Hey there! Welcome back to our selection of this week's highlights in natural sciences.
Humans are not the only ones, whose memory is not to be trusted. Details of events are stored separately in the brain and must be pieced together during recall. Errors in this process can create false memories. Researchers found that cuttlefish, like humans, might also form false memories.
Scientists created false memories in cuttlefish by exposing them to events with common features. They first showed the cuttlefish three different tubes—one with their favorite food, shrimp, one with crab, and one empty—each with a distinct visual pattern. Later, they presented two of these tubes again, the shrimp tube and the empty tube, but the contents of the tube were not visible. By using overlapping visual patterns and odors, they wanted to see if the cuttlefish would mistakenly remember shrimp in the empty tube. When given a choice between the empty and crab tubes, the cuttlefish often picked the empty tube, suggesting they falsely remembered shrimp being there.
This suggests cuttlefish can form false memories based on visual information. This ability to store smaller memory pieces and reconstruct them might help cuttlefish manage memory better and imagine different scenarios. However, individual cuttlefish varied in their susceptibility to false memories, similar to humans. Future studies will explore why some individuals are more prone to false memories and how factors like age, attention, and emotional state might affect this.
Source: Cell iScience
Time flies - but only when we do fun stuff. A new study by UNLV researchers, published in Current Biology, reveals that our perception of time is based on experiences, not an internal clock. The study found that brain activity patterns change based on the number of events we experience. James Hyman, the study's senior author, explains that when we’re bored, time drags because little happens, but when many events occur, time seems to fly.
The research focused on the anterior cingulate cortex (ACC) of the brain, important for tracking activities. Using rodents, the team showed that brain patterns consistently change as tasks progress, indicating that experiences, not actual time, affect our perception.
The study suggests that keeping busy can make time seem to move faster, as activities drive our brain's perception of time. This has implications for understanding memory, emotional states, and mental health. For example, taking breaks can help with studying, while engaging in activities can aid in moving on from events.
The findings provide insights into the brain's role in managing time perception, especially in relation to psychiatric and neurodegenerative disorders affecting the ACC, such as PTSD and Alzheimer's disease. More research is needed to fully understand these processes.
Source: Current Biology
Shedding some light on long-term effects of psychedelics. Psilocybin, the active compound in "magic mushrooms," induces profound shifts in perception and cognition. Recent clinical trials suggest that psilocybin, combined with therapy, can effectively treat major depressive disorder, addiction, and existential distress, with lasting effects. However, the brain mechanisms behind these effects were unclear. A study published in Nature, used fMRI to analyze brain changes in healthy adults after ingesting psilocybin.
Participants' brain activity was monitored before, during, and for three weeks after taking psilocybin. The researchers found significant neural desynchronization during the psychedelic experience, reducing within-network integration and increasing between-network communication. This effect was less pronounced when participants engaged in a perceptual task, suggesting that reducing external stimuli enhances the psychedelic experience.
Post-psilocybin, most brain networks normalized except for persistent changes between the default mode network and the anterior hippocampus, involved in emotion and memory. This enduring alteration might explain psilocybin's long-term therapeutic effects, making brain connections more flexible and aiding in the treatment of conditions like depression and addiction. Further large-scale trials are needed to confirm these findings and explore the potential of other psychedelics and psychoactive substances.
Source: Nature
Cover image: False memories is a common phenomena in humans. Image generated using DALL-E (copilot.microsoft.com)
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