Sensation and Perception Sensation: your window to the world Perception: interpreting what comes in your window.

Transduction The key event of sensation! Transforming signals into neural impulses. Information goes from the senses to the thalamus , then to the various areas in the brain. .

Sensory Adaptation Decreased responsiveness to stimuli due to constant stimulation. Do you feel your underwear all day?

Cocktail-party phenomenon The cocktail party effect describes the ability to focus one's listening attention on a single talker among a mixture of conversations and background noises, ignoring other conversations. Form of selective attention.

Coding Is the translation of a stimulus’ physical properties into a pattern of neural activity the brain can interpret. Temporal Codes: reading the timing of the firing neurons. Spatial code: identifies the location of the firing of the neuron.

Vision Our most dominating sense. Visual Capture

Phase One: Gathering Light The height of a wave gives us it’s intensity (brightness). The length of the wave gives us it’s hue (color). ROY G BIV The longer the wave the more red. The shorter the wavelength the more violet.

Phase Two: Getting the light in the eye 3 4 5 2 1

A walk through the eye! Cornea: protective layer, where light enters the eye Pupil Iris: adjust the amount of light by constricting or relaxing Lens: bends light to the retina Retina surface at the back of the eye,..where transduction occurs!!!!!! Info sent via the optic nerve, thalamus (Lateral geniculate nucleus==has a map of the retina), to the visual cortex in the occipital lobe.

Transduction Takes places in the retina, contains neurons: Photoreceptors Rods: light sensitive/cannot discriminate color Cones: indentify color

Phase Four: Processing In the Brain Feature Detectors. Cells that respond to specific features. Parallel Processing: the what system ( the form of objects/color) and the where system (movement, distance) We have specific cells that see the lines, motion, curves and other features of this turkey. These cells are called feature detectors.

Color Vision Two Major Theories

Trichromatic Theory Three types of cones: Red Blue Green These three types of cones can make millions of combinations of colors. Does not explain afterimages or color blindness well.

Opponent-Process theory The sensory receptors come in pairs. Red/Green Yellow/Blue Black/White If one color is stimulated, the other is inhibited.

Afterimages

Hearing Our auditory sense

We hear sound WAVES The height of the wave gives us the amplitude of the sound. The frequency of the wave gives us the pitch if the sound.

The Ear

Transduction in the ear Sound waves hit the eardrum then anvil then hammer then stirrup then oval window. Everything is just vibrating. Then the cochlea vibrates. The cochlea is lined with mucus called basilar membrane. In basilar membrane there are hair cells. When hair cells vibrate they turn vibrations into neural impulses which are called organ of Corti. Sent then to thalamus up auditory nerve. It is all about the vibrations!!!

Place Theory and Frequency Theory Pitch Theories Place Theory and Frequency Theory

Place Theory Different hairs vibrate in the cochlea when they different pitches. So some hairs vibrate when they hear high and other vibrate when they hear low pitches.

Frequency Theory All the hairs vibrate but at different speeds.

Nerve (sensorineural) Deafness Conduction Deafness The hair cells in the cochlea get damaged. Loud noises can cause this type of deafness. NO WAY to replace the hairs. Cochlea implant is possible. Something goes wrong with the sound and the vibration on the way to the cochlea. You can replace the bones or get a hearing aid to help.

Touch Receptors located in our skin. Gate Control Theory of Pain

Taste We have bumps on our tongue called papillae. Taste buds are located on the papillae (they are actually all over the mouth). Sweet, salty, sour and bitter.

Smell Olfaction (smell): detects chemicals that are airborne. Olfactory receptors are located on the dendrites of specialized neurons that extend into the moist lining of the nose. Is the on only sense that does not synapse at the thalamus…extends directly into the brain to synapse in the olfactory bulb which connects to the amygdala==== close connection to emotion and memory!!!

Vestibular Sense Tells us where our body is oriented in space. Our sense of balance. Located in our semicircular canals in our ears.

Kinesthetic Sense Tells us where our body parts are. Receptors located in our muscles and joints. Without the kinesthetic sense you could touch the button to make copies of your buttocks.