We can have a “reality check” within our brain. Discovery may prove important to our understanding of visual hallucinations caused by diseases such as Parkinson and Schizophrenia.
We already know where – and how – we can distinguish between the real visual experiences we have from the imaginary.
Researchers led by Nadine Dijkstrafrom University College London, identified a via cerebral that helps us make this distinction – a discovery that may exponentially improve our understanding of visual hallucinations caused by diseases such as the Parkinson e schizophrenia.
The line is fresh. It was already known that imagining something active regions of the brain similar to the zones that are activated when we perceive and interpret the real world, explains the, but it was not yet known how our brain distinguishes these visual stimuli.
Scientists asked 26 study participants to look at a static gray block in a screen for several attempts. They were instructed to imagine diagonal lines in the blocks – although in half of the attempts the lines were really present. After each attempt, the participants classified the liveliness of what they saw and indicated if they believed that the lines were real or imaginary.
Posterior magnetic resonances revealed that the Fusiform turna region of the brain associated with perception and imagination, became more active in the proportion of the liveliness with which participants experienced the visual lines, regardless of whether the lines were real or not.
It is important to point out that, when the activity in this area reached a certain limit, it triggered an intensified activity in another region, the previous insula. This leap in the activity of this region was related to the participants who judged the lines as real.
“Perhaps, in people who have visual hallucinations, a very strong activity in the fusiform turnaround when they are imagining … or the previous insula is not correctly monitoring the signs,” says Dijkstra.
The anterior insula can act as a kind of “Reality Verifier”receiving information from fusiform turning and helping the brain decide whether a visual experience is based on reality.
The findings have potential implications for clinical treatment in people with visual hallucinations, such as those with Parkinson’s disease or schizophrenia, where this neural process can be interrupted-either by excessive fusiform turnover or defective monitoring of the anterior insula, according to the study on Thursday at Cell Neuron.
The team is now investigating how this brain pathway works in individuals with Parkinson’s disease, with the aim of filling the gap between basic sensory interpretation and complex hallucinations.
