Stewart et al. studied mental representations used in music reading, as well as their instantiation within the brain. They performed a fMRI training study in which musically untrained adults were taught to read music and play piano keyboard over a period of three months. Specific learning-related changes were seen in the superior parietal cortex and fusiform gyrus, for melody reading and rhythm reading, respectively.

Meister at al. studied the neural correlates of piano playing. In the analysis of the fMRI data while the subjects played piano on a MRI-compatible keyboard, a predominantly frontoparietal cortical network was found to be active during piano performance.The activations comprise the primary sensorimotor cortex in the left hemisphere and the premotor cortex and the cerebellum bilaterally, in addition to a parietal network of precuneus and BA 40. An occipital network was also activated. The authors suggest that the frontoparietal network and the cerebellum are involved slightly more in rhythm processing, whereas the precuneus and the occipital regions seem to play a role in the processing of pitch and notereading.

Bengtsson et al. studied dissociation between melodic and rhythmic processing during piano performance from musical scores. They found that the medial occipital lobe, the superior temporal lobe, the rostral cingulate cortex, the putamen and the cerebellum process the melodic information, whereas the lateral occipital and the inferior temporal cortex, the left supramarginal gyrus, the left inferior and ventral frontal gyri, the caudate nucleus, and the cerebellum process the rhythmic information.

Who has never dreamt reading a boss's, a colleague's or a relative’s mind? Will new brain imaging techniques replace divination and other fortune-tellers?

When you are thinking about something (let's say a bird), fMRI can show which voxels are activated (let's say voxels 33-52-20 and 34-12-40). Mind reading through functional MRI is inverting this relationship: if fMRI shows you are activating voxels 33-52-20 and 34-12-40, can we guess you are thinking about a bird?

Several groups have taken up this challenge, using artificial intelligence techniques to infer subjects' thoughts or actions from patterns of pixels activated in fMRI images.

For example, the hippocampus is known to process experience into memories, and to be involved in the recall of spatial locations. With stimuli generated by a virtual reality system, Hassabis et al. (Current Biology 2009) asked subjects to virtually move between 8 locations within 2 rooms. Using a pattern classification algorithm to analyse the fMRI results, they were able to guess at which location a subject was standing at a given moment, from the pattern of activation of specific voxels in the hippocampus and parahippocampal gyrus.

Haynes et al. (Current Biology 2007) used similar pattern classification algorithms to predict the subject's intention to perform either an addition or a subtraction of two numbers he was shown. Decoding the activity in the anterior medial prefrontal cortex, they were able to predict the subject's intention with 71% accuracy, which is significantly above chance level.

Kay et al. (Nature 2008) used receptive-field models to build a visual decoder from fMRI data. In the algorithm training step, they established how the activity of each voxel in the visual cortex responded to locations, orientations and spatial frequencies presented in 1750 images. In the image identification step, they presented images out of a set which was not used during the training session. By measuring the response of each voxel to the novel image, and comparing it with the predicted response for each image out of this new set, they were able to guess which image was actually seen by the subject. Out of 1000 images (for example, bird 1, bird 2, bird 3,..., dog 1, dog 2, dog 3,...etc.), fMRI can decipher which one you are seeing (for example, dog 2). The next (but far more complex) step would be to reconstruct the image you are seeing or thinking about from scratch. For instance, imagine a monster, then ask the machine to draw a picture of it.

The 3 experiments described above are a first step towards mind reading. Despite their experimental complexity, the scenarios described remain relatively simple: it is a matter of guessing what you are seeing, doing or planifying within a pre-defined set of possibilities. But the number of thoughts is infinite. A mind reading experiment in a broader context would be much more complex.

In addition, all of these experiments are based on a direct relationship between a feature of the stimulus (for example, the locations, frequencies and orientations in an image) and a neuroanatomical location. This relationship is clear for some functions (somatotopy, retinotopy, tonotopy), it is more than uncertain for other functions.

To conclude, functional MRI is a promising tool for potentially reading a mind. The possible applications go beyond the imaginable: reading unconscious thoughts; mind reading in a patient with an altered state of consciousness; lie detector; and so on. This is a powerful kind of tool, which deals with the most private aspect of Self, hence it must be manipulated with care and ethics.

Version française: L'IRM fonctionnelle peut-elle lire dans vos pensées ?

Functional MRI (fMRI), a magnetic resonance imaging technique that permits localizing areas of the brain activated by a stimulus, is gaining more and more interest among advertisers. How does our brain react to an advertisement? This is the question that Imagilys, a company specialized in neuroimaging, is attempting to answer in partnership with Brain Impact, a company specialized in neuromarketing.

The application of recent neuroscience techniques to marketing (neuromarketing) may give insights into the unconscious purchasing behaviours of the consumer. These unconscious behaviours may represent up to 95% of the decision-making process, while the visible tip of the iceberg (the conscious processes), which have been studied by classical marketing research (market studies, product tests, pre- and post-advertising tests) may only represent 5% of this process.

The founding article for neuromarketing by functional MRI was published in the prestigious scientific journal Neuron (McClure et al. Neuron 2004). A team of researchers studied the Coke-Pepsi paradox: during blind taste tests, the majority of testers preferred the taste of Pepsi, despite the fact that they buy more Coke. Functional MRI permitted demonstrating an astonishing fact: invoking the Coke trademark activates large areas of the brain, linked to memory, which shows that consumers are more influenced by their memory of the trademark than they are by the taste of the product.

During a neuromarketing test, the volunteer is stretched out in an MRI scanner. Audiovisual stimuli are presented to him or her while images of the brain are acquired every few seconds. Statistical analysis of the signal variations of these images permits identifying the cerebral areas activated during the presentation of a given stimulus (advertisement, product test, etc.).

Neuromarketing developments could assist advertisers and trademark or product managers to improve the effectiveness of their communications and the quality of their products to best satisfy the conscious and unconscious needs of the consumer. Optimizing the memorability of a trademark, choice of advertising formats, assistance in creation, etc., the applications are broad and are only beginning.

Manipulation? That an ad seeks to influence our choice cannot be denied, that is its purpose. Neuromarketing is only one of the increasing number of tools in the arsenal of advertisers. In any case, it does not permit changing the choice of the consumer or manipulating his or her brain unwittingly. The miracle "buy button" does not exist, but the lovely top-model on the advertising probably still has a bright future!

About Imagilys and Brain Impact:

Imagilys is a company specializing in cerebral imaging, more specifically in functional magnetic resonance imaging. It has joined forces with Brain Impact, a neuromarketing company, in order to propose targeted neuroimaging services applied to marketing in Europe.

After a brain injury, distinction between coma, vegetative state, minimally conscious state, akinetic mutism, and locked-in syndrome is a complex challenge for the neurologist (Giacino 1997, Gaciano 2004). The limits which separates these states, and even the definition of "consciousness" are unclear. Some behavioral tests can help in the differential diagnosis, but are impaired by the lack of input/output caused by lesions in primary areas or in white matter pathways.

Minimally conscious state (MCS), which refers to patients with severe brain damage but who demonstrate unequivocal, but intermittent, behavioral evidence of awareness of self or their environment (Giacino et al. 2002), is the most interesting state to study with functional MRI. Identifying any form of consciousness can have great psychological impact on the patient and its family and potentially influence the therapeutic approach.

Functional MRI has the power to detect brain activation elicited by a stimuli even in the absence of patient output. It could therefore be used as a marker of brain activity or even "consciousness" in patient in a vegetative or minimally conscious state. Shiff et al. found similar activations in 2 patient in a MCS than in a group of healthy volunteers presented with passive language (Wernicke's area) and tactile stimulation (post-central gyrus) paradigms. It suggests that some MCS patients may retain widely distributed cortical systems with potential for cognitive and sensory function despite their inability to follow simple instructions or communicate reliably.

Owen et al. 2006 applied a more complex paradigm to further investigate the state of consciousness of a patient in a vegetative state. The patient was asked to perform 2 mental imagery tasks: tennis playing versus walking in a her house. Brain activations observed were identical to the one obtained in healthy volunteers: supplementary motor area (SMA) while mentally playing tennis, parahippocampal gyrus, posterior parietal cortex, and lateral premotor cortex while visiting her house. Of the 54 patients enrolled in a study performed by the same group (Monti et al. 2010), 5 were able to willfully modulate their brain activity. One patient, without any form of communication at the bedside, was able to modulate his brain activity (tennis playing versus walking in his house) to answer yes or no to questions during functional MRI.

Resting state fMRI, i.e. functional MRI without any stimulus, has also been used to assess patients with disorders of consciousness. The default network is defined as a number of areas including the precuneus, bilateral temporo-parietal junctions and medial prefrontal cortex, which are more active at rest than when the subjects are involved in an attention-demanding cognitive task. Vanhaudenhuyse et al. 2009 have showed that the connectivity of this default network is decreased in severely brain-damaged patients, in proportion to their degree of consciousness impairment.

Functional MRI (fMRI) enables the researcher to specifically view the areas of the brain activated by a task or an emotion. Many research groups focused on sex (Maravilla et al. Int J Imp Res 2007)! What happens in the brain in a situation of sexual excitement ? Is it the same thing for men and women ? A trip behind the scenes of pleasure…

Different studies have used the projection of erotic images or video in the MRI, with the aim of stimulating sexual excitement. Easier for men… Even if men and women present many similar bilateral areas of activation: anterior cingulate, medial prefrontal, orbitofrontal, insular, and occipitotemporal cortices, amygdala and ventral striatum. Men activate thalamus and hypothalamus as well, proportionately to their excitement (Karama et al. Hum Brain Mapp 2002). The amygdala as well, which is part of the limbic system, seems to be playing a major role in men (Hamann et al. Nat Neurosci 2004).

Studies in positron emission tomography (PET scan), a technique which is older than the functional MRI, have gone further. They imaged some male volunteers while their partners were stimulating them manually until ejaculation and orgasm (Holstege et al. J Neurosc 2003). Activations were additionally seen in the ventral tegmental area, which is also stimulated by the ecstasy associated with heroin use. Maybe the two phenomenon are not so different!

Please note that in a jealous condition, men present activation in areas linked to sexuality and aggression (amygdala and hypothalamus), whereas in women the rear area of the superior temporal sulcus is stimulated (Takahashi et al. Neuroimage 2006). Beware...

Version française: Sexe et cerveau: quand la Science est "hot"!