Mental scanning in auditory imagery for songs

Four experiments examined how people operate on memory representations of familiar songs. The tasks were similar to those used in studies of visual imagery. In one task, subjects saw a one word lyric from a song and then saw a second lyric; then they had to say if the second lyric was from the same song as the first. In a second task, subjects mentally compared pitches of notes corresponding to song lyrics. In both tasks, reaction time increased as a function of the distance in beats between the two lyrics in the actual song, and in some conditions reaction time increased with the starting beat of the earlier lyric. Imagery instructions modified the main results somewhat in the first task, but not in the second, much harder task. The results suggest that song representations have temporal-like characteristics. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

Mental concerts: Musical imagery and auditory cortex

Most people intuitively understand what it means to “hear a tune in your head.” Converging evidence now indicates that auditory cortical areas can be recruited even in the absence of sound and that this corresponds to the phenomenological experience of imagining music. We discuss these findings as well as some methodological challenges. We also consider the role of core versus belt areas in musical imagery, the relation between auditory and motor systems during imagery of music performance, and practical implications of this research.

More than Tunes in Your Head: Dynamic Aspects of Auditory Imagery for Music

Auditory imagery is more than just mental “replaying” of tunes in one’s head. I will review several studies that capture characteristics of complex and active imagery tasks, using both behavioral and neuroscience approaches. I use behavioral methods to capture people’s ability to make emotion judgments about both heard and imagined music in real time. My neuroimaging studies look at the neural correlates of encoding an imagined melody, anticipating an upcoming tune, and also imagining tunes backwards. Several studies show voxel-by-voxel correlates of neural activity with self-report of imagery vividness. These studies speak to the ways in which musical imagery allows us not just to remember music, but also how we use those memories to judge temporally changing aspects of the musical experience.

Auditory Imagery and the Poor-Pitch Singer

The vocal imitation of pitch by singing requires one to plan laryngeal movements on the basis of anticipated target pitch events. This process may rely on auditory imagery, which has been shown to activate motor planning areas. As such, we hypothesized that poor-pitch singing, although not typically associated with deficient pitch perception, may be associated with deficient auditory imagery. Participants vocally imitated simple pitch sequences by singing, discriminated pitch pairs on the basis of pitch height, and completed an auditory imagery self-report questionnaire (the Bucknell Auditory Imagery Scale). The percentage of trials participants sung in tune correlated significantly with self-reports of vividness for auditory imagery, although not with the ability to control auditory imagery. Pitch discrimination was not predicted by auditory imagery scores. The results thus support a link between auditory imagery and vocal imitation.

Possible dysregulation of cortical plasticity in auditory verbal hallucinations-A cortical thickness study in schizophrenia

Investigations of gray matter changes in relation with auditory verbal hallucinations (AVH) have reported conflicting results. Assuming that alterations in gray matter might be related to certain symptoms in schizophrenia this study aimed to investigate changes in cortical thickness specific to AVH. It was hypothesized that schizophrenia patients suffering from persistent AVH would show significant differences in cortical thickness in regions involved in language-production and perception when compared to schizophrenia patients which had never experienced any hallucinations.

Resting-state EEG in schizophrenia: auditory verbal hallucinations are related to shortening of specific microstates

Abnormal perceptions and cognitions in schizophrenia might be related to abnormal resting states of the brain. Previous research found that a specific class (class D) of sub-second electroencephalography (EEG) microstates was shortened in schizophrenia. This shortening correlated with positive symptoms. We questioned if this reflected positive psychotic traits or present psychopathology.

Neuroimaging Auditory Hallucinations in Schizophrenia: From Neuroanatomy to Neurochemistry and Beyond

Despite more than 2 decades of neuroimaging investigations, there is currently insufficient evidence to fully understand the neurobiological substrate of auditory hallucinations (AH). However, some progress has been made with imaging studies in patients with AH consistently reporting altered structure and function in speech and language, sensory, and nonsensory regions. This report provides an update of neuroimaging studies of AH with a particular emphasis on more recent anatomical, physiological, and neurochemical imaging studies. Specifically, we provide (1) a review of findings in schizophrenia and nonschizophrenia voice hearers, (2) a discussion regarding key issues that have interfered with progress, and (3) practical recommendations for future studies.

Cerebral blood flow identifies responders to transcranial magnetic stimulation in auditory verbal hallucinations

Auditory hallucinations comprise a critical domain of psychopathology in schizophrenia. Repetitive transcranial magnetic stimulation (TMS) has shown promise as an intervention with both positive and negative reports. The aim of this study was to test resting-brain perfusion before treatment as a possible biological marker of response to repetitive TMS. Twenty-four medicated patients underwent resting-brain perfusion magnetic resonance imaging with arterial spin labeling (ASL) before 10 days of repetitive TMS treatment. Response was defined as a reduction in the hallucination change scale of at least 50%. Responders (n=9) were robustly differentiated from nonresponders (n=15) to repetitive TMS by the higher regional cerebral blood flow (CBF) in the left superior temporal gyrus (STG) (P<0.05, corrected) before treatment. Resting-brain perfusion in the left STG predicted the response to repetitive TMS in this study sample, suggesting this parameter as a possible bio-marker of response in patients with schizophrenia and auditory hallucinations. Being noninvasive and relatively easy to use, resting perfusion measurement before treatment might be a clinically relevant way to identify possible responders and nonresponders to repetitive TMS.

Common mechanisms of auditory hallucinations-perfusion studies in epilepsy

Auditory hallucinations (AH) occur in various neurological and psychiatric disorders. In psychosis, increased neuronal activity in the primary auditory cortex (PAC) contributes to AH. We investigated functional neuroanatomy of epileptic hallucinations by measuring cerebral perfusion in three patients with AH during simple partial status epilepticus. Hyperperfusion in the temporal lobe covering the PAC occurred in all patients. Our perfusion data support the hypothesis of PAC being a constituting element in the genesis of AH independent of their aetiology.

Reduced neuronal activity in language-related regions after transcranial magnetic stimulation therapy for auditory verbal hallucinations

Transcranial magnetic stimulation (TMS) is a novel therapeutic approach, used in patients with pharmacoresistant auditory verbal hallucinations (AVH). To investigate the neurobiological effects of TMS on AVH, we measured cerebral blood flow with pseudo-continuous magnetic resonance-arterial spin labeling 20 ± 6 hours before and after TMS treatment.

Auditory motion direction encoding in auditory cortex and high-level visual cortex

The aim of this functional magnetic resonance imaging (fMRI) study was to identify human brain areas that are sensitive to the direction of auditory motion. Such directional sensitivity was assessed in a hypothesis-free manner by analyzing fMRI response patterns across the entire brain volume using a spherical-searchlight approach. In addition, we assessed directional sensitivity in three predefined brain areas that have been associated with auditory motion perception in previous neuroimaging studies. These were the primary auditory cortex, the planum temporale and the visual motion complex (hMT/V5+). Our whole-brain analysis revealed that the direction of sound-source movement could be decoded from fMRI response patterns in the right auditory cortex and in a high-level visual area located in the right lateral occipital cortex. Our region-of-interest-based analysis showed that the decoding of the direction of auditory motion was most reliable with activation patterns of the left and right planum temporale. Auditory motion direction could not be decoded from activation patterns in hMT/V5+. These findings provide further evidence for the planum temporale playing a central role in supporting auditory motion perception. In addition, our findings suggest a cross-modal transfer of directional information to high-level visual cortex in healthy humans.