Slide 1 ___________________________________ - PDF document

Slide 1 ___________________________________ ___________________________________ Sensation and Perception ___________________________________ Principals of Behavior Chapter Three ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 2 ___________________________________ Sensation ___________________________________  Sensation is the process by which we detect and process stimuli in the environment. ___________________________________  Sensation is the process by which we detect physical energy such as light, sound and heat from the environment by specialized sensory receptors and encoding it as neural signals. ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 3 ___________________________________ Transduction ___________________________________  The process of transforming physical energy into neural signals via sensory signals.  Sensory receptors cells in one the sense ___________________________________ organs ( eye) receive stimulus such as light. If the amount of stimuli, via the light is strong enough the receptor cell (neuron) fires sending a neural signal (action ___________________________________ potential) to the appropriate area of the brain  occipital lobe.  ___________________________________ ___________________________________ ___________________________________

Slide 4 ___________________________________ Psychophysics  The field that studies links between the ___________________________________ physical properties of stimuli and a person’s experience of them.  Thresholds- as we are constantly bombarded with ___________________________________ energy,( x-rays, radio waves, ultraviolet and infrared light) Our senses allow only a restricted awareness of this energy as in what stimuli we can detect. ___________________________________  This “restricted awareness” are called thresholds, and they are different for each sensory system. ___________________________________ ___________________________________ ___________________________________ Slide 5 ___________________________________ Sensory Thresholds ___________________________________  Absolute threshold  Difference threshold ___________________________________  Just noticeable Difference ___________________________________  Subliminal Perception ___________________________________ ___________________________________ ___________________________________ Slide 6 ___________________________________ The Visual System ___________________________________  Properties of Light  Energy is the form of light wave  Brightness-amplitude of the wave ___________________________________  Saturation-purity of the wave (presence of more than one wave is less pure or saturated)  Color-length of the wave. ___________________________________ ___________________________________ ___________________________________ ___________________________________

Slide 7 ___________________________________ The Structure of the Eye ___________________________________  Cornea -transparent protector through which light enters the eye. Curved surface bends the light to focus at the back of th eye Pupil -a small adjustable opening that regulates the amount of light  that enters the eye through a colored muscle called the iris. Lens -transparent structure behind the pupil that also focuses The  ___________________________________ cornea does most of the bending, while the lens fine tunes the focus in process called accommodation.  accommodation – affects acuity which is the sharpness of our vision, which can be affected by small distortions in the shape of the eye.  The shape of the eye influences the focus of the image on the ___________________________________ retina. ___________________________________ ___________________________________ ___________________________________ Slide 8 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 9 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________

Slide 10 ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 11 ___________________________________ Accommodation ___________________________________  Farsightedness- lens is longer and flatter than normal and therefore unable to bring close objects into focus. Focusing the image behind the retina ___________________________________  Nearsightedness- - eyeball is shorter than normal, causing focus to later than normal and therefore objects up ___________________________________ close appear blurred. Focusing the image in front of the retina. ___________________________________ ___________________________________ ___________________________________ Slide 12 ___________________________________ Parts of the Eye ___________________________________ Retina- the light sensitive outer surface of the eye,  containing the receptors that begin visual processing  receptor cells - located at the back of the retina and converts light into a neural signal Two types of receptor cells, rods and cones. ___________________________________  rods - located around the outside of the retina, responsible for black, white & gray vision, vision in dim light, and peripheral vision.  cones -located near the fovea, which was the central focal point in the retina, which is ___________________________________ responsible for color, fine detail and vision in day light. ___________________________________ ___________________________________ ___________________________________

Slide 13 ___________________________________ Photoreceptors ___________________________________ Receptor Cells (Rods & Cones) ___________________________________ Bipolar Cells Ganglion Cells ___________________________________ Optic Nerve ( axons of Bipolar cells) ___________________________________ ___________________________________ ___________________________________ Slide 14 ___________________________________ How the Eye Works  Blind spot -is the point at which the optic ___________________________________ nerve leaves the eye and is called the blind spot because there are no receptors there .  Optic nerve- the bundle of axons that ___________________________________ carries neural messages from each eye to the brain.  Optic chiasm -point near the base of the brain where some, not all of the ___________________________________ optic nerve fibers split and cross to the other side of the brain. ___________________________________ ___________________________________ ___________________________________ Slide 15 ___________________________________ Hemispheric projection:Visual fields ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________

Slide 16 ___________________________________ Theories of Color Perception Trichromatic Theory ___________________________________  Proposed three types of cones: red, blue, green  Different shades of color correspond to different amounts of light received by each of these three types of cones. ___________________________________  Cones fire message to the occipital lobe  Combination of which cones are firing as well as the rate of firing that determines the color ___________________________________ perceived.  Problem: After image ___________________________________ ___________________________________ ___________________________________ Slide 17 Stare at the cross in center of the ___________________________________ flag for 30 seconds, now stare at white wall or piece of paper ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 18 ___________________________________ Theories of Color Perception: Opponent Process ___________________________________  Four primary colors: red, green, blue, yellow  Cones are arranged in pairs, red with green, blue with yellow  If one memory of the pair is stimulated, i.e. red, ___________________________________ the other member of the pair is turned off, i.e. green.  Afterimage-if a person stares at a red object too ___________________________________ long, it weakens that members ability to inhibit the other cell. So, if staring at a red image for too long, one might begin to see green as an after-image. ___________________________________ ___________________________________ ___________________________________