Chapter 3 Flashcards
Visual agnosia
An inability to identify objects visually even though they can be identified using other senses (eg. touch).
Perception
The processing of sensory information in such a way that it produces conscious experiences and guides action in the world.
Cornea
The outer tissue of the eye and the first layer that light passed through on its way to the back of the eye, where you’d put your contacts on.
Pupil
The space through which light passes on its way to the back of the eye; adjusted in size by the iris; to an observer the pupil appears black.
Iris
The tissue that surrounds the pupil and is responsible for the distinct colour of the eye.
Lens
The transparent tissue in the eye that refracts light and focuses it on the back of the eye.
Retina
The tissue at the back of the eye that contains light receptors.
Photoreceptors
Cells that transduce light energy into a neural signal.
Fovea
The region of the retina where photoreceptors are most densely packed.
Primary visual cortex
The area at the back of the brain that is primary responsible for the basic processing of visual information.
Retinotopic
A principle of organization of the primary visual cortex, whereby information falling on adjacent areas of the retina is processed in adjacent areas of the cortex. Visual processing is highly modular as this principle suggests.
Achromatopsia
A visual deficit characterized by inability to perceive colour because of damage to the area of the brain that processes colour information.
Akinetopsia (motion blindness)
An inability to perceive the motion of objects.
Ventral (“what”) pathway
The stream of visual processing in the brain that is responsible for determining object shape, colour, and meaningful identity.
Dorsal (“where”) pathway
The stream of visual processing in the brain that is responsible for determining object location and motion, and which guides action.
Feedforward sweep
The propagation of visual information from the primary visual cortex down the “what” and “where” pathways.
Re-entrant (feedback) connections
Connections between brain areas that allow the propagation of visual information from the endpoints of the “what” and “where” pathways back to the primary visual cortex.
Bottom-up influences
The feedforward influence of the external environment on the resulting perceptual experience.
Top-down influences
The feedback of context and the individual’s knowledge, expectations, and high-level goals on perceptual experience. Moves quicker than bottom-up influences.
Fusiform face area (FFA)
An area in the inferior temporal cortex that is responsible for the conscious recognition of faces. Located in the inferior temporal cortex.
Prosopagnosia
A selective deficit in the ability to consciously recognize faces resulting from damage to the FFA.
Percept
The visual experience of sensory information.
Parahippocampal place area (PPA)
An area in the ventral stream that is responsible for the conscious recognition of places.
Extrastriate body area (EBA)
An area in the ventral stream that is involved in processing non-facial body parts.
Pattern recognition
The ability to recognize an event as an instance of a particular category of event.
Memory trace
The trace that an experience leaves behind in memory.
Hoffding function
The process whereby an experience makes contact with a memory trace, resulting in recognition.
Feature detection theory
Detecting patterns on the basis of their features or properties.
Pandemonium
A model of pattern recognition consisting of three levels: data, cognitive demons, and decision demons.
Feature
A component or characteristic of a stimulus.
Cognitive demon
A feature detector in the pandemonium model that decides whether the stimulus matches its pattern.
Decision demon
A feature detector in the pandemonium model that determines which pattern is being recognized.
Contrast energy
The relative ease with which a stimulus can be distinguished from the background against which it is displayed.
Squelching
The tendency of the nervous system to inhibit the processing of unclear features.
Recognition by components (RBC)
The theory that we recognize objects by breaking them down into their fundamental geometric shapes. We are actually more efficient at recognizing more complex objects than less complex ones.
Geons
The set of 36 basic three-dimensional shapes from which all real-world objects can be constructed.
Prototypical
Representative of a pattern or category
Template-matching theory
The hypothesis that the process of pattern recognition relies on the use of templates or prototypes.
Multiple-trace memory model
Traces of each individual experience are recorded in memory. No matter how often a particular kind of event is experienced, a memory trace of the individual event is recorded each time (Hintzman).
Probe
A “snapshot” of information in primary memory that can activate memory traces in secondary memory.
Echo
When a probe goes out from primary to secondary memory, memory traces are activated to the extent that they are similar to the probe.
Context effects
The change in perception of a visual component of a scene based on the surrounding information in the scene and the observer’s prior knowledge.
Moon illusion
The tendency for the moon to appear different in size depending on whether it is near the horizon or high in the night sky.
Holistic
Focusing on the entire configuration of an object (Gestalt).
Atomistic
Focusing on the components of objects.
Grouping
The combination of individual components to form a percept of a whole object.
Organizational principles
The rules (or laws) that govern the perception of whole objects or events from a collection of individual components or features.
Principle of experience
Visual components are grouped together based on the prior experience and knowledge of the observer.
Apparent-distance theory
An explanation for the moon illusion based on the idea that the perceived size of the moon depends on the assumptions the visual system makes about the distance of the moon from the observer.
Principle of similarity
Visual features that have a high degree of visual similarity are combined.
Principle of proximity
Visual components that are close to one another are grouped to form a whole.
Principle of symmetry
Symmetrical lines are perceived as going together.
Principle of parallelism
Lines that are parallel or similar in orientation are perceived as going together.
Figure-ground segmentation (segregation)
The separation of a scene such that one component of the scene becomes a figural object and the other components become the backdrop.
Denotivity
The degreased to which an object is meaningful and familiar to an individual observer.
Jumbled word effect
The ability to read words in sentences even when some of the letters are mixed up.
Word superiority effect
It’s easier to identify a letter (ex. p) when it appears in a word (warp) than if it appears alone.
Empirical theory of colour vision
The theory that colour perception is influenced by prior experience with the way different illuminations affect colour (the dress).
Optic ataxia
A condition characterized by a deficit in the ability to successfully reach for objects, especially when they are presented in the periphery of vision, with unimpaired ability to identify them. Involves the dorsal (“where”) pathway.
Theory of ecological optics
The proposition that perception results from direct contact of sensory organs with stimulus energy emanating from the environment and that an important goal of perception is action.
Ambient optical array (AOA)
All the visual information that is present at a particular point of view.
Transformation
Gibson’s term for the changes in the optical information hitting the eye that occur as the observer moves through the environment.
Optic flow field
The continually changing (i.e. transforming) pattern of information that results from the movement of either objects or the observer through the environment.
Gradient of texture density
Incremental changes in the pattern on a surface, which provide information about the slant of the surface.
Topological breakage
The discontinuity created by the intersection of two textures. Gives us information about the edges of objects.
Scatter-reflection
The degree to which light scatters when reflected from a surface.
Intentional binding effect
Events that take place after one has taken some action are perceived as occurring sooner than they actually did.
Principle of common movement
Visual features that move simultaneously and follow the same path are perceived to form a whole entity.
Modality appropriateness hypothesis
The hypothesis that different senses are better at processing different stimuli, and therefore that different sensory modalities dominate at different times, depending on circumstances.
Visual prepotency effect
The hypothesis that the visual system dominates the other senses when it comes to perceptual processing.
McGurk effect
The auditory experience of the syllable “da” when seeing a mouth silently saying “ga” while at the same time hearing a voice say “ba”.
Drumsticks/Arms Crossed Experiment
People can determine which hand was touched first (when touched quickly in succession) when their hands or drumsticks are on the same side of their body as the hand they are in. If their arms or drumsticks were crossed performance went down.
Multimodal Perception
At least two or more of our senses are actively perceiving the world around us and they can influence each other (Eating different coloured food can make us feel sick, McGurk effect).
Rods vs. cones
Cones are sensitive to colour and really good for detail. Rods are better for night vision. Cones come online really quickly but rods take time.
