This month, despite a paper on the Hearing Voices Movement’s approach, and a couple of papers on CBT-related aspects of voice-hearing, the majority of the papers are neurological in focus. Given this, I’ve put a sprinkling of other talks/articles at the end of this post, to give things a more rounded bouquet. Sláinte!
Accessible summary: Around three in four people who hear voices will have some voices that tell or command them to do things. This study examined what factors predicted whether people did the harmful things (either to themselves or others) that voices told them to do. In people interviewed, 25/32 heard voices commanding them to hurt themselves (31% obeyed these voices), and 10/32 heard voices commanding them to hurt others (11% obeyed these voices). It was found that the more impulsive and angry the person hearing voices was, and the less able they were to regulate their anger, the more likely they were to obey the harmful dictates of the voice. Additionally, the more powerful people perceived such voices to be, the more likely they were to obey their harmful commands. Bucci and colleagues conclude that “aspects of anger and impulsiveness might also be worth consideration when assessing and formulating the risk of a person complying with command hallucinations”.
Link to paper: http://dx.doi.org/10.1016/j.schres.2013.02.037
Accessible summary: After reviewing the differences between the biomedical model of hallucinations and the HVN model of voice-hearing, and highlighting the role of trauma in many voice-hearing experiences, the article discusses how Romme and Escher’s tool, the Maastricht Interview, can be used to make sense of who voices are and what they represent.
Link to paper: http://dx.doi.org/10.1177/1468017312475278
Accessible summary: Some people hear voices and cope fine (healthy voice-hearers), others become psychiatric patients. Why? This study looked at whether a number of ways of thinking (cognitive biases) differ between these two types of voice-hearers. These ways of thinking included ‘intentionalizing’, ‘jumping to conclusions’,
‘catastrophizing’, ‘dichotomous thinking’ and ‘emotional reasoning’.
It was found that the patient voice-hearers were more likely to show ‘intentionalizing’, ‘jumping to conclusions’, ‘catastrophizing’, and ‘dichotomous thinking’ biases than the non-voice hearers (who in these respects were similar to non-voice hearing people from the general population), suggesting that all these ways of thinking may contribute to voices being experienced as distressing. The authors suggest that cognitive behavioural therapy that attempts to change such ways of thinking may help voice-hearers distressed by their voices.
The study found that the only similarity between patient and healthy voice-hearers was on emotional reasoning. Both of the voice-hearing groups showed a way of reasoning based on emotions, feeling or instinct instead of ‘logic’. This was hence the only thinking bias that was related to the presence of voice-hearing per se.
Link to paper: http://dx.doi.org/10.1017/S0033291713000275
Accessible summary. TMS works by placing a coil, with a rapdily changing magnetic field, over a specific area of the brain. This induces an electrical current in the parts of the brain under the coil, changing the brain’s activity. It is a painless and non-intrusive process. There is some evidence that TMS can reduce the severity of the voice-hearing experience. The authors of this study examined what using TMS with voice-hearers did to their brain (i.e., how does it have its effect?)
They found whereas TMS for voice-hearers led to reduced blood flow in the primary auditory cortex (the first part of the brain which is involved in processing words/sounds), left Broca’s area (involved in speech and inner speech production), and the cingulate gyrus (involved in the sense of agency, i.e., the feeling I caused something to happen, and error monitoring, i.e., detecting when what is expected to happen, doesn’t happen). They also found that decrease in blood flow in the primary auditory cortex correlated with the decrease in AVH scores, i.e., for those in whom the voices got less severe, the blood flow in their primary auditory cortex became less. The authors suggest that when the activity in this brain region becomes less, it increases people’s ability to differentiate between their own inner speech (the normal experience we have of talking to ourselves in our heads) and voice-hearing.
Link to paper: http://dx.doi.org/10.1016/j.biopsych.2012.06.019
The Hague, Netherlands. Looijestijn and colleagues examine which parts of the brain are involved in the experience of hearing voices that specifically appear to come from the external world (i.e.., feel like they have a source outside the head).
Accessible summary. It’s the planum temporale and the dorsolateral prefrontal cortex, regions of the brain which are normally involved in helping people detect where the voices of ‘real’ people come from. If these regions aren’t activated during voice-hearing, then people locate their auditory verbal hallucinations as coming from inside their head.
Link to paper: http://dx.doi.org/10.1016/j.schres.2013.02.004
Durham, England. Lucy Alba-Ferrara and colleagues examine the interplay between attention and emotion in people who hear voices.
Accessible summary: The authors argue that people diagnosed with schizophrenia cannot ignore emotional stimuli, even if they are irrelevant, and that such stimuli may grab attention at the cost of more relevant external attention, resulting in “abnormal perceptions”. To test this they looked at implicit emotional prosody, i.e., the effects of the feelings expressed in speech based on variations in pitch amplitude and tempo, when people were not explicitly focussed on this. They argue that people with hallucinations may have “aberrant brain organization”, resulting in “atypical lateralization” in the brain of the processes which allow us to detect emotional prosody, causing its “impaired processing”. And yes, this article is a tour de force of ‘deficit’ terminology.
They gave people with and without voices a task where they had to identify the gender of a speaking voice, which could speak in happy, angry and neutral tones. Basically, they found that patients diagnosed with schizophrenia who heard voices (as compared to non-voice hearing patients and non-voice hearing non-patients) did not use their right hemisphere as much when making judgements as to the emotional prosody of these voices, with the left hemisphere being more involved. The authors conclude that this could “explain why hallucinators focus on irrelevant features of the auditory environment and their attention is captured by the voices.” Make of this what you will.
Link to paper: http://dx.doi.org/10.3389/fnhum.2013.00059
Acccessible summary: Part of the brain’s job is to filter out sounds that aren’t terribly useful to us, and to let us focus on things that are useful. For example, at a cocktail party (do people still have these? maybe I just don’t get invited to them.), we can pretty much filter out the background conversations, but if something potentially relevant to us appears in these background conversations (like our name being mentioned), our brain jumps on this and lets us know.
One way psychology studies this is through something called P50 sensory gating. 50 milliseconds after a sound occurs, there is a distinct change in our brain’s electrical activity, which we can see on an electroencephalograph (EEG), which is called the P50 response. If we hear two clicks in very short succession (i.e. half a second apart), then the brain reacts less to the second click, and the P50 response to this second click is lower than that for the first click. This phenomenon is called ‘sensory gating’ and is based on the fact that the brain needs to be able to filter out information that isn’t useful (in the ‘two clicks’ case, the second click doesn’t add much useful information, so the brain gives it less weight).
This study found that the more severe peoples’ voice-hearing was, the less the brain suppressed the P50 response to the second click, i.e., people with more severe voice-hearing had worse sensory gating.
Link to paper: http://dx.doi.org/10.1016/j.clinph.2013.02.004
Other papers this month:
- Kelly Diederen and colleagues examine whether the parts of the brain that activate when people hear voices can be reliably determined. They can. http://dx.doi.org/10.1016/j.schres.2013.01.025
- Shinn and colleagues look at the role of running commentary voices and voices conversing (conventionally understood as ‘first rank symptoms’) in the diagnosis of schizophrenia. http://dx.doi.org/10.1016/j.schres.2013.02.040
And for some balance…
- A recent talk by Jacqui Dillon – link here.
- New York Times Op-Ed piece by Prof Tanya Luhrmann – link here.
- Recent ‘Ruminations on Madness’ blog post – link here.
More next month!