Examples of pattern-recognition and fMRI applied to real-world problems: Pain also Class-recap and discussion

Notes on grades, submitting, etc. If you haven’t sent in answers to all the mini-Qs yet, please do 50% of grade is for mini-Qs. Mostly present/absent I’ll be sending out list of what you have and haven’t sent, but check your own mail archive first Graduating seniors: I’m meant to upload your grades first Don’t panic or stress out about the project If you are having difficulties, send me a mail

Pain Pain is good! - in small doses People lacking pain perception break their bones, burn themselves, etc. Chronic pain is a huge problem Lots of suffering, lost productivity, health issues, etc. Chronic pain syndrome: Pain that lasts more than 3 months E.g. injury has healed, but pain doesn’t go away There’s no obvious target for surgery Is it “in your head” ? Is it “in your brain” ? Are the above two statements different?

Social pain Eisenberger, Naomi I., Matthew D. Lieberman, and Kipling D. Williams. "Does rejection hurt? An fMRI study of social exclusion." Science 302.5643 (2003): 290-292. Video: https://www.youtube.com/watch?v=X7EFYwUopf8

Social pain and the anterior cingulate Eisenberger, Naomi I., et a.. "Does rejection hurt? An fMRI study of social exclusion." Science (2003)

Social pain and physical pain Kross, E., Berman, M. G., Mischel, W., Smith, E. E., & Wager, T. D. (2011). Social rejection shares somatosensory representations with physical pain. PNAS, 108(15), 6270-6275.

Not so fast! Reverse inference What is wrong with the following reasoning? Pain activates the anterior cingulate cortex (ACC) Therefore, if the ACC is active then someone is feeling pain Iannetti, G. D., Salomons, T. V., Moayedi, M., Mouraux, A., & Davis, K. D. (2013). Beyond metaphor: contrasting mechanisms of social and physical pain. Trends in cognitive sciences, 17(8), 371-378.

Some possible alternative explanations Maybe the anterior cingulate cortex is involved in lots of different functions, and pain is just one of them Maybe physical pain and social pain activate the same regions of neural tissue, but finer-scale neural patterns within that region are different

Neural decoding of pain Video: http://www.aparchive.com/metadata/DV-Pain- Brain/ab830bde7d3e998d26f64365ed2028be

Neural decoding of pain Wager, T. D., Atlas, L. Y., Lindquist, M. A., Roy, M., Woo, C. W., & Kross, E. (2013). An fMRI-based neurologic signature of physical pain. New England Journal of Medicine, 368(15), 1388-1397. Key points: Expose normal healthy subjects to thermal pain Ask people to give behavioural ratings Train a classifier to decode experienced level of pain Test: can it generalise across people? Specificity: can it distinguish physical pain from social pain? Clinial relevance: can classifier detect action of pain-reducing drug?

Neural decoding of pain Wager, T. D. et al., (2013). An fMRI-based neurologic signature of physical pain. New England Journal of Medicine, 368(15), 1388-1397.

Different measures of accuracy (often used in medicine) http://en.wikipedia.org/wiki/Sensitivity_and_specificity Positive Predictive Value and Precision are different names for the same thing

Neural decoder output scales with pain intensity Wager, T. D. et al., (2013). An fMRI-based neurologic signature of physical pain. New England Journal of Medicine, 368(15), 1388-1397.

Neural decoder discriminates pain from no-pain Wager, T. D. et al., (2013). An fMRI-based neurologic signature of physical pain. New England Journal of Medicine, 368(15), 1388-1397.

Distinguishing social from physical pain Wager, T. D. et al., (2013). An fMRI-based neurologic signature of physical pain. New England Journal of Medicine, 368(15), 1388-1397.

Key take-aways from class fMRI can reveal help us to understand the structure of neural representations “What lit up?” is no longer an interesting question At its best, neuroimaging can provide information over and above what can be learned from behaviour