Introduction to Psychology
Sensation & Perception
Senses
Above the 5 senses are many different senses our bodies naturally sustain.
Temperature Hunger Full Bladder
Pain Thirst Time
Sensation: nervous system detects or encodes information from the environment.
Perception: how we interpret nerve sensations or give meaning to them
We ask questions like:
○ What is it?
○ How Bright?
○ What color?
○ Where is it?
Light & Brain Response
Light passes through the cornea (front part of our eye) which helps focus the light. Then, it goes through
the pupil which can change size depending on how much light there is. After that, it passes through the
lens, which further focuses the light onto the retina at the back of the eye.
The retina has special cells called photoreceptors, made up of rods and cones, that detects color and
light. These cells turn the light into electrical signals. These signals travel through sensory neurons
(optic nerve) to the brain.
The brain processes these signals and turns them into images, allowing us to see and understand what
we’re looking at.
Transduction: the way the nervous system turns physical energy into action potential.
NOTE: Sensation and perception are NOT the same thing.
Perception
Perceptions are unique to each of us, but there are commonalities.
For example, when we’re asked what color we see, not everyone sees the same color.
We do not perceive everything in the physical world
, ○ We miss events that happen around us, and even in front of us
We perceive things that aren’t there.
Construction of our nervous system and certain parts of our retina can detect motion in static images, like
optical illusions. Although it seems like something is moving, the image is always still.
Perceptions are reconstructions, not reproductions of the physical world.
○ Perceptions are not true representations of the physical world.
Three Themes of Perception
1. Perception depends on context
2. Perception is about objects
3. Perception is multimodal
Perception depends on context
EXAMPLE: “the dress” 2015 social media battle
○ Blue & Black OR White & Gold
Visible Spectrum
The segment of the electromagnetic spectrum that the human eye can view.
Light
○ Electromagnetic waves with wavelengths between 400 and 700 nanometers
○ Can be a wave, and also consists of particles known as photons
Reflection & Refraction
○ Light reflects when it bounces off of objects (mirror)
○ Light refracts when it passes through objects and bends (water or glass)
Lenses work by bending (refracting) light
Key Parts of the Eye
Ciliary Muscle Retina Lens
Changes shape of the lens Has sensory cells that transduce Bends light so that it focuses on
light retina
Coming Into Focus
Unaccommodated: the ciliary muscle is relaxed and sees far away objects
Accommodated: contracted ciliary muscle and sees close-up objects
Corrective Measures
Sensation & Perception
Senses
Above the 5 senses are many different senses our bodies naturally sustain.
Temperature Hunger Full Bladder
Pain Thirst Time
Sensation: nervous system detects or encodes information from the environment.
Perception: how we interpret nerve sensations or give meaning to them
We ask questions like:
○ What is it?
○ How Bright?
○ What color?
○ Where is it?
Light & Brain Response
Light passes through the cornea (front part of our eye) which helps focus the light. Then, it goes through
the pupil which can change size depending on how much light there is. After that, it passes through the
lens, which further focuses the light onto the retina at the back of the eye.
The retina has special cells called photoreceptors, made up of rods and cones, that detects color and
light. These cells turn the light into electrical signals. These signals travel through sensory neurons
(optic nerve) to the brain.
The brain processes these signals and turns them into images, allowing us to see and understand what
we’re looking at.
Transduction: the way the nervous system turns physical energy into action potential.
NOTE: Sensation and perception are NOT the same thing.
Perception
Perceptions are unique to each of us, but there are commonalities.
For example, when we’re asked what color we see, not everyone sees the same color.
We do not perceive everything in the physical world
, ○ We miss events that happen around us, and even in front of us
We perceive things that aren’t there.
Construction of our nervous system and certain parts of our retina can detect motion in static images, like
optical illusions. Although it seems like something is moving, the image is always still.
Perceptions are reconstructions, not reproductions of the physical world.
○ Perceptions are not true representations of the physical world.
Three Themes of Perception
1. Perception depends on context
2. Perception is about objects
3. Perception is multimodal
Perception depends on context
EXAMPLE: “the dress” 2015 social media battle
○ Blue & Black OR White & Gold
Visible Spectrum
The segment of the electromagnetic spectrum that the human eye can view.
Light
○ Electromagnetic waves with wavelengths between 400 and 700 nanometers
○ Can be a wave, and also consists of particles known as photons
Reflection & Refraction
○ Light reflects when it bounces off of objects (mirror)
○ Light refracts when it passes through objects and bends (water or glass)
Lenses work by bending (refracting) light
Key Parts of the Eye
Ciliary Muscle Retina Lens
Changes shape of the lens Has sensory cells that transduce Bends light so that it focuses on
light retina
Coming Into Focus
Unaccommodated: the ciliary muscle is relaxed and sees far away objects
Accommodated: contracted ciliary muscle and sees close-up objects
Corrective Measures
