Receiving Vision
Summary
TLDRThe script explores the complex process of human vision, starting with the absolute threshold required for sensory detection. It delves into the mechanics of sight, detailing the roles of rods and cones in detecting light and color. The journey of visual information from the eye to the brain is outlined, emphasizing the stages of reception, transduction, and transmission. The script promises further lessons on perception, hinting at the fascinating interplay between what the eye captures and what the brain interprets.
Takeaways
- 👀 The process of seeing is both fascinating and complex, involving multiple steps from reception to interpretation.
- 🔍 The absolute threshold is the minimum level of energy required for a stimulus to be detected by the senses about 50% of the time.
- 🕯️ Examples of absolute thresholds include detecting a candle flame from 50 kilometers away or a ticking watch from six kilometers away.
- 🧠 Vision is the most studied sense in psychology because it provides significant insights into how our body and mind work.
- 🖼️ Visual illusions, like the pictures of the owl wedding and the dog in a bubble, demonstrate how our eyes can be tricked.
- 👁️🗨️ The visual system processes information rapidly, going through reception, transduction, transmission, selection, organization, and interpretation.
- 📸 If you could see the raw image from your eye, it would be upside down, back to front, blurry, and have missing patches.
- 🧬 The eye is a complex organ with parts that control light entry and bending to focus accurately on the retina.
- 👀 Photoreceptors, rods, and cones, play different roles in vision; rods are sensitive to light and used in night vision, while cones provide detailed color vision.
- 🌐 Rods are concentrated around the edge of the retina for peripheral vision, while cones are used for focused, detailed vision.
- 🚀 The process of vision involves the organization of photoreceptors into receptive fields, which help identify boundaries and edges.
Q & A
What is the absolute threshold in the context of senses?
-The absolute threshold is the minimum level of energy required for a stimulus to be detected by any one of the senses about 50% of the time.
What are some examples of absolute thresholds for the average adult human?
-Examples include detecting a candle flame 50 kilometers away on a clear dark night, the ticking of a watch six kilometers away, a wing of a fire falling on the cheek from one centimeter, one drop of perfume in a large house, and one teaspoon of sugar in ten liters of water.
Why is vision particularly interesting in psychology?
-Vision is of great interest in psychology because it provides a lot of information about how our body and mind work, and involves complex processes from reception to interpretation.
What happens when light first enters the eye?
-When light enters the eye, it passes through the cornea and pupil, and is focused by the lens onto the retina.
What are photoreceptors and what is their function?
-Photoreceptors are cells in the retina that are sensitive to light energy. They convert light into electrical or nerve signals that are sent to the brain.
What are rods and cones, and how do they differ?
-Rods and cones are two types of photoreceptors. Rods are more sensitive to light and are used for night vision, providing peripheral vision and black and white information. Cones require more light and provide high visual acuity and color information.
How does the brain interpret the raw image from the eye?
-The brain interprets the raw image by processing the electrical signals sent by the photoreceptors, organizing and interpreting the information to create a coherent visual perception.
What is the role of the visual cortex in the process of vision?
-The visual cortex, located in the occipital lobe of the brain, is responsible for processing the information received from the optic nerves to create visual perceptions.
What is the process of transduction in the context of vision?
-Transduction in vision is the process where light energy is converted into electrical or nerve signals by the photoreceptors in the retina.
How does the concept of receptive fields contribute to vision?
-Receptive fields are groups of rods and cones that help identify boundaries and edges in vision, contributing to the organization and interpretation of visual information.
What is the significance of the optic nerve in the process of vision?
-The optic nerve is significant as it transmits the visual information from the retina to the brain, specifically to the visual cortex, where it is processed into what we perceive as sight.
Outlines
👀 Understanding Visual Sensation
This paragraph delves into the fascinating complexity of the human visual process. It starts by discussing the absolute threshold, which is the minimum energy level required for a stimulus to be detected by our senses about 50% of the time. The script provides examples of absolute thresholds for various senses, such as detecting a candle flame from 50 kilometers away or a drop of perfume in a large house. The focus then shifts to vision, which is of particular interest in psychology. The speaker uses two pictures to illustrate how our eyes can be tricked and emphasizes the rapid and complex process that occurs between the moment we see something and when our brain interprets it. The visual system goes through reception, transduction, transmission, selection, organization, and interpretation. The speaker also explains that if we could see the raw image from our eye, it would be upside down, back to front, blurry, and have missing patches, but our brain processes this information to create a clear, coherent image. The paragraph concludes with an introduction to the anatomy of the eye, focusing on the cornea, pupil, lens, and retina, and the role of photoreceptors—rods and cones—which are sensitive to light and convert it into electrical signals for the brain.
🔍 Deeper Look into the Eye's Function
The second paragraph continues the exploration of the visual process by focusing on the inner workings of the eye. It introduces the concept of receptive fields, which are groups of rods and cones that help identify boundaries and edges in vision. The paragraph then explains the third step in the visual process, transmission, where information from photoreceptors is sent to the brain via a series of cells including bipolar cells, retinal ganglion cells, and optic nerves, ultimately reaching the visual cortex located in the occipital lobe of the brain. The speaker reassures the audience not to stress about the intricate details of receptive fields but to understand their role in vision. The paragraph ends with a teaser for the next video, which will focus on how we perceive vision.
Mindmap
Keywords
💡Absolute Threshold
💡Sensation
💡Perception
💡Reception
💡Transduction
💡Photoreceptors
💡Rods and Cones
💡Receptive Fields
💡Transmission
💡Visual Cortex
💡Optic Nerve
Highlights
The process of seeing is fascinating and extraordinarily complicated.
Absolute threshold is the minimum level of energy required for a stimulus to be detected by the senses.
Examples of absolute thresholds for the average adult human include detecting a candle flame 50 kilometers away and a ticking watch 6 kilometers away.
Vision is the most studied sense in psychology.
Pictures can trick our eyes, illustrating the complexity of vision.
The visual system processes information in a split second through reception, transduction, transmission, selection, organization, and interpretation.
The eye captures raw images that are upside down, back to front, blurry, and with missing patches.
The brain processes the raw image from the eye into a coherent visual perception.
The eye is an incredible organ with parts that control light entry and focus.
The retina contains photoreceptors sensitive to light energy.
There are two types of photoreceptors: rods and cones, each playing different roles in vision.
Rods are more sensitive to light and are important for night vision.
Cones require high levels of light and provide high detail and color vision.
Rods are concentrated around the edge of the retina for peripheral vision.
Cones are responsible for focused, high-detailed central vision.
Receptive fields in the retina help identify boundaries and edges in vision.
The process of transmission involves the information from photoreceptors making its way to the brain via several cell types.
The visual cortex is located in the occipital lobe of the brain.
The next lesson will explore how we perceive vision.
Transcripts
the process by which we see is both
fascinating but also extraordinarily
complicated but understandably is
something that we're really interested
in in psychology now to be fair all of
the senses are pretty interesting
because they tell us a lot about how our
body and our minds work one way that we
study them is by using this thing called
an absolute threshold which is the
minimum level of energy required for a
stimulus to be detected by any one of
these senses about 50% of the time here
are some absolute thresholds for the
average adult human the smallest
stimulus that we should be able to
detect is a flame of a candle 50
kilometers away on a clear dark night
the ticking of a watch six kilometers
away a wing of a fire falling on the
cheek from one centimeter I feel like
I'm reading like a potion for some kind
of witch brew one drop of perfume in a
large house and one teaspoon of sugar in
ten liters of water how does obviously
some room for interpretation here and
it's interesting to think about how they
tested these things but take it as you
may now as mentioned before of all these
senses vision is probably the one that
interests us the most in psychology so
enter my gallery and have a look at
these two pictures over here we have a
lovely wedding between mr. and mrs. owl
it seems and on this side we have a good
little dog Oh keeping inside his little
bubble boundary now these are both
freaky pictures and we'll talk a bit
more in some future lessons about how
things can trick our eyes but the point
I'm trying to make here is that you see
these pictures like instantly but
there's actually so much going on
between the moment that we first lay our
eyes on these things and then I'll brain
telling us what we're looking at you see
in just a split second your visual
system goes through this entire process
of reception transduction transmission
selection organization and
interpretation it's pretty crazy but
let's go step by step to try and
understand it so if it was possible to
put a camera behind your eye and see
literally what your eye sees not what
your brain is telling you that you're
seeing but literally the raw image from
your eye you might see something like
this it's upside down back to front it's
blurry there seems to be like missing
patches and all sorts of things but when
this information is sent to your brain
this is what your brain then tells you
that you see
this is the power of our visual system
and it's something we're gonna be
looking at um through the next few
lessons so you may have noticed that
this diagram splits up quite nicely into
two sections sensation so us receiving
vision and then perception or perceiving
the vision we're gonna have a little
look at the first part now in other
words the way that our eye tells the
brain what it's seen so one thing you've
probably never seen is the inside of
your eye because well I don't really
need to answer that but it's an
incredible organ starting with this part
over here you've got sections that
control just how much light gets lit
through how the light might Bend so that
it can focus accurately on the back of
the eye after passing through this in a
thick liquidy bit the back of the eye
specifically the retina is what we're
interested in focusing the light on and
then information then gets bundled up
into the optic nerve that makes its way
to the brain so in a bit more detail
step number one reception that's when
light passes through the cornea and
pupil and it's focused by the lens onto
the retina now here's a little diagram
of what the retina is like it contains
lots of things but of special interest
photoreceptors which are cells that are
sensitive to light energy there are two
types of photoreceptors rods and cones
and when these fire this process is now
called transduction because a light has
now been converted into like an
electrical or nerve signal which goes to
the brain why do we have two x rods and
cones well they play different roles for
status we have a lot more rods than
cones in each eye rods are also very
sensitive to light which makes them very
good in night vision we rely on them
quite a lot when light is very low
now cones however require high levels of
light before they can be activated rods
also have low visual acuity or low
detail and they also only really convey
like black and white information to the
brain or gray cones on the other hand
transmit high levels of detail in terms
of what they're seeing to the brain and
also tell it brain information to do
with color rods are concentrated around
the edge of the retina and so they're
really important for providing our
peripheral vision whereas cones are what
we predominantly rely on for that really
focused high detailed vision here's a
diagram that shows how that stuff is
organized at the back of the
the only one thing a bit confusing about
this is that this rectangle is sort of a
little bit flips like this here is the
inside of the eye that be there and this
is the back of the eye but if you keep
that in mind you've got like coming this
way getting detected by the
photoreceptors see the rods or cones and
then you can see behind that it's like a
whole mesh network of things it's like
opening up a computer and realizing oh
hi there's a lot of stuff going on
here's like wires and cables everywhere
amongst this mess though there's
actually a high level of organization
going on here one of which is something
called receptive fields which are groups
and rods and cones get organized into
don't stress too much about trying to
figure out exactly how receptive fields
work but now at least that they help
with identifying boundaries and edges in
vision and the third step of course is
transmission which is when information
from those photoreceptors makes its way
to the brain via bipolar cells and then
the retinal ganglion cells and then
optic nerves and finally to the
occipital lobe where the visual cortex
is and of course you know which part of
the brain that's located right yeah
that orange beta right there alright
well that covers sensation in the next
video we're gonna have a look at how we
perceive vision
تصفح المزيد من مقاطع الفيديو ذات الصلة
Sensation and Perception: Crash Course Psychology #5
Vision: Crash Course Anatomy & Physiology #18
Vision: Anatomy and Physiology, Animation
Fisiologi Melihat (Refraksi & Visual Pathway) #1 BASIC OPTHALMOLOGY
How Our (More Than) Five Senses Work | Introduction to Psychology 6 of 30 | Study Hall
Camera or eye: Which sees better? - Michael Mauser
5.0 / 5 (0 votes)