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Stroke and Transient Ischemic Attacks of the Brain and Eye
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Some anatomically localizing neurologic deficits require a cooperative and conversant patient to elicit them, such as: Alexia and agraphia (dominant hemisphere angular gyrus).Apraxia (dominant parietal lobe).Visual agnosia (nondominant parieto-occipital cortex).Visual and sensory inattention (nondominant parietal lobe).
Neurology
Published in Roy Palmer, Diana Wetherill, Medicine for Lawyers, 2020
The brain is divided into two halves. The cerebral cortex in each half is responsible for motor and sensory function on the opposite side of the body. It sits astride a central, deeply-placed portion of the brain known as the brain stem which, apart from acting as a conduit for the long nerve fibre tracts that pass to and from the spine, also contains a number of important nuclei (nerve relay stations). The cortex is divided into four lobes (on each side): frontal, parietal, occipital, and temporal. The motor cortex, controlling movement, lies at the back of the frontal lobe and, immediately behind it, in front of the parietal lobe, lies the sensory section of the cortex, which is important in the perception of sensation. The primary visual area is at the back of the brain, in the occipital cortex. Speech is in the left hemisphere in right-handed people and half the left-handed population. The frontal lobe has important functions in behaviour and important cognitive ‘executive’ functions (Figure 14.1). The corollary is that focal damage to the brain often produces easily recognizable clinical syndromes.
Biological Basis of Behavior
Published in Mohamed Ahmed Abd El-Hay, 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.
Evaluation of Memory and Language Network in Children and Adolescents with Visual Impairment: A Combined Functional Connectivity and Voxel-based Morphometry Study
Published in Neuro-Ophthalmology, 2021
A Ankeeta, Rohit Saxena, S Senthil Kumaran, Sada Nand Dwivedi, Naranamangalam Raghunathan Jagannathan, Vaishna Narang
The role of the visual cortex while reading Braille words has been confirmed by neuroimaging techniques like functional neuroimaging, positron emission tomography (PET), and transcranial magnetic stimulation (TMS).6–10 In blind participants, the occipital cortex has been reported to process non-visual stimuli in the early years of blindness.11 During the Braille reading task, the primary visual cortex was found to be activated in late blind (LB), but not in early blind (EB) participants.12 Varying nature of utilisation and reorganisation of primary visual cortex in EB and LB participants suggests an alteration in dorsal and ventral perception pathways.7,13–16 Visual and somatosensory network involvement has been reported during language processing in blind population, but memory network performance during the encoding of language component is yet to be explored. Visual cortical area, language area, and the learning network may differ in children and adolescent participants, and may contribute to different levels of plasticity in EB and LB participants.17–19 Understanding the extent of neuro-plasticity associated with visual loss onset, neurobiology and cognition would help in developing a training pattern for better adaptation during early and late onset of blindness.
Time estimation exposure modifies cognitive aspects and cortical activity of attention deficit hyperactivity disorder adults
Published in International Journal of Neuroscience, 2020
Rhailana Medeiros Fontes, Victor Marinho, Valécia Carvalho, Kaline Rocha, Francisco Magalhães, Iris Moura, Pedro Ribeiro, Bruna Velasques, Mauricio Cagy, Daya S. Gupta, Victor Hugo Bastos, Ariel Soares Teles, Silmar Teixeira
In our findings, the DLPFC bilaterally showed a significant decrease in the theta band absolute power in the experimental condition. This finding agrees with the DLPFC participation in the identification of relevant behavioral stimuli, in addition to helping focus attention, which is fundamental for the time perception and cognitive control performance [67]. For instance, when subjects underwent a color attention task, it was observed that directing attention to a color increases the occipital cortex activity. However, when attention was directed to time estimation, there was an increase in activity in the DLPFC. This finding is related to the memory stage of the Scalar Expectancy Theory model [68]. From this perspective, the DLPFC is related to reward, sustenance of attention levels and executive processes, which are important for time perception, as demonstrated in a past study by Vallesi, Shallice and Walsh [69], that involved the right DLPFC in temporal processing in an implicit task. Therefore, it has been pointed out that the right DLPFC participation corroborates for the time interval interpretation since it is activated mainly in tasks involving interval timing when compared to other cortical areas.
Developmental prosopagnosia with concurrent topographical difficulties: A case report and virtual reality training programme
Published in Neuropsychological Rehabilitation, 2019
Sarah Bate, Amanda Adams, Rachel Bennetts, Hannah Line
Such an investigation would also be of particular value given that topographical disorientation deficits following brain injury appear to have a broad range of underpinnings, where various taxonomies have identified difficulties in landmark and scene recognition, as well as in the processing of spatial relationships or the formation and retrieval of cognitive maps (e.g., Aguirre & D’Esposito, 1999; Arnold et al., 2013; De Renzi, 1982; Liu et al., 2011). This variability in acquired cases is unsurprising given the widespread nature of brain lesions: landmark agnosia has been associated with damage to right ventral temporo-occipital cortex (McCarthy, Evans, & Hodges, 1996; Pai, 1997), scene categorisation with the transverse occipital sulcus (Bettencourt & Xu, 2013; Dilks, Julian, Paunov, & Kanwisher, 2013), and both processes to the parahippocampal place area (Epstein, Harris, Stanley, & Kanwisher, 1999; O’Craven & Kanwisher, 2000). Cognitive map formation has been linked to both the right and left hippocampi and the retrosplenial cortex (Iaria, Chen, Guariglia, Ptito, & Petrides, 2007).