Perception is defined as the process of assigning meaning to information received about the environment based on the past experiences.
The two types of processing and Top-down processing and Bottom-up processing.
(i) Top-down processing – If we pay attention to each of our senses all the time, our senses would be overwhelmed. Therefore, many times, our brain uses the context in which it appears or existing knowledge about it while perceiving a particular stimulus. This process is called as top-down processing. When we utilize top-down processing, our ability to understand information is influenced by cognition and context.
Our brain applies what it knows or expects to perceive to understand the stimulus. Top-down processing happens when we work from the general to the specific. It helps us to quickly make sense of the environment. However, perceptual set (our fixed way of viewing stimuli based on past experience/expectations) can hinder our ability to be creative/open-minded.
(ii) Bottom-up processing – Many times our perceptual experience is based entirely on the sensory stimuli and is not influenced by the context in which it appears. In such situations, we take in energy from the environment and convert it to neural signals (sensation) and then try to interpret it (perception). This process is called as bottom-up processing. Bottom-up processing is a process that starts with an incoming stimulus and works upwards until a representation of the object is formed in our brain. Our perceptual experience is based entirely on the sensory stimuli that we piece together. It is only data based i.e., takes place as it happens and requires no previous knowledge or learning.
For e.g.,
13 may be viewed as letter B or the number 13.
This is bottom-up processing-
- 11, 12, 13, 14 – It is perceived as 13 in the number sequence.
- ‘I enjoyed the film A13CD’. It is perceived as letter B.