Perception and Sensation Flashcards
Sensation
A physiological process involving sensory receptions detecting and responding to stimuli..
Perception
.A mental process of organising and interpreting sensory stimuli sent from the sensory organs.
Absolute threshold
the minimum amount of stimulation required for a person to detect the stimulus 50 percent of the time.
the difference threshold
the smallest difference in stimulation that can be detected 50 percent of the time. The difference threshold is sometimes called the just noticeable difference (jnd), and it depends on the strength of the stimulus.
The senses
- Psychophysics studies the relationship between the physical properties of stimuli and people’s experience of stimuli.
- Psychologists assess the acuity of our senses by measuring the absolute threshold and the difference threshold and by applying signal detection theory.
- Sensory adaptation is the decrease in sensitivity to an unchanging stimulus.
- Babies are born with all the basic sensory abilities and some perceptual skills, which develop and become more sensitive over time.
Vision
• The sense of vision depends on light, which is a kind of electromagnetic radiation emitted by the sun, stars, fire, and lightbulbs.
• We experience light as colour, brightness, and saturation, which depend respectively on wavelength, amplitude, and complexity of light waves.
• The eye is composed of the cornea, the iris, the pupil, the lens, the retina, and the fovea. The lens adjusts its shape to focus light from objects that are near or far away in a process called accommodation
.• Dark and light adaptation are processes by which receptor cells sensitize and desensitize to light, respectively.
• The retina has millions of photoreceptor cells called rods and cones. Rods and cones connect via synapses to bipolar neurons, which connect to ganglion cells. The axons of the ganglion cells make up the optic nerve, which connects to the eye at the optic disk, also called the blind spot.
• After being processed in the brain, visual signals reach the primary visual cortex, where feature detectors respond to the signals.
Colour
a psychological experience created when the eyes and the brain interpret light.
Binocular and monocular cues
enable people to determine distance from an object
Perceptual constancy
the ability to recognize that an object is the same when it produces different images on the retina. Visual constancies relate to shape, size, brightness, colour, and location.
Visual illusions
are misinterpretations of visual stimuli.
Selective attention
the ability to focus on some pieces of sensory information and ignore others.
Hearing
- Hearing depends on sound waves. Sound has three features: loudness, pitch, and timbre, which depend respectively on wave amplitude, frequency, and complexity.
- The ear comprises the outer ear, the middle ear, and the inner ear. These parts contain the pinna, the eardrum, ossicles, oval window, cochlea, and cilia.
- Neurons in the ear form the auditory nerve, which sends impulses from the ear to the brain. The thalamus and auditory cortex receive auditory information.
Taste and Smell
- The stimuli for taste and smell are chemicals.
- Taste occurs when chemicals stimulate receptors in the tongue and throat.
- The five tastes are salty, sweet, sour, bitter, and umami.
- Smell occurs when chemicals in the air are inhaled into the nose. Smell receptors send impulses along the olfactory nerve to the brain.
Kinesthesis
The sense of the position and movement of the body parts
Vestibular System
• The sensory system involved in balance.The main structures in the vestibular system are three fluid-filled tubes called semicircular canals, which are located in the inner ear.
