AP Psychology - 4.1

Sensations

the stimulation of sensory receptors and the transmission of sensory information to the central nervous system

Sense receptors

specialized neural cells in sense organs that respond to stimuli and change physical energy into neural impulses

Transduction

The process of stimulus info being converted into a neural impulse that the brain can interpret

Sensation is mechanical

it just happens

Perception

the process by which sensations are organized into an inner representation of the world by the brain

Perception is not mechanical

 involves more than sensation; it reflects learning and expectations and organization of information

Schema

Your personal reality, based on concepts and prior knowledge

How is perception of a sense produced?

1. Your body detects some form of energy

2. The energy is transduced into neural activity

3. The brain interprets the info and produces perception of the sense

Under normal circumstances, sensation and perception….

bend together into one continuous process

Bottom-Up processing

basic sensory processing and works up to higher levels of processing (how we process when we have no prior knowledge); external content

Top-Down processing

constructs perceptions from this sensory input by drawing on your culture, experiences, and expectations (how we process if we have prior knowledge); internal factors

Attention

an interaction of sensation & perception that is affected by internal and external processes

Selective attention

the focusing of conscious awareness on a particular stimulus

How many bits of information is it estimated that we take in?

11,000,000 bits of information per second

Cocktail Part Effect

our ability to attend to mentions of our name or specific topics in loud, distracting environments

Inattention

• failing to perceive when our attention is directed elsewhere

  • It is a by-product of what we are really good at; focusing our attention on some part of our environment

Change blindness

failing to notice changes in the environment (a form of Inattention)

Absolute Threshold

minimum amount of stimulus that must be present to produce a sensation 50% of the time

Signal-detection theory

idea that the perception of stimuli involves not only the strength of the stimuli, but also the interaction of physical, biological, and psychological factors

Just noticeable difference

minimal amount of difference in intensity between two stimuli so that they will be perceived as being different; AKA differences threshold

Weber’s Law

the minimal percentage by which a source of physical energy must be increased or decreased so that a difference in intensity will be perceived…it is a constant proportion to initial stimulus

Sensory Adaptation

Sensory change in response to environmental stimuli (i.e.. Becoming more/less sensitive to stimuli); tends to be physiological

Perceptual Set

a mental predisposition to perceive one thing and not another

Synesthesia

•  a condition in which one sense is simultaneously perceived as if by one or more additional senses

  • Just about any combination of sense s is possible, and no two people really experience it the same way

Diagnosis of Synethesia

• It just happens - not something that has to be thought about perceive

• Must be the same experience every time