Title: Researchers Uncover Brain Mechanism Behind Conscious Perception
Subtitle: Groundbreaking study sheds light on sustained visual perception and its implications for understanding consciousness
Date: [Insert Date]
Researchers from the Hebrew University of Jerusalem and the University of California, Berkeley, have made a significant breakthrough in understanding the mechanisms behind conscious perception. Their study, published in the journal Cell Reports, reveals how the brain retains sustained visual images for several seconds.
The study stems from a puzzling affliction known as unilateral neglect, which affects more than a quarter of all stroke victims. Individuals with this disorder lose conscious awareness of half of what their eyes perceive. For example, they may only eat food from one side of the plate or fail to notice a person on their left side. Strikingly, these stroke victims can still emotionally react to the entire scene, despite only being consciously aware of half.
The team of neuroscientists aimed to investigate the difference between perceiving something and being consciously aware of perceiving it. They sought to understand the neural basis for sustained perception, as current studies mainly focus on the initial surge of brain activity when stimuli are perceived.
In their study, the researchers implanted electrodes on the brain surface of 10 individuals with epilepsy, allowing them to record neural activity associated with epileptic seizures. The participants were shown various images on a computer screen for up to 1.5 seconds, and their brain activity was monitored.
Contrary to previous studies, which only observed a brief burst of brain activity when new stimuli were perceived, the researchers found that the visual areas of the brain retained information about the perception for much longer. This sustained pattern of neural activity remained consistent, similar to the initial spike, and changed when the participants viewed a new image.
The findings provide insights into the neural basis for stable perception over time. The prefrontal and parietal cortices become active when something new is perceived, but the information disappears within half a second. In contrast, the occipitotemporal area of the visual cortex remains active at a low level, accounting for 10% to 20% of the initial spike. This sustained activity is believed to play a role in conscious awareness.
The researchers believe that conscious awareness occurs when the prefrontal cortex accesses this sustained activity in the visual cortex. However, there are multiple theories of consciousness, and further research is needed to develop a comprehensive, testable theory.
This groundbreaking study could have practical applications in the future, such as helping doctors determine whether coma patients are still aware of the outside world. Understanding consciousness may also lead to enhanced treatments for disorders of consciousness.
Lead author Gal Vishne, a graduate student at Hebrew University, emphasized the significance of everyday experiences and the importance of studying consciousness. “Consciousness, and in particular, visual experience, is the most fundamental thing that everyone feels from the moment they open their eyes when they wake up to the moment they go to sleep. Our study is about your everyday experience,” Vishne said.
The research team plans to explore the electrical activity associated with consciousness in other regions of the brain, including those involved in memory and emotions. As they delve further into the complexities of consciousness, their studies could contribute to the development of a comprehensive theory of conscious perception.
The study was supported by grants from the U.S.-Israel Binational Science Foundation and the National Institute of Neurological Disorders and Stroke.