This month in voices: September 2014

There wasn’t a great quantity of research published in September, but the two papers I summarise below are hopefully helpful in showcasing how cognitive behavioural therapy is actually done for voice-hearing, and how researchers are looking at the role of altered neural connectivity in voice-hearing.

BostonBoston, USA. Wigand and colleagues examine if changes to the wiring in the brain that link the auditory areas in the left hemisphere to the auditory areas in the right hemisphere may play a role in causing voice-hearing.

CC auditory

The corpus callosum (blue) extracted from the rest of the brain (side view, front of the brain on the left). The part which links the left and right auditory areas is show in orange (taken from Wigand et al).

Accessible summary: The corpus callosum is a bundle of white matter fibers (the brain’s signalling cables) which link the right and left hemispheres of the brain. This pathway has an important role in hearing because we process language primarily in our left hemisphere (if you are right handed). This means that when speech comes into the right hemisphere of the brain (which happens when sound goes into our left ear, due to the way the brain is wired), this info is transferred to the left hemisphere,via the corpus callosum, for processing.

ShufflebotI could tell you of a study in Italian nightclubs testing the implications of this, i.e., that we should favour listening with our right ear, because this is linked directly to our language dominant left hemisphere. This involved female researchers approaching random people in Italian nightclubs, mumbling “an inaudible meaningless utterance, such as ‘babababa’ while maintaining a face-to-face position and direct eye contact” (which wouldn’t freak you out too much) to see if people really did favour listening with their right ears in situations where it is hard to hear. But to discuss this in length would be a digression, and this blog hates digressions.

Anyway, returning to the Boston study in-hand, this used a technique called diffusion tensor imaging (DTI) to examine the integrity of the ‘cable’ in the brain that links the left and right hemisphere auditory areas. DTI looks at the direction of flow of water in these cables of the brain. If the water is all flowing in pretty much the same direction, this is seen as the cabling being ordered and intact (imagine troops marching in a ordered column to a battle).

ShufflingHowever, if the water tends more to be flowing in all different directions (imagine troops marching to the battle whilst all listening to LMFAO on their iPods, and dancing/shuffling there in a slightly chaotic, manner), then this is seen as representing some form of damage to the cabling.

The study found that people with a history of hearing voices had reduced integrity in the part of the corpus callosum that links the right and left auditory regions, compared to people who didn’t hear voices. Furthermore, findings emerging from the use of a specific measure of structural integrity called radial diffusivity, suggested that this change may specifically involve demyelination. Demyelination is a reduction to the fatty myelin sheath that surrounds signalling cables (axons) in the brain that helps electrical signals travel quickly along them. This finding can be tied into a popular contemporary theory (I won’t say that it’s sexy and it knows it) that proposes that the brain has an internal signalling system which gives auditory regions a ‘heads-up’ that we are producing thoughts in our head. If the signals involved in letting auditory regions know that we are thinking to ourselves don’t get there in time (i.e., they are ‘shuffling’, to continue the LMFAO analogy), then we may not ‘be told’ that these thoughts are our own, and hence experience them as a voice of another person instead.

Link to paper: http://informahealthcare.com/doi/abs/10.3109/15622975.2014.948063

 

Essex

An inoffensive picture of Essex. This took me a while to find.

Essex, UK. Mankiewicz and Turner present a single case study of a psychological therapy (cognitive behaviour therapy) for voice-hearing.

Accessible summary: Raymond, aged 40, was referred to a specialist service for adults with psychosis. He was hearing threatening voices (“You’ve wasted your life, you screwed it all!”, “You should be punished and dead, you will pay!”), and had paranoid delusions and high levels of anxiety. As a result of these experiences he lived an isolated life on his own in a house, where he had installed surveillance cameras, in which he barricaded his bedroom at nights. No clear information was given on what was happening in Raymond’s life when the voices started, but a distressing home situation and alcohol/drug use are mentioned.

During his initial assessment with the psychologist, Raymond identified a number of
triggers of his voices. He would hear voices while he was bored at home, kept silent, or had nothing to occupy his mind with, and the voices would become particularly active in the late evening, as night drew in. Raymond agreed on the following intervention goals for his psychological therapy: enhancement of strategies to cope with voices, paranoid/delusional beliefs and anxiety, and reestablishment of autonomy at nights.

Techniques used to achieve these goals included:

  • Understanding links between his own thoughts and his voices. Raymond recognised he had recurrent negative internal dialogues (which would tend to occur when he was bored), which frequently preceeded the experiences of auditory hallucinations. The voices, in turn, seemed to represent his own worries about his life, e.g., “I’ve wasted my life.” To address this, Raymond begun changing his inner dialogue, saying things to himself such as “I do not need to be punished for anything, as I have never hurt anyone. I have already improved my life, quit drinking and drugs, and deserve to be happier.”
  • Challenging negative appraisals of the voices, i.e., was what he believed about the voices true? Guided discovery was used to help Raymond see that there was no evidence to support his persecutory beliefs about voices, with Raymond realising that he had remained safe and had not been attacked or even threatened by anyone for years.
  • Examining safety behaviours, seeing that they stopped disconfirmatory evidence being obtained, and using behavioural training to change this. Raymond had the assumption that “If I do not remain isolated and vigilant, activate the security system and barricade the bedroom, then I’ll be assaulted.” He learnt that by barracading himself in his room he could never see if this assumption was actually true. Raymond’s assumption was slowly reframed by first getting him to remove the doorstop, then unlocking the bedroom door, then substituting watching security cameras in the evening with watching movies, and eventually removing the barricade. He was also encouraged to get involved in social situations, such as taking walks, shopping, and visiting family.

Whereas before therapy Raymond felt that his voices were “scary and they freak me out”, at the end of therapy he now felt that “They’re still there but I don’t attend to them as much now”. Whereas he used to think his voices meant that “I’m being chased and will be punished”, he now felt that “These are probably my own thoughts”. As a result he now felt that “I’m not as anxious as before. I can relax more often now.” whereas before he’d fel “I cannot cope. I’m losing control.”

As a result of this, his abilities to cope with voices and persecutory beliefs increased and his anxiety reduced, and Raymond decided to explore evening courses provided in the local college and pursue further qualifications.

Link to paper: http://dx.doi.org/10.1155/2014/124564

 

Other papers this month

More voice-hearing research next month, when I’ll try to explain voxel based morphometry using Katy Perry’s greatest hits.

SMJ

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