Defining sensation and perception
Sensation is an awareness resulting from the stimulation of the sensory organs (e.g., eyes and ears).
Sensation is a function of the low level, biochemical, and neurological mechanisms that allow the
receptor cells of a sensory organ to detect an environmental stimulus. The goal of sensation is
detection.
Perception refers to the way sensory information is organised, interpreted, and consciously
experienced. Perception involves both bottom‐up processing and top‐down processing.
On one hand, bottom‐up processing refers to the fact that perceptions are built from sensory input.
On the other hand, how we interpret those sensations is influenced by our available knowledge, our
experiences, and our thoughts. This is called top‐down processing.
The goal of perception is to create useful information about our environment.
Sensation is when our senses detect things around us, like seeing or hearing. Perception is how our
brain interprets and makes sense of those sensations. Our experiences and thoughts affect how we
perceive things. Both sensation and perception work together to help us understand and interact
with our environment. Our sense organs have a minimum requirement of stimulation to detect a
stimulus, which is called an absolute threshold. Signal detection is the process of measuring this
threshold to determine how well our sense organs can detect a signal.)
Sense Absolute thresholds
Vision‐ A streetlight seen 10 kilometres away on a dark and clear night.
Hearing -The ticking of a watch heard from six metres in absolute silence.
Taste -One teaspoon of sugar in eight litres of water.
Smell - One drop of perfume in a three-bedroom house
Touch -The wing of a bee falling on your back from a height of one centimetre.
The absolute threshold is the minimum level of stimulation required for our senses to detect
something. This threshold differs for each sense and can be measured through experiments. For
example, the absolute threshold for vision is being able to see a streetlight from 10 kilometres away
on a dark and clear night. For hearing, it's hearing the ticking of a watch from six meters away in
complete silence. The absolute threshold for taste is detecting one teaspoon of sugar in eight litters
of water, while for smell, it's detecting one drop of perfume in a three-bedroom house. Finally, the
touch threshold is the wing of a bee falling on your back from a height of one centimetre.
Understanding the absolute threshold is important in understanding how our senses work and how
we perceive the world around us.
The differential threshold is the smallest difference between two stimuli that we can detect. This
means that the difference between two things needs to be big enough for us to notice it. The size of
the difference needed depends on how big the things are to begin with. For example, it's easier to
tell the difference between a 5-pound weight and a 10-pound weight than it is to tell the difference
between a 100-pound weight and a 105-pound weight, even though the difference is the same in
both cases.
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, Our experiences affect how our brain understands and makes sense of the things we see, hear, taste,
or touch. When we encounter something new, our brain first processes it by looking at its individual
parts and putting them together, which is called bottom‐up processing. However, sometimes our
past experiences can influence how we interpret new information, which is called top‐down
processing. In this way, our brain uses what it already knows to understand and anticipate what
comes next, filling in the gaps based on our expectations and prior knowledge.
Sensory adaptation is when we stop noticing a sensory stimulus that remains the same for a long
time. For example, if you wear a wristwatch for a while, you may not feel the weight of it on your
arm anymore. This happens because our senses get used to the constant stimulus and stop
responding to it. Our brain is wired to pay attention to changes in our environment because they
may signal important information. When there is no change in a stimulus, our brain filters it out so
we can focus on other things.
What is the difference between sensation and perception?
A) Sensation is the awareness resulting from the stimulation of sensory organs, while perception
refers to the way sensory information is organized and interpreted.
B) Sensation and perception are the same thing.
C) Sensation refers to the way sensory information is organized and interpreted, while perception is
the awareness resulting from the stimulation of sensory organs.
What is the goal of sensation?
A) To create useful information about our environment.
B) To detect external stimuli.
C) To choose appropriate behaviors.
What is bottom‐up processing?
A) The fact that perceptions are built from sensory input.
B) The way we interpret sensations based on our experiences and thoughts.
C) The minimum amount of stimulation required to detect a stimulus.
What is top‐down processing?
A) The fact that perceptions are built from sensory input.
B) The way we interpret sensations based on our experiences and thoughts.
C) The minimum amount of stimulation required to detect a stimulus.
What is an absolute threshold?
A) The fact that perceptions are built from sensory input.
B) The way we interpret sensations based on our experiences and thoughts.
C) The minimal amount of stimulation required to detect a stimulus.
Question 1: What is the absolute threshold for smell?
A) Detecting the smell of a single flower in a large garden
B) Detecting the smell of one drop of perfume in a three-bedroom house
C) Detecting the smell of a freshly baked pie from across the street
Question 2: What is the differential threshold?
A) The minimum level of stimulation required for our senses to detect something
B) The smallest difference between two stimuli that we can detect
C) The process by which our brain uses our past experiences to interpret new information
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