Cognitive psych

Perception

It is a set of processes by which individuals are able to recognize, organize and make sense of the sensations they receive from environmental stimuli.

Ecological Theory

Perception can be explained solely in terms of environment.

DISTAL (FAR) OBJECT

The object in the external world (e.g., a falling tree). 

NFORMATIONAL MEDIUM

 A pattern of sound waves, reflected light, chemical molecules, or tactile information coming from the environment. (e.g., reflect light waves from the falling tree) 

PROXIMAL (NEAR) STIMULATION

Occurs when the informational medium comes into contact with the appropriate sensory receptors. (e.g., the cells in your retina absorb the light waves of the falling tree).

PERCEPTUAL OBJECT

Perception occurs when a perceptual object is created in the sensory organs that reflect the properties of the external world. (e.g., what you see: a falling tree).

PERCEPT

A mental representation of a stimulus that is perceived.

PERCEPTUAL CONSTANCIES

Occurs when our perception of an object remains the same even when our proximal sensation of the distal object changes.

SIZE CONSTANCY

Perception that an object maintains the same size despite changes in the size of the proximal stimulus.

SHAPE CONSTANCY

Perception that an object maintains the same shape despite changes in the shape of the proximal stimulus.

DEPTH

is the distance from a surface, usually using your own body as a reference surface.

MONOCULAR DEPTH CUES

 Represented in just two (2) dimensions and observed with just one eye. Texture gradients, relative size, interposition, linear perspectives, aerial perspective, location in the picture plane and motion parallax.

BINOCULAR DEPTH CUES

Based on the receipt of sensory information in three dimensions from both eyes.

CORNEA

Protective covering of the eye where light passes through.

PUPIL

Opening in the center of the iris where light passes through after the cornea.

CRYSTALLINE LENS

Transparent membrane located behind the iris that flexes or relaxes to allow one to view objects both close and at a distance. 

VITREOUS HUMOR

Gel-like substance that comprises the majority of the eye and provides support for the eye. 

RETINA

Network of neurons extending over most of the back surface of the interior of the eye; focuses refracted light.

PHOTORECEPTORS

Transduce light energy into electrochemical energy that can be transmitted by neurons to the brain. 

RODS

Utilized for vision in dim light

CONES

Utilized for vision in brighter light.

PHOTOPIGMENTS

Chemical substances that react to light and is present in rods and cones

FOVEA

- Small pit

- Small, thin region of the retina

- Most directly in the line of sight

- Its visual receptive field is approximately as big as the size of the grape held at arms’ length. 

PATHWAY

The path that the visual information took from it entering the human perceptual system through the eyes to its being completely processed

Dorsal pathway

Ascends toward the parietal lobe (along the dorsal pathway) and is responsible for processing location and motion information.

Ventral pathway

Descends to the temporal lobe (along the ventral pathway) and is mainly responsible for processing the color, shape, and identity of visual stimuli.

VIEWER-CENTERED REPRESENTATION

Individual stores the way the object looks to him/her.

Focused on the appearance of the object to the viewer

OBJECT-CENTERED REPRESENTATION

Individual stores a representation of the object independent of its appearance to the viewer.

LANDMARK-CENTERED REPRESENTATION

Information is characterized by its relation to a well-known or prominent item.

Kurt Koffka

co-founded Gestalt psychology, emphasizing holistic perception, explaining how humans organize sensory information into meaningful patterns and structures.

Wolfgang Köhler

advanced Gestalt psychology, demonstrating insight learning through experiments showing problem solving involves perception and cognitive restructuring, not trial-and-error.

Max Wertheimer

founded Gestalt psychology, discovering the phi phenomenon and proposing that perception operates through organized wholes, not isolated sensory elements.

LAW OF PRAGNANZ

- Law of simplicity

- Tendency to perceive any given visual array in a way that most simply organizes the disparate elements into a stable and coherent form.

Reality is organized or reduced to the simplest form possible

FIGURE GROUND

When perceiving a visual field, some objects (figures) seem prominent and other aspects of the field recede into the background (ground).

PROXIMITY

When we receive an assortment of objects, we tend to see the objects that are close to each other as forming a group. 

SIMILARITY

We tend to group objects on the basis of their similarity.

CONTINUITY

Tendency to perceive smoothly flowing or continuous forms rather than disrupted or discontinuous ones. 

CLOSURE

We tend to perceptually close up, or complete objects that are not, in fact, complete.

SYMMETRY

We tend to perceive objects as forming mirror images about their center. 

ELEMENT-BASED SYSTEM

Recognition of parts of the object and assembling those parts into distinctive wholes. 

CONFIGURATIONAL SYSTEM

Specializes in recognizing larger configurations, not analyzing parts of objects or the construction of the object.

PANDEMONIUM MODEL

proposed by Oliver Selfridge in 1959, is a classic cognitive psychology and AI theory for pattern recognition using "demons" (sub-programs) that process information in parallel

FACIAL RECOGNITION

Cognitive processing of faces and emotion of the face interact. 

DIRECT PERCEPTION

he array of information in our sensory receptors, including the sensory context, is all we need to perceive anything.

ECOLOGICAL PERCEPTION

The environment supplies us with all we need to perceive anything; we do not need higher cognitive processes or anything else to mediate between our sensory experiences and our perceptions.

BOTTOM-UP

- We perceive items through sensation

- Template theories

- Prototype theories

- Feature theories

- Structural-description theory

TEMPLATE THEORIES

- Templates are highly detailed models for patterns we potentially might recognize.

- Choose the exact template that perfectly matches what we observe.

PROTOTYPE THEORIES

Mental representation of the most typical and characteristic example of a category.

Prototypes

 are average classes of related objects or patterns which integrates all the most typical features of the class. 

FEATURE THEORIES

Feature-matching, match features of a pattern to features stored in memory.

IMAGE DEMONS

retinal image

FEATURE DEMONS

evaluate matches between the stimulus and the given feature

COGNITIVE DEMONS

check possible patterns stored in memory that conform to one or more of the features noticed by the feature demons 

DECISION DEMONS

listens to the pandemonium of cognitive demons, decides what has been seen, based on which cognitive demon is shouting the most frequently.

RECOGNITION-BY-COMPONENTS (RBC) THEORY

• Irving Biederman

•  Recognize the general classification for multitudinous objects quickly, automatically, and accurately.

Geons

We recognize 3D objects by manipulating simple geometric shapes called geons (geometrical ions). These objects include bricks, cylinders, wedges, cones.

TOP DOWN APPROACH

Driven by high-level cognitive processes, existing knowledge and prior expectations that influence perception.

UP

A representation of the object in view is gradually built up from visual image taken in by retina in the eye

top

Identification of objects using existing knowledge to guide processing of the sensory information

Top-up processing

Using models, ideas and expectations to interpret sensory insofrmation

Bottom-up processing

Taking sensory information and then assembling and integrating it

CONSTRUCTIVE PERCEPTION

Use of sensory information as foundation for the structure but also using other sources of information to build the perception

• Also known as intelligent perception
  

CONTEXT EFFECTS

- Influences of the surrounding environment on perception 

- Objects that were appropriate to the established context were recognized more rapidly than were objects that were inappropriate to the established context. 

CONFIGURAL-SUPERIORITY EFFECTS

Objects presented in certain configurations are easier to recognize than the objects presented in isolation even if the objects in the configuration are more complex than those in isolation.

Word superiority effect (WSE)

 refers to a phenomenon where it can be demonstrated that people can more easily recognize letters presented within words as compared to isolated letters and to letters presented within non-word strings

AGNOSIA

Inability to recognize and identify objects or persons despite having knowledge of the characteristics of the objects or persons

Shows the specialization of our perceptual systems

VISUAL AGNOSIA

Normal sensation but unable to recognize what is in front of them.

SIMULTAGNOSIA

Unable to pay attention to more than one object at a time.

SPATIAL AGNOSIA

- Severe difficulty in negotiating the everyday environment.

- Cannot navigate in even familiar environment

- Gets lost

Prosopagnosia

Inability to recognize faces, including one's own

Cannot recognize person from face

Knows a face is a face

Can recognize individuals from voice

Can recognize objects

Can discriminate whether two faces are same or different.

Auditory Agnosia

• Cannot recognize certain sounds

• Can not tell if two melodies are the same or different

APPERCEPTIVE AGNOSIA

Failure in object recognition that is linked to a failure in perceptual processing.

ASSOCIATIVE AGNOSIA

Ability to represent objects visually but unable to use this information to recognize things.

Ataxia

Disruption of the “how” pathway

Optic ataxia

• Cannot use vision to guide movement

• Unable to reach for items

DICHROMACY

- Deficit in color perception

- Most common: RED-GREEN Colorblindness

PROTANOMALY

Less extreme form of red-green color blindness

DEUTERANOPIA

Have trouble seeing medium wavelength colors (green)

DEUTERANOMALY

Less serious form, not see red or green but can distinguish the two.

TRITANOPIA

Insensitivity to short wavelength colors (blue)

MONOCHROMACY

True color blindness, cannot see color at all

MONOCHROMACY / ACHROMACY

- Hereditary disorder that results in the absence of cones in the retina

- Rely on rods for their vision

- Lack color vision and have difficulty seeing details.

AKINETOPSIA

Selective loss of motion perception - - Bilateral damage to the temporoparietal cortices
Result of a lesion in the prestriate cortex

AKINETOPSIA

Patients have profound motion blindness and struggle in performing the activities of daily living. 

• Frozen frames