, Yunmeng Liu, Kai-Yu Tong
A global measure of asymmetry was obtained using 36 channels with 18 channels in each hemisphere. To understand the changes in different brain regions, the electrodes were divided into four subregions based on the lobes marked as frontal, central, parietal and occipital. A group of two to six electrodes was defined to indicate activity in each region of the brain as indicated in Figure 1 based on the divisions done in some other studies.38,39 Left Frontal (LF) included: FP1, AF1, F1, F3, and right frontal (RF) included FP2, AF2, F2, F4. Left central (LC) included C1, C3, C5, FC1, FC3, and FC5 channels and right central (RC) electrode included C2, C4, C6, FC2, FC4, and FC6 channels. Left parietal (LP) included P1, P3, P5, CP1, CP3, and CP5 channels, and Right parietal(RP) included P2, P4, PP6, CP2, CP4, and CP6 channels. Left occipital (LO) included O1 and PO3, and right occipital (RO) included O2 and PO4 channels. The frontal region covers Brodmann areas including dorsolateral prefrontal cortex (ba09) and frontopolar region (ba010).40 Likewise, central region covers Brodmann areas including primary motor cortex (ba01- 04), somatosensory association cortex(ba05), and premotor and supplementary motor cortex (ba06).41,42 Parietal electrodes cover superior parietal lobule (ba07), angular gyrus (ba039), and supramarginal gyrus (ba040),40,43 and occipital region covers visual cortex (ba018, ba019).41 Detailed information is provided at (http://www.brainm.com/software/pubs/dg/BA_10-20_ROI_Talairach/nearesteeg.htm).
Related Knowledge Centers
- Anatomy
- Cerebral Cortex
- Cytoarchitecture
- Histology
- Homology
- Postcentral Gyrus
- Brain
- Cell
- Neuron
- Laminar Organization