hearing voices

While difficult, trying to retroactively diagnose Vincent Van Gogh was by far my favorite journal prompt. My group and I eventually decided that, based on the evidence we examined, Van Gogh most likely had schizophrenia. The Diagnostic and Statistical Manual of mental disorders (DSM-5) is a list of psychiatric conditions and their symptoms that helps professionals diagnose patients. It includes criteria to help diagnose schizophrenia today. For symptom-based identification it instructs that schizophrenia patients are expected to exhibit catatonic behavior, negative symptoms, delusions, disorganized speech, and hallucinations (American Psychiatric Association, 2013). Van Gogh showed many of these symptoms but the one that most clearly pointed to schizophrenia was his hallucinations.

According to the note from the Director of the St Rémy mental home, Vincent Van Gogh exhibited both visual and auditory hallucinations (Van Gogh Museum, 2016). The importance of hallucinations in both his life and the diagnosis of schizophrenia made me wonder about their underlying biological mechanisms. I was particularly intrigued by the idea that patients sometimes hear voices talking to them when no one else is there. The idea of “hearing voices” may be familiar from Hollywood’s portray of mental illness, but what actually drives these hallucinations?

In the scientific community, this phenomenon is known as auditory verbal hallucinations. One major theory is that these hallucinations are a result of malfunctions in the brain systems that monitor inner speech. This idea is that, when these brain systems are impaired, people misinterpret their own internal dialogue as the speech of someone or something outside of them (Catani and Ffytche, 2005). While this theory has been around for decades, there are still many unanswered questions about the specific biology and brain areas that are associated auditory verbal hallucinations.

Auditory verbal hallucinations are when patients
believe they hear voices speaking to them

A recent study by Cui et al. investigated the neuroanatomical differences that may be connected to this type of hallucination. The authors studied healthy control patients as well as a large population of schizophrenia patients who did and did not exhibit auditory verbal hallucinations from hospitals across China. The patients they gathered is an important aspect of this study because previous work had only compared schizophrenia patients with hallucinations to healthy controls. Here, the researchers wanted to specifically investigate what neuroanatomical difference leads to auditory verbal hallucinations, so it was important for them to look at schizophrenia patients that did not experience these hallucinations as well as those that did.

Once the authors had gathered this group of patients and controls, they used a magnetic resonance imaging (MRI) scanner to get a structural image of the subjects’ brains. They then used a computer software program to compute the thickness of the subjects’ cortex, the brain’s outer layer.In particular, these researchers were interested in measuring and comparing the thickness of the middle temporal gyrus (MTG).

The middle temporal gyrus (MTG)

Previous scientific studies have indicated that the MTG may be important for the monitoring of inner speech and is often less activated in schizophrenic patients (Shergill et al. 2000; Seal et al. 2004). The function and development of the MTG is well-suited for it playing a role in auditory verbal hallucinations. First, the MTG is involved in brain pathways that make it important for interpreting certain sounds we hear, especially processing language (Cabeza and Nyberg, 2000). The MTG is also unique in the way it develops. This area of the brain develops relatively late in life (Gogtay et al. 2004). This makes sense for hallucinations associated with schizophrenia, which is a disease known to be associated with brain development that often doesn’t appear until patients are around 30 years old (Lewis and Levitt, 2002).

Previous studies had shown that the volume of the MTG is smaller in schizophrenic patients than it is in healthy people (McGuire et al., 1995). The point of this study was to test if that reduced size was associated with schizophrenia in general or auditory verbal hallucinations specifically.  When Cui et al. calculated the volume of the subjects’ middle temporal gyrus they found that it was significantly smaller in schizophrenia patients that had auditory verbal hallucinations than patients that did not. They also found that there was not a significant difference between the schizophrenia patients that did not have hallucinations and the healthy controls. These results suggest that a thinner MTG is not only connected to schizophrenia but is specifically associated with schizophrenia patients that experienced auditory verbal hallucinations.

Starry Night, a famous Van Gogh painting some
believe is the result of his hallucinations

While this new study offers great evidence comparing schizophrenia patients with different symptoms, there is still a lot to figure out about this kind of hallucination. Scientists are still working to discover what exact processes lead to cortical thinning and how those processes begin. However, what we do know about auditory verbal hallucinations emphasizes how heavily we rely on our perception of the world around us. We will not ever get to know the thickness of Vincent Van Gogh’s MTG, but the auditory hallucinations Van Gogh experienced were probably the result of his hearing system malfunctioning in some way. Today, many people believe that some of Van Gogh’s most famous decisions and artworks were informed by his hallucinations (Jones, 2016; New York Times Archive, 1981). Modern neuroscience tells us that those hallucinations may have actually been an erroneous interpretation of his own inner dialogue all along. 

 

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.

Binney RJ, Parker GJ, Ralph MAL (2012). Convergent connectivity and graded specialization in the rostral human temporal lobe as revealed by diffusion-weighted imaging probabilistic tractography. Journal of Cognitive Neuroscience 24, 1998–2014.

Catani M, Ffytche DH (2005). The rises and falls of disconnection syndromes. Brain 128, 2224–2239.

Cabeza R, Nyberg L (2000). Imaging cognition II: an empirical review of 275 PET and fMRI studies. Journal of Cognitive Neuroscience 12, 1–47.

Cui Y, Liu B, Song M, Lipnicki D, Li J, Xie S, . . . Jiang T. (2018). Auditory verbal hallucinations are related to cortical thinning in the left middle temporal gyrus of patients with schizophrenia. Psychological Medicine, 48(1): 115-122

Jones, J. (2016). Vincent van Gogh: Myths, madness and a new way of painting. Retrieved from https://www.theguardian.com/artanddesign/2016/aug/05/vincent-van-gogh-myths-madness-and-a-new-way-of-painting

Gogtay N, Giedd JN, Lusk L, Hayashi KM, Greenstein D, Vaituzis AC, Nugent TF, Herman DH, Clasen LS, Toga AW, Rapoport JL, Thompson PM (2004). Dynamic mapping of human cortical development during childhood through early adulthood. Proceedings of the National Academy of Sciences 101, 8174–8179.

Lewis DA, Levitt P (2002). Schizophrenia as a disorder of neurodevelopment. Annual Review of Neuroscience 25: 409–432.

McGuire PK, David AS, Murray RM, Frackowiak RSJ, Frith CD, Wright I, Silbersweig DA (1995) Abnormal monitoring of inner speech: a physiological basis for auditory hallucinations. The Lancet, 346(8975): Pages 596-600,

New York Times Archive (1981) Van Gogh’s Hallucinations. Retrieved from https://www.nytimes.com/1981/07/07/science/science-watch-van-gogh-s-hallucinations.html

Seal ML, Aleman A, McGuire PK (2004). Compelling imagery, unanticipated speech and deceptive memory: neurocognitive models of auditory verbal hallucinations in schizophrenia. Cognitive Neuropsychiatry 9, 43–72.

Shergill SS, Brammer MJ, Williams SCR, Murray RM, McGuire PK (2000). Mapping auditory hallucinations in schizophrenia using functional magnetic resonance imaging. Archives of General Psychiatry 57, 1033–1038

Van Gogh Museum (2016). Shortly before 27 February 1889 In Concordance, lists, bibliography (Documentation). Retrieved from: http://www.vangoghletters.org/vg/documentation.html

 

Images: 

https://search.creativecommons.org/photos/71b807e7-29fd-445d-95a1-4d282ccf02e5

https://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Gray726_middle_temporal_gyrus.png/250px-Gray726_middle_temporal_gyrus.png

https://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/Van_Gogh_-_Starry_Night_-_Google_Art_Project.jpg/757px-Van_Gogh_-_Starry_Night_-_Google_Art_Project.jpg

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