Sensation and Perception

Sensation and Perception

Sensation * The process of receiving stimulus and energies from the external environment and transforming those energies into neutral energies
Perception * The process of organizing and interpreting sensory information so that it makes sense

Types of Processing-

Bottom-up * The operations in S and P in which sensory receptors register info about the external environment and send it up to the brain for interpretation * Data-driven * Focus on incoming data * It takes place in real-time
Top-down * The operation in S and P is launched by cognitive processing at the brain's high levels that allow the organism to sense what's happening and to apply that framework info to the world * Rely on contextual cues to interpret info * Use previous experience and expectations as cues

What's the Process?

Reception * The stimulation of the sensory receptor cells by energy (sound, light, heat, etc.) * Psychophysics- the study of the psychological effect of the forms of energy
Transduction * Transforming this cell stimulation into neural impulses
Transmission * Delivering this neural information to the brain to be processed

Thresholds

Absolute threshold * The minimum level of stimulus intensity needed to detect a stimulus half the time * Anything below this threshold is considered subliminal
Signal detection theory- whether or not we detect a stimulus, especially amidst background noises * It depends not just on the intensity of the stimulus but also on psychological factors
Subliminal Detection * Below our threshold for being able to detect a stimulus consciously
Just noticeable difference * The minimum difference (color, pitch, weight, temp., etc.) for a person to detect the difference half the time * Weber's Law- for two stimuli to be perceived as different we must differ by a minimum percentage * Weight= 2% * Light intensity= 8% * Sound = 0.3% frequency
Sensory adaption * To help detect more novel stimuli in our environment, our senses will tune out constant stimuli * When you switch your phone from one pocket to the other do you feel it? * The brain wants to focus on one sensation at a time
Perceptual set * When what we EXPECT to see influences what we DO see
Context effect on perception * Double pair apple pear payee payor

The Effect of emotion, psychical state, and motivation on perception

Experiments have shown that * Destinations appear to be farther when your tired * Targets look farther when your cross bow is heavier * A hill looks steeper with a heavy backpack, or listening to sad music, or being alone