CHAPTER 4 sensation and perception Flashcards
sensation
simple stimulation of a sense organ
perception
the organization, identification and interpretation a sensation in order to form a mental representation
transduction
what takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system
psychophysics
methods that measure strength of a stimulus and the observer’s sensitivity to that stimulus
Vision sensory input
light reflected from surfaces provides the eyes with information about the shape, color, and, positions of objects
Sound sensory input
vibrations cause changes in air pressure that move through space to the listener’s ear
touch sensory input
pressure of a surface against the skin, signals its shape, texture, and temperature
tastes and smell sensory input
molecules dispersed in the air or dissolved in saliva reveal the identity of substances
absolute threshold
the minimal intensity needed to just barely detect a stimulus in 50% of the trials
just noticeable difference
the minimal change in a stimulus that can just barley be detected
Weber’s Law
the just noticeable stimulus is a constant proportion despite variations in intensity
sensory adaptation
sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditons
visual acuity
the ability to see fine detail
Light waves
length- determines color
amplitude- determines brightness
purity- (number of distinct wavelengths) determines saturation
cones
detect color
rods
detect low light shades of grey more rods than cones
visual form agnosia
the inability to recognize objects by sight
change blindness
when people fail to detect changes to the visual details of a scene
inattentional blindnes
a failure to perceive objects that are not the focus of attention
gate control theory of pain
signals arriving from pain receptors in the body can be stopped or gated, by interneurons in the spinal cord via feedback from two directions
