Some more interesting papers this month. In terms of helping people with their voices, there is a pilot study which involves the use of avatars to help people distressed by their voices. In terms of brain activity associated with voices, there are a number of studies which have looked how altered connectivity between different parts of the brain may underpin the experience of hearing voices. Plus plenty of other interesting research for good measure.
Accessible summary: Leff and colleages allowed people who heard voices to create an avatar, a virtual reality creation of the dominant voice they heard. The voice-hearer could select a face for their voice, and a sound for their voice, from a range of options presented to them. They were then shown this face on a computer screen and could speak to it. The avatar would then talk back to them in real-time, which was done by the therapist speaking, and their words being transformed into the voice chosen by the voice-hearer which then seemed to be spoken by the face as the faces’ lips were synched with what the therapist was saying (the therapist sat in another room and could hear what the voice-hearer was saying to the avatar, allowing the dialogue to take place).
The voice-hearer was prompted by the therapist to enter into a dialogue with their avatar in which the therapist encouraged them to stand up to it. Over the course of the therapy the character of the avatar was changed by the therapist from being abusive to becoming helpful and supportive of the voice-hearer.
This therapy significantly improved people’s experiences of hearing voices, and in three of the voice-hearers, their voices even stopped. There is now a need for a controlled trial of this approach, to see if the benefits stemmed from the specific method used here.
Link to paper: http://dx.doi.org/10.1192/bjp.bp.112.124883
Accessible summary: This study picked four areas of the brain which are known to be involved in speech perception and examined how they communcinated with other areas of the brain in voice-hearers compared to non-voice-hearers. Participants brains were scanned when they were just lying in the scanner, not doing anything in particular (a ‘resting state scan’).
A number of regions of voice-hearer’s brains were found to communicate differently with other parts of their brains, compared to non-voice hearers, in three basic ways. Specifically, there were altered connections within regions involved in processing heard words, altered connections within regions involved in producing speech, and altered connections within regions involved in monitoring our production of speech.
The authors conclude that two mechanisms might be involved in voice-hearing. First, an altered connection between areas of the brain involved in producing inner speech (Broca’s area) and areas of the brain that monitor whether speech is being produced could lead to one’s one inner speech being experienced as that of another person. Second, altered connections between areas involved in perceiving speech may result in perceptions being experienced in the absence of any external speech actually being present.
Link to paper: http://dx.doi.org/10.1007/s00429-013-0519-5
Accessible summary: As we’ve discussed in previous posts, I think, there is a signalling cable in the brain which links up the speech production area in the frontal lobe of the brain (Broca’s area) with speech perception areas of the brain in the temporal lobe of the brain. This pathway is called the arcuate fasciculs. Here’s a helpful diagram:
de Weijer and colleagues looked to see how intact this arcuate fasiculus pathway was in people diagnosed with schizophrenia who heard voices, healthy voice-hearers and non-voice hearing controls. They found that one measure of the structural integrity of this tract (fractional anisotropy) was different in people diagnosed with schizophrenia who heard voices but not in healthy voice-hearers, suggesting that such changes in this measure were associated with the diagnosis of schizophrenia, and not hearing voices specifically. However, when looking at a second measure of the structural integrity of this tract (magnetization transfer ratio), they found both groups of voice-hearers differed in this measure to non-voice hearing controls, suggesting that there are specific changes to the arcuate fasciculus that are associated with hearing voices.
The authors conclude that damage to this arcuate fasciculs pathway may stop speech production areas telling speech perception areas that inner speech is about to be produced, allowing voice-hearers own inner speech to be experienced as a heard voice, not seemingly produced by the self.
Utrecht, Netherlands, 2 (The scanner stikes back). This study led by Remko van Lutterveld from the same Dutch research group as above, looked at connectivity between different parts of the brain in healthy voice-hearers compared to non-voice hearers.
Accessible summary: Basically, in voice-hearers, the temporal areas were more strongly connected to the posterior cingulate/precuneus complex (PPC) in voice-hearers. Due to the function of the PPC, the authors suggested this indicated that voice-hearers were likely to be having a greater focus on memory processes and self-referential thoughts (thoughts relating to one’s self). They also noted that this and other altered connectivity tended to be found in areas involved in the default network. This is a network which is activated when our attention is not externally focussed and we are basically thinking away to ourselves. Such thoughts may hence have a role in generating the content of voices.
Link to paper: http://dx.doi.org/10.1002/hbm.22264
Utrecht, Netherlands, 3 (Return of the scanner). Another paper from the great Utrecht research group. This was also led by Remko Van Lutterveld.
Accessible summary: Researchers scan people’s brains when they are ‘hearing voices’ to see what part of the brain are active (symptom capture studies). However, they usually do this by asking the participants to press a button when they hear one of their voices, introducing some potential confounds into the study (i.e., the effect of pressing the button also results in brain activity). This study performed a review of studies which looked at brain activity when non-voice hearing people pressed a button whilst in the scanner to indicate they had detected a sound, and compared this to the findings of symptom capture studies. They were hence able to pin down the specific regions of the brain that are active when people are ‘hearing voices’. Basically, their findings were still consistent with an involvement of inner speech and memory in ‘hearing voices’.
Link to paper: http://dx.doi.org/10.1016/j.schres.2013.01.004
Accessible summary: Hearing voices has been proposed to be due to altered self-monitoring abilities, i.e., the ability to successfully differentiate between things one did and things one only imagined doing. This study found that people diagnosed with schizophrenia who heard voices were more likely to incorrectly think they had performed an action that they had actually only imagined doing, than people diagnosed with schizophrenia who didn’t hear voices, or people from the general population. The authors argue that an altered self-monitoring ability may play a role in creating voice-hearing.
Link to paper: http://dx.doi.org/10.1016/j.schres.2012.12.003
Accessible summary: The authors developed a 10-lesson
internet-based self-guided program for coping with auditory hallucinations, called “Coping with Voices.” This involved “multiple exercises and games to exemplify
CBT principles (e.g., thoughts influence feelings and behaviors), as
well as behavioral (use of humming and earphones to quiet auditory
hallucinations) and cognitive (e.g., challenging beliefs that voices have
power over the person) coping techniques”. They found that the severity of people’s voices had reduced at the end of the program. However, there was no control group, so we can’t be sure that this intervention, or its specific elements, were what caused the improvement. The authors are now doing a randomized controlled trial.
Link to paper: http://dx.doi.org/10.1016/j.schres.2013.01.002
Accessible summary: When we hear sounds, the first part of the cortex of the brain to start working on these is the primary auditory cortex, a key part of which is called Heschl’s gyrus. This study looked at how this part of the brain was connected up to the rest of the brain in people diagnosed with schizophrenia who hear voices, as compared to people diagnosed with schizophrenia who don’t hear voices and people from the general population who also didn’t hear voices.
Firstly, they found that the more strongly connected Heschl’s gyrus was the left inferior frontal gyrus (Broca’s area; involved in inner speech production) the greater voice-hearing severity people had. This was taken to support the idea that voice-hearer’s own inner speech may play a role in creating their voices,
Secondly, they found that the more strongly connected Heschl’s gyrus was to the cingulate cortex (involved in self-monitoring, e.g., distinguishing between self-produced and other produced experiences; and suppressing activation of primary auditory cortex) the greater voice-hearing severity people had. This was taken to support the idea that a problem with monitoring one’s own inner thoughts could lead to experiencing voices.
Finally (for the purposes of this summary), they found reduced connectivity between Heschl’s gyrus and the hippocampal region (involved in memory), in voice-hearers compared to people who didn’t hear voices, suggesting memories may also be playing a role in the generation of voices.
Link to paper: http://dx.doi.org/10.1016/j.schres.2012.11.037
- The more childhood victimisation female prisoners have experienced, the more likely they are to exhibit hallucinations and delusions. Link to abstract here.
- Self-directedness and self-transcendence (groovy baby!) are related to hallucination-proneness. Link to paper here.
- EEG study of theta and gamma wave activity in AVHs. Link to paper here.
Until next month, my friends….