Psych Mod 3: Sensation and Perception

• Transduction is the conversion of stimulus to neural signal
• Sensation is the activation of special receptors in the senses that converts environmental stimuli into neural signals
• Perception is the method by which brain takes all sensations a person experiences at any given moment and allows them to be interpreted in some meaningful fashion
• Receptors are neurons that are activated by energy of physical information such as light, sound, touch, taste, etc. 
• The smallest difference between two stimuli that can be detected 50% of the time is called Weber's law or also known as just noticeable difference (jnd)
• Absolute threshold is the lowest level of stimulation that a person can consciously detect 50 percent of the time that the stimulation is present
• Sensory adaptation is the decrease in neural sensitivity to receptor
• Habituation is the decrease in response to stimuli
• Brightness - is our psychological perception of a light wave's amplitude or height. Higher wavelength corresponds to brighter light, and lower wavelengths correspond to dimmer lights.
• Color - depends on the length of the wave. Shorter waves represent the color blue in the visible spectrum, while longer waves are represented by the color red.
• Saturation - refers to the purity of the hue or color. If saturation is high for the color yellow, then the wavelength is purer
• Cones are responsible for our ability to see colors in bright light.
• Rod function mostly in dim light
• The two theories of color perception are: Trichromatic Theory and Opponent Process Theory.
• Trichromatic theory is the theory that we perceive different shades of color depending on the amount of light received by three different types of cones
• Opponent Process Theory proposes that there are four primary colors: red, green, blue, and yellow. These colors form pairs (red and green; blue and yellow). Activation of one color in the pair inhibits the other.
• Sound waves are the vibration of air molecules around us
• Wavelength - we perceive it as pitch or how "high" or "low" the sound
• Amplitude is perceived as volume or loudness
• Purity or 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 fast the basilar membrane moves
• Volley principle - It states that with sounds that have frequencies beyond 100Hz, instead of firing alone, hair cells fire together in groups. These groups of hair cells take turns firing in order to produce the needed amount of frequency.
• Taste buds can be found in the papillae
• Nose collect sensory information and is processed by cilia or hair cells in the nasal cavity
• Visceral pain is the pain you feel from your internal organs,
• Somatic pain is the type of pain you feel in your skin, muscles, joints, and bones.
• Kinesthetic sense is the ability to perceive the extent, direction, or weight of movement.
• Proprioceptive sense, meanwhile, informs us about the position of our body parts.
• Vestibular sense allows us to see feel where our head is in relation to our body and the ground. In a sense, it helps us with balance. 
• Perception is our ability to organize and interpret sensations.
• Figure-ground relationship refers to the tendency to perceive objects or figures as existing on a background
• Expectations and past experiences affect perception