Articles tagged with Visual Cortex
A recent study in monkeys found that auditory stimulation directly improves visual perception without involving higher brain areas. The researchers recorded neuronal responses and measured latency, showing a 5-10% decrease in response time when visual signals were weaker, suggesting the auditory cue speeds up the response.
The study found that antidepressants like fluoxetine enhance neuronal plasticity in the visual system by increasing brain-derived neurotrophic factor (BDNF), allowing for improved vision in individuals with amblyopia. Environmental stimuli, such as rehabilitation or therapy, are required to guide the rearrangement of cortical connections.
Researchers discovered neurons in monkeys' prefrontal cortex respond to specific Arabic numerals and shapes, similar to children's activation patterns. This suggests the brain builds on existing numerical precursor systems to acquire symbolic numerical abilities.
A new study confirms that colour contrast is first detected by the primary visual cortex at the back of the brain. The brain processes colour contrast earlier than previously thought, making it a significant contribution to understanding how the brain functions.
Research using fMRI and behavioral studies confirms that adult human brain can reorganize and adapt after damage, such as stroke or visual disorders. The study found that the visually deprived cortex assumed new functional properties, affecting visual perception and leading to distortions in perception.
A University of Houston engineer is using a new device to study the adult brain's ability to adjust and recover from injuries. The research aims to understand the level of plasticity in adult brains and potentially develop new treatments for brain damage.
Researchers at the Salk Institute found that motion-sensitive neurons can perform both integration and segmentation tasks, but not simultaneously. They can access information from other neurons to recover true direction of motion, suggesting a flexible processing mechanism.
Parkinson's disease impacts brain's centers of touch and vision, affecting more than just motor control. Functional magnetic resonance imaging (fMRI) reveals widespread abnormalities in somatosensory and visual cortex.
A new study from Harvard Medical School identifies neurons in the parietal cortex that assist in categorizing visual stimuli, and how brain activity patterns change with learning. The findings suggest categories are encoded by individual neurons and the parietal cortex plays a key role in learning and recognizing visual images.
Researchers used trans-cranial magnetic stimulation to trigger activity in specific brain regions, enhancing peripheral vision and altering visual cortex activity. The study suggests potential applications for treating neurological conditions that impair vision.
Researchers confirm ventral word-form area's causal role in recognizing words by studying a patient whose surgery disrupted the region. The patient showed impaired reading skills but retained object recognition and naming abilities.
Research reveals that as people age, their brains become less specialized, a phenomenon likely driven by age-related changes in brain volume or efficiency. To compensate, older adults exhibit increased activity in the frontal cortex.
Studies using functional magnetic resonance imaging (fMRI) found that the visual cortex uses a specific region known to detect motion of other people, but also engages areas responding to static human form. This clarifies the emerging picture of how the brain makes sense of other individuals' appearances and actions.
Researchers used fMRI to examine how brains process object size under illusions, finding the primary visual cortex activated more area for a distant object. This challenges the long-held view that the image is just a precise reflection of the retina.
A study published in PNAS found that even when the primary visual cortex is temporarily shut down, the brain can still process visual information unconsciously. Researchers used transcranial magnetic stimulation (TMS) to induce temporary blindness in nine volunteers with normal vision.
Researchers at Salk Institute discover that inhibitory neurons in visual cortex 'talk' with excitatory neurons to keep balance of chemical signals, excluding surrounding neurons. This fine-scale network organization enables the brain to focus attention on specific stimuli rather than all visual inputs.
Scientists at University College London found that the parietal cortex is crucial for detecting changes in a visual scene, explaining why we often miss dramatic changes while concentrating. The discovery sheds new light on 'change blindness,' a phenomenon where people fail to notice large visual changes.
A Johns Hopkins University study reveals the brain's subconscious process of organizing images into a 'whole' even when focusing on only one part. The research, based on nerve cell recordings in macaque monkeys, suggests that the brain continuously organizes scenes, even when attending to small parts.
A recent study using fMRI found limited reorganization in the primary visual cortex of adult monkeys after retina injury, contradicting previous thinking on brain plasticity. The results suggest that adult brains may not be as capable of compensating for injuries as previously believed.
Blind individuals with superior localization skills exhibit increased activity in the visual cortex while performing monaural tasks. This suggests that the visual cortex is specifically recruited to process subtle monaural cues more effectively.
A recent study using binocular rivalry demonstrates the importance of feedback in interpreting visual images. The experimenters found that once a walking figure is recognized, it can cause dominance of signals from one eye and suppression of signals from the other.
Researchers René Marois and J. Jay Todd found that the human brain's visual short-term memory has a limited storage capacity of about four objects. This is attributed to the posterior parietal cortex, which plays a key role in holding information from visual scenes.
Researchers at Duke University Medical Center have identified a brain area, the posterior cingulate cortex, that plays a crucial role in weighing costs and benefits for decision-making. This region is also linked to neurological disorders such as Alzheimer's disease, obsessive-compulsive disorder, and schizophrenia.
Researchers discovered that visually impaired individuals like Michael May struggle with object and face recognition due to delayed development of these processes. Despite challenges, May has made progress in interpreting motion and shading cues, adapting to his new visual world.
Duke University researchers found that individual clusters in the visual cortex do not specialize in recognizing specific combinations of stimulus features. Instead, they respond to a broad range of stimulus combinations predicted by spatial and temporal properties of the visual stimulus.
Researchers found that older macaque monkeys have reduced GABA levels, leading to increased neuronal firing and decreased visual function. This study provides insight into the potential causes of age-related cognitive decline and may lead to the development of new treatments.
A recent study by David Heeger and David Ress of NYU found that brain activity in the visual cortex corresponds to subjects' precepts, not the physically presented stimulus. This suggests that distortions occur at the first stages of brain processing and may shed light on conditions like amblyopia.
A new study confirms that Braille is crucial for visual cortex development in blind individuals, regardless of age of blindness. The research used fMRI to compare early and late blind subjects, finding similar activation patterns in the visual cortex.
A study by Northwestern University found that aging slows brain activity in language areas, particularly in the left front lobe and parietal cortex. However, this decrease is associated with increased processing efficiency, as older adults perform equally well on language tasks compared to younger counterparts.
Researchers used fMRI to study how the brain processes visual patterns. They found that a higher area of the brain recognizes patterns and sends a message back down to lower areas to stop responding, allowing for better detection of new or different items. This improved ability can enhance the brain's overall processing efficiency.
Researchers used fMRI to directly compare human and monkey brain activity, discovering differences in areas of the visual cortex. The study found that humans have distinct regions involved in processing 3-D images, which do not exist in monkeys.
Researchers at Baylor College of Medicine trained macaque monkeys to recognize changes in a display screen, rewarding them with juice for correct responses. The study found that neurons in the visual cortex increased activity when an event was likely to occur, allowing primates to develop expectations and prepare accordingly.
A study found that blind individuals using Braille reading strategies activate areas of the brain normally reserved for vision, suggesting a novel way of utilizing occipital cortex. This activation is similar to what is observed in sighted individuals when reading print or receiving tactile stimulation.
Scientists create detailed computer simulations of brain neurons and their assemblies to understand how the brain computes. They're building VLSI chips that accurately model retinas and can produce output spikes matching real retinae, with potential applications in retinal implants.
Researchers found that brains of blind-from-birth individuals exhibited unique activation patterns when reading Braille, suggesting a distinct mental imagery related to language. The study suggests that early visual experience may hinder brain plasticity in certain areas.
A new test measuring visual field responses to discordant images has provided clues about the brain activity underlying visual consciousness. The researchers found that binocular rivalry occurs at a lower level in the visual cortex, specifically in the primary visual cortex.
The study suggests that normal visual experience is necessary for proper brain development, with abnormal experiences disrupting neural pathways in the visual cortex. This challenges the long-held belief that either experience or innate wiring alone determines orientation selectivity.
Emory researchers verify the role of visual cortex in processing sensory information, including touch. The study reveals that visual imagery facilitates tactile discrimination tasks, such as distinguishing orientation via touch.
A team of NYU/U.Rochester researchers found evidence that viewing any image for as little as 0.5 seconds causes an after-affect on visual neurons. This rapid adaptation helps the brain distinguish subtle differences in visual patterns, a critical component of normal visual perception.
Researchers at Duke University have discovered that spontaneous neural activity plays a key role in organizing the visual cortex, contradicting current theories on ocular dominance. The study used young ferrets with closed eyes to record brain activity patterns and found that input from one eye drives the entire system.
The primary visual cortex, V1, is found to process optical illusions and complex images, contrary to previous beliefs. This discovery provides insights into how the brain cooperates to process different aspects of vision.