Electrical microstimulation via intracortical electrodes is a widely used method for deducing functions of the brain. In this study, we compared the spatial extent and amplitude of BOLD responses evoked by intracortical electrical stimulation in primary visual cortex with BOLD activations evoked by visual stimulation. The experiments were performed in anesthetized rhesus monkeys. Visual stimulation yielded activities larger than predicted from the well-established visual magnification factor. However, electrical microstimulation yielded an even greater spread of the BOLD response. Our results confirm that the effects of electrical microstimulation extend beyond the brain region expected to be excited by direct current spread.
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http://dx.doi.org/10.1016/j.mri.2007.03.014 | DOI Listing |
Arch Rehabil Res Clin Transl
December 2024
Section of Neurorehabilitation, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
Nystagmus has various clinical manifestations, including downbeat, upbeat, and torsional types, each associated with distinct neurologic features. Current rehabilitative interventions focusing on fixation training and optical correction often fail to achieve complete resolution. When nystagmus coexists with fragile X-associated tremor/ataxia syndrome (FXTAS), functional impairments worsen, particularly affecting balance.
View Article and Find Full Text PDFPLoS Biol
January 2025
Neuroscience Institute, New York University Grossman School of Medicine, New York, New York, United States of America.
Perceptual awareness results from an intricate interaction between external sensory input and the brain's spontaneous activity. Pre-stimulus ongoing activity influencing conscious perception includes both brain oscillations in the alpha (7 to 14 Hz) and beta (14 to 30 Hz) frequency ranges and aperiodic activity in the slow cortical potential (SCP, <5 Hz) range. However, whether brain oscillations and SCPs independently influence conscious perception or do so through shared mechanisms remains unknown.
View Article and Find Full Text PDFJ Vis
January 2025
Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
Recent studies have suggested that autistic perception can be attributed to atypical Bayesian inference; however, it remains unclear whether the atypical Bayesian inference originates in the perceptual or post-perceptual stage or both. This study examined serial dependence in orientation at the perceptual and response stages in autistic and neurotypical adult groups. Participants comprised 17 autistic and 23 neurotypical adults.
View Article and Find Full Text PDFClin Psychopharmacol Neurosci
February 2025
Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru, India.
Auditory/visual hallucinations and perceptual anomalies are one of the core symptoms experienced by patients with schizophrenia. Studies have implicated lateral occipital cortex (LOC) as one of the areas to be aberrantly functioning in schizophrenia, possibly associated with the auditory/visual symptoms of schizophrenia. Here we report of a case of a 29-year-old female diagnosed with treatment resistant schizophrenia on clozapine with persistent auditory verbal hallucinations (AVH) and visual anomalies.
View Article and Find Full Text PDFThe role of cerebellum in controlling eye movements is well established, but its contribution to more complex forms of visual behavior has remained elusive. To study cerebellar activity during visual attention we recorded extracellular activity of dentate nucleus (DN) neurons in two non-human primates (NHPs). NHPs were trained to read the direction indicated by a peripheral visual stimulus while maintaining fixation at the center, and report the direction of the cue by performing a saccadic eye movement into the same direction following a delay.
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