• The activation of receptors in the various
sense organs is Sensation.
• Sensory receptors are specialized forms of
• Sensory receptors are stimulated by
different kinds of Energy e.g. light
stimulates receptors in eyes whereas
vibrations trigger the receptors in the ears.
Sensation and perception
• Sensation is the stimulus- detection process by which our
sense organs respond to and translate environmental
stimuli into nerve impulses that are sent to the brain
• Perception is making “sense” of what are senses tells us. It
is the active process of organising this stimulus input and
giving it meaning.
(Mather, 2006; May 2007)
• Stimuli that are below the level of
conscious awareness are called subliminal
• These stimuli are just strong enough to
activate the sensory receptors but not strong
enough for people to be consciously aware
of them. Many people believe that these
stimuli act upon the unconscious mind,
influencing behaviour in a process called
• Habituation: The tendency of the brain to stop
attending to constant, unchanging information.
• Sensory Adaptation: The tendency of sensory
receptor cells to become less responsive to a stimulus that
is unchanging eg piercing of nose and ears are not felt by
woman all times
Perception: is a process
by which individuals organize
and interpret their sensory
impressions in order to give
meaning to their environment.
Perceptual Processing functions
• Bottom-up processing: the system takes in
individual elements of the stimulus and then
combines them into a unified perception.
• Top-down processing: sensory information
is interpreted in light of existing knowledge,
concepts, ideas, and expectations.
Role of attention in perception
• Attention involves two processes of
• 1) Focusing on...