Sensation and Perceptions

Sensation 

is the process by which we receive information from the environment

stimuli

A stimulus is a detectable
input from the environment

Sensory receptors do what?

nerve
endings) recieve stimuli

Perception

the process of organizing and interpreting sensory information, enabling us to

recognize meaningful objects and events.

Transduction

Transduction is the process of
converting the energy of a stimulus
into neural activity. The stimulus is
recoded as a neural pattern.

AKA: Transduction=translation

Transduction Process

1. receive sensory stimulation, often using specialized receptor cells.

2. transform that stimulation into neural impulses.

3. deliver the neural information to our brain.

Absolute Threshold

the minimum stimulation necessary to detect a

particular light, sound, pressure, taste, or odor 50
percent of the time.

Difference Threshold

the minimum stimulation necessary to detect a
difference in a particular light, sound, pressure,
taste, or odor 50 percent of the time.

Weber‘s Law

that the just-
noticeable difference (JND) between
two stimuli are in a constant proportion of
the original stimulus intensity.

In simple terms, the bigger the original
stimulus, the bigger the change needed
to be for you to notice it

Signal Detection Theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person’s experience expectations, motivation, and alertness

Priming

the activation, often unconsciously, of certain associations, thus predisposing

one’s perception, memory, or response.

selective attention

the focusing of conscious awareness on a particular stimulus

Inattentional blindness

not noticing stimuli when focused on others

Change blindness

a form of inattentional blindness; not noticing a change in the environment due to selective attention

BOTTOM-UP

information flowing from the
sensory receptors to the brain

TOP-DOWN

Stimuli processed by one’s
experiences and predictions

Schema

A cognitive framework, based on previous
knowledge and experiences, that helps
humans organize and interpret incoming
information.

Perceptual Set

Psychological sets that rely on familiar ways of
perceiving stimuli