More research this April…
Accessible summary: This study examined how the feeling that “I am the one who caused something” might be related to hearing voices.
The main part of the study involved people speaking into a microphone and then hearing their speech played back to them. Their speech could be either as-normal (i.e., non-distorted) or distorted by a number of semitones. People were asked to rate the extent to which the voice they heard played back felt like it was their own or someone elses. People who tended to report the voice sounded like someone else were found to have higher scores on an auditory hallucination questionnaire.
Link to paper: http://dx.doi.org/10.1016/j.psychres.2012.09.055
Porirua, New Zealand. Bush and NiaNia examine voice-hearing in a Maori teenager.
Accessible summary: Within a Maori world view, it is considered normal for some people to occasionally experience hearing the voices of deceased relatives, or others. This paper describes describe a Maori traditional healing approach to hearing voices in a young man. The techniques used to help the young man included those which addressed unresolved
intergenerational and family issues through a ritual called ‘whakawetewete’. This is a “ritual of forgiveness and releasing past hurts in which participants are invited to write down all the hurts that have happened to them and all the hurts that they have inflicted on others. They are then invited to choose a place they feel connected to and burn or tear up the paper and release and farewell the unresolved hurts and troubles, so that they are no longer their burden.” The young man’s voice-hearing was viewed as “evidence of a spiritual gift and he was educated about the need to look after this gift by taking care of unresolved relationship issues, avoiding use of cannabis and not abusing alcohol.” Such techniques appeared to help.
Link to paper: http://dx.doi.org/10.1177/1039856212456090
Accessible summary: The authors note that who voice-hearers take the identity of their voices to be is important to the amount of distress they experience. They then go on to examine how the perception of hallucinated voices’ identities may be grounded in the normal mechanisms that people use to recognise the voices of real people in the external world. There is a lot of interesting information here, and the article is open-access so you are able to read it for yourself.
Link to paper: http://dx.doi.org/10.3389/fnhum.2013.00114
Accessible summary: This study used used magnetoencephalography (MEG: when electrical activity in the brain occurs, this also causes small changes in magnetic fields which can be measured using this technique) to examine how the brains of voice-hearers (who had diagnoses of schizophrenia) reacted to sounds that they were played, as compared to non-voice hearers (who did not have a diagnosis of schizophrenia). The brain activity of the two groups did not differ when listening to white noise. However, voice-hearers’ left auditory cortex was found to react differently to speech sounds, as compared to non voice-hearers.
Link to paper: http://dx.doi.org/10.1016/j.clinph.2012.07.022
Accessible summary: The study reviewed previous studies in this area and found that the more severe people’s voices were, the smaller was a region of their brain called the superior temporal gyrus (STG). The association with this area is thought to be due to the left hemisphere STG normally playing a role in speech perception, and the right STG playing a role in the processing of prosody and emotional salience.
Link to paper: http://dx.doi.org/10.1016/j.cortex.2012.01.009
Accessible summary: The study compared the neural activity of people when external speech was being played to them. Three groups were employed, people diagnosed with schizophrenia who heard voices, people diagnosed with schizophrenia who didn’t hear voices, and healthy controls . It was found that the connecitivity between the superior temporal gyrus (STG) in the right hemisphere and the STG in the left hemisphere was reduced in people with schizophrenia who heard voices, relative to both non-voice hearing people diagnosed with schizophrenia, and healthy controls.
Link to paper: http://dx.doi.org/10.1016/j.pnpbp.2013.03.006
Accessible summary: The authors note that hallucinatory experiences are a common experience during childhood and adolescence, with most studies estimating rates of 5-9%. They state that these experiences may occur as normal variations of development. Their review of the existing literature in this area suggested that most of these experiences discontinue in the short term.
Link to paper: http://dx.doi.org/10.1016/j.schres.2012.03.012
Other notable studies:
Seville, Spain. Salvador Perona-Garcelan and colleagues find that proneness to hallucinations in a student sample is associated with higher levels of absorption, depersonalisation, and self-focused attention. Link to paper here.
São Paulo, Brazil. A single case study of the relatively new technique of transcranial Direct Current Stimulation (tDCS) by Shiozawa and colleagues. Link to paper here.
More next month. SMJ