Wednesday, November 24, 2010

Trouble with numbers? Try zapping your brain.

Kodosh et al. in the Nov. 4 issue of Current Biology (noted by ScienceNow) report that administering a small electrical charge (transcranial direct current stimulation) to stimulate a center implicated in math operations located on the right side of the parietal lobe (beneath the crown of the head) can enhance a person's ability to process numbers for up to 6 months. The mild stimulation is said to be harmless, and might be tried to restore numerical skills in people suffering from degenerative diseases or stroke. Here is their abstract:
* Brain stimulation to the parietal cortex can enhance or impair numerical abilities
* The effects were specific to the polarity of the current
* The improvement in numerical abilities lasts up to 6 months
* The brain stimulation affected specifically the material that was recently learned
Around 20% of the population exhibits moderate to severe numerical disabilities  and a further percentage loses its numerical competence during the lifespan as a result of stroke or degenerative diseases. In this work, we investigated the feasibility of using noninvasive stimulation to the parietal lobe during numerical learning to selectively improve numerical abilities. We used transcranial direct current stimulation (TDCS), a method that can selectively inhibit or excitate neuronal populations by modulating GABAergic (anodal stimulation) and glutamatergic (cathodal stimulation) activity. We trained subjects for 6 days with artificial numerical symbols, during which we applied concurrent TDCS to the parietal lobes. The polarity of the brain stimulation specifically enhanced or impaired the acquisition of automatic number processing and the mapping of number into space, both important indices of numerical proficiency. The improvement was still present 6 months after the training. Control tasks revealed that the effect of brain stimulation was specific to the representation of artificial numerical symbols. The specificity and longevity of TDCS on numerical abilities establishes TDCS as a realistic tool for intervention in cases of atypical numerical development or loss of numerical abilities because of stroke or degenerative illnesses.


  1. Hi Deric,

    It seems that tDCS can be used for many different purposes. During my reading of a number of different tDCS-related studies, I have found it curious that both anodal and cathodal tDCS can have beneficial affects on various cognitive processes.

    Knowing your interest in piano, and that piano playing has been described as "most likely the activity that creates the most complex and detailed use of perceptual, motor, cognitive and emotional skills." - I was wondering if you had given any thought to the possibility that tDCS could be use to enhance one's piano practice or performance, and if you had, what area of the brain would be the optimal effect.

  2. That is a good question. Even though I routinely do 'self experiments' I've never considered playing with external magnetic or electrical stimulation of my own brain. The "said to be harmless" part worries me, because it has been shown that TMS may cause some long term damage. Because piano playing recruits so many parts of the brain, I would really know where to start in terms of location of stimulus.