Psychology Chapter 6 Lecture notes
Some things can easily be perceived (ie. Sound, sight), so we hardly think of it. However, some parts can
be difficult to process. Ie: an experiment where you test your smell. You blindfold someone and let them
smell some obvious stuff, like oranges, but others are more difficult to figure out- that involves the
perception, as different people perceive different things from the unidentifiable object.
Slide 3: If you look at the middle horizontally, it’d look like 13, but vertically you would see it as B. This is
related to the perception, as you decide what it ultimately looks like. This is an item that you see as
something in your mind. Other things outside the raw sensory input are involved memory. You try to
perceive something using memory to make sense out of it. Memory is active and helps you recognize
things every second, and is part in producing perception.
If you focus on one point, the retina in the back, opposite of the eye records parts that are outside the
point. There are visual fields, and some overlap, so that certain retinas are stimulated depending on the
visual fields. Some fields are tighter packed on central retina. Things you’d like to see more and get more
details from, you’d look at them directly so that more nerve cells fixate on the details.
Nerve cells react to specific stimulations and get excited. These nerve cells only function and react to
those stimulations, and don’t do anything else (kind of like motion detectors).
These are mostly detected by primary visual receptors, so when you remove these, you won’t recognize
motion. Ex. You can’t tell if cars in front of you are moving. Same goes for other detecting cells, like
Slide 6: Visual agnosia: you can’t connect what you see to memory. Anything the person sees would
seem new; they’d see everything for the first time every time. They don’t immediately recognize
something, but would need time to figure out what they do.
Looking at faces would show no features. Every feature we have is common, but the way they’re put
together is how they are distinguished. Prospagnosia would lead you to not recognize faces that are very
close to you. The person could tell if the faces are familiar, but the features would not be very
distinguishable (actions and voices would help recognize the person though).
Capgras syndrome: face is recognizable, but it doesn’t look familiar. Ex. A woman living with husband
could tell he was the husband, but she felt there was something different about him, so she cut his head
off to prove he was an alien or robot.
Slide 7: European response to Siegmund Freud with studies on perception.
North American responded with behaviourism.
When you look at a scene, you figure out what is the subject, the foreground (figure), and which is the
background (ground). In the image, the blue part is the figure. But how does the visual system figure this out?
Looking at a figure, you see the edges, and that would assume that the figure is the focus.
Slide 8: left image- you can see both two people and a white vase. This one is an ambiguous image in
that both parts can be figures.
Right image- image by Esher, another famous one is the impossible staircase.
Slide 9: you can have a single image that can be ambiguous- you can see a young, fashionable woman,
but also an old woman.
This is a way where sensation and perspective play a role. You can flip the image from one perspective
to another, but the sensory is not changed.
Slide 10: Left image: Stare at the cube for a while, and the image will start changing in that one square
will be in more focus. Now you can easily switch back and forth between the faces (and supposedly the
easier you can flip, the higher your IQ).
Right Image: you can see the yellow cube pop out, and also the red cube stand out.
Slide 11: Gestalt laws- gestalt means that when more than one are put together, they become larger
then added up.
Slide 12: the notion that you see objects over elements. Here the green dots emerge and produce a
higher level perception (‘Hi’).
The global local pact- global: the big shape (the blue shapes are Es). These are made up of Es and Fs on
the local level. It’s easy to pick out the global shape, but it’s more difficult to perceive the local level,
especially the Fs in the global E (like the Stroop feature, it’s incongruent). The global interferes with the
local level, but not vice versa.
Slide 13: First law is proximity- how would you perceive the one on the left differently from the right?
Globally you could give shapes, like rectangle and square. But more specifically you could mention
circles that are arranged in columns.
The proximity, the distance between the objects, of features can get objects grouped. This is one of the
laws in Gestalt laws.
Slide 14: Some dots are yellow, other are red. You arrange the yellows together because they have
Ex: car drivers are not used to looking for motorcycles, therefore motorcyclists are easier to see when
two are close together with colours standing out. This enhances visibility and makes them figures
instead of backgrounds. Slide 15: left image- two lines together, but you assume it’s the same line that moves through the black
box. In reality, it’s two lines (as seen on the right). Your visual system, however, refuses to see them as
separate on the first image though.
Slide 16: Law of closure- while the line is visible, the idea is that the line is supposed to be invisible.
Anyway, even thought he shapes are not fully closed, you visual system makes up for it and perceives
the whole shapes.
Ex: even though a jacket is crossed between legs, you do not think that the legs and torso are separate.
Your visual system perceives a closure.
Slide 17: Left image- you could see three circles and a triangle, and a white circle stacked on top of them
all. There’s no sensory input to support it, but there is a illusion that the triangle is present.
Right image- you perceive 3D shapes and three white lines crossing through them.
Right bottom image- the illusion is ineffective because the lines are closed.
Slide 18: An camouflaged animal is difficult to spot until it starts moving.
Ex: Slide 19-22- because the four circles change position, you start seeing them as objects. The law of
common fate: The objects are bound to each other and move together.
However, some animals try to go around that law using camouflage and not moving.
Ex: the octopus camouflage to the environment they are in.
Fun fact- if you place octopus and shark in one aquarium, the octopus eats the shark. The octopus is
camouflaged and grabs onto the shark, keeping it immobile. Sharks are unable to get oxygen, because
they need mobility to get water through the gills, so they reach a tonic state and the octopus devours it.
Slide 24: Using the laws you can determine the two objects. The right is recognized as a clock, but how
was that determined?
Slide 25: reverse cookie-cutters- when you place the cutters on top of the dough, you create shapes,