Experiment 2: Beat perception abilities in people with and without Parkinson’s disease.
Overview of study written by Dr Dawn Rose
January 2017: This study has received ethical approval and is in the data collection phase.
This study investigates whether Parkinson’s disease (PD) affects the perception of an underlying beat (tactus) embedded in real musical excerpts as ecologically valid stimuli.
Studies have shown that although rhythm and pitch can be separately perceived, they can also interact creating a musical percept. Several neural areas (including the cerebellum, basal ganglia, pre and supplementary motor areas, as well as the primary auditory cortex) are implicated in perceiving and producing musical timing. These involve feedforward and feedback as well as error-correction processing and appear to directly and in-directly connect auditory processing to motor timing (see Zatorre, Chen & Penhune, 2007 for review).
The perception of an underlying beat appears to be specifically affected by PD (Grahn & Brett, 2009). This may be because the neurology of PD is focused in the basal ganglia, a subcortical area of the brain known to be involved in temporal processing and movement automation (Grahn & McAuley, 2009).
Paradoxically, music and dance-based activities and therapeutic interventions are being used to ameliorate a range of symptoms of PD including balance, gait, and mood for example (see e.g. Thaut, 2005, Nombela et al., 2012; Benoit et al., 2014; Lewis et al., 2014).
Zentner & Eerola (2010) suggest “one of the most curious effects of music” (p. 5768) is that it appears to compel us to move our bodies. This effect is universal and apparent in even in young children (5-24 months), and depends on the ability to abstract rhythmic patterns from external sources. The perception of a strong pulse, or underlying beat (tactus) is beneficial to this end (Large & Palmer, 2002).
If we are to understand how dance benefits some people with Parkinson’s, we need to understand whether music enhances their beat perception as one potential variable of interest, hence the employment of ecologically valid stimuli in this study.
This study compares the beat perception ability of people with and people without Parkinson’s disease using ecologically valid stimuli, Müllensiefen et al., 2014). Grahn and Brett (2009) provided evidence that Parkinson’s disease affected beat perception in their study. The stimuli used that study was originally devised and used in an earlier study (Grahn & Brett, 2007). It is a same/different auditory discrimination task using metric simple (regular inter onset intervals) and metric complex (irregular inter onset intervals) rhythms. Intentionally, typical musical cues (such as changes in timbre, pitch and/or volume) were not used and the underlying beat was not emphasised. The authors hypothesised that people with PD would be impaired when discriminating changes in the metric simple condition (which healthy volunteers found easier) due to the dopaminergic deficiency which compromises the basal ganglia functioning. 15 people with PD (6 female) and 15 healthy volunteers (7 female) took part. The National Adult Reading Test (NART: Nelson & Willison, 1991) was used a pre-morbid estimate of IQ. NART scores were predictive of performance, though age was not. Controls were significantly more accurate overall than people with PD and there was a significant interaction between group and rhythm type. People with PD performed significantly worse than controls on only the metric simple condition. No correlation was found between UPDRS severity and task performance.
In the early stages of the disease, it has been suggested that auditory cues can offer a compensatory system (Eckhart et al., 2006; Lewis et al., 2007). Kotz & Schwartze (2010; 2011) have suggested a dedicated temporal processing subcortico-thalamo-cortical network as the alternative pathway. Grahn and Brett (2009) suggest that as their study shows, the capacity to process the beat is not completely lost in people with PD. Therefore, it is “likely that when a more obvious beat is present in the auditory stimulus, such as during listening to music (when volume, pitch, timbre, harmony etc. all provide cues to the beat) this deficit may be mitigated.” (p. 59).
It is important to understand this deficit in studies that do not rely on motor tasks (such as tapping paradigms) in order to be able to utilise this knowledge in terms of application for music and dance-based activities and interventions.
This is a matched pairs design with beat perception accuracy score (from the Gold Musical Sophistication Index (MSI), Müllensiefen et al., 2014) as the (within subject) dependent variable and group (healthy volunteers or people with Parkinson’s) as the (between subjects) independent variables. NART scores may be co-varied in analysis if significantly different levels are found between groups. Levels of dance and music sophistication will be entered into multiple regression analysis to explore their predictive power with regard to accuracy.
Methods and Measures:
Participants will be asked to complete a questionnaire. This will ask about general descriptive data such as age, gender, handedness, level of education, whether they have any known and uncorrected auditory difficulties (see Appendix C).
All participants will also be asked to complete:
- The Mini Mental State Examination (Folstein, Folstein, & McHugh, 1975)
- The Gold Musical Sophistication Index (Gold MSI: Müllensiefen et al. 2014,) with supplementary questions related to their previous and current experience with dance activities
- The National Adult reading Test (NART; Nelson & Willison, 1991) – see Appendix H for word (and pronunciation) list.
People with PD will also be asked to complete a Unified Parkinson’s Disease Rating Scale (UPDRS – Appendix D), a Hoehn & Yahr scale (Hoehn & Yahr, 1967 - Appendix A) and provide information confirming their current medication is stable and that they are being tested during their ‘ON’ state.
The experimental paradigm will utilise a 15-minute auditory stimuli test that includes 3 priming examples and 17 trials. The stimuli, known as the Gold Beat Perception Test (BPT), a subtest of the Gold MSI (Müllensiefen et al., 2014) and is presented online via Qualtrics. Participants will use headphones at a comfortable sound pressure level. See Figures 1-3 in Section 8 for screen shots of the Gold BPT online via Qualtrics.
Hypothesis and Analysis:
Our hypotheses are as follows:
H1 – There will be no significant difference between matched pairs of healthy volunteers and people with PD with regard to performance accuracy on the Gold Beat Perception Test.
H2 –Music and/or dance experience will predict accuracy in detecting whether the embedded tactus is synchronised with the music for both groups. This hypothesis will be tested using multiple regression analyses (i.e. levels of musicianship and dance experience will be analysed using multiple regression in order to ascertain whether they are predictive of the beat perceptions score).
An a priori power analysis, based on 1 tailed dependent means matched pairs t tests (effect size = .35, alpha p = .05) suggests that power =.8 can be achieved with N=52 (2x 26). The critical t value for would be 1.67.
Benoit, C.-E., Dalla Bella, S., Farrugia, N., Obrig, H., Mainka, S., & Kotz, S. A. (2014). Musically Cued Gait-Training Improves Both Perceptual and Motor Timing in Parkinson’s Disease. Frontiers in Human Neuroscience, 8, 494. http://doi.org/10.3389/fnhum.2014.00494
Eckert, T., Peschel, T., Heinze, H. –J., & Rotte, M. (2006). Increased pre–SMA activation in early PD patients during simple self–initiated hand movements. Journal of Neurology, 253(2), 199–207. http://doi.org/10.1007/s00415-005-0956-z
Folstein, M., Folstein, S. E., & McHugh, P. R. (1975). “Mini-Mental State” a Practical Method for Grading the Cognitive State of Patients for the Clinician. Journal of Psychiatric Research, 12(3), 189–198.
Grahn, J. A., & Brett, M. (2007). Rhythm and beat perception in motor areas of the brain. Journal of cognitive neuroscience, 19(5), 893-906.
Grahn, J. A., & Brett, M. (2009). Impairment of beat-based rhythm discrimination in Parkinson’s disease. Cortex, 45(1), 54–61. http://doi.org/10.1016/j.cortex.2008.01.005
Grahn, J. A., & McAuley, J. D. (2009). Neural bases of individual differences in beat perception. NeuroImage, 47(4), 1894-1903.
Hoehn, M. M., & Yahr, M. D. (1967). Parkinsonism: onset, progression, and mortality. Neurology, 17, 427–442.
Kotz, S. A. E., & Schwartze, M. (2011). Differential input of the supplementary motor area to a dedicated temporal processing network: functional and clinical implications. Frontiers in Integrative Neuroscience, 5, 86. http://doi.org/10.3389/fnint.2011.00086
Kotz, S. A., & Schwartze, M. (2010). Cortical speech processing unplugged: a timely subcortico-cortical framework. Trends in Cognitive Sciences, 14(9), 392–399. http://doi.org/10.1016/j.tics.2010.06.005
Large, E. W., & Palmer, C. (2002). Perceiving temporal regularity in music. Cognitive science, 26(1), 1-37.
Lewis, M. M., Slagle, C. G., Smith, A. B., Truong, Y., Bai, P., McKeown, M. J., … Huang, X. (2007). Task specific influences of Parkinson’s disease on the striato-thalamo-cortical and cerebello-thalamo-cortical motor circuitries. Neuroscience, 147(1), 224–35.
Lewis, C., Annett, L. E., Davenport, S., Hall, A. A., & Lovatt, P. (2014). Mood changes following social dance sessions in people with Parkinson’s disease. Journal of Health Psychology, 21(4), 483–92. http://doi.org/10.1177/1359105314529681
Müllensiefen, D., Gingras, B., Musil, J., & Stewart, L. (2014). The musicality of non-musicians: an index for assessing musical sophistication in the general population. PloS one, 9(2), e89642.
Nelson, H. E., & Willison, J. (1991). National Adult Reading Test (NART). Windsor: Nfer-Nelson.
Nombela, C., Hughes, L. E., Owen, A. M., & Grahn, J. A. (2013). Into the groove: Can rhythm influence Parkinson’s disease? Neuroscience & Biobehavioral Reviews, 37(10), 2564–2570. http://doi.org/10.1016/j.neubiorev.2013.08.003
Thaut, M. H. (2005). Rhythm, Music, and the Brain: Scientific Foundations and Clinical Applications. New York: Routledge.
Zatorre, R. J., Chen, J. L., & Penhune, V. B. (2007). When the brain plays music: auditory–motor interactions in music perception and production. Nature reviews neuroscience, 8(7), 547-558.
Zentner, M., & Eerola, T. (2010). Rhythmic engagement with music in infancy. Proceedings of the National Academy of Sciences, 107(13), 5768-5773.