cognitive psych chapter 3

Four conceptions of object perception

Helmholtz's unconscious inference, the Gestalt laws of organization, regularities in the environment, and Bayesian inference

light from above constancy - color -size

Heuristics for perception

proximity, similarity, continuity, connectedness, closure

Laws of grouping

perception pathway aka what pathway

Neural pathway, extending from the occipital lobe to the temporal lobe, that is associated with perceiving or recognizing objects. Corresponds to the what pathway.

According to this model, pain occurs when receptors in the skin called nociceptors are stimulated and send their signals in a direct pathway from the skin to the brain

direct pathway model

The mechanism through which the structure of the brain is changed by experience, called

experience-dependent plasticity,

feature search

find the target by looking for a single feature"horizontal.

Balint's syndrome is an inability to

focus attention on individual objects.

According to Treisman, the second step in processing an image of an object is the

focused attention stage where the free-floating" features are combined and we perceive the object

Applying this idea of what and where pathways to our example of a person picking up a cup of coffee, the what pathway would be involved in the _________ ________ of the cup and the where pathway in determining its ____________

initial perception, location

The prior probability, or simply the prior,

is our initial belief about the probability of an outcome,

The extent to which the available evidence is consistent with the outcome is called

likelihood

preattentive stage

objects are analyzed into separate features.

It is therefore no coincidence that people can perceive horizontals and verticals more easily than other orientations, an effect called the

oblique effect

speech segmentation

our ability to perceive individual words even though there are often no pauses between words in the sound signal

We can distinguish two types of regularities:

physical regularities and semantic regularities.

This decrease in pain from a substance that has no pharmacological effect is called the

placebo effect.

Studies have also shown that a significant proportion of patients with pathological pain get relief from taking a

placebo,

According to Treisman, the first step in processing an image of an object is the

preattentive stage, objects are analyzed into separate features. For example, the rolling red ball would be analyzed into features such as color (red), shape (round), and movement (rolling to the right

Modern perceptual psychologists have introduced the idea that perception is influenced by our knowledge of

regularities in the environment—characteristics of the environment that occur frequently.

physical regularities

regularly occurring physical properties of the environment

two types of photoreceptors

rods and cones

Neuron sensory organ called ________/__________ change that energy into neural energy via a process called ______________

sensory receptor neurons change via transduction

Which of the following is an example of an effect of top down processing

speech segmentation

are able to tell when one word ends and the next one begins, a phenomenon called

speech segmentation.

Feature Integration Theory (FIT)

tackles the question of how we perceive individual features as part of the same object by proposing a two-stage process, shown in Figure 4.30. As we will see, attention becomes important in the second stage.

Helmholtz's unconscious inference

that we perceive what is most likely to have created the stimulation we have received—in terms of probabilities.

viewpoint invariance

the ability to recognize an object seen from different viewpoints

The question of how an object's individual features become bound together, which is called

the binding problem,

The Gestalt psychologists, in contrast, emphasized the idea that

the principles of organization are built in.

This function of attention is to help create binding

the process by which features such as color, form, motion, and location are combined to create our perception of a coherent object.

Perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

top-down processing

the use of preexisting knowledge to organize individual features into a unified whole ( maria and her milk) (speech segmentation)

In our everyday experience, in which we often perceive familiar objects, top-down processing combines with feature analysis

to help us perceive things accurately.

there is a spatial map of visual stimuli on the visual cortex. This map is called a

topographic map

The ability to recognize an object seen from different viewpoints is called

viewpoint invariance

The approaches of Helmholtz, regularities, and Bayes all have in common the idea that

we use data about the environment, gathered through our past experiences in perceiving, to determine what is out there. Top-down processing is therefore an important part of these approaches.

the pathway leading from the striate cortex to the temporal lobe is called the

what pathway

The perception pathway corresponds to the _____ pathway, while the action pathway corresponds to the _____ pathway.

what, where

the pathway leading from the striate cortex to the parietal lobe is called the

where pathway

in the preattentive stage an object's features are "_________________ ____________" Because they are not attached to a particular object, they can potentially become associated with any object in a display. When this happens, an illusory conjunction is created.

"free floating."

illusionary conjunction

( put together wrong) a combination of features from two different stimuli this occurs because in the pre-attentive stage each feature exist independently of others

Bayesian inference was named after 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

Principle(s) of good continuation, good figure, similarity, simplicity

A Gestalt principle of perceptual organization that states that points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and that lines tend to be seen in such a way as to follow the smoothest path.

scene schema

A person's knowledge about what is likely to be contained in a particular scene. This knowledge can help guide attention to different areas of the scene. For example, knowledge of what is usually in an office may cause a person to look toward the desk to see the computer.

object discrimination problem

A problem in which the task is to remember an object based on its shape and choose it when presented with another object after a delay. Associated with research on the what processing stream.

The law of pragnanz, also called the principle of good figure or the principle of simplicity, states:

Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible.

The principle of good continuation states the following:

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.

landmark discrimination problem

Problem in which the task is to remember an object's location and to choose that location after a delay. Associated with research on the where processing stream.

principles of perceptual organization

Rules proposed by the Gestalt psychologists to explain how small elements of a scene or a display become perceptually grouped to form larger units. These "laws" are described as "heuristics" in this book.

conjunction search

Search for a target defined by the presence of two or more combinations of attributes ( horizontal and green )

the principle of similarity:

Similar things appear to be grouped together.

Law of Pragnanz

The most general Gestalt principle, which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure. (kiss)

Transduction

The process of converting outside stimuli, such as light, into neural activity

Our perception in these two situations has been explained by the 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

Gestalt psychologists

a group of psychologists who proposed principles governing perception, such as laws of organization, and a perceptual approach to problem solving involving restructuring

Gestalt Laws of Organization

a set of rules describing the circumstances--such as proximity, good continuation, similarity, closure, and good form--under which visual characteristics will be grouped into perceptual units

Binding is the process by which these separated signals are combined to create

a unified percept.

Neuronal energy causes electrical change in the neuron called a(n) ___________ _________________which results in a ______________________ being discharged into the synaptic cleft.

action potential, neurotransmitter

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information

Visual search is something we do

anytime we look for an object among a number of other objects, such as you did when you looked for Jennifer Hudson in the group of musicians

principle behind the illusion of movement created by the stroboscope, which is called ______________ _____________because although movement is perceived, nothing is actually moving.

apparent movement

Physical regularities

are regularly occurring physical properties of the environment.

Semantic regularities

are the characteristics associated with the functions carried out in different types of scenes.

In F.I.T theory __________ is considered a key component

attention

The sequence of events from eye to brain is called

bottom-up processing, because it starts at the "bottom" or beginning of the system, when environmental energy stimulates the receptors.

removing part of a monkey's brain affected its ability to identify an object and to determine the object's location. This experiment used a technique called

brain ablation—removing part of the brain.