mechanical pain stimulation: a time-resolved FMRI study’, Cerebral Cortex, 24, no. 11 (2014), pp. 2991–3005; J. Gonzalez-Castillo, Z. S. Saad, D. A. Handwerker, S. J. Inati, N. Brenowitz and P. A. Bandettini, ‘Whole-brain, time-locked activation with simple tasks revealed using massive averaging and model-free analysis’, Proceedings of the National Academy of Sciences of the United States of America, 109, no. 14 (2012), pp. 5487–92; J. W. Ibinson and K. M. Vogt, ‘Pain does not follow the boxcar model: temporal dynamics of the BOLD fMRI signal during constant current painful electric nerve stimulation’, Journal of Pain, 14, no. 12 (2013), pp. 1611–19.103 103 M. R. Bennett, L. Farnell and W. G. Gibson, ‘Quantitative relations between transient BOLD responses, cortical energetics, and impulse firing in different cortical regions’, Journal of Neurophysiology, 122, no. 3 (2019), pp. 1226–37.
104 104 N. J. Maandag, D. Coman, B. G. Sanganahalli, P. Herman, A. J. Smith, H. Blumenfeld, R. G. Shulman and F. Hyder, ‘Energetics of neuronal signaling and fMRI activity’, Proceedings of the National Academy of Sciences of the United States of America, 104, no. 51 (2007), pp. 20546–51; A. J. Smith, H. Blumenfeld, K. L. Behar, D. L. Rothman, R. G. Shulman and F. Hyder, ‘Cerebral energetics and spiking frequency: the neurophysiological basis of fMRI’, Proceedings of the National Academy of Sciences of the United States of America, 99, no. 16 (2002), pp. 10765–70.
105 105 M. R. Bennett, L. Farnell and W. G. Gibson, ‘Quantitative relations between BOLD responses, cortical energetics, and impulse firing’, Journal of Neurophysiology, 119, no. 3 (2018), pp. 979–89.
106 106 F. Hyder, R. K. Fulbright, R. G. Shulman and D. L. Rothman, ‘Glutamatergic function in the resting awake human brain is supported by uniformly high oxidative energy’, Journal of Cerebral Blood Flow & Metabolism, 33, no. 3 (2013), pp. 339–47; F. Hyder, D. L. Rothman and M. R. Bennett, ‘Cortical energy demands of signaling and non-signaling components in brain are conserved across mammalian species and activity levels’, Proceedings of the National Academy of Sciences of the United States of America, 110, no. 9 (2013), pp. 3549–54.
107 107 M. T. Alkire, ‘Loss of effective connectivity during general anesthesia’, International Anesthesiology Clinics, 46, no. 3 (2008), pp. 55–73; idem, ‘Probing the mind: anesthesia and neuroimaging’, Clinical Pharmacology & Therapeutics, 84, no. 1 (2008), pp. 149–52; Hyder, Fulbright, Shulman and Rothman, ‘Glutamatergic function in the resting awake human brain is supported by uniformly high oxidative energy’.
108 108 R. M. Birn, J. B. Diamond, M. A. Smith and P. A. Bandettini, ‘Separating respiratory-variation-related fluctuations from neuronal-activity-related fluctuations in fMRI’, Neuroimage, 31, no. 4 (2006), pp. 1536–48; R. G. Wise, K. Ide, M. J. Poulin and I. Tracey, ‘Resting fluctuations in arterial carbon dioxide induce significant low frequency variations in BOLD signal’, Neuroimage, 21, no. 4 (2004), pp. 1652–64.
109 109 G. K. Aguirre, E. Zarahn and M. D’Esposito, ‘The inferential impact of global signal covariates in functional neuroimaging analyses’, Neuroimage, 8, no. 3 (1998), pp. 302–6; P. M. Macey, K. E. Macey, R. Kumar and R. M. Harper, ‘A method for removal of global effects from fMRI time series’, Neuroimage, 22, no. 1 (2004), pp. 360–6.
110 110 K. Murphy, R. M. Birn, D. A. Handwerker, T. B. Jones and P. A. Bandettini, ‘The impact of global signal regression on resting state correlations: are anti-correlated networks introduced?’ Neuroimage, 44, no. 3 (2009), pp. 893–905;M. D. Fox, D. Zhang, A. Z. Snyder and M. E. Raichle, ‘The global signal and observed anticorrelated resting state brain networks’, Journal of Neurophysiology, 101, no. 6 (2009), pp. 3270–83.
111 111 K. Murphy and M. D. Fox, ‘Towards a consensus regarding global signal regression for resting state functional connectivity MRI’, Neuroimage, 154 (2017), pp. 169–73.
112 112 M. L. Schölvinck, A Maier, F. Q. Ye, J. H. Duyn and D. A. Leopold, ‘Neural basis of global resting-state fMRI activity’, Proceedings of the National Academy of Sciences of the United States of America, 107, no. 22 (2010), pp. 10238–43; C. W. Wong, P. N. DeYoung and T. T. Liu, ‘Differences in the resting-state fMRI global signal amplitude between the eyes open and eyes closed states are related to changes in EEG vigilance’, Neuroimage, 124, Pt A (2016), pp. 24–31; C. W. Wong, V. Olafsson, O. Tal and T. T. Liu, ‘The amplitude of the resting-state fMRI global signal is related to EEG vigilance measures’, Neuroimage, 83 (2013), pp. 983–90; C. W. Wong, V. Olafsson, O. Tal and T. T. Liu, ‘Anti-correlated networks, global signal regression, and the effects of caffeine in resting-state functional MRI’, Neuroimage, 63, no. 1 (2012), pp. 356–64.
2 The Cortex and the Mind in the Work of Sherrington and His Protégés
2.1 Charles Sherrington: The Continuing Cartesian Impact
Sherrington’s work left the role of the mind and its relation to the cortex problematic
As we have seen, it was the brilliant research of Sherrington that finally revealed the true nature of the spinal cord as a reflex centre and the role of the cortex in the generation of reflexes. He also clarified the beautiful specificity of the localization of function within the motor and somatosensory cortex. However, although the notion of a ‘spinal soul’ no longer figured in neurophysiology, the question of whether a ‘cortical soul’ existed remained moot. Or, to put it more perspicuously, the question of the relationship between the mind and the cortex remained deeply puzzling. Sherrington considered this question, tackling it in his usual methodical manner by first considering it in a historical setting through the work of Jean Fernel and the beginnings of the conception of physiology and neurophysiology. Later, he took up the problem at length in Man on his Nature, his Gifford Lectures of 1937/8.1
Sherrington’s dualism
Sherrington studied Fernel carefully, and read extensively in the works of philosophers, from Aristotle onwards. But, as we shall see, his grasp of philosophical problems and his understanding of the differences between scientific problems and philosophical ones were infirm. Despite acquaintance with Aristotle’s De Anima, he failed to see the depth and fruitfulness of the Aristotelian conception of the psuche¯ and its bearing on the essentially conceptual questions that plagued him. He noted Aristotle’s ‘complete assurance that the body and its thinking are just one existence’, and that ‘the “oneness” of the living body and its mind together seems to underlie the whole [Aristotelian] description as a datum for it all’.2 Nevertheless, Sherrington did not probe the Aristotelian philosophical doctrine properly. Instead, he moved towards a dualist conception of the relation between mind and body, unsurprisingly encountering the same insoluble problems as Descartes had in the seventeenth century. Using the term ‘energy’ to signify matter as well as energy, Sherrington held that ‘evolution has dealt with … us as compounded of “energy” and “psyche”, and has treated in us each of those two components along with the other. The two components are respectively, on our analysis, an energy-system and a mental system conjoined into one bivalent individual’ (MN 250). ‘Energy’, or matter, and mind are, he thought,
