if you had no senses → you would not be able to react to anything.
without sensation, there is no mental life.
sensation: the basic processes by which sensory organs & the nervous system
respond to stimuli in the environment and to the psychological experiences
that result from those processes
→ bitterness of a taste / loudness of a sound
perception: the more complex organizing of sensory information within the
brain and to the meaningful interpretations extracted from it.
→ this is a strong coffee / my alarm clock is ringing
the process of sensation
physical stimulus → physiological response → sensory experience
something is perceived by someone
● something = physical stimulus: the trigger
● stimulus causes a physiological response (activates receptors): the
pattern of chemical and electrical activity in the sensory organs after
the trigger
● this response creates a sensory experience: the subjective sensation/
perception we experience after the stimulation of the sensory organs
→ the sensory experience tells us something about the physical stimulus but it
is very different.
sensory receptors: specialized structures (nerve endings) that respond to
physical stimuli by producing electrical changes that can initiate neural
impulses in sensory neurons.
sensory neurons: specialized neurons that carry information from sensory
receptors to the central nervous system.
a neuron is a nerve cell (zenuwcel) that can send and receive (electrical) signals
, aristoteles 5 senses: smell, taste, hearing, vision & touch. but there are more
than 5 senses:
the neurons for any sense lead to their own pathway in the nervous system
conscious sensory experiences happen in the cerebral cortex which has
different sensory areas.
→ you see light because receptors in your eyes are connected to visual
areas of your cortex
transduction: the process by which a
receptor cell produces an electrical
change in response to physical
stimulation.
receptor potential: the electrical
change that happens across the
membrane of the receptor cell during
the process of transduction.
sensory coding: sensory organs
preserve (maintain) information about
the physical stimuli to know the
patterns
energy can vary along 2 dimensions:
1. quantitative variation: the amount or the intensity of energy. (a weak or
strong light)
2. qualitative variation: the kind of energy. (lights of different wavelengths
(colors), sounds with different frequencies (high/low))
coding stimulus quantity:
● stronger stimuli produce larger receptor potentials → they produce
faster rates of action in the sensory neurons → strong stimulus
● slow rate of action → weak stimulus