Psychology Chapter: Sensation and Perception

Sensation and Perception

• Sensation is the activation of sense organs by a source of physical energy
• Perception is the sorting out, interpretation, analysis, and integration of stimuli by the sense organs and brain.

Sensory Systems

• Interoceptors or Visceroceptors are found in the visceral organs.
• The skin contains receptors for touch, pressure, temperature, and pain.

Psychophysics

• Psychophysics studies the relationship between the physical aspects of stimuli and our psychological experience of them.
• The absolute threshold is the minimal intensity of a stimulus that can be detected 50% of the time.
• The difference threshold is the smallest difference between two stimuli that can be detected 50% of the time.

Visual Phenomena

• Normal color vision can distinguish at least 7 million different colors.
• The Ishihara test is used to identify color blindness.
• Trichromatic Theory of Color Vision posits that three kinds of cones exist in the retina, each most responsive to blue-violet, green, or yellow-red.
• Prosopagnosia is the inability to distinguish among faces.
• Scotomas are areas of blindness in the contralateral visual field due to damage to the primary visual cortex.
• Blindsight is the response to visual stimuli outside conscious awareness of “seeing”.

Auditory System

• Sound waves are movements of air molecules brought about by vibrations.
• The auditory receptor is the ear
• The ear is sensitive to sound waves within 20-20,000Hz.
• The ear is composed of an outer, middle, and inner ear.
• The inner ear contains the cochlea, a snail-shaped tube filled with fluid that vibrates in response to sound.
• Hair cells in the organ of Corti are mounted on the basilar membrane and are the auditory receptors.
• The auditory cortex is located in the temporal lobe.
• The core region of the auditory cortex includes the primary cortex surrounded by the belt, a band of secondary cortex.
• Secondary cortex outside the belt is referred to as parabelt areas.

Auditory Phenomena

• Pitch is related to the frequency of sound waves.
• Loudness is related to the intensity of sound waves.
• Tonal quality, or timbre, is related to the complexity of sound waves.

Somatosensory System

• The dorsal-column medial lemniscus system mainly carries touch and proprioception.
• The anterolateral system mainly carries pain and temperature.
• Phantom limbs are sensations experienced in a missing limb.

Olfactory System

• More than a thousand receptor cells, known as olfactory cells, are spread across the olfactory epithelium (nasal cavity).
• The olfactory bulb, located near the front of the brain, is where olfactory axons end.
• The olfactory tract is a bundle of nerves starting at the bulb and going to the brain.

Olfactory Phenomena

• The nose shapes the sound of a person's voice.
• The nasal voice heard in someone with a cold or allergies is due to the loss of nasal resonation.

Explore the fascinating world of sensation and perception in this quiz. Test your understanding of how we interpret stimuli through our senses, the role of psychophysics, and visual phenomena including color vision. Learn about interoceptors, absolute thresholds, and more as you delve into psychological principles.