real time fMRI feedback

Now that fMRI can be presented to subjects in nearly real-time feedback it is possible to directly observe the result of subjective mental experience on neural activity (or vice versa). This is another way to look at consciousness. Kalina Christoff and group have a recent paper (see citation) on feedback regulation of the rostrolateral prefrontal cortex (RLPRC), an area associated with awareness of meta-cognition or control of introspection. Here is the abstract:

Recent real-time fMRI (rt-fMRI) training studies have demonstrated that subjects can achieve improved control over localized brain regions by using real-time feedback about the level of fMRI signal in these regions. It has remained unknown, however, whether subjects can gain control over anterior prefrontal cortex (PFC) regions that support some of the most complex forms of human thought. In this study, we used rt-fMRI training to examine whether subjects can learn to regulate the rostrolateral prefrontal cortex (RLPFC), or the lateral part of the anterior PFC, by using a meta-cognitive awareness strategy. We show that individuals can achieve improved regulation over the level of fMRI signal in their RLPFC by turning attention towards or away from their own thoughts. The ability to achieve improved modulation was contingent on observing veridical real-time feedback about the level of RLPFC activity during training; a sham-feedback control group demonstrated no improvement in modulation ability and neither did control subjects who received no rt- fMRI feedback but underwent otherwise identical training. Prior to training, meta-cognitive awareness was associated with recruitment of anterior PFC subregions, including both RLPFC and medial PFC, as well as a number of other midline and posterior cortical regions. Following training, however, regulation improvement was specific to RLPFC and was not observed in other frontal, midline, or parietal cortical regions. These results demonstrate the feasibility of acquiring control over high-level prefrontal regions through rt-fMRI training and offer a novel view into the correspondence between observable neuroscientific measures and highly subjective mental states.

Previous studies have suggested the RLPFC’s role is to monitor, coordinate, integrate and evaluate the products of of higher level stages of cognitive processing. Subjects used observation of their own thoughts to increase RLPFC activity and they used external sensory and bodily sensations to decrease the activity. With real time feedback they significantly increased their ability to control the level of activity in the RLPFC. Controls attempted the same effects without any feedback or with sham feedback and did not achieve significant changes. However, trained mediators achieve similar (not identical) effects.

While previous rt-fMRI feedback training studies have shown that subjects could learn to regulate activation with the sensorimotor contex by imagining hand movements, the insula by recalling personal affectively charged events, the anterior cingulate by attending to and away from the painful properties of a stimulus, and the inferior frontal gyrus through the use of various strategies involving sub-vocal speech, here we show that subjects can use an abstract mental process such as metacognitive awareness of one’s own thoughts to regulate activation levels in one of the highest-order cortical association regions.

This is a very powerful tool. It is a fairly probable guess that what the subjects are doing is steering attention – the focus of conscious attention. We will hear much more from this experimental setup in the future and it will shine a light on consciousness.

McCaig, R., Dixon, M., Keramatian, K., Liu, I., & Christoff, K. (2011). Improved modulation of rostrolateral prefrontal cortex using real-time fMRI training and meta-cognitive awareness NeuroImage, 55 (3), 1298-1305 DOI: 10.1016/j.neuroimage.2010.12.016

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