Lecture# 3 Flashcards
Perception
Experiences resulting from the stimulation of the senses
inverse projection problem
the difficulty of reconstructing a three-dimensional (3D) scene from a two-dimensional (2D) image. It’s a fundamental challenge in computer vision and image processing.
viewpoint invariance
People’s ability to recognize an object
even when it is seen from different viewpoints
bottom-up processing
a cognitive process that involves the brain using sensory information to understand stimuli. It’s also known as stimulus-driven or data-driven perception.
top-down processing
cognitive process that uses existing knowledge and expectations to interpret new information. It’s also known as conceptually driven processing.
speech segmentation
he process of identifying the boundaries between words, syllables, or phonemes in spoken language
transitional probabilities
the likelihood that one sound will follow another within a word. For example, consider the words pretty baby. In English it is likely that
pre and ty will be in the same word (pre-tty) but less likely that ty and ba will be in the same word (pretty baby)
statistical learning
the process of learning patterns from repeated exposure to sensory input. It’s a cognitive process that happens without conscious awareness.
Helmholtz’s Theory of Unconscious Inference
Hermann von Helmholtz (1821–1894)
-a physicist who made important contributions to fields as diverse as thermodynamics, nerve physiology, visual perception, and aesthetics.
He also invented the ophthalmoscope, versions of which are still used today to enable physicians to examine the blood vessels inside the eye.
likelihood principle
which states that we perceive the object that is most likely to have caused the pattern of stimuli we have received.
unconscious inference
our perceptions are the result of unconscious assumptions,
or inferences, that we make about the environment
Gestalt psychologists
psychologists who study how people organize their experiences into patterns.
apparent movement
the perception of movement when static objects are presented in quick succession. It’s a type of illusory perception, or perceptual illusion.
principles of perceptual organization
a set of rules that explain how people group and interpret visual information.
principle of good continuation
Points that, when connected, result in straight or smoothly curving lines are seen as belonging together,
and the lines tend to be seen in such a way as to follow the smoothest path. Also, objects that
are overlapped by other objects are perceived as continuing behind the overlapping object.
law of pragnanz
aka principle of good figure or the principle of simplicity
-Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible.
principle of similarity
Similar things appear to be grouped together. A striking example of grouping by similarity of color. Grouping can also occur because of similarity of size, shape, or orientation.
two types of regularities
physical regularities and semantic
regularities.
Physical Regularities
regularly occurring physical properties
of the environment. For example, there are more vertical and horizontal orientations in the environment than oblique (angled) orientations. This occurs in human-made environments
(for example, buildings contain lots of horizontals and verticals) and also in natural environments (trees and plants are more likely to be vertical or horizontal than slanted)
oblique effect
people can perceive horizontals
and verticals more easily than other orientations
light-from-above assumption
We usually assume that light is coming from above, because light in our environment, including the sun and most artificial light, usually comes from above.shows how light coming from above and from the left illuminates an indentation, leaving a shadow
on the left.shows how the same light illuminates a bump, leaving a shadow on the right.
Semantic Regularities
are the characteristics associated with the functions carried out in different types of scenes.
scene schema
contains prior information about the objects and the. spatial relations that are likely to be found in a particular scene
Bayesian inference was named after who? and why
Thomas Bayes (1701–1761), who proposed that our estimate of the probability of an outcome is determined by two factors: (1) the prior
probability, or simply the prior, which is our initial belief about the probability of an outcome, and (2) the extent to which the available evidence is consistent with the outcome.
This second factor is called the likelihood of the outcome.
theory of natural selection
which states that characteristics that
enhance an animal’s ability to survive, and therefore reproduce, will be passed on to future generations.
brain ablation
a technique that includes removing
part of the brain.
What pathway aka?
ventral pathway- because the lower part of the brain, where the temporal lobe is located, is the ventral part of the brain
where pathway aka?
dorsal pathway- ventral part of the brain, and the upper part of the brain, where the parietal lobe is located, is the dorsal part of the brain
perception pathway
the pathway from the visual
cortex to the temporal lobe
action pathway
the pathway from the visual cortex to the parietal lobe
mirror neurons
neurons that respond both when a monkey observes someone else grasping an object such as food on a tray and when the monkey itself grasps
the food
mirror neuron system
neurons are distributed throughout the brain in a network
size-weight illusion:
When a person is presented with two similar objects, such as two cubes, that are the same weight but different sizes, the larger one seems lighter when they are lifted together.
