checkpoint 4 notes
Reading 1: Understanding Sensation and Perception
sensory receptors: cells that detect + respond to different types of stimuli such as light, sound, and touch
transduction: the process of transformation of physical energy from the environment into electrochemical signals within the nervous system
info that the brain receives through transductions are sensations
other types of sensory sources
balance (vestibular sense): provides info about balance spacial orientation, and head movement
body position (proprioception): allowed the brain to sense body parts’ position, movement, and orientation without relying on vision
movement (kinesthesia): works w proprioception to provide feedback about the body’s movement + position
pain (nociception): detects potentially harmful stimuli like pain + triggers appropiate brain responses
temperature (thermoception): lets us perceive temp changes such as sensing hot/cold stimuli
difference threshold: the smallest detectable difference between two stimuli
sensory adaptation: when sensory receptors become less responsive to constant/repetitive stimuli over time
prevents sensory overload + lets organisms focus their attention on new/changing stimuli in their environment
perception: how people organize, interpret, and experience sensory info to make sense of the world around them
involves bottom-up and top-down processing
bottom-up processing: sensory info is taken from the environment to create a complete perception
data-driven process
relies on the intensity + characteristics of the stimuli
top-down processing: knowledge + expectations that already existed are used to guide the interpretation of sensory outputs
attention, motivation, and cultural differences all affect our sensation and perception
absolute threshold: the minimum intensity of a stimulus required to be detected by someone’s sensory system with a specific level of accuracy
represents the point where a stimulus becomes consciously perceptible to the observer
signal detection theory: how people make decisions about detecting the presence of stimulus in the presence of background stimulation
takes sensitivity to signals and decisions criteria in account when it comes to detecting stimuli
Reading 2: Waves and Wavelengths
crest: the highest surface part of a wave
trough: the lowest surface part of a wave
amplitude: the distance from the cent line to either the top point of the crest or the bottom point of the trough
wavelength: the length of a wave from one peak to the next
frequency: the number of waves that pass a given point and a given time period
often expressed in hertz (Hz) or cycles per second
the electromagnetic spectrum includes different types of radiation such as high-energy gamma rays + x-rays, ultraviolet light infrared light, microwaves, and radio waves\
different colors = specific ranges of wavelengths in the visible spectrum
light waves with larger amplitudes are brighter to us
high-frequency = high-pitched / low-frequency = low-pitched
loudness is measured in decibels (dB)
timbre: how pure the sound is
affected by frequency, amplitude, and timing of sound waves
ex: different timbres when playing the same note on a piano vs violin
Reading 3: Vision, Hearing, and Other Senses
perception: the process where sensory info is interpreted + organized to understand + interact with the environment
lights enters the eye through the cornea + passes through the pupil > light crosses the lens > the lens adjusts its shape for focus and reaches the fovea
fovea: specialized for bright lights and color perception
a part of the retina containing densely packed cones
cones operate the best under bright light conditions
rods: excels in low light conditions and peripheral vision
a type of photoreceptor that’s located throughout the retina
trichromatic theory: cones that are sensitive to different wavelengths create color perception
opponent-process theory of color vision: colors are coded in opposite pairs (black/white, red/green, etc), and cells are excited by one color and inhibited by the other
afterimage: a continuation of a visual sensation after the removal of the stimulus
outer ear: includes the pinna, auditory canal, and eardrum (tympanic membrane) that vibrates w sound waves
middle ear: three ossicles that transmit + amplify these vibrations
malleus, incus, and stapes
inner ear: the semicircular canals and the cochlea
semicircular canals are crucial for balance
cochlea converts sound vibrations into neural signals using hair cells
hair cells: auditory receptor cells of the inner ear
embedded in the basilar membrane
basilar membrane: a thin strip of tissue within the cochlea
temporal theory: sensory neurons fire at rates corresponding to sound frequency
relied on by both high and low frequencies
place theory: different regions of the basilar membrane respond to various frequencies with the base sensitive to high frequencies and the tip to low frequencies
relied on by higher frequencies
taste info is processed through the medulla, thalamus, limbic system and the gustatory cortex
depth perception uses both monocular and binocular cues
Reading 4: The Gestalt Perceptions
gestalt: a psychological movement that emphasizes understanding the whole experience instead of just its parts
the whole is greater than the sum of its parts
gestalt principle: the brain perceives patterns/shapes/configurations as whole forms instead of merely the sum of their parts
our visual perception separates the world into figure and ground
figures are the main object/person that captures our attention
ground is the background that the figure stands out against, greatly influences how we perceive/interpret visual info
things that are alike + close together tend to be grouped together
principle of closure: we organize our perceptions into complete objects instead of series of parts
our ability to perceive patterns relies on principles such as closure, continuity, and similarity
perceptual hypotheses: educated guesses formed as we interpret sensory input
influenced by personalities past experiences, and expectations
shapes our perceptual set
influenced by our tendency to seek our meaningful patterns in our environment