Sensation – Process of receiving information about the external (and internal) world.
Perception – To impose a meaningful interpretation on the information sensation provides
Dark background makes a brighter view
Sense Receptors of all organs; have to transforming sensory information into neural signals.
Johannes Muller (1926) – People experience different types of sensations because sense organs send signals to different parts of the brain
Synasethesia – stimulation of one sensory modality evokes sensation in another modality
Everything we see is a reflection of light from an object to our retina (eye ball)
Longer wavelengths = orange/red
Shorter wavelengths = violet/blue
All wavelengths combined=White
Amplitude of light energy is the perception of brightness.
(The more light is reflected the brighter it will appear)
Single wavelength = Pure light high in saturation
Multiple wavelength = complex light low in saturation
The Eye is for Vision:
Cornea – Front of the eye: rounded and transparent helps bend light toward the lens
Lens – can be made fat/curved (light bends a lot) or skinning (light bends a little).
Fat lens is for brining close objects into focus
Skinny lens is or bringing far objects into focus
(With age lens become less flexible)
Iris –Controls how much Light enters the eye through the pupil. Comes in blue, green, brown, hazel, etc
Introduction: The rate of photosynthesis varies greatly with changes in wavelengths of light. Light’s colour is determined by its wavelength of light, and thus it is possible to devise an experiment to determine which wavelengths of light are most productive for photosynthesis than others. In this experiment I use a plant called Elodea (pond weed). Elodea is native to North America and it is ...
If bright outside, iris constricts letting less light in.
If dark outside, iris dilates letting more light in.
Retina – Patch of sensory receptors at the back of the eye. Detect the amount of light reflected from different parts of the “visual field”
* Receptors away from the center report on periphery of the visual field, those closer to the center report on the central part of the visual field.
* 2 Kinds of Photoreceptors:
1) Rods – Very sensitive to light, most numerous away from the center (or fovea) of the retina
* Responsible of vision in poor lightning conditions and peripheral vision.
* Rods are not sensitive to color
* Rods adapt to darkness more slowly than cones but are much more sensitive (allow fairly clear vision in dark movie theaters)
2) Cones – less sensitive to light, most numerous at the center (or fovea) of the retina
* Responsible for vision in good lightning conditions and focused vision at the center of the visual field
* Cones are sensitive to color
* Cones adapt to darkness quickly but are not very sensitive to dim light
* Rods and cones report information about light energy reflected off objects to:
* Bipolar Neurons which report to Ganglion Cells which exit the eye at the Optic Disc and form the Optic Nerve
Visual Information as Neural Messages
Photoreceptors – respond to amounts of light at a certain part of the visual field.
* Amount of light determines rate of firing in Ganglion Cells (which send the information on to the brain)
Study of Hubel and Wiesel (1968):
* Visual Cortex neurons (back of the brain) use information from Ganglion Cells to detect edges, colors, and motion trajectories.
Trichromatic or Young-Helmholtz Theory
Retina contained three types of cones:
1) Prefers (very sensitive to) Blue
2) Prefers (very sensitive to) Green
3) Prefers (very sensitive to) Red
* All colors result from combined responses of three types of cones
I work at The Breakers hotel in West Palm, and have had the pleasure of seeing various works of art on the daily basis. I chose to analyze a self-portrait of a man named Henry Flagler. This painting is located on the south side of the hotel, and has a great amount of historical significance. Henry Flagler founded The Breakers and is very well known in West Palm, not only for his advancements in ...
Color Blindness – genetic variation that leads one or more of the three cone types to be missing
* Most common is problems distinguishing RED from GREEN (sometimes BLUE from YELLOW)
The opponent- Process Theory
Opponent Process Cells in the retina increase firing rate when exposed to wavelength for one color but decrease firing rate when exposed to wavelength of a different color
Color Afterimages – cells inhibited when exposed to one color (e.g. red) will “bounce back” after that
* color is removed leading to perception of the opposing color (e.g. green)
Binocular Cues to Depth and Distance
* Eyes point inward to bring close objects into focus
* The more “crossed” eyes become in focusing an object, the closer the object is
2) Retinal Disparity
* The difference in the perceived separation of two objects by the left and right eye
* This difference increase as the distance between the two objects increases
Monocular Cues to Depth and Distance
* Close things obscure father things
4) Linear Perspective
* Parallel lines are perceived as closer together when farther away
5) Motion Parallax
* When one is moving, far objects appear to move more slowly than near objects.
6) Texture Gradient
* Objects seem more clustered together if father away
7) Relative size
* Objects that project a smaller image on the retina seem father away
8) Relative Clarity
* Far objects will be perceived as more blurry than other objects
* a wave length of pressure caused by object vibrations (object vibration cause vibration of air molecules)
Characteristics of SOUND:
* Determined by the height of sound waves
* More amplitudes perceived as higher intensity sound
* Amplitude determines loudness (measures in disables)
* Determined by the wavelength of sound waves
* Higher frequency perceived as higher pitch sound (low = lower pitch)
Sound is part of our everyday lives. Just like we have eyes for, we are given ears for hearing sound. We rarely take the time to think about the characteristics of sound and the ways that they are made. The basis for an understanding of sound and hearing is the physics of waves. Sound is a wave, which is created by vibrating objects and spread through a medium from one location to another. In this ...
* Determined by the ranges of wavelengths (or frequencies) in a sound waves perceived as a sound’s TIMBRE
* One wavelength = Pure Tone (real life sounds all consist of multiple frequencies)
* Shaped to collect sound waves and send them toward the middle ear
* Sound waves vibrate the eardrum at the same amplitude and frequency, which then vibrates three bones (hammer, Anvil, Stirrup)
* Stirrup vibrates the Oval Window of the Inner Ear.
* Organ of Corti runs along the length of the Cochlea, contains hair cells (or cilia) that sit on top of the basilar membrane.
* Stirrup tapping on the oval window sends waves of fluid in the cochlea, causing the basilar membrane to move, and effecting movement of the hair cells.
Inner Ear to the Brain:
* Hair cells press against a membrane initiating signals about sound frequency and amplitude to be sent to the brain via the auditory nerve
* Many bumps on your tongue (called Papillae) contains taste buds
* Taste Receptors are fibers found inside taste buds.
* provide information about basic tastes (salty, sour,) based on chemicals in your mouth
1) The unique combination of basic tastes
* Neurons at the upper part of the nasal passage detect presence of chemical molecules in the air
* Information about the presence of such molecules are sent to the brain’s olfactory bulb through the olfactory nerve
* Fluid filled structures in the inner ear
* Provide information about the body’s position relative to gravity. (maintaining balance)
* Receptors in joints, muscles, and tendons provide information about the position of body parts relative to one another
We generally think of the speakers in our stereo or home theater systems as the final link in the audio chain — and the one that makes the biggest difference to our ears. But there’s much more to the sound we hear than just where you place your speakers in a stereo or home theater setup, and what comes out of them. You might not even realize it, but your room plays a rather large part in the ...
* Skin contains receptors that provide the brain information about pressure, temperature (hot/cold), and pain
Perception of Pain
* Pain signals damage to body tissue.
* Same amount of tissue damage can produce different pain experiences
Unconscious Influences of Perception
* Flashing a face at people so quickly they are not aware of having seen it leads them to rate that face as more attractive than some other face
* Unconscious exposure to personality traits (e.g. honesty) will cause people to judge someone the read about as having that trait