Optogenetic fMRI

OF all the techniques used by neuroscientists, none has captured the imagination of the general public more than functional magnetic resonance imaging (fMRI). The technique, which is also referred to as functional neuroimaging and, more commonly, “brain scanning”, enables us to peer into the human brain non-invasively, to observe its workings and correlate specific thought processes or stimuli to activity in particular regions. fMRI data affect the way in which people perceive scientific results: colourful images of the brain have persuasive power, making the accompanying data seem more credible.

Functional neuroimaging is used widely by researchers, too, with tens of thousands of research papers describing fMRI studies being published in the past decade. Yet, a big question mark has been hanging over the validity of the technique for over a year and, furthermore, the way in which fMRI data are interpreted has also been called into question. Using a novel combination of fMRI and a recently developed state-of-the-art technique called optogenetics, researchers now provide the first direct evidence that the fMRI signal is a valid measure of brain activity.

Continue reading

Near misses fuel gambling addiction

GAMBLING is extremely popular, with lottery tickets, casinos, slot machines, bingo halls and other forms of the activity generating revenues of more than £80 billion each year in the UK alone. For most people, gambling is nothing more than an entertaining way to pass the time. But for some, it becomes a compulsive and pathological habit – they spend increasing amounts of time gambling, because tolerance builds up quickly, and experience withdrawal symptoms when they aren’t gambling.

The terms “tolerance” and “withdrawal” are normally associated with drug addiction, and indeed pathological gambling is now considered as being akin to substance abuse. We know, for example, that monetary wins activate the brain’s reward circuitry. In pathological gamblers, however, these responses are dampened, so that increasingly larger wins are needed to produce the same rewarding effects. And according to a new study published in the Journal of Neuroscience, near misses fuel the habit in regular gamblers, because they are almost as rewarding as wins.

Continue reading