How brain functioning influences behaviour

Human behaviour, no matter how simple or complex, is orchestrated by the highly intricate and ordered functioning of convoluted white and grey matter, collectively know as the brain. The brain has been termed “the single most complex object in the known universe” (Reber & Reber 2001, p.99). Piano playing involves many of these elaborate functions. This behaviour will be discussed as it relates to normal brain functioning. In contrast, a study of Alzheimer’s disease will be examined briefly, in terms of how neurological damage may affect piano-playing, and how this type of brain damage may (or may not) lead to a deterioration in brain functioning in certain areas.

When a pianist sits in front of a piano, looks as a page of musical notes, and strikes a chord as a result, a very organized sequence of events is taking place within the body, and specifically within the brain and neural pathways.

To expound on the above, the following processes are happening. Looking at the musical contour of a note, for example, a crochet (?), denoting a “C” on the keyboard, involves bottom-up processing (Santrock, 2003, p.177). This is processing that starts with sensory receptors recording information from the environment, triggering action potentials (“changes in electrical potential which occur when an impulse is propagated by a neuron” (Reber ; Reber, 2001, p.8)), and thereby relaying information to the brain. In this instance, the information is relayed via the optic nerve. The brain then analyses this information. The class of sensory receptor involved in this visual input is called photoreception (Santrock, 2003, p.179).

The afferent (sensory) visual impulse is directed via the thalamus, a structure located at the top of the brain stem, to the occipital lobe, part of the cerebral hemisphere, and situated at the posterior of the skull (Santrock, 2003, p.94). The thalamus, in this way, operates as a kind of ‘relay station’. The information is then processed and combined into a known object. Thus, the note “C”, with a certain timing value, i.e. a crochet, is recognised.

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Knowledge of how to interpret this symbol would have been stored in the cerebellum (a structure in the hindbrain) as implicit memory (Santrock, 2003, p.325). Implicit memory is memory “in which behaviour is affected by prior experience without that experience being consciously recollected.” (Santrock, 2003, p.318) Piano-playing is a skill that is learned and stored in implicit memory, in much the same way as learning to driving a car (Santrock, 2003, p.318).

The memory information of the note would then be relayed via the cerebellum as efferent (motor) impulses, which would co-ordinate the movement of the arm, and subsequently, the finger, to strike the piano key (Reber ; Reber, 2001, p.113). A section of both the motor and sensory cortices, regions situated in the cerebral cortex (the former directly behind the frontal lobes and the latter at the front of the parietal lobes), would be involved in this activity. In processing the information, the motor cortex would co-ordinate how the finger strikes the key, and the sensory cortex would co-ordinate the amount of pressure to be applied (Santrock, 2003, p.97).

In a journal article, Marc Bangert et al (2003), concluded from brain imaging studies, that “musical training triggers instant plasticity in the cortex, and that right-hemisphere anterior areas provide an audio-motor interface for the mental representation of the keyboard” (Bangert et all, 2003, p.1471). Plasticity is the term used to describe the brain’s ability to be flexible, adaptable and malleable (Reber & Reber, 2001, p.42). In other words, Bangert et al, established that a brain ‘map’ starts to form (within 20 minutes in fact) of listening to a piece of music. They also found a hand-to-ear link was established with regards to what the keyboard looks like, which registered in the front right hemisphere of the brain.

Returning to the pianist who has just struck a note, the auditory information, which “consists of molecular movement represented as sounds waves” (Jordaan & Jordaan, 1998, p.256) is picked up by mechanoreceptors (in this instance, hair cells) by the outer ear, and sent to the cochlear/auditory nerve (Jordaan & Jordaan, 1998, p.255). The movement of the hair cells changes the physical stimulation of sound waves into the action potential of neural impulses (Santrock, 2003, p.208). From the auditory nerve the impulse is relayed to the brain stem and onward to the temporal lobe, part of the cerebral cortex, which perceives the sound (Jordaan & Jordaan, 1998, p.256). Specifically, the input is received by the primary and secondary auditory areas and projected to the auditory association area.

All neural impulses work hand-in-hand with neurotransmitters in terms of synaptic transmission. Neurotransmitters are chemical substances, which function as mediums of communication between presynaptic (sending) and postsynaptic (receiving) neurons (i.e. nerve cells)(Reber & Reber, 2001, p.466). In particular, in terms of piano-playing, the neurotransmitters serotonin, dopamine, norepinephrine and acetylcholine (ACh) are involved. ACh, an excitatory neurotransmitter, is responsible for transmission in terms of memory (of notes), learning (of new music), and the actions of the muscles (in the arms, hands and fingers, and legs and feet, if the foot pedal is pressed). Norepinephrine would control the pianist’s alertness. Dopamine and serotonin would play a role in attention, and would also be involved in the learning process.

Just as normal brain functioning influences behaviour, so too can neurological damage or deterioration affect it in different ways. Amusia is a type of agnosia for music (Reber ; Reber, 2001, p.29). Agnosia is a loss of ability to recognise objects, sounds and shapes, among other things, while the specific sense, in this instance, hearing and vision, is not defective nor is there any significant memory loss (Reber ; Reber, 2001, p.29). In other words, amusia is an impairment or loss of the aptitude to produce or comprehend musical notes or intonations. Damage to the temporal and/or occipital lobes may be involved in this disease.

Along a similar vein, in a single case study by William W. Beatty et al (1999, p.459), piano-playing by a patient with advancing Alzheimer’s disease (AD) was examined. Alzheimer’s is a progressive type of dementia characterised by gradual deterioration in intellectual abilities, for example, memory, which is a higher-level cortical function (Reber ; Reber, 2001, p.25). The disease also shows changes in personality and behaviour. Atrophy (wasting away) of areas of the brain characterises the disease (Reber ; Reber, 2001, p.25).

The adult patient in the study had learned to play the piano as a child. Part of the outcome of the study was evidence that “preserved musical performance in AD seems to depend on circuits involving the basal ganglia, cerebellum and motor areas of the thalamus and cerebral cortex that remain relatively intact until the late stages of the disease” (Beatty et al, 1999, p.459). The basal ganglia, a cluster of neurons, works in conjunction with the cerebral cortex and cerebellum. It co-ordinates and directs voluntary movement (Santrock, 2003, p.94).

What Beatty et al (1999), established was that memory and performance of musical compositions learned prior to the onset of the disease remained unaltered. After three years of the study, the patient also exhibited severe limb apraxia (the loss of ability to correctly perform coordinated movements of the limbs, in the absence of motor or sensory impairment.) (Reber ; Reber, 2001, p.48). Interestingly enough though, the quality in her piano-playing ability of familiar (i.e. previously known) compositions showed only subtle losses (Beatty et al, 1999, p.459).

However, learning of new compositions appeared to be significantly impaired (Beatty et al, 1999, p.467). The group’s conclusion was that the impairment could either relate to the brain’s inability to acquire new motor learning, or it may be attributed to incapacity of the patient with AD to sustain attention. Future studies in this area may be able to clarify the previous point (Beatty et al, 1999, p.467).

The brain demonstrates remarkable abilities to mastermind, co-ordinate and therefore influence behaviour, as has been shown in the above essay. Progressive neurological deterioration, as in Alzheimer’s disease, or damage such as amusia, has a marked effect on behaviour. However the brain’s ability to retain implicit memory in the face of Alzheimer’s, for example, been revealed via the skill of piano-playing.