CHAPTER 3 PERCEPTION

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. It involves the detection of physical stimuli (such as light) by the sensory organs (such as eyes) and converting these stimuli into neural signals.

Perception

Conscious experience that results from stimulation of the senses.

Machine Learning

A form of artificial intelligence that uses algorithms and statistical models enabling computers to perform specific tasks by learning from data and improve their performance over time (instead of using explicit instructions).

Deep Learning

A form of artificial intelligence that uses neural networks with many layers (hence the term "deep") to model complex patterns in large datasets. Deep learning algorithms are particularly powerful for tasks involving high-dimensional data, such as image and speech recognition and natural language processing.

Inverse Projection Problem

Task of determining the object that caused a particular image on the retina.

Occlusion

The perceptual phenomenon in which part or all of an object or scene are obscured (blocked or hidden) from view.

Viewpoint Invariance

The ability to recognize an object seen from different viewpoints.

Bottom-up Processing

Processing that starts with information received by the receptors. This type of processing is also called data-based processing.

Top-down Processing

Processing that involves a person's knowledge or expectations. This type of processing has also been called knowledge-based processing.

Speech Segmentation

The process of perceiving individual words within the continuous flow of the speech signal.

Transitional Probabilities

In speech, the likelihood that one speech sound will follow another within a word.

Statistical Learning

The process of learning about transitional probabilities and about other characteristics of language. Statistical learning also occurs for vision, based on learning about what types of things usually occur in the environment.

Likelihood Principle

Part of Helmholtz's theory of unconscious inference that states that we perceive the object that is most likely to have caused the pattern of stimuli we have received.

Unconscious Inference

Helmholtz's idea that some of our perceptions are the result of unconscious assumptions that we make about the environment.

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.

Apparent movement

An illusion of movement perception that occurs when stimuli in different locations are flashed one after another with the proper timing.

Perceptual organization

The principles of 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.

Good continuation

The principle of the Law of perceptual organization states that points that, when connected, result in straight or smoothly curving lines are seen as belonging together. In addition, lines tend to be seen as following the smoothest path.

Pragnanz, law of

The law of perceptual organization states that every stimulus pattern is seen in such a way that the resulting structure is as simple as possible. Also called the law of good figure and the law of simplicity.

Similarity, principle of

The law of perceptual organization states that similar things appear to be grouped together.

Regularities in the environment

Characteristics of the environment that occur frequently.

Physical regularities

Regularly occurring physical properties of the environment.

Oblique effect

The finding that vertical and horizontal orientations can be perceived more easily than other (slanted) orientations.

Light-from-above assumption

The assumption that light is coming from above. This is a heuristic that can influence how we perceive three-dimensional objects that are illuminated.

Semantic regularities

Characteristics associated with the functions carried out in different types of scenes. For example, food preparation, cooking, and perhaps eating occur in a kitchen.

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.

Bayesian inference

The idea that our estimate of the probability of an outcome is determined by the prior probability (our initial belief) and the likelihood (the extent to which the available evidence is consistent with the outcome).

Prior

A person's initial belief about the probability of an outcome.

Likelihood

In Bayesian inference, the extent to which the available evidence is consistent with the outcome.

Theory of natural selection

Darwin's theory that characteristics that enhance an animal's ability to survive and reproduce will be passed on to future generations.

Brain ablation

A procedure in which a specific area is removed from an animal's brain. It is usually done to determine the function of this area by assessing the effect on the animal's behavior.

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.

Perception 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.

Action pathway

Neural pathway, extending from the occipital lobe to the parietal lobe, that is associated with neural processing that occurs when people take action. Corresponds to the where pathway.

Mirror neurons

Neurons in the premotor cortex, originally discovered in the monkey, that respond both when a monkey observes someone else (usually the experimenter) carrying out an action and when the monkey itself carries out the action. There is also evidence for mirror neurons in humans.

Mirror neuron system (MNS)

A network of neurons in the brain that have mirror neuron properties.

Size-weight illusion

When a person is presented with two similar objects that are the same weight but different sizes, the larger one seems lighter when they are lifted together.