Auditory verbal hallucinations in schizophrenia as aberrant lateralized speech perception: Evidence from dichotic listening

A synthesis of evidence on inhibitory control and auditory hallucinations based on the Research Domain Criteria (RDoC) framework

“…A vertical synergy agenda is inspired by the ideas in the RDoC approach and represents a “rows × columns” matrix for advancing our knowledge of one of the most severe symptoms, AH, in one of the most severe mental disorders, schizophrenia. Starting at the top, most empirical evidence points to the fact that the phenomenology of AH involves a subjective experience of hearing a “voice.” This means that at the second level of explanation—the cognitive level—AH involves a perceptual quality, and in particular the quality of a speech percept since the subjective experience is typically of a person “speaking to the patient.” The perceptual nature of AH has been evidenced in the studies by Green et al (1994), Woodruff et al (1997), and Hugdahl et al (2012). Granted a speech perception explanation at the cognitive level of analysis, the next question is: “what could be causing such an experience in the absence of a physical stimulus, at the neuronal level?” A reasonable first hypothesis would be to look for neuronal abnormality in brain areas connected with speech perception in the temporal lobes, moving down to a circuitry, or systems, level of explanation.…”

“…Originally an experimental paradigm for the assessment of cerebral localization of speech perception, the forced-attention dichotic listening paradigm has become a tool for clinical assessment of a wide range of psychiatric and neurological disorders (see Hugdahl et al, 2009a,b for an overview), and would nicely fit the requirements for an assessment paradigm that cuts across cognitive domains as indicated in the RDoC. In two recent papers, Hugdahl et al (2012, 2013) have shown that patients with AH clearly deviate from healthy controls on the three cognitive constructs—perception, attention, and cognitive control—and that this paradigm could be a valuable tool for assessing AH in both psychotic and non-psychotic individuals hearing “voices.” There are several advantages with being able to study different cognitive constructs with a single paradigm, which is opposite to the more traditional approach of studying a single construct with different paradigms. First of all a single paradigm allows for within-construct comparisons on the same individual, i.e., differences in degree of impairment between the implicated cognitive constructs can be statistically evaluated on an individual level.…”

Quantifying cerebral asymmetries for language in dextrals and adextrals with random-effects meta analysis

“…In other studies, particularly ones with smaller sample sizes, mean differences between dextrals and adextrals on any particular dependent measure were not statistically significant, leading authors to conclude that handedness has no effect (e.g., Goodglass and Barton, 1963; Hugdahl et al, 2012) or more recently, that any effects of handedness are small relative to larger effects of more direct measures of language dominance (Van der Haegen et al, 2013b). Remarkably (to us, at least) Kimura herself, who helped launch dichotic listening as a valid paradigm in asymmetry research, had argued from some of her earliest data that dichotic listening scores do not discriminate between dextrals and adextrals (Kimura, 1961).…”

Neuropsychopharmacology of auditory hallucinations: insights from pharmacological functional MRI and perspectives for future research

“…It is hypothesized that auditory hallucinations may be perceptually 'triggered' by hyperactivation of the default-mode network, producing spontaneous neuronal firing in temporal and adjacent areas. Review stimulus, giving rise to the subjective experience of an external 'voice' speaking to the patient [112].…”

“…The biological mechanisms underlying AVHs are far from clear although important new insights into the phenomenon are steadily reported, such as the recent consolidating evidence of AVH being aberrant speech perceptions stemming from the left part of the brain [112], see also [102]. However, AVH are nonspecific and can be seen in several mental and neurological conditions, as well as in individuals with no apparent brain disorder [5].…”