Visual agnosia: a deficiency in the ability to recognize visual information despite being able to see
no sensory impairment, but cant cognitively interpret visual information
visual recognition not always completely impaired
specific to visual domain, objects can be identified by touch
Associative agnosia: a form of agnosia marked by a difficulty naming objects
cant identify objects, but can draw them
Time spaces: The perceptual experience of time units such as days of the week or months of the year as occupying
spatial location outside of the body.
Illustration of how a perceptual experience can sometimes be very different from the sensory stimulation
Perception: Processing sensory information such that it produces a meaningful understanding of the information.
Important to distinguish between the external environment and the internal knowledge of the observer.
both the environment and the observers knowledge contribute to the perception
Stimulus: an entity in the external environment that can be perceived by an observer.
Perception as a function of the environment
J.J. Gibson (1961, 1966): in real-world situations, the sensory organs receive a complex array of information that
can be directly apprehended and used to guide action.
Thought that perception is accomplished by the sensory organs themselves
Believed that optical illusions were not relevant for everyday life
he was concerned with veridical perceptions
more interested in situations where people are moving and picking up information fom a complex,
Theory of ecological optics: The proposal that perception involves directly absorbing the visual information present in
Ambient optical array (AOA): All the visual information that is present at a particular point of view.
from any view point, a unique pattern of light enters the eyes
the environment is textured and the textures consist of repeating patterns
Texture gradients: Gradual changes in the pattern of a surface that is normally assumed to be uniform, which provides
information about surface characteristics such as whether the surface is receding or curved.
Topological breakages: The discontinuity created by the intersection of two texture gradients.
useful indicators for edges of objects
Scatter-reflection: The degree to which light scatters when reflected from a surface.
Gibson included both the observer and environment motion as fundamental components of perception
He thought that as the observer moves, the entire optical array undergoes a change
Transformation: In Gibsons theory, the change of optical information hitting the eye when the observer moves through
Optic flow field: The movement of objects/observer through the environment produces changes in what is seen.
e.g. moving dots on a computer display / the view from your car while drivingPattern recognition
Theories of pattern recognition are different from Gibsons theory:
1. They do not consider the complex array of light information reflecting from all surfaces/objects. The focus is
on specific objects or patterns.
2. They focus on how it is that we build internal representation of objects/patterns
Pattern recognition: The ability to recognize an event as an instance of a particular category of event.
came from computer science
People are able to identify ++ of the configurations with which they are presented
e.g. recognize words in a sentence/recognize a coffee cup
Machines outperform humans in highly constrained situations
Humans outperform machines in real-world tasks.
Percept: Meaningful interpretation of sensory information
Memory trace: the trace that an experience leaves in the brain
Recognizing an object involves contact between the emerging percept and memory.
Hffding function: when an experience makes contact with a memory trace, resulting in recognition.
Possible that we store templates in memory that correspond to the standard forms of the configurations we see
Template: A model against which a stimulus is compared to determine whether it belongs to a particular category
Prototype: A model that possesses all the typical characteristics of its class.
Template-matching theory: Comparing a stimulus with templates. When they match, the stimulus is recogn