The feeling of what (does not) happen: A multimodal neurobehavioural account of somatosensory misperceptions

Description

A major goal of cognitive neuroscience is to explain the causal links between brain function and behaviour. This novel research project brings together experts in:

  • neuroscience
  • psychology
  • engineering

By collaborating, we can try and determine the role of pre-stimulus brain activity in the subsequent detection of near-threshold tactile events particularly when an absent tactile event is misperceived as being present. In three work packages we will extend the behavioural, EEG and fMRI approaches used successfully in our previous work to develop an overarching model of the influence of baseline neural activity on somatosensory perception using a signal detection approach.

We predict that the correct detection of touch will be preceded by activity in lateral fronto-parietal (lFP) brain regions, involved in monitoring external events, whereas the misperception of touch will be preceded by activity in medial fronto-parietal (mFP) regions, involved in monitoring internal bodily sensations. We will then use interoceptive and exteroceptive attention tasks to increase the ‘top-down’ influence from these frontal brain regions on somatosensory perception. We predict that focussing on internal bodily sensations (counting heartbeats) prior to the task will activate mFP (and insula) cortex and increase the number of tactile misperceptions more than focussing on external tactile sensations.

In the final phase of the research we will directly stimulate somatosensory cortex (using transcranial Direct Current Stimulation) to determine the causal role of intrinsic neural activity on tactile perception. We predict that applying stimulation at a frequency that increases resting alpha-oscillatory activity will increase the number of tactile misperceptions, thereby establishing a causal link between intrinsic neural activity and somatosensory perception. Overall, the outcomes of this research will reveal the fundamental role of dynamic brain networks and oscillatory activity in bodily consciousness.