Sensation & Perception Flashcards
Sensation
The process by which you detect physical energy from your environment and encode it as neural signals
Perception
The process that organizes sensory input and makes it meaningful
Psychophysics
The study of the relationship between physical energy and psychological experiences
Absolute threshold
The weakest level of a stimulus that can be correctly detected at least half the time
Signal detection theory
There is no actual absolute threshold because the threshold changes with a variety of factors (fatigue, attention, etc)
Subliminal stimulation
The receipt of messages that are below one’s absolute threshold for conscious awareness
Difference threshold
The minimum difference between any two stimuli that a person can detect 50% of the time
Ernst Weber =
Just noticeable difference (jnd)
Just noticeable difference (jnd)
How much you can add before you notice it
Weber’s Law
Difference thresholds increase in proportion to the size of the stimulus
Sensory adaptation
Permits you to focus your attention on informative changes in your environments without being distracted by irrelevant data such as odors or background noises
Receptors
Tranduce energy from one form to another
Transduction
Refers to the transformation of stimulus energy to the electrochemical energy of neural impulses
Visual information first processed by
Occipital lobes
Auditory information first processed by
Temporal lobes
Body senses first processed by
Parietal lobes
Smell first processed by
Lower portion of the frontal lobes
Rods and cones are
Photoreceptors that convert light energy to electrochemical neural impulses
Cornea
Transparent tissue in the front of your eye
Near-sighted
Near objects are seen more clearly
Far-sighted
Distant objects are seen more clearly
Astigmatism
Caused by an irregularity in the shape of the cornea and/or lens
Distorts and blurs the image at the retina
Dark adaptation
Gradual increase in sensitivity to the low level of light
Bipolar cells
Rods and cones with a second layer of neurons in front of them in your retina
Visual acuity is also called
Resolution
Ganglion cells
Bipolar cells transmit impulses to another layer of neurons in front of them in your retina
Axons of ganglion cells form the
Optic nerve, the blind spot
Feature detectors
Respond only to specific features of visual stimuli
Parallel processing
Simultaneous processing of stimulus elements
Trichromatic theory
Three different types of photoreceptors are each most sensitive to a different range of wavelengths
Most common type of color blindness is
Red-green (sex linked, males more likely to have it)
Ewald Hering’s opponent-process theory
Certain neurons can be either excited or inhibited, depending on the wavelength of light, and complementary wavelengths have opposite effects
Audition
Sense of hearing
How do you hear?
Sound waves result from the mechanical vibrations of molecules -> vibrations move in a medium (like air) -> they compress and expand
The greater the compression the ____ the amplitude
Larger
Amplitude
The height of the sound wave
dB =
Decibels
Frequency
The number of compete wavelengths that pass a point in a second
Hz =
Hertz
Pitch
The highness or lowness of a sound
Timbre
Difference in the purity of the wave form or mixture of the sound waves
Ossicles
Hammer, anvil, and stirrup
Sound localization
Process by which you determine the location of a sound
Place theory
The position on the basilar membrane at which waves reach their peak depends on the frequency of a tone
Frequency theory
The rate of neural impulses traveling up the auditory nerve matches the frequency of a tone, enabling you to sense it’s pitch
Individual neurons can fire at a maximum of _____ times per second
1000
Conduction deafness
A loss of hearing that results when the eardrum is punctured or any of the ossicles lose their ability to vibrate
Nerve (sensorineural) deafness
Results from damage to the cochlea, hair cells, or auditory neurons
