The authors acknowledge financial support for this research from Secretari&#769;a de Salud de Me&#769;xico (HIM/2011/058 SSA. 1009), CONACYT (SALUD-2012-01-182160), and DGAPA UNAM (PAPIIT IN109214).

This protocol has been approved by the Research, Ethics, and Safety Committee of the Hospital Infantil de Me&#769;xico &#34;Federico Go&#769;mez&#34;.
1. Behavioral Pretest
<ol>
	<li>Perform a standard, pure-tone audiometric test to confirm that all prospective participants possess normal hearing (20-dB Hearing Level (HL) over octave frequencies of -8,000 Hz). Use the Edinburgh Handedness Inventory31 to ensure that all participants are right-handed.</li>
	<li>...

<ol>
	<li>Burns, E., Deutsch, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Intervals, scales, and tuning. The psychology of music. , 215-264 (1999).</li><li>Lundin, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+a+cultural+theory+of+consonance.">Toward a cultural theory of consonance.</a> J. Psychol. 23, 45-49 (1947).</li><li>Fritz, T., Jentschke, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Universal+recognition+of+three+basic+emotions+in+music.">Universal recognition of three basic emotions in music.</a> Curr. Biol. 19, 573-576 (2009).</li><li>Schellenberg, E. G., Trehub, S. 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Dev. 21 (1), 483-492 (1998).</li><li>Terhardt, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pitch,+consonance,+and+harmony.">Pitch, consonance, and harmony.</a> J. Acoust. Soc. America. 55, 1061 (1974).</li><li>Minati, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+MRI/event-related+potential+study+of+sensory+consonance+and+dissonance+in+musicians+and+nonmusicians.">Functional MRI/event-related potential study of sensory consonance and dissonance in musicians and nonmusicians.</a> Neuroreport. 20, 87-92 (2009).</li><li>Helmholtz, H. L. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> On the sensations of tone. , (1954).</li><li>McDermott, J. H., Lehr, A. J., Oxenham, A. 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This work describes a protocol in which singing is used as a means of studying brain activity during the production of consonant and dissonant intervals. Even though singing provides what is possibly the simplest method for the production of musical intervals22, it does not allow for the production of chords. However, although most physical characterizations of the notion of consonance rely, to some degree, on the superposition of simultaneous notes, a number of studies have shown that intervals c...

Certain combinations of musical pitches are generally acknowledged to be consonant, and they are typically associated with a pleasant sensation. Other combinations are generally referred to as dissonant and are associated with an unpleasant or unresolved feeling1. Although it seems sensible to assume that enculturation and training play some part in the perception of consonance2, it has been recently shown that the differences in perception of consonant and dissonant intervals and chords probably depend less on musical culture than was previously thought3 and may even derive from simple biological bases4,5,6. In order to prevent an ambiguous understanding of the term consonance, Terhardt7 introduced the notion of sensory consonance, as opposed to consonance in a musical context, where harmony, for example, may well influence the response to a given chord or interval. In the present protocol, only isolated, two-note intervals were used&#160;precisely to single out activations solely related to sensory consonance, without interference from context-dependent processing8.
Attempts to characterize consonance through purely physical means began with Helmholtz9, who attributed the perceived roughness associated with dissonant chords to the beating between adjacent frequency components. More recently, however, it has been shown that sensory consonance is not only associated with the absence of roughness, but also with harmonicity, which is to say the alignment of the partials of a given tone or chord with those of an unheard tone of a lower frequency10,11. Behavioral studies confirm that subjective consonance is indeed affected by purely physical parameters, such as frequency distance12,13, but a wider range of studies have conclusively demonstrated that physical phenomena cannot solely account for the differences between perceived consonance and dissonance14,15,16,17. All of these studies, however, report these differences when listening to a variety of intervals or chords. A variety of studies using Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) have revealed significant differences in the cortical regions that become active when listening to either consonant or dissonant intervals and chords8,18,19,20. The purpose of the present study is to explore the differences in brain activity when producing, rather than listening to, consonant and dissonant intervals.
The study of sensory-motor control during musical production typically involves the use of musical instruments, and very often it then requires the fabrication of instruments modified specifically for their use during neuroimaging21. Singing, however, would seem to provide from the start an appropriate mechanism for the analysis of sensory-motor processes during music production, as the instrument is the human voice itself, and the vocal apparatus does not require any modification in order to be suitable during imaging22. Although the neural mechanisms associated with aspects of singing, such as pitch control23, vocal imitation24, training-induced adaptive changes25, and the integration of external feedback25,26,27,28,29, have been the subject of a number of studies over the past two decades, the neural correlates of singing consonant and dissonant intervals were only recently described30. For this purpose, the current paper describes a behavioral test designed to establish the adequate recognition of consonant and dissonant intervals by participants. This is followed by an fMRI study of participants singing a variety of consonant and dissonant intervals. The fMRI protocol is relatively straightforward, but, as with all MRI research, great care must be taken to correctly set up the experiments. In this case, it is particularly important to minimize head, mouth, and lip movement during singing tasks, making the identification of effects not directly related to the physical act of singing more straightforward. This methodology may be used to investigate the neural mechanisms associated with a variety of activities involving musical production by singing.

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	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Achieva 1.5-T magnetic resonance scanner</td>
			<td style="width:297px;">Philips</td>
			<td style="width:119px;">Release 6.4</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Audacity</td>
			<td style="width:297px;">Open source</td>
			<td style="width:119px;">2.0.5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Audio interface&#160;</td>
			<td style="width:297px;">Tascam</td>
			<td style="width:119px;">US-144MKII&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Audiometer</td>
			<td style="width:297px;">Br&#252;el &#38; Kjaer</td>
			<td style="width:119px;">Type 1800</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">E-Prime Professional</td>
			<td style="width:297px;">Psychology Software Tools, Inc.</td>
			<td style="width:119px;">2.0.0.74</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Matlab</td>
			<td style="width:297px;">Mathworks</td>
			<td style="width:119px;">R2014A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">MRI-Compatible Insert Earphones</td>
			<td style="width:297px;">Sensimetrics</td>
			<td style="width:119px;">S14</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Praat</td>
			<td style="width:297px;">Open source</td>
			<td style="width:119px;">5.4.12</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Pro audio condenser microphone</td>
			<td style="width:297px;">Shure</td>
			<td style="width:119px;">SM93</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">SPSS Statistics</td>
			<td style="width:297px;">IBM</td>
			<td style="width:119px;">20</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:343px;">Statistical Parametric Mapping</td>
			<td style="width:297px;">Wellcome Trust Centre for Neuroimaging</td>
			<td style="width:119px;">8</td>
			<td></td>
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	</tbody>
</table>

fmri mapping of brain activity associated with the vocal production of consonant and dissonant intervals

The neural correlates of consonance and dissonance perception have been widely studied, but not the neural correlates of consonance and dissonance production. The most straightforward manner of musical production is singing, but, from an imaging perspective, it still presents more challenges than listening because it involves motor activity. The accurate singing of musical intervals requires integration between auditory feedback processing and vocal motor control in order to correctly produce each note. This protocol presents a method that permits the monitoring of neural activations associated with the vocal production of consonant and dissonant intervals. Four musical intervals, two consonant and two dissonant, are used as stimuli, both for an auditory discrimination test and a task that involves first listening to and then reproducing given intervals. Participants, all female vocal students at the conservatory level, were studied using functional Magnetic Resonance Imaging (fMRI) during the performance of the singing task, with the listening task serving as a control condition. In this manner, the activity of both the motor and auditory systems was observed, and a measure of vocal accuracy during the singing task was also obtained. Thus, the protocol can also be used to track activations associated with singing different types of intervals or with singing the required notes more accurately. The results indicate that singing dissonant intervals requires greater participation of the neural mechanisms responsible for the integration of external feedback from the auditory and sensorimotor systems than does singing consonant intervals.

All 11 participants in our experiment were female vocal students at the conservatory level, and they performed well enough in the interval recognition tasks to be selected for scanning. The success rate for the interval identification task was 65.72 &#177;21.67%, which is, as expected, lower than the success rate when identifying dissonant and consonant intervals, which was 74.82 &#177;14.15%.
In order to validate the basic desi...

Watch this Scientific Journal Video about fMRI Mapping of Brain Activity Associated with the Vocal Production of Consonant and Dissonant Intervals at JoVE.com

fMRI Mapping of Brain Activity Associated with the Vocal Production of Consonant and Dissonant Intervals

The neural correlates of listening to consonant and dissonant intervals have been widely studied, but the neural mechanisms associated with production of consonant and dissonant intervals are less well known. In this article, behavioral tests and fMRI are combined with interval identification and singing tasks to describe these mechanisms.

The neural correlates of consonance and dissonance perception have been widely studied, but not the neural correlates of consonance and dissonance ...

The overall goal of this methodology is to monitor neural activations associated with the vocal production of consonant and dissonant intervals, through the use of functional magnetic resonance imaging. This method can help answer key questions in the field of auditory cognitive neuroscience, such as, how does integration of external feedback from the auditory and sensory motor systems differ when singing consonant and dissonant intervals? The main advantage of this technique is that it is designed to track activity of both the motor and the auditory system, while simultaneously obtaining a measure of vocal accuracy during singing.Generally, individuals new to this method will struggle because it is difficult to record some tones faithfully from within the scanner as the entirety of the scanner is extremely noisy. Demonstrating the procedure will be Lucero Pacheco, a grad student from my laboratory. To begin producing pure tones spanning two octaves from G four to G six, open a new project folder in sound editing software.Then, under the generate menu select tone. In the window that appears, select a sine waveform, an amplitude of 0.8, and a duration of one second. Enter the value of the frequency that corresponds to the desired note and click on the okay button.Under the file menu select export. In the window that open enter the desired name for the audio file and choose wav as the desired file type. Click save.Next, generate all possible combinations of notes corresponding to two consonant and two dissonant intervals in the range between G four and G six. To do this for each interval open a new project in the sound editing software and choose import audio under the file menu to import the two wav files to be concatenated. Place the cursor at any point over the second tone and click to select.Click on select all under the edit menu. Under the same menu click on copy. Then, place the cursor at any point over the first tone and click.Under the edit menu, click on move cursor to track end and then click paste under the same menu. Finally, under the file menu select export. In the window that opens enter the desired name for the audio file and choose wav as the desired file type.Click save. Begin by having the participant sit down in front of a laptop computer and wear the provided headphones. Ensure that the sound level is comfortable for the participant.Use behavioral research software to open two previously created tasks with e-run. In the window that appears enter the session and subject Number and click okay. Then, for the two alternative force choice tasks, ask the participants to identify whether the intervals they hear are consonant or dissonant by pressing either c on the computer keyboard for consonant and d for dissonant.Next, in the four alternative force choice tasks have the participants identify the intervals themselves by pressing the numerals four, five, seven, and eight on the computer keyboard, to identify the intervals of an augmented fourth. Perfect fifth. Major seventh.And octave respectively. Finally, at the end of each task press okay to automatically save the results for each participant. Begin by connecting a non-magnetic, MR compatible headset to a laptop, and ensure the sound level is comfortable for the participant.Then, connect a small condenser microphone to an audio interface that is in turn connected to the laptop using a shielded, twisted, triplet cable. To check the microphone frequency response, start a new project in the sound editing software and select the condenser microphone as the input device. Then, generate a 440 hertz test tone with a duration of 10 seconds.After the tone is generated, use sound reproduction software to press play to send the test tone through the headphones to two locations. Inside on top of the head rest and outside of the scanner in the control room with the microphone placed between the sides of the headset in each case. Next, press record in the sound editing software to record approximately one second of the test tone at each location.Then, select plot spectrum from the analyze menu for each case and compare the response of the microphone to the test tone, both inside and outside the scanner by checking that the fundamental frequency of the signal received at each location is 440 hertz. Finally, tape the condenser microphone to the participant's neck just below the larynx, and have them wear the headset. Then, place the participant in the magnetic resonance scanner.Begin by opening the magnetic resonance user interface MRUI software package. Within the MRUI software select the patient option from the onscreen menu. Enter the participant's name, age and weight.Then, click on the exam button. First, choose head and then brain from the available options. Next, select 3D and then T1 isometric with the following values for the relevant parameters:repetition time equals 10.2 milliseconds, echo time equals 4.2 milliseconds, flip angle equals 90 degrees, and voxel size equals one by one by one millimeters cubed.Then, click on program and begin the acquisition of the functional T2 star weighted whole head scan with the values of the relevant parameters as follows:TE equals 40 milliseconds, TR equals three seconds, field of view equals 256 millimeters squared, flip angle equals 90 degrees, matrix dimensions equal 64 by 64, delay in TR equals seven seconds. Note that in this case TR is the total time during which the acquisition takes place. Use the dummy option to acquire five volumes while entering a value of 55 for the total number of volumes.Click copy to make a copy of this sequence. Place the cursor at the bottom of the list of sequences and then click paste twice to set up three consecutive sparse sampling sequences. Then, click start to begin the T1 weighted anatomical volume acquisition.Finally, present three runs to the participant. Synchronize the start of the runs with the acquisition by the scanner using the scanner trigger box and differentiate between each run using the session number. Then, save the results of each run.This study identified neural activity during singing in the regions known to constitute the singing network, which match those reported in prior literature. Results from a two way repeated measures analysis of variance indicated that for the contrast resulting from singing dissonant as opposed to consonant intervals, increased activations were observed in the right primary somatosensory cortex, right primary auditory cortex, left midbrain, right posterior insula, left amygdala, and left putamen. Once mastered, this technique can be done in four hours per subject.If it is performed properly, taking into account, the behaviors test, the fMRI session, and the data analysis. While attempting this procedure, it is important to remember to check that the recording equipment is functioning correctly and to instruct the participants clearly that they should sing by humming, moving their heads as little as possible to avoid artifacts. Following this procedure, which is used to track differences in brain activation between binary conditions, a modified version of the method can be performed in order to study, for example, differences between singing wide and narrow intervals.After each development the fMRI technique paves the way for researchers in the field of auditory neuroscience to explore neural mechanisms associated with audition and vocal production. After watching this video, you should have a good understanding of how to use fMRI to monitor the activity of both the motor and auditory systems during singing, in order to study the neural correlates of vocal production. Don't forget that working with a magnetic resonance scanner can be extremely hazardous and great care should always be taken to keep metallic objects away from the scanner.

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7.1K Views.  Hospital Infantil de México "Federico Gómez". The overall goal of this methodology is to monitor neural activations associated with the vocal production of consonant and dissonant intervals, through the use of functional magnetic resonance imaging. This method can help answer key questions in the field of auditory cognitive neuroscience, such as, how does integration of external feedback from the auditory and sensory motor systems differ when singing consonant and dissonant intervals? The main advantage of this technique is that it is de...