Metacognitions in patients with hallucinations and obsessive-compulsive disorder: the superstition factor

On the basis of the analogy between intrusive thoughts and auditory hallucinations established by Morrison et al. [(1995). Intrusive thoughts and auditory hallucinations: a cognitive approach. Behavioural and Cognitive Psychotherapy, 23, 265-280], the present work compares the metacognitive beliefs and processes of five groups of patients (current hallucinators, never-hallucinated people with a diagnosis of schizophrenia, recovered hallucinators, obsessive-compulsive disorder (OCD) patients, and a clinical control group) and a non-clinical group. The results show that of the five metacognitive factors considered in this study, two were found to be different in the current hallucinators group in comparison to any other group in the design. Likewise, it is found that the metacognitive beliefs of the current hallucinators coincide with those of the OCD patients in various factors, particularly that relating to superstition, and this is interpreted as lending support to the model of Morrison et al. (1995). Furthermore, the results are discussed in the light of existing research on Thought-Action Fusion, stressing the role that may be played by superstitious beliefs and magical thinking in auditory hallucinations and OCD.     

Stuttering and sensory gating: a study of acoustic startle prepulse inhibition

It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the acoustic startle prepulse inhibition (PPI) paradigm. A group of 22 adults with developmental stuttering were compared with controls regarding the degree of PPI. No significant differences were found between the stuttering adults and the control group; the groups showed similar means and distribution. Likewise, no relation between the degree of PPI and the effect of altered auditory feedback on stuttering was found. In summary, the results of the study indicate that there is no relation between stuttering and PPI.     

Hearing what the body feels: auditory encoding of rhythmic movement

Phillips-Silver and Trainor (Phillips-Silver, J., Trainor, L.J., (2005). Feeling the beat: movement influences infants' rhythm perception. Science, 308, 1430) demonstrated an early cross-modal interaction between body movement and auditory encoding of musical rhythm in infants. Here we show that the way adults move their bodies to music influences their auditory perception of the rhythm structure. We trained adults, while listening to an ambiguous rhythm with no accented beats, to bounce by bending their knees to interpret the rhythm either as a march or as a waltz. At test, adults identified as similar an auditory version of the rhythm pattern with accented strong beats that matched their previous bouncing experience in comparison with a version whose accents did not match. In subsequent experiments we showed that this effect does not depend on visual information, but that movement of the body is critical. Parallel results from adults and infants suggest that the movement-sound interaction develops early and is fundamental to music processing throughout life.     

Auditory local bias and reduced global interference in autism

Processing local elements of hierarchical patterns at a superior level and independently from an intact global influence is a well-established characteristic of autistic visual perception. However, whether this confirmed finding has an equivalent in the auditory modality is still unknown. To fill this gap, 18 autistics and 18 typical participants completed a melodic decision task where global and local level information can be congruent or incongruent. While focusing either on the global (melody) or local level (group of notes) of hierarchical auditory stimuli, participants have to decide whether the focused level is rising or falling. Autistics showed intact global processing, a superior performance when processing local elements and a reduced global-to-local interference compared to typical participants. These results are the first to demonstrate that autistic processing of auditory hierarchical stimuli closely parallels processing of visual hierarchical stimuli. When analyzing complex auditory information, autistic participants present a local bias and a more autonomous local processing, but not to the detriment of global processing.     

Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing.