Page 1 - Sensory, Attentional and Perceptual Processes

Class XI

Chap 5

Sensory, Attentional and Perceptual Processes

Lesson Notes

Module 1

We get aware of various objects with the help of our sense organs (e.g., eyes, ears). These
organs collect information not only from the external world, but also from our own body.
The information collected by our sense organs forms the basis of all our knowledge.
However, in order to be registered, the objects and their qualities (e.g., size, shape, colour)
must be able to draw our attention. The registered information must also be sent to the

brain that constructs some meaning out of them. Thus, our knowledge of the world
around us depends on three basic processes, called sensation, attention, and
perception.These processes are highly interrelated; hence, they are often considered as
different elements of the same process, called cognition.

NATURE AND VARIETY OF STIMULUS OR SENSORY PROCESSES

The external environment that surrounds us contains a wide variety of stimuli. Some of
them can be seen, or can be heard only, or that we can smell, or taste or we can experience
by touching. Human beings are bestowed with a set of seven sense organs. These sense
organs are also known as sensory receptors or information gathering systems, because

they receive or gather information from a variety of sources. Five of these sense organs
collect information from the external world. These are eyes, ears, nose, tongue, and skin.
Besides these five external sense organs, we have also got two deep senses. They are
called kinesthetic and vestibular systems. They provide us with important information
about our body position and movement of body parts related to each other.

SENSE MODALITIES
The initial experience of a stimulus or an object registered by a particular sense organ is
called sensation. It is a process through which we detect and encode a variety of physical

stimuli. Sensation also refers to immediate basic experiences of stimulus attributes, such