At the edge of my vision, a wiggling spoon reflected the light in a particular way. And for a split second my brain told me “it’s probably an insect”. I immediately looked closer and understood that it was a wiggling spoon. While it hasn’t happened since, it changed my intuition about hallucinations.
This matches my own experience with sleep deprivation in principle. When I have been severely sleep-deprived (sober; I don’t drink and don’t use drugs), my brain has started overreacting to motion. Something moving slightly in my peripheral vision caught my attention as if it were moving dramatically. This even happened with stationary objects that appeared to move as I shifted position. I have experienced about a dozen such false positives in my life and interpreted the motion as an insect only a couple of times. Most times it didn’t seem like anything in particular, just movement that demanded attention. However, “insect” seems an obvious interpretation when you suddenly notice small rapid motion in your peripheral vision. (“Suddenly” and “rapid” because your motion detection is exaggerated.) In reality, it was things like wind gently flapping a curtain.
However, this is not the only way people can hallucinate insects. There is another where they seem to see them clearly. Here is Wikipedia on delirium tremens:
Other common symptoms include intense perceptual disturbance such as visions or feelings of insects, snakes, or rats. These may be hallucinations or illusions related to the environment, e.g., patterns on the wallpaper or in the peripheral vision that the patient falsely perceives as a resemblance to the morphology of an insect, and are also associated with tactile hallucinations such as sensations of something crawling on the subject—a phenomenon known as formication. Delirium tremens usually includes feelings of “impending doom”. Anxiety and expecting imminent death are common DT symptoms.
From this and a few articles I have read over the years, I get a sense that when people are suffering from delirium tremens, they see small creatures of different types distinctly and vividly. So you can probably say there are “insect hallucinations” and “Huh? Is that motion an insect?” hallucinations.
This matches my own experience with sleep deprivation in principle. When I have been severely sleep-deprived (sober; I don’t drink and don’t use drugs), my brain has started overreacting to motion. Something moving slightly in my peripheral vision caught my attention as if it were moving dramatically. This even happened with stationary objects that appeared to move as I shifted position. I have experienced about a dozen such false positives in my life and interpreted the motion as an insect only a couple of times. Most times it didn’t seem like anything in particular, just movement that demanded attention. However, “insect” seems an obvious interpretation when you suddenly notice small rapid motion in your peripheral vision. (“Suddenly” and “rapid” because your motion detection is exaggerated.) In reality, it was things like wind gently flapping a curtain.
However, this is not the only way people can hallucinate insects. There is another where they seem to see them clearly. Here is Wikipedia on delirium tremens:
From this and a few articles I have read over the years, I get a sense that when people are suffering from delirium tremens, they see small creatures of different types distinctly and vividly. So you can probably say there are “insect hallucinations” and “Huh? Is that motion an insect?” hallucinations.