A collection of new papers on brain function on LSD is in the process of being published by Imperial College in London.
One of the studies inquired into the visual hallucinations so prevalent with LSD. They used brain imaging and compared volunteers who had taken the drug with volunteers who had taken a placebo. They observed during visual tasks that activity was observed throughout the brains the individuals who had taken LSD, while it was concentrated in the visual cortex in those that hadn't. So they believe that LSD makes the whole brain communicate more than is normal in adults where activity has become compartmentalized. (They note that the kind of activation seen with LSD is also seen in infants.)
As an old acid-head in the day, I've always believed that LSD takes down the filters that remove noise in the visual system, thus stimulating feature detectors randomly, creating the characteristic 'patterns', a jumble of unconnected edges, corners and colors that don't cohere into perceptual objects. That might be consistent with what these researchers observed, since if the visual system is receiving all kinds of inputs from the rest of the brain and not just from the eyes, it might become overstimulated.
Another interesting paper to be published examined LSD's effect on the sense of self. They observed that LSD tends to decrease the resting background activity of the brain that they call the 'default mode network', associated with alpha-waves on EKGs. And they hypothesize (I wonder how speculative this is) that this activity is associated with our sense of self-consciousness and that as this activity decreases, the sense of 'me' decreases as well. The researchers hope the research like this using psychoactive drugs might cast new light on the phenomenon of consciousness.
There's more besides that. See here:
https://www.newscientist.com/article/208...ciousness/
and here:
http://www.techtimes.com/articles/149361...ntists.htm
and here:
http://www.nature.com/news/brain-scans-r...ss-1.19727
It's interesting how each news story emphasizes something different, whatever's of interest to the reporter who wrote it.
One of the studies inquired into the visual hallucinations so prevalent with LSD. They used brain imaging and compared volunteers who had taken the drug with volunteers who had taken a placebo. They observed during visual tasks that activity was observed throughout the brains the individuals who had taken LSD, while it was concentrated in the visual cortex in those that hadn't. So they believe that LSD makes the whole brain communicate more than is normal in adults where activity has become compartmentalized. (They note that the kind of activation seen with LSD is also seen in infants.)
As an old acid-head in the day, I've always believed that LSD takes down the filters that remove noise in the visual system, thus stimulating feature detectors randomly, creating the characteristic 'patterns', a jumble of unconnected edges, corners and colors that don't cohere into perceptual objects. That might be consistent with what these researchers observed, since if the visual system is receiving all kinds of inputs from the rest of the brain and not just from the eyes, it might become overstimulated.
Another interesting paper to be published examined LSD's effect on the sense of self. They observed that LSD tends to decrease the resting background activity of the brain that they call the 'default mode network', associated with alpha-waves on EKGs. And they hypothesize (I wonder how speculative this is) that this activity is associated with our sense of self-consciousness and that as this activity decreases, the sense of 'me' decreases as well. The researchers hope the research like this using psychoactive drugs might cast new light on the phenomenon of consciousness.
There's more besides that. See here:
https://www.newscientist.com/article/208...ciousness/
and here:
http://www.techtimes.com/articles/149361...ntists.htm
and here:
http://www.nature.com/news/brain-scans-r...ss-1.19727
It's interesting how each news story emphasizes something different, whatever's of interest to the reporter who wrote it.