Perception and attention in human cognition

Perception is our own individual sense of the world we live in and it is comprised of our recognition of stimuli in the environment as well as actions made in response to these environmental stimuli (Cherry, 2012). The function and purpose of the process of perception is to provide us with information regarding the environment that is necessary for continued survival (Cherry, 2012). Furthermore, perception dictates the way our environment is experienced and it also provides the stage where we can choose different actions within the environment.

Human perception is comprised of five distinct senses that provide the brain with different information about the world. These five senses are sight, sound, taste, smell, and touch. Proprioception is also a component of perception, which involves the brain effectively detecting changes occurring with regard to movement or position of the body (Cherry, 2012). Cognitive processes are also involved in perception, as they are used to process information provided by the senses (Cherry, 2012).

The steps involved in taking in information from the environment and ultimately acting in response to a certain stimulus is known as the perceptual process. There are eight steps involved in this continual process that allows us to make organizational sense of the stimuli in the world around us. With regard to visual stimuli, these perceptual steps are: the environmental stimulus; the attended stimulus; the image on the retina; transduction; neural processing, perception; recognition; and action (Cherry, 2012).

The environmental stimulus includes anything and everything that could possibly be perceived within our environment (Cherry, 2012). All of the five senses are used in the perception of environmental stimuli, and proprioception is used to take in information regarding the movement or position of the body. The next step, the attended stimulus, represents the specific stimulus upon which attention is focused on in the environment (Cherry, 2012). These attending stimuli may be familiar or novel (Cherry, 2012).

With regard to visual processing, the next step in the perceptual process involves the projection of the image on the retina (Cherry, 2012). In this step, light enters the eye through the pupil and cornea, which focuses the light, and ends up on the lens. The lens and cornea function together in order to create an inverted image upon the retina (Cherry, 2012).

Transduction is the next step in the perceptual process. This step involves the transformation of the retinal image into a series of electrical signals. These signals are the vehicle upon which visual messages are sent to the brain and then interpreted (Cherry, 2012). Photoreceptors are cells on the retina responsible for the action of transduction through functioning of proteins known as rods and cones (Cherry, 2012). Rods and conse have different functions, as rods are responsible for the perception of visual stimuli in dimmer light, while cones are involved in perceiving stimuli in normal levels of light (Cherry, 2012). The specific molecule involved in transduction contained within the rods and cones is called retinal (Cherry, 2012).