Week 12 - Behavioral Neuroscience
Week 12 - Behavioral Neuroscience PSYC 4183-001
Popular in Behavioral Neuroscience
verified elite notetaker
Popular in Psychlogy
This 6 page Class Notes was uploaded by Celine Notetaker on Sunday April 17, 2016. The Class Notes belongs to PSYC 4183-001 at University of Arkansas taught by Nathan Parks in Spring 2015. Since its upload, it has received 12 views. For similar materials see Behavioral Neuroscience in Psychlogy at University of Arkansas.
Reviews for Week 12 - Behavioral Neuroscience
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 04/17/16
Week 12- Behavioral Neuroscience Hearing The Stimulus The Sensory Apparatus Neural Pathways Cortical Representations The Stimulus: Sound Dimensions of Sound 1. Amplitude (Loudness) a. Greater pressure = Greater amplitude= louder b. Amplitide = height of waves (image ) 2. Frequency (Pitch) a. How close together the vibrations are b. Smaller wavelengths = smaller pitch, larger wavelengths = larger pitch c. Wavelengths = distance between waves 3. Complexity (Timbre) a. Multiple frequencies with a base frequency creates a complex sound b. How fast a sound ramps up or is created is affected by complexity c. Being able to tell the difference between a note on the piano or the guitar is due to complexity Amy Frequently Collects Little Purple Tins The Sensory Apparatus Pinna – Allows you to localize sound Auditory canal – brings sounds in which bands on the eardrum -Eardrum vibrates at the same frequency as the sound and transfers it to ossicles Cochlea: Spiral shaped structure where all transduction of sound occurs -Filled with fluid which poses an issue since sound is vibrations through the air - Eardrum counters this by transferring the vibrations from a large surface area through the ossicles to the small surface area of the oval window This condenses the sound so that way it can go through the cochlea a smaller surface area INCREASES the pressure which is what allows the signals to go through the denser cochlea Semicircular canals: Involved in vestibular sense (filled with fluids) Inner Ear Cochlear Structures 1. Basilar membrame- membrane upon which the organ of corti is situates. L a. Lines all of the cochlea 2. Organ of Corti: Sensory organ that contains auditory hair cells (contains mechanoreceptors) a. Continuous along the entire basilar membrane b. Vibrations of these hair cells is what turns into neural code 3. Tectorial Membrane: Membrane above the organ of Corti. Hair cells move against this membrane a. Means of helping the mechanoreceptors have something to be flexed/pushed against aids in transduction Organ of Corti - Has outer hair cells and inner cells o Inner hair cells: transduce sound by responding to perturbations of the basilar membrane. o Outer hair cells: act as an amplifier pushes against the tectorial membrane to create greater graded potential for the innerhair cells tectorial and outer hair cells push back and forth to AMPLIFY the vibration and thus stimulate the inner hair cells (depolarizes it) Basilar membrane -It is tapered in width so that it is wider at the apex of the cochlea than at the base -This causes a difference in what part of the basilar membrane is being agitated the most by different frequency sounds The base is moved more by high frequency sounds The apex is moved more by low frequency sounds **Another way to explain it :Sound causes the stapes to move in and out which in turn causes fluid within the cochlea to flow. This generates a travelling wave within the basilar membrane. The region of the basilar membrane deformed by sound is dependent on the sound’s frequency. The neurons along the basilar membrane is what codes these sounds and are set for high or low frequency based off their location in the basilar membrane Cochlear implants: mimic neurons by placing electrodes along the cochlea and uses a microcomputer that detect and encode for certain frequencies. - It then stimulates the cochlea via electrodes without requiring actual movement from the basilar membrane Neural Pathway =Mostly contralateral organization but not completely - This is because we have to figure out where sound is arising from (localizing) - In order to localize better you need to combine sound from both ears Left cochlea auditory nerve Left Cochlear Nuclei = Partially decussates to the contralateral side and some decussates to the ipsilateral side Superior Olive Superior Olive: First structure in the auditory pathway to receive binaural inputs - Anything damaged AFTER the superior olive will not necessarily cause total loss of hearing from that side (because it is ipsilateral up until the superior olive) - Uses interaural time differences and interaural intensity differences to figure out where a sound is coming from o Interaural Time Differences: Difference in arrival time of sound between the two ears Allows localization in the horizontal plane (either side of your head/ across) o Interaural Intensity Differences: Difference in sound intensity between the two ears Allows localization in the horizontal plane o Pinnae Cues: Difference in sound patterns caused by filtering by the pinnae Allows localization in the vertical plane (high above or below you) ** if you put silly putty on you pinnae to smooth out all the fold you would have trouble locating sources of sound on the vertical plane because your brain is used to the pattern of echoes for your unique pinnae folds (AKA the patterns and source identification is LEARNED)