Common cat parasite can cause schizophrenia and suicidal tendancies in HUMANS!

This comes across as just a little bit creepy… Here’s some bits and pieces:

More than a quarter of the world’s population – ranging from about seven per cent of the UK population to almost 70 per cent in Brazil – is infected with Toxoplasma -gondii, a relative of the malaria bug, which also infects rats, giving them a suicidal attraction to cats. [...]

“In populations where this parasite is very common, mass personality modification could result in cultural change.” He suggests that attitudes to ego, money, material wealth, work and rules may be affected by the parasite.

Those infected by T. gondii are prone to guilt.

See the rest of it at The Telegraph article. The idea that a parasite could literally alter society at large is both fascinating and terrifying. A fascinating article about this parasite also exists at DamnInteresting, which by the way happens to be one of my favorite sites in the world.

Brains “gambling circuitry” identified

I felt the first half of it was rather boring and unneccessary. They used fMRI. The full info can be found here.

Quartz and colleagues found they could distinguish brain regions that specifically responded to either reward expectation or risk. Importantly, these areas showed activity that increased with the level of expected reward and perceived risk. The researchers found that the activation related to expected reward was immediate, while the activation related to risk was delayed.

These regions were part of the brain circuitry governed by the neurotransmitter dopamine that is also involved in learning, motivation, and salience. However, emphasized the researchers, the design of their gambling task and analysis of their data ruled out involvement of these functions, meaning that they had, indeed, isolated the “gambling” function of these regions.

Of the practical implications of their findings, the researchers wrote that “pathological behaviors ranging from addiction to gambling, as well as a variety of mental illnesses such as bipolar disorder and schizophrenia, are partially characterized by risk taking. To date, it is unknown whether such pathological decision making under risk is due to misperception of risk or disruptions in cognitive processes, such as learning, planning, and choice.

“For example, a bipolar subject during a manic episode may invest in a risky business proposition either because they misperceive the risk to be lower than it actually is, or because they accurately perceive the risk to be high but may have impaired learning, attentional, working memory, or choice processes.”

Previous research approaches had not been able to distinguish the processes underlying such risky behavior, wrote the researchers. However, they wrote, “Since our task was designed to minimize the involvement of these high-level processes, in the future it may be utilized with clinical populations to determine whether alterations in risk perception accompany their changes in risky behavior. This may lead to a better understanding of the relative contributions of risk misperception versus cognitive impairments in these pathological cases, may suggest different treatment approaches, and may also gauge the impact on and the feedback from higher-level brain regions known to contribute to decision making.

Interesting simply in the fact that since they’ve isolated the area dealing with gambling they should be able to learn more about it in the future. I think fMRI studies like these are great because they allow for us to slowly understand what different areas of the brain do for us. For example, in the future when someone has a gambling problem they may simply go directly to checking this area, find it to be acting strangely, and (ideally, though not likely in the near future) treating it with something like neurofeedback.