Sensation and perception plays two complimentary but totally different roles in how we interpret the world around us. Sensation is the process by which we sense our environment through touch, smell, sight, taste and smell. This raw information from our sensory organs is then transmitted to the brain where perception is made. Perception is our way of interpreting what these sensations mean and how to make sense of it.
Sensory abilities are measure by the absolute threshold, which the weakest level of stimulus that can be accurately detected. For humans, this could be a candle seen 30 miles away on dark, clear night or the scent of a drop of perfume in a large room. The stimuli come from receptors in our bodies which are located in our eyes, ears, nose, skin, muscles and even in the certain parts of our digestive tract. These receptors are designed to detect certain types of physical energy, such as light and sound waves. Stimulation is then converted to electrochemical signals called neural impulses, which the nervous system transmits to the different regions of the brain’s cortex. The different regions of the cortex translate different neural impulses into different psychological experiences.
During perception the brain computes the size and distance relationship, determines where edges and boundaries exist and identify figures. The brain automatically computes the sensory feedback and guides the body to perform the necessary task. When our perception of an object is distracted, our calculations pertaining to size and distance are also affected. Our previous experiences and what we expect to see or not to see contributes a lot to our perception of things around us.