Temporal dynamics of music and language
The temporal dynamics of music and language describes how the brain coordinates its different regions to
Neuroanotomy of language and music
Key areas of the brain are used in both music processing and
The
In addition to the specific regions mentioned above many "information switch points" are active in language and music processing. These regions are believed to act as transmission routes that conduct information. These neural impulses allow the above regions to communicate and process information correctly. These structures include the thalamus and the basal ganglia.[2]
Some of the above-mentioned areas have been shown to be active in both music and language processing through PET and fMRI studies. These areas include the primary motor cortex, the Brocas area, the cerebellum, and the primary auditory cortices.[2]
Imaging the brain in action
The imaging techniques best suited for studying temporal dynamics provide information in real time. The methods most utilized in this research are functional magnetic resonance imaging, or fMRI, and positron emission tomography known as PET scans.[3]
Positron emission tomography involves injecting a short-lived radioactive tracer isotope into the blood. When the radioisotope decays, it emits positrons which are detected by the machine sensor. The isotope is chemically incorporated into a biologically active molecule, such as glucose, which powers metabolic activity. Whenever brain activity occurs in a given area these molecules are recruited to the area. Once the concentration of the biologically active molecule, and its radioactive "dye", rises enough, the scanner can detect it.[3] About one second elapses from when brain activity begins to when the activity is detected by the PET device. This is because it takes a certain amount of time for the dye to reach the needed concentrations can be detected.[4]
Another important tool for analyzing temporal dynamics is magnetoencephalography, known as MEG. It is used to map brain activity by detecting and recording magnetic fields produced by electrical currents generated by neural activity. The device uses a large array of superconducting quantum interface devices, called SQUIDS, to detect magnetic activity. Because the magnetic fields generated by the human brain are so small the entire device must be placed in a specially designed room that is built to shield the device from external magnetic fields.[5]
Other research methods
Another common method for studying brain activity when processing language and music is transcranial magnetic stimulation or TMS. TMS uses induction to create weak electromagnetic currents within the brain by using a rapidly changing magnetic field. The changes depolarize or hyper-polarize neurons. This can produce or inhibit activity in different regions. The effect of the disruptions on function can be used to assess brain interconnections.[6]
Recent research
Many aspects of language and musical melodies are processed by the same brain areas. In 2006, Brown, Martinez and Parsons found that listening to a melody or a sentence resulted in activation of many of the same areas including the primary motor cortex, the supplementary motor area, the Brocas area, anterior insula, the primary audio cortex, the thalamus, the basal ganglia and the cerebellum.[7]
A 2008 study by Koelsch, Sallat and Friederici found that language impairment may also affect the ability to process music. Children with specific language impairments, or SLIs were not as proficient at matching tones to one another or at keeping tempo with a simple metronome as children with no language disabilities. This highlights the fact that neurological disorders that effect language may also affect musical processing ability.[8]
Walsh, Stewart, and Frith in 2001 investigated which regions processed melodies and language by asking subjects to create a melody on a simple keyboard or write a poem. They applied TMS to the location where musical and lingual data. The research found that TMS applied to the left frontal lobe had affected the ability to write or produce language material, while TMS applied to the auditory and Brocas area of the brain most inhibited the research subject's ability to play musical melodies. This suggests that some differences exist between music and language creation.[9]
Developmental aspects
The basic elements of musical and lingual processing appear to be present at birth. For example, a French 2011 study that monitored fetal heartbeats found that past the age of 28 weeks, fetuses respond to changes in musical pitch and tempo. Baseline heart rates were determined by 2 hours of monitoring before any stimulus. Descending and ascending frequencies at different tempos were played near the
A 2010 study researched the development of lingual skills in children with speech difficulties. It found that musical stimulation improved the outcome of traditional
Applications in Rehabilitation
Recent studies found that the effect of music in the brain is beneficial to individuals with brain disorders.
Parkinson's disease
Individuals with
Huntington's disease
Huntington's disease affects a person's movement, cognitive as well as psychiatric functions which severely affects his or her quality of life.[18] Most commonly, patients with Huntington's Disease most commonly experience chorea, lack of impulse control, social withdrawal and apathy. Schwarz et al. conducted a review over the published literature concerning the effects of music and dance therapy to patients with Huntington's disease. The fact that music is able to enhance cognitive and motor abilities for activities other than those of music related ones suggests that music may be beneficial to patients with this disease.[13] Although studies concerning the effects of music on physiologic functions are essentially inconclusive, studies find that music therapy enhances patient participation and long term engagement in therapy[13] which are important in achieving the maximum potential of a patient's abilities.
Dementia
Individuals with Alzeihmer's disease caused by dementia almost always become animated immediately when hearing a familiar song.[14] Särkämo et al. discusses the effects of music found through a systemic literature review in those with this disease. Experimental studies on music and dementia find that although higher level auditory functions such as melodic contour perception and auditory analysis are diminished in individuals, they retain their basic auditory awareness involving pitch, timbre and rhythm.[14] Interestingly, music-induced emotions and memories were also found to be preserved even in patients suffering from severe dementia. Studies demonstrate beneficial effects of music on agitation, anxiety and social behaviors and interactions.[14] Cognitive tasks are affected by music as well, such as episodic memory and verbal fluency.[14] Experimental studies on singing for individuals in this population enhanced memory storage, verbal working memory, remote episodic memory and executive functions.[14]
References
- ^ PMID 11230091.
- ^ S2CID 199667772.
- ^ S2CID 14341862.
- ISBN 978-1852337988.
- ^ PMID 20884360.
- S2CID 31458874.
- S2CID 15189129.
- S2CID 6678801.
- S2CID 31971115.
- PMID 22213904.
- PMID 20663139.
- ^ PMID 29323122.
- ^ PMID 31450508.
- ^ S2CID 52971959.
- ^ PMID 25316915– via Oxford Academic.
- PMID 25890145– via Elsevier Science Direct.
- ^ Tiarhou, Lazaros (2013). "Dopamine and Parkinson's Disease". Madame Curie Bioscience Database – via NCBI.
- ^ Mayo Clinic Staff (May 16, 2018). "Huntington's disease". Mayo Clinic.