Neuronal Correlates of Perception, Imagery, and Memory for Familiar Tunes

We used fMRI to investigate the neuronal correlates of encoding and recognizing heard and imagined melodies. Ten participants were shown lyrics of familiar verbal tunes; they either heard the tune along with the lyrics, or they had to imagine it. In a subsequent surprise recognition test, they had to identify the titles of tunes that they had heard or imagined earlier. The functional data showed substantial overlap during melody perception and imagery, including secondary auditory areas. During imagery compared with perception, an extended network including pFC, SMA, intraparietal sulcus, and cerebellum showed increased activity, in line with the increased processing demands of imagery. Functional connectivity of anterior right temporal cortex with frontal areas was increased during imagery compared with perception, indicating that these areas form an imagery-related network. Activity in right superior temporal gyrus and pFC was correlated with the subjective rating of imagery vividness. Similar to the encoding phase, the recognition task recruited overlapping areas, including inferior frontal cortex associated with memory retrieval, as well as left middle temporal gyrus. The results present new evidence for the cortical network underlying goal-directed auditory imagery, with a prominent role of the right pFC both for the subjective impression of imagery vividness and for on-line mental monitoring of imagery-related activity in auditory areas

Musical Tasks Targeting Preserved and Impaired Functions in Two Dementias

Studies of musical abilities in dementia have for the most part been rather general assessments of abilities, for instance, assessing retention of music learned premorbidly. Here, we studied patients with dementias with contrasting cognitive profiles to explore specific aspects of music cognition under challenge. Patients suffered from Alzheimer\u27s disease (AD), in which a primary impairment is in forming new declarative memories, or Lewy body disease (PD/LBD), a type of parkinsonism in which executive impairments are prominent. In the AD patients, we examined musical imagery. Behavioral and neural evidence confirms involvement of perceptual networks in imagery, and these are relatively spared in early stages of the illness. Thus, we expected patients to have relatively intact imagery in a mental pitch comparison task. For the LBD patients, we tested whether executive dysfunction would extend to music. We probed inhibitory skills by asking for a speeded pitch or timbre judgment when the irrelevant dimension was held constant or also changed. Preliminary results show that AD patients score similarly to controls in the imagery tasks, but PD/LBD patients are impaired relative to controls in suppressing some irrelevant musical dimensions, particularly when the required judgment varies from trial to trial. 2014 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences

Hearing in the mind\u27s ear: A PET investigation of musical imagery and perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory

Correlating Resting-State Functional Connectivity with Mental Imagery Vividness in a Healthy Population

Mental imagery is the act of using the “mind’s eyes and ears” to generate and experience sensory information that is absent in the external environment. The vividness of mental imagery varies across individuals, but not much is known about what contributes to these differences. This exploratory study investigates the possible relationship between resting-state functional connectivity and the vividness of mental imagery. We performed a seed-based connectivity analysis on resting-state scans of two groups of healthy control subjects with Brodmann area 19, the precuneus, the superior temporal gyrus, the hippocampus, and the posterior cingulate cortex as regions of interest. Although the underlying functional network connectivity was the same across groups, there was no groupwise replication of pairwise connectivities associated with either visual or auditory mental imagery vividness. The lack of replication may be due to a number of factors, but we highlight the impact of asking one group about the vividness of their imagery after each task-based trial and not the other. This may have primed the individuals in the former group to be in a self-referential state of mind during the resting-state scan, affecting the pairwise connectivity relationships to either imagery modality

Electromagnetic Correlates of Musical Expertise in Processing of Tone Patterns

Using magnetoencephalography (MEG), we investigated the influence of long term musical training on the processing of partly imagined tone patterns (imagery condition) compared to the same perceived patterns (perceptual condition). The magnetic counterpart of the mismatch negativity (MMNm) was recorded and compared between musicians and non-musicians in order to assess the effect of musical training on the detection of deviants to tone patterns. The results indicated a clear MMNm in the perceptual condition as well as in a simple pitch oddball (control) condition in both groups. However, there was no significant mismatch response in either group in the imagery condition despite above chance behavioral performance in the task of detecting deviant tones. The latency and the laterality of the MMNm in the perceptual condition differed significantly between groups, with an earlier MMNm in musicians, especially in the left hemisphere. In contrast the MMNm amplitudes did not differ significantly between groups. The behavioral results revealed a clear effect of long-term musical training in both experimental conditions. The obtained results represent new evidence that the processing of tone patterns is faster and more strongly lateralized in musically trained subjects, which is consistent with other findings in different paradigms of enhanced auditory neural system functioning due to long-term musical training

Mental reversal of imagined melodies: A role for the posterior parietal cortex

Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation

Differences in Auditory Imagery Self-Report Predict Neural and Behavioral Outcomes

Mental imagery abilities vary among individuals, as shown both by objective measures and by self-report. Few imagery studies consider auditory imagery, however. The Bucknell Auditory Imagery Scale is a short self-report measure encompassing both Vividness and Control subscales for musical, verbal, and environmental sounds. It has high internal reliability, no relation to social desirability, and only a modest relation to musical training. High scores on Vividness predict fewer source memory errors in distinguishing heard from imagined tunes on a recognition test, and better performance on pitch imitation tasks. Furthermore, higher scores are related to hemodynamic response and gray matter volume in several brain areas that are known to be involved in auditory imagery. Even though self-report measures encompass both cognitive and metacognitive aspects, they are useful tools in accounting for individual differences in high-level cognitive skills. (PsycINFO Database Record (c) 2016 APA, all rights reserved

Assessing Vividness of Mental Imagery: The Plymouth Sensory Imagery Questionnaire

Publisher allows archiving of submitted msMental imagery may occur in any sensory modality, although visual imagery has been most studied. A sensitive measure of the vividness of imagery across a range of modalities is needed: the shorter version of Bett’s QMI (Sheehan, 1967) uses outdated items and has an unreliable factor structure. We report the development and initial validation of the Plymouth Sensory Imagery Questionnaire (Psi-Q) comprising items for each of the following modalities: Vision, Sound, Smell, Taste, Touch, Bodily Sensation and Emotional Feeling. An Exploratory Factor Analysis on a 35-item form indicated that these modalities formed separate factors, rather than a single imagery factor, and this was replicated by confirmatory factor analysis. The Psi-Q was validated against the Spontaneous Use of Imagery Scale (Reisberg, Pearson & Kosslyn, 2003) and Marks’ (1995) Vividness of Visual Imagery Questionnaire-2. A short 21-item form comprising the best three items from the seven factors correlated with the total score and subscales of the full form, and with the VVIQ-2. Inspection of the data shows that while visual and sound imagery is most often rated as vivid, individuals who rate one modality as strong and the other as weak are not uncommon. Findings are interpreted within a working memory framework and point to the need for further research to identify the specific cognitive processes underlying the vividness of imagery across sensory modalities

Musical tasks targeting preserved and impaired functions in two dementias.

Studies of musical abilities in dementia have for the most part been rather general assessments of abilities, for instance, assessing retention of music learned premorbidly. Here, we studied patients with dementias with contrasting cognitive profiles to explore specific aspects of music cognition under challenge. Patients suffered from Alzheimer's disease (AD), in which a primary impairment is in forming new declarative memories, or Lewy body disease (PD/LBD), a type of parkinsonism in which executive impairments are prominent. In the AD patients, we examined musical imagery. Behavioral and neural evidence confirms involvement of perceptual networks in imagery, and these are relatively spared in early stages of the illness. Thus, we expected patients to have relatively intact imagery in a mental pitch comparison task. For the LBD patients, we tested whether executive dysfunction would extend to music. We probed inhibitory skills by asking for a speeded pitch or timbre judgment when the irrelevant dimension was held constant or also changed. Preliminary results show that AD patients score similarly to controls in the imagery tasks, but PD/LBD patients are impaired relative to controls in suppressing some irrelevant musical dimensions, particularly when the required judgment varies from trial to trial