Entrainment (biomusicology)

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A female California sea lion bobbing her head to an external beat.

Entrainment in the biomusicological sense refers to the synchronization (e.g. foot tapping) of organisms to an external perceived rhythm such as human music and dance. Humans are the only species for which all individuals experience entrainment, although there are documented examples of entrained nonhuman individuals.

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Beat induction

Beat induction is the process in which a regular isochronous pulse is activated while one listens to music (i.e. the beat to which one would tap one's foot). It was thought that the cognitive mechanism that allows us to infer a beat from a sound pattern, and to synchronize or dance to it, was uniquely human.[ citation needed ] No primate tested so far—with exception of the human species—can dance or collaboratively clap to the beat of the music. Humans know when to start, when to stop, when to speed up or to slow down, in synchronizing with their fellow dancers or musicians.[ citation needed ] Although primates do not appear to display beat induction, some parrots do. The most famous example, Snowball was shown to display genuine dance, including changing his movements to a change in tempo (Patel et al., 2009 [1] )

Beat induction can be seen as a fundamental cognitive skill that allows for music (e.g., Patel, 2008; Honing, 2007; 2012). We can hear a pulse in a rhythmic pattern while it might not even be explicitly in there: The pulse is being induced (hence the name) while listening—like a perspective can be induced by looking at an arrangement of objects in a picture.

Neuroscientist Ani Patel proposes beat induction—referring to it as "beat-based rhythm processing"—as a key area in music-language research, suggesting beat induction "a fundamental aspect of music cognition that is not a byproduct of cognitive mechanisms that also serve other, more clearly adaptive, domains (e.g. auditory scene analysis or language)" (Patel, 2008).

Evolutionary function

Joseph Jordania recently suggested that the human ability to be entrained was developed by the forces of natural selection as an important part of achieving the specific altered state of consciousness, battle trance. [2] Achieving this state, in which humans lose their individuality, do not feel fear and pain, are united in a shared collective identity, and act in the best interests of the group, was crucial for the physical survival of our ancestors against the big African predators, after hominids descended from the safer trees to the dangerous ground and became terrestrial.

Biological neuron model

Rapid motion of the fingers up and down together in phase (top), and finger motion that is out of phase (bottom.) Biologically synchronized finger motion.svg
Rapid motion of the fingers up and down together in phase (top), and finger motion that is out of phase (bottom.)

In addition to transmitting signals to other parts of the brain, neurons can modify the rules which neighboring neurons to in a process called biological synchronization. [3] The figure to the right illustrates entrainment between finger motion of the left and right hands, but only if the motion of both hands are moving in the same direction. To illustrate this, begin by slowly moving the index fingers slowly in an anti-phase manner, as shown in the bottom portion of the figure. Then, gradually increase the frequency to make the motion as rapid as possible. Eventually your fingers will be moving in phase, as shown in the top portion of the figure. [4] It has been proposed that this behavior resembles the process by which neurons create a phase-locked loop that permits recognition of consonant musical intervals. [5] [6]

See also

Related Research Articles

Rhythm generally means a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions". This general meaning of regular recurrence or pattern in time can apply to a wide variety of cyclical natural phenomena having a periodicity or frequency of anything from microseconds to several seconds ; to several minutes or hours, or, at the most extreme, even over many years.

<span class="mw-page-title-main">Synchronization</span> Coordination of events to operate a system in unison

Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or in time. Systems that operate with all parts in synchrony are said to be synchronous or in sync—and those that are not are asynchronous.

Musicality is "sensitivity to, knowledge of, or talent for music" or "the quality or state of being musical", and is used to refer to specific if vaguely defined qualities in pieces and/or genres of music, such as melodiousness and harmoniousness. These definitions are somewhat hampered by the difficulty of defining music, but, colloquially, "music" is often contrasted with noise and randomness. Judges of contest music may describe a performance as bringing the music on the page to life; of expressing more than the mere faithful reproduction of pitches, rhythms, and composer dynamic markings. In the company of two or more musicians, there is the added experience of the ensemble effect in which the players express something greater than the sum of their individual parts. A person considered musical has the ability to perceive and reproduce differences in aspects of music including pitch, rhythm, and harmony. Two types of musicality may be differentiated: to be able to perceive music and to be able to reproduce music in addition to creating music.

<span class="mw-page-title-main">Pyramidal cell</span> Projection neurons in the cerebral cortex and hippocampus

Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons are also one of two cell types where the characteristic sign, Negri bodies, are found in post-mortem rabies infection. Pyramidal neurons were first discovered and studied by Santiago Ramón y Cajal. Since then, studies on pyramidal neurons have focused on topics ranging from neuroplasticity to cognition.

<span class="mw-page-title-main">CREB</span> Class of proteins

CREB-TF is a cellular transcription factor. It binds to certain DNA sequences called cAMP response elements (CRE), thereby increasing or decreasing the transcription of the genes. CREB was first described in 1987 as a cAMP-responsive transcription factor regulating the somatostatin gene.

The consciousness and binding problem is the problem of how objects, background and abstract or emotional features are combined into a single experience.

A phase response curve (PRC) illustrates the transient change in the cycle period of an oscillation induced by a perturbation as a function of the phase at which it is received. PRCs are used in various fields; examples of biological oscillations are the heartbeat, circadian rhythms, and the regular, repetitive firing observed in some neurons in the absence of noise.

A gamma wave or gamma rhythm is a pattern of neural oscillation in humans with a frequency between 25 and 140 Hz, the 40 Hz point being of particular interest. Gamma rhythms are correlated with large-scale brain network activity and cognitive phenomena such as working memory, attention, and perceptual grouping, and can be increased in amplitude via meditation or neurostimulation. Altered gamma activity has been observed in many mood and cognitive disorders such as Alzheimer's disease, epilepsy, and schizophrenia.

Brainwave entrainment, also referred to as brainwave synchronization or neural entrainment, refers to the observation that brainwaves will naturally synchronize to the rhythm of periodic external stimuli, such as flickering lights, speech, music, or tactile stimuli.

<span class="mw-page-title-main">Neural oscillation</span> Brainwaves, repetitive patterns of neural activity in the central nervous system

Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macroscopic neural oscillations is alpha activity.

Evolutionary musicology is a subfield of biomusicology that grounds the cognitive mechanisms of music appreciation and music creation in evolutionary theory. It covers vocal communication in other animals, theories of the evolution of human music, and holocultural universals in musical ability and processing.

Music psychology, or the psychology of music, may be regarded as a branch of both psychology and musicology. It aims to explain and understand musical behaviour and experience, including the processes through which music is perceived, created, responded to, and incorporated into everyday life. Modern music psychology is primarily empirical; its knowledge tends to advance on the basis of interpretations of data collected by systematic observation of and interaction with human participants. Music psychology is a field of research with practical relevance for many areas, including music performance, composition, education, criticism, and therapy, as well as investigations of human attitude, skill, performance, intelligence, creativity, and social behavior.

Injection locking and injection pulling are the frequency effects that can occur when a harmonic oscillator is disturbed by a second oscillator operating at a nearby frequency. When the coupling is strong enough and the frequencies near enough, the second oscillator can capture the first oscillator, causing it to have essentially identical frequency as the second oscillator. This is injection locking. When the second oscillator merely disturbs the first but does not capture it, the effect is called injection pulling. Injection locking and pulling effects are observed in numerous types of physical systems, however the terms are most often associated with electronic oscillators or laser resonators.

Snowball is a male Eleonora cockatoo, noted as being the first non-human animal conclusively demonstrated to be capable of beat induction: perceiving music and synchronizing his body movements to the beat. He currently holds the Guinness World Record for most dance moves by a bird.

The neuroscience of music is the scientific study of brain-based mechanisms involved in the cognitive processes underlying music. These behaviours include music listening, performing, composing, reading, writing, and ancillary activities. It also is increasingly concerned with the brain basis for musical aesthetics and musical emotion. Scientists working in this field may have training in cognitive neuroscience, neurology, neuroanatomy, psychology, music theory, computer science, and other relevant fields.

Cognitive musicology is a branch of cognitive science concerned with computationally modeling musical knowledge with the goal of understanding both music and cognition.

<span class="mw-page-title-main">Trance</span> Abnormal state of wakefulness or altered state of consciousness

Trance is a state of semi-consciousness in which a person is not self-aware and is either altogether unresponsive to external stimuli or is selectively responsive in following the directions of the person who has induced the trance. Trance states may occur involuntarily and unbidden.

Beat deafness is a form of congenital amusia characterized by a person's inability to distinguish musical rhythm or move in time to it.

Pigment dispersing factor (pdf) is a gene that encodes the protein PDF, which is part of a large family of neuropeptides. Its hormonal product, pigment dispersing hormone (PDH), was named for the diurnal pigment movement effect it has in crustacean retinal cells upon its initial discovery in the central nervous system of arthropods. The movement and aggregation of pigments in retina cells and extra-retinal cells is hypothesized to be under a split hormonal control mechanism. One hormonal set is responsible for concentrating chromatophoral pigment by responding to changes in the organism's exposure time to darkness. Another hormonal set is responsible for dispersion and responds to the light cycle. However, insect pdf genes do not function in such pigment migration since they lack the chromatophore.

Aniruddh (Ani) D. Patel is a cognitive psychologist known for his research on music cognition and the cognitive neuroscience of music. He is Professor of Psychology at Tufts University, Massachusetts. From a background in evolutionary biology, his work includes empirical research, theoretical studies, brain imaging techniques, and acoustical analysis applied to areas such as cognitive musicology, parallel relationships between music and language, and evolutionary musicology. Patel received a Guggenheim Fellowship in 2018 to support his work on the evolution of musical cognition.

References

  1. Patel, A.D.; Iversen, J.R.; Bregman, M.R.; Schulz, I. (2009). "Experimental evidence for synchronization to a musical beat in nonhuman animals". Current Biology. 19 (10): 827–830. Bibcode:2009CBio...19..827P. doi: 10.1016/j.cub.2009.03.038 . PMID   19409790. S2CID   8133846.
  2. Joseph Jordania. Why do People Sing? Music in Human Evolution. Logos, 2011
  3. Strogatz, S. H.; Stewart, I. (1993). "Coupled oscillators and biological synchronization" (PDF). Scientific American. 269 (6): 102–109. Bibcode:1993SciAm.269f.102S. doi:10.1038/scientificamerican1293-102. PMID   8266056.
  4. Haken, H.; Kelso, J. A. S.; Bunz, H. (1985). "A theoretical model of phase transitions in human hand movements" (PDF). Biological Cybernetics. 51 (5): 347–356. doi:10.1007/BF00336922. PMID   3978150. S2CID   14960818.
  5. Shapira Lots, I.; Stone, L. (2008). "Perception of musical consonance and dissonance: An outcome of neural synchronization". Journal of the Royal Society, Interface. 5 (29): 1429–1434. doi:10.1098/rsif.2008.0143. PMC   2607353 . PMID   18547910.
  6. Heffernan, B.; Longtin, A. (2009). "Pulse-coupled neuron models as investigative tools for musical consonance". Journal of Neuroscience Methods. 183 (1): 95–106. doi:10.1016/j.jneumeth.2009.06.041. PMID   19591870. S2CID   1658167.

Further reading