Phrenology redux

What follows having been set off by perusal of the history of consciousness studies at reference 5, to which I shall return in due course. By way of the elderly reference 1, I eventually arrived at reference 2, taking in references 3 and 4 along the way. Much of this material is about bilateralism, the extent to which the left half of the brain is the same as the right half. And with  some of it being around forty years old – from those far off times when we did not have brain scanners, we did not have the Internet and many working scientists did not have very convenient access to any kind of computer. References listed oldest first.

While from reference 8, from even further back, we have the story of a phrenologist, a subject which got a mention back at reference 6 and with phrenologists believing that one could read a person’s character by feeling around the bumps on their skull. A  trade which had thrived through the nineteenth century, certainly in this country, even surviving into the twentieth, despite science having largely disposed of it by the middle of the nineteenth.

So this memoir, interesting and entertaining though it is, was already rather dated by the time it was written, long after other folk had moved onto looking at the brains themselves, rather than their manifestations, such as they were, on the outside, on the scalp. Furthermore, it had turned out that the bumps on the outside of the skull did not even reproduce the bumps on the cerebral surface, never mind map the functions of the brain – with the skull and layers of tissue covering the brain not being like, for example, a clinging dress at all – much more like a smooth coat of cement based rendering covering over a rough brick-work wall.

But some people hung on, looking at casts taken from the inside of skulls – mostly human – a mixture of fossil casts and plaster of Paris casts – and seeing what could be made of them. An approach which had the advantage of making a lot of very old material available, something which the people looking at actual brains could not manage at all.

Some more phrenological matters

Figure 1: the first phrenological head

Figure 2: the second phrenological head

Figure 3: the phrenological flyer

As noted above, phrenology was the science and practise of reading character from the bumps and lumps which could be felt on a subject’s head, with the head being carved up into areas in something of the way of the more successful Brodmann areas, which came later, at the start of the twentieth century, and which are illustrated at Figure 13 of reference 7. A couple of samples of these phrenological areas are given above, one from a dictionary of the time, the other from Millot Severn himself. Both suggesting bilateral symmetry, but without taking explicit account of the central fissure between the two hemispheres, which would have been well known at the time from the dissection of cadavers. Unfortunately, I have yet to find any reference to symmetry – or lack or it – in reference 8.

Plus what appears to be a flyer used during a stay in Brighton, a flier suggesting charges which were quite steep when compared with the skilled working man’s wages of something more than £1 a week around 1900. The demand for phrenological readings must have been strong.

Figure 4: the naked head

The quite small phrenological areas do not stand out loud and clear in the snap above, no worse in that regard, that any of the other pictures of scalps turned up by Bing. Perhaps a phrenologist’s fingers could detect things not visible to the naked eye, even with the confusion caused by possibly voluminous hair. By way of acknowledgement, Google Image suggests that the gentleman in question is Patrick Stewart of ‘Star Trek’ fame.

Phrenology was perhaps at its height in the second half of the nineteenth century and there was plenty of demand for talks and for readings, no doubt helped along by the large numbers of people living away from home, in big towns, who were looking for entertainment. I get the impression that practitioners were largely self-taught, mostly from the working and lower middle classes. And if Millot Severn is typical of the consulting variety, they made an itinerant living, taking up residence in towns for a few weeks at a time, perhaps for a season. In his case, he and his (second) wife worked as a team, together with a manager to organise consulting rooms, lodgings and other practical matters.

Interestingly, Millott Severn suggests that heads change shape during a person’s life, quite apart from the massive growth of a skull in the first fifteen years or so of life, changes which reflected changes in personality. I have not been able to check this suggestion. [page 103]

There was a sister science called physiognomy, the study of faces rather than scalps – and so perhaps better suited to postal consultations by photograph. Better suited, but perhaps lacked the all-necessary mystery and allure of phrenology. Perhaps also, better founded in fact, with it seeming much more likely that one can deduce character from faces than from scalps – something which portrait painters of old managed well enough. Something which computer programs may well manage well enough in due course. [page 113]

Some cerebral matters

A lot of animals, particularly the larger ones, are organised with a front end and a back end, a mouth and an anus, with a pipe joining the two up, with various specialisations along the way, like stomachs and intestines. The end product of an embryonic process called gastrulation. Of those animals, a lot are also bilaterians, that is to say they are symmetrical about an axis joining front and back. Particularly animals with legs. And more particularly, the general organisation of all vertebrates, including ourselves, is bilaterian – that is to say that one side is much the same as the other. Two arms, two legs, two eyes, two lungs, two kidneys and so on – and in particular the two hemispheres of the brain. Now the right hand kidney does the same job as the left hand kidney, but is that true of the two hemispheres? Even when allowing for the fact that, in round terms, the left hand hemisphere looks after the (contralateral) right hand part of the body – including the right eye and right ear, while the right hand hemisphere looks after the other part?

Over the years, a lot of effort has been put into finding out exactly how bilaterian the human brain is.

So, perhaps 90% of people are right handed, that is to say they prefer to use their right hand for most tasks for which just one hand is needed. Or as the lead hand when two are needed.

Perhaps 90% of people are left hemisphere dominant for language, that is to say more of the work needed to process language is done in the left hemisphere than the right hemisphere. Few right handed people are right hemisphere dominant for language, but perhaps 30% of the people who are left handed are. This can be deduced, for example, by work with people who have had brain lesions – particularly now that we can see where these lesions are without taking the brain apart.

Figure 5: a view from underneath a brain

A lot of people, say more than half, have visible asymmetry in their brains, which can be seen by looking at the results of a suitable scan, for example the one which is included above, and which, as if happens, includes some of the larger such asymmetries. Petalias, where a lobe sticks out more than one might expect. Deviations, where a fissure deviates from the expected line, in this case the saggital midline. Plus the splendidly named Yakovlevian anticlockwise torque, a measure of how much the brain has been twisted. All of which is complicated by the need to overlay any particular brain with a coordinate system, preferably a standardised one. Some of this was sketched at reference 7 – while the people at McGill – my mother’s alma mater – are very good at it – and for which see reference 10.

In which connection Chiu and Damasio mention the orbitomeatal plane, the plane spanned by a landmark on each ear and a landmark on each eye, with all four of these landmarks nearly always being well defined and pretty much coplanar. A standard plane from which to measure things. I believe that facial recognition software does something similar.

And as part of the bilaterian quest, a lot of effort has been put into determining the extent to which these three phenomena, these three asymmetries, are related.

The paper

 

Figure 6: looking for big bumps

I now turn to the paper written by Chiu and Damasio, that is to say reference 2, written when the pair of them were working in Iowa City. This paper reports the results of looking at the shape of 75 brains in live subjects with a scanner, with the intention of finding out whether the gross asymmetries so revealed had anything to do with handedness. A sample of the sort of thing they worked with is included above – a view looking down, rather than up in the previous figure, Figure 5, so right is right rather than left.

And their answer was that while more than half the brains they looked at exhibited asymmetry, this asymmetry was not correlated with handedness. They thought it was maybe more to do with language dominance.

So despite this rear-guard action, even this residual bit of bump theory has not given us any useful purchase on character. At least not yet.

Figure 7: little bumps

Worse still, while we are told that the gross Chiu and Damasio bumps can be seen on casts taken of the inside of skulls, we are not told whether they could be felt from the outside of the skull, phrenologist mode, never mind the more modest bumps (of the left temporal lobe) snapped above. Can the lobes – say the temporal lobe – be felt from the outside? Are there interesting bumps on the outside of brains at all, interesting in the sense that most people have them, at least roughly in the same position? Surely there was something for the fingers of phrenologists to feel?

Nevertheless while the science may be lacking, phrenology thrived for at least half a century or so, and I imagine that the successful consultant phrenologist would be a sort of cross between gypsy fortune teller and psychotherapist. He would be good at reading people while he felt around their heads, would be good at sensing their various reactions to his patter and adjusting that patter accordingly. He would tell a story which pleased both subject and audience – and so everybody was happy.

Maybe there was also an element of head massage about it, with the probing fingers being quite soothing.

Additional matters

In additional to the gross, macro-anatomical asymmetries noted above, lots of both chemical and micro-anatomical asymmetries have been identified in human brains.

Some of the asymmetries observed in human brains have been observed in animals, along with some new ones. Brain asymmetry is not a defining feature of humans, as was once thought.

Asymmetry extends down from the cortex to subcortical structures and to the brain stem.

Are the all important facial whiskers in animals like rats in identical positions, right and left?

Were hearts, in evolutionary times, bilaterally symmetrical? While they still have four chambers arranged in two pairs, they are far from symmetrical now, with the two halves, while both being pumps, serving quite different functions.

Some but not all studies have reported elevated rates of left handedness among those with autism, stuttering, dyslexia, allergies, alcohol abuse and various other disorders. Furthermore, there are more left handed men than left handed women.

Systems people argue, from the point of view of large computer programs, about the relative merits of hemispheric specialisation and hemispheric duplication.

One entry point to all this was the possibility of each hemisphere supporting its own instance of consciousness, a possibility raised at reference 1. A possibility to which I shall return in due course.

Figure 8: influenza in Sheffield

But I close with something more topical. Millot Severn had no working capital to speak of when he started out as a consulting phrenologist and there were plenty of expenses in the way of travel, consulting rooms or shop and lodgings – which meant that one was sometimes stuck with very little – if any – cash in hand at all. This happened on one occasion in Sheffield where he and his wife had arrived just before a serious epidemic of influenza which carried away many residents and carried off his business there. Can’t be sure as I have not cross checked the various dates scattered about by Millot Severn, but the epidemic is possibly that of the early 1890’s briefly described at reference 11 and snapped above. [page 164]

References

Reference 1: A divided mind: Observations on the conscious properties of the separated hemispheres - Joseph E. Ledoux, Donald H. Wilson, Dr. Michael S. Gazzaniga – 1977.

Reference 2: Human cerebral asymmetries evaluated by computed tomography - Chiu and Damasio – 1980. The source for Figure 6.

Reference 3: Cerebral lateralization: biological mechanisms, associations, and pathology. A Hypothesis and a Program for Research – Geschwind, N. & Galaburda, A. M. – 1985.

Reference 4: Mapping brain asymmetry - Arthur W. Toga & Paul M. Thompson – 2003. Inter alia, the source for Figure 5, a computer generated view of the underside of the brain. Note the consequent flipping of right and left.

Reference 5: A little history goes a long way toward understanding why we study consciousness the way we do today - Joseph E. LeDoux, Matthias Michel and Hakwan Lau – 2020.

Reference 6: https://psmv3.blogspot.com/2017/11/reading-brain.html.

Reference 7: https://psmv4.blogspot.com/2018/11/places-in-brains.html.

Reference 8: The life story and experiences of a phrenologist – J. Millott Severn, fellow and past president BPS – 1929.

Reference 9: https://en.wikipedia.org/wiki/Phrenology. The source for Figure 1.

Reference 10: https://www.mcgill.ca/neuro/.

Reference 11: A history of epidemics in Britain: Volume 2: from the extinction of the plague to the present time - Charles Creighton – 1894. Turned up in Google Scholar. The source for Figure 8.