Every week I look back at what caught my eye. This is for those of you who hate/are scared of/don’t understand/can’t be bothered by/had a bad experience with/never heard of/simply avoid reading my feed (please circle only one) on Twitter, because these stories were all listed there. If you are coming from Twitter, consider this a refresher on the tweets that got away.

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Multi-modality sensory bonding
Human subjects learned novel associations between visual and auditory cues using two different strategies. In the “classic” mode, visual stimuli were explored with, well…errrr….vision. In the multi-modality learning mode, visual stimuli were explored using visual and haptic (touch) means. Subjects were more effective learning arbitrary visual-audio associations when using both vision and touch were allowed when exploring the visual stimuli. So our memory likes to integrate information from a variety of sources when consolidating learned information. Not a surprise, but cool.

Is psychiatry filling the social roles previously occupied by religion?
A really interesting write-up from Vaughan Bell inspired by a recent article in Journal of the Royal Society of Medicine. The article is not intended to be taken literally, but it does raise a lot of questions regarding the role of psychiatry in our lives, whether we fear God or otherwise. Wisely, Vaughan does not buy into the whole “psychiatry is religion” argument but suggests that the dialogue is useful in that it raises concern about how medical theories have become the standard explanation for problems of human living.

Facial muscle feedback influences emotional state representation
Found this one while perusing through Research Blogging. As described by the Research Digest Blog, a study examined the question of whether facial expression can affect emotional state. It has been long hypothesized that muscle feedback (like the pulling of the face during smiling) can influence our transient happiness or sense of well-being, but if true, it is still uncertain whether this influence arises from the cognitive commands to change facial expression, or the actual sensory feedback from the muscles and skin. The authors designed a clever experiment in which they used botox patients as subjects. These individuals lose the ability to make faces about 2 weeks after treatment, thus dissociating the higher order command to make an emotional face from the actual sensory feedback produced through the facial expression itself. Subjects were scanned using fMRI while imitating emotional faces shown to them on a screen. Essentially, the authors found lower activity in the amygdala, known to be an area that processes emotion, for botox-injected women attempting to imitate an angry face as compared to women who had not been injected and were imitating the same face. This suggested to the authors that the actual sensory/muscular feedback may influence emotional state. I’d need to see more controls to determine what effect botox treatment had on cerebral blood flow (just as a start), but in general, it was a neat correlation.

Wiring and plumbing in the brain
Speaking of what cerebral blood flow really means, this commentary/review is an absolute must-read for anyone interested in or conducting experiments involving fMRI. It nicely details the positions of the two main camps at odds over how to interpret fMRI data. The clash is ‘metabolic’ vs. ‘neurogenic’; with the former suggesting a direct correlation between the amount of blood flow and neuronal activity vs. the latter, which suggests that blood flow simply signals future neuronal activity; an anticipatory signal, if you will. Nature published a ground-breaking study strongly supporting the neurogenic hypothesis in January.

Implicit effect of language-specific terminology on human color perception
We know that native language can affect our perception of the world. But really, how powerful is this? Can specific language actually make your perception of the color blue different? The authors here say yes. Comparing Greek- and English-speaking subjects on their performance in a perceptual discrimination task, the Greeks performed better. When all else is controlled, the only thing left is the fact that in Greek, there are two words for blue (depicting light and darker shades).

Apotemnophilia may arise from faulty integration of limb into self-image
If you look through Nature Precedings, you can find some nice stuff. This preprint caught my eye because I had never heard of this bizarre affliction (which involves the desire to amputate an otherwise healthy limb) . Previously thought to be a purely psychological phenomenon (well, defect), these data may suggest otherwise. When apotemnophiliacs were touched on the affected limb while being scanned for somatoseneory activation in the cortex using MEG, the researchers found that in fact, the touched limb does not elicit appropriate activation and does not seem to be properly represented in the cortex (i.e., it lacks normal activation signals). This led the authors to propose that there may actually be a neurological basis to this problem because since the affected limb does not fully integrate into the sense of self or body plan, the owner thus feels a strong desire to remove the “foreign” limb. Strange stuff. The data are suggestive, but we’ll monitor this one and see what the expert reviewers think.

Using optogenetics for deep-brain stimulation to elicit therapeutic effects in Parkinsonian mice
Is the Deisseroth lab on a role or what? After the AOP release on Wednesday of their interesting new work on optogenetic tools for signaling pathway activation, they turn back around with a hot new paper in Science as well, demonstrating the first use of optical tools for deep-brain stimulation (DBS). Being able to specifically drive brain tissue of choice is virtually impossible using electrodes, especially with a technical hammer like DBS. Genetically targeting a specific sub-population of cells allows one to drive only the cells of interest, in this case, a variety of motor circuit elements in Parkinson’s disease mouse models. This specificity allowed the authors to dissect the circuit and better understand the mechanism underlying the efficacy of DBS. Oh yeah, and the motor defect symptoms of the diseased mice improved as well.

Schizophrenia gene DISC1 regulates neural progenitor proliferation
Examining development and circuit issues in the context of psychiatric disease is red hot. Tsai and colleagues raise the bar for these studies with this Cell paper describing a role for DISC1, the single best candidate gene for schizophrenia that we have right now, in the regulation of neural progenitor cell proliferation. It seems that DISC1 directly regulates signaling pathways modulating progenitor proliferation and that these proliferation defects seem to be the source of the observed behavioral phenotypes in the DISC1 mutant mouse model of the disease. The work also identifies a downstream kinase, GSK-3β as a mediator of these DISC1-dependent effects and a potential therapeutic target in patients who have problems with their DISC1 gene.