Sensory information is accurate, but the interpretation of sensory information is unreliable and biased. While senses were traditionally considered passive mechanisms, it is now evident that the interpretation of information received through the senses is an active mechanism based on inherited traits and past experiences. Several factors, both internal and external, influence perception, and those factors are always subjective because all individuals possess different internal traits and experience different external events. Sensory information cannot be accurate and reliable because it depends on individual factors for interpretation and evaluation.
A sensory organ will always receive sensory input objectively, but the interpretation of that information in the brain is always subjective. Contemporary science is aware of the interactions between internal and external factors and how those interactions define perception (Stiles, 2011). For example, every sensory input is forwarded to the brain, and the brain will compare every input with previous experiences to categorize it. Because interpretation occurs in the brain, and because it is linked to previous experiences, the brain can adjust sensory information it receives to classify it under familiar experiences, and that is how sensory perception becomes subjective and inaccurate.
Furthermore, Bergson (1912/2007) indicates that pure memory, memory-image, and perception are three distinct processes that occur together, and the quality of perception is affected by all those processes. When our consciousness recollects memories, affection and actual psychological states interfere with the accuracy of data retrieved. According to Bergson (1912/2007), perception is not linked to reality because the consciousness considers affection and memory when interpreting input, so it is not possible to obtain “pure consciousness.” Because sensory information can be accurate only when a person lacks affection and previous sensory input memories, sensory perception cannot be accurate.
Another reason why sensory input is inaccurate is because our mind is also a source of sensory information that provides the consciousness with internal sensory input. According to some theories, the consciousness can perceive sensory input from both external sources and the internal sources, but the consciousness has to distinguish them to achieve accurate perception (Heidelberger, 2004). As the result, only subjective self-certainty and willpower define the objectivity of sensory perception (Heidelberger, 2004). Because the consciousness is not always capable of distinguishing personal input and external input, sensory perception is inaccurate.
With scientific studies and observations in mind, it is possible to notice that all theories suggest both innate and external factors contribute to the interpretation of sensory data. The accuracy of sensory data greatly depends on personal affection, memory (Bergson, 1912/2007), physiological mechanisms that interpret and modify it, and social circumstances (Stiles, 2011). Although those are the main determinants for perception accuracy, they are only a segment of the complex interaction between innate and external influences that define perception accuracy.
Both nature and nurture are equally accountable for the accuracy of data interpretation. Stiles (2011) criticizes contemporary researchers who use outdated models that dismiss the relevance of social factors in defining human development. Furthermore, Stiles (2011) points out that the relationship between nature and nurture is reciprocal. If nurture can affect nature, nature changes with social influences and life events. If a person’s nature changes, interpretation of sensory information and recollection of memories will also change. Therefore, nature and nurture are equally accountable for the accuracy of sensory data interpretation and evaluation.
It is possible to notice that perception can only be subjective because it depends on subjective factors. Each sensory input that reaches the brain is adjusted to fit previous experiences, so it cannot be considered accurate. Furthermore, psychological and sociological influences determine how the information will be filtered, associated, and memorized once it reaches the brain. It is obvious that sensory perception can be accurate only when interpretation is objective. However, interpretation cannot be objective, so sensory perception is inaccurate.
Bergson, H. (2007). Matter and memory. New York, NY: Cosimo, Inc. (Original work published 1912).
Heidelberger, M. (2004). Nature from within: Gustav Theodor Fechner and his psychophysical worldview. (C. Klohr, Trans.). Pittsburgh, PA: University of Pittsburgh Press.
Stiles, J. (2011). Brain development and the nature versus nurture debate. Progress in Brain Research, 189, 3-22. doi:10.1016/B978-0-444-53884-0.00015-4
