MODULE 3: SENSATION AND PERCEPTION

• Sensation


  The stimulation of receptors found in different sense organs in our body by stimuli that activates the neural signals that eventually get transmitted and processed in the brain
• Transduction


  Conversion of stimulus to neural signal/ activity
• Sensory Receptors


  • Receive stimuli in the form of energy such as light, sound waves, chemical particles, or pressure
• Receptors


  • Neurons that are activated by the energy of physical information such as light, sound, touch, taste, etc.
• Just Noticeable Difference (JND)


  Smallest difference between two stimuli that can be detected 50% of the time
• Weber's Law


  Smallest difference between two stimuli that can be detected 50% of the time
• Absolute Threshold


  The lowest level of stimulation that a person can consciously detect 50% of the time that the stimulation is present
• Sensory Adaptation


  Decrease in neural sensitivity to receptor
• Habituation


  Decrease in response to stimuli
• Brightness


  Amplitude, height of the wave. Higher wave = brighter, Lower wave = dimmer
• Color/ Hue


  Wavelength, length of the wave. Shorter waves = blue, Longer waves = red
• Saturation


  Purity. High saturation = wavelength is purer. Adding black will result to a less saturated yellow
• Cornea


  • Does the focusing
• Lens


  • Can change its shape and therefore the focus. Hardens as we grow old
• Presbyopia


  Lens is slowly losing its ability to change shape and focus on objects that are far or near
• Retina


  • Where light is received and gets converted into signals that reach the brain
• Cones


  • Visual acuity
• Rods


  • Black, white, and shades of gray
• Trichromatic Theory


  There are 3 types of cones depending on its peak sensitivity (range of colors)
• Opponent Process Theory


  We have cones that respond to four primary colors: red, green, blue, and yellow. Colors are arranged in opponent pairs: BLUE-YELLOW, GREEN-RED
• Sound Waves


  Vibration of air molecules around us
• Purity/ Timbre


  Allows you to differentiate sounds of instruments
• Place Theory


  Pitch depends on which hair cells and area in the Organ of Corti are stimulated
• Frequency Theory


  Pitch depends on how the basilar membrane moves
• Volley Principle


  Accounts for pitches between 400 Hz to 4000 Hz. Groups of auditory neurons take turns in firing
• Taste


  One of the two dimensions of gustation
• Mouth-Feel


  One of the two dimensions of gustation
• Taste Buds


  • Taste receptor cells can be found in the papillae
• Gustatory Cortex


  Insula and frontal operculum
• Olfactory Sense


  Nose collect sensory information. Processes by cilia or hair cells in the nasal cavity
• Nose and Olfactory Bulbs


  • Olfactory is only sense that does not go through the thalamus. Goes straight to higher cortical areas and amygdala
• Somatic pain


  Pain in muscle, joints
• Visceral pain


  Pain in organs
• Kinesthetic sense


  Sense of movement
• Proprioceptive sense


  Sense of the direction of body movement
• Vestibular Sense


  Sense of body orientation, whether upwards/ downwards/ sideways
• Size Constancy


  Perceiving objects as having a constant size despite changes in the retinal image
• Shape Constancy


  Perceiving objects as having a constant shape despite changes in the retinal image
• Brightness Constancy


  Perceiving objects as having a constant brightness despite changes in illumination
• Figure-Ground Relationship


  Tendency to perceive objects or figures as existing on a background