Decussations -Neuroscience Prompts

Decussations

Decussation occurs when fibers in the body cross from one side of the structure to the other and cross the midline and travel through the spinal cord to the opposite side of their origins. Decussation is a very hotly debated topic among biologist and neuroscientists to the extent that many theories have been developed to explain the neural crossings which are referred to as decussations. The neural crossing at the midline occurs as a result of an evolutionary change that involved a shift from ventral nerve cord to a dorsal nerve cord. Decussations only occur in vertebrates, and according to the somatic twist theory at some point in evolution, the body structure of the vertebrae underwent a 180-degree twist that resulted to the rearrangement of its body structure along a dorsal nerve cord. The evolution of decussation happened in many distinct systems and organism, and this shows that they had a significant functional advantage. However, the nature of this advantage is not clearly understood and defined.

Bigger Brains

The relationships between brain size and level of intelligence among humans and other species have never been well defined.  Despite human having exceptional cognitive capabilities, they do not have the biggest brain size in the animal kingdom. Big brains that people correlate to being intelligence could merely mean that they have more neurons and hence the greater processing power increasing their intelligence level. This is because according to evolution a Neanderthal had bigger brains than modern man and their intelligence ways way lower and on the other side men have bigger brains than women, but this does not mean men are smarter than women. Hence, the size of the brain does not influence their level of intelligence.

However, the brain structure correlates with intelligence more that size. Thicker cortices which are the wrinkly outer layer of the brain has been associated with higher intelligence levels for intelligence among people as it is responsible for higher level functions such computational capacity (Dicke & Roth, 2016). Subcortical regions are involved with memory, special awareness, decision making, and emotion. This indicates that the size of different parts of the brain determines an individual’s intelligence.

Muscle Memory

Muscle memory is not from the muscles as most people often think, but it forms as a procedural memory whereby the brain stores the memory of the activities that are done repeatedly. Repetition of the same action improves the muscle memory making it easier for people to carry out specific tasks without much thinking. Thus practice and repetition of a task form muscle memory. Certain brain areas are associated with muscle memory such as motor cortices, cerebellum, striatal areas and thalamus which facilitate motor learning that is achieved through long-lasting neuronal changes.

One of my muscle memories is playing the piano. As a middle school student, I attended piano classes through which I perfected my pianist skills. Having not played piano since middle school, I thought that the skills had diminished; however, in my sophomore year I signed up for in a piano contest which I eventually emerged the winner. This shows that the practice of piano in middle school resulted in muscle memory which I utilized in my piano competition. Therefore, muscle memory develops as a task is done in repetition and practice sharpens the memory.

References

Dicke, U., & Roth, G. (2016). Neuronal factors determining high intelligence. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 371(1685), 20150180.