Tag Archives: Neuroskeptic

Neuroskeptic Review: Patient H.M.

Blogs, Book Reviews, ,

Neuroskeptic, part of Discover Magazine’s series of blogs, recently posted a review of a new book, Patient H.M.: A Story of Memory, Madness, and Family Secrets. The book, written by Luke Dittrich who is himself the grandson of H.M.’s neurosurgeon, tells the story of the infamous case study of the patient now known to be Henry Molaison.

In the review Neuroskeptic focuses on three troubling aspects of H.M.’s story as discussed in the book. First, the psychosurgery performed on H.M. to address his epilepsy had no medical basis. Second, H.M.’s life was not nearly as sedate and content as it often portrayed and he threatened suicide at various points in time. Finally, the ethics of Suzanne Corkin’s longterm study of H.M. is thrown into doubt as, following the death of his parents, H.M. lacked a legal conservator to speak to his interests. This meant that H.M. himself provided consent for many of Corkin’s studies, though whether this can be understood as informed consent is doubtful. Moreover, the cousin eventually appointed conservator for H.M., it turns out, was not related to H.M. at all and simply provided blanket consent for Corkin’s tests of H.M.

Read Neuroskeptic’s full review online here.

Angelo Mosso & “Weighing Brain Activity with the Balance”

Blogs, Journals, , , , , ,

Neuroskeptic, over on Discover Blogs, has just posted a review of an article now in press at Brain on nineteenth century Italian physiologist Angelo Mosso’s attempts to measure blood flow to the brain. As Neuroskeptic describes, Mosso’s

…early work included studies of the blood pressure in the brains of individuals with skull defects. His most ambitious project, however, was his balance – or as he sometimes called it, according to his daughter, his ‘metal cradle’ or ‘machine to weigh the soul’….

It was in essence just a large balance. A volunteer lay on a table, their head on one side of the scale’s pivot and their feet on the other. It was carefully adjusted so that the two sides were perfectly balanced.

The theory was that if mental activity caused increased brain blood flow, it ought to increase the weight of the head relative to the rest of the body, so that side of the balance would fall.

Mosso claimed that this, indeed, occurred – starting to read a newspaper caused the brain to get weightier, while a difficult book of philosophy was even more effective, presumably because it required more mental effort to understand.

You can read Neuroskeptic’s review online here. Full article details follow below.

“Weighing brain activity with the balance: Angelo Mosso’s original manuscripts come to light,” by S. Sandrone, M. Bacigaluppi, M. R. Galloni, S. F. Cappa, A. Moro, M. Catani, M. Filippi, M. M. Monti, D. Perani, & G. Martino. The abstract reads,

Neuroimaging techniques, such as positron emission tomography and functional magnetic resonance imaging are essential tools for the analysis of organized neural systems in working and resting states, both in physiological and pathological conditions. They provide evidence of coupled metabolic and cerebral local blood flow changes that strictly depend upon cellular activity. In 1890, Charles Smart Roy and Charles Scott Sherrington suggested a link between brain circulation and metabolism. In the same year William James, in his introduction of the concept of brain blood flow variations during mental activities, briefly reported the studies of the Italian physiologist Angelo Mosso, a multifaceted researcher interested in the human circulatory system. James focused on Mosso’s recordings of brain pulsations in patients with skull breaches, and in the process only briefly referred to another invention of Mosso’s, the ‘human circulation balance’, which could non-invasively measure the redistribution of blood during emotional and intellectual activity. However, the details and precise workings of this instrument and the experiments Mosso performed with it have remained largely unknown. Having found Mosso’s original manuscripts in the archives, we remind the scientific community of his experiments with the ‘human circulation balance’ and of his establishment of the conceptual basis of non-invasive functional neuroimaging techniques. Mosso unearthed and investigated several critical variables that are still relevant in modern neuroimaging such as the ‘signal-to-noise ratio’, the appropriate choice of the experimental paradigm and the need for the simultaneous recording of differing physiological parameters.