Our brain is a complex system that receives and processes information, similar to a computer processor. But human brain is more powerful because we are able to modify our information based on our thoughts and past experiences. For example, our perspective is the conscious experience resulting from results stimulation (Goldstein, 2019). Our brain does not make an exact copy of the things and attributes of our world; instead, it creates a representation of our surroundings (Abdollahi, 2024). This representation is created from two parts: the bottom-up processing, where we get information from our environmental energy without any preconceived ideas; and the top-down processing, where we build-on with our past knowledge and experience to understand what we see.  

Each of our senses is capable of detecting a specific type of energy in the environment. When we use our vision sense, for example, our receptor converts environmental energy into action potentials for our mind; this process is known as transduction (Abdollahi, 2024). Our bottom-up processing helps us understand our environmental energy, as other important factors further shape our perception. This continues with the interaction of top-down processing, where we modify our initial perception by connecting it with our past experiences, expectations, and knowledge. In other words, what we visually see is just one aspect that contributes to how we perceive things; other factors from the top-down can significantly change the way we perceive specific information. For example, those who don’t suffer from vision problems will all see the same colors; but, when other factors such as cultural influence are considered, it will be different for some people.

As an American-born Chinese, I noticed a few differences on how Americans and Chinese perceive things. Many people perceive colors as simply “colors” with no special meaning; for example, white is just white, and red is just red; this represents the bottom-up processing. However, people from different cultures may visually see the same color, but their perceptions are different. For example, in most Western cultures, white represents purity and innocence, so it is usually used for meaningful occasions such as weddings. However, in most Eastern cultures, white represents death and mourning and is commonly used at funerals. Similarly, when receiving white flowers, people from different cultures will perceive them differently based on their experience and knowledge. For example; Chinese might find it inappropriate because it has an offensive meaning for living people, while others find it special and romantic such as Americans. 

All of these perceptions are influenced by the up-down processing, which uses cultural beliefs and knowledge to interpret and make sense of our sensory input. To further understand how top-down processing works, we have to first know what information they send to the neurons they affect. Top-down processing modifies how neurons are tuned, allowing them to share more useful information about the stimulus. “Neurons can increase the degree of modulation of their responses over a set of stimuli, making these responses more informative about stimulus identity” (Gilbert et al., 2013). In simpler terms, cultural beliefs and experiences serve as top-down factors that affect how neurons respond to specific colors. When people from diverse cultural backgrounds see the color white, for example, their specific top-down changes the brain reactions related to this color. 

The way that cultural background and beliefs influence color perception shows the interaction between bottom-up and up-down processing. At first, colors are only “colors” with no cultural or other influences. However, when cultural beliefs are introduced, top-down processing will begin to modify our understanding of things. Even people’s perceptions of common things, such as white flowers, can be changed by these cultural factors through top-down processing.

Reference: 

Goldstein, E. B. (2019). Cognitive Psychology: Connecting Mind, Research, and Everyday Experience.

Gilbert, C. D., & Li, W. (2013). Top-down influences on visual processing. Nature reviews. Neuroscience, 14(5), 350–363. https://doi.org/10.1038/nrn3476

Abdollahi, F. (2024). Lesson 3: Perception [Commentary]. The Penn State University Introduction to Cognitive Psychology Backboard: https://psu.instructure.com/courses/2313612

Kastanakis, M., & Voyer, B. G. (2014). The effect of culture on perception and cognition: A conceptual framework. Journal of Business Research, 67(4), 425-433. doi:10.1016/j.jbusres.2013.02.009