2011.01.13: Nick Lesica - Adaptation and precision in auditory midbrain
- Sense -> encode -> represent -> decode
- Cochlea -> brainstem -> inferior colliculus -> thalamus -> cortex
- Amplitude modulation is critical for speech
- AM (low Hz) and FM (high Hz) are separated in frequency space
- Does timing in AM matter? If so, what precision in timing is important?
- Used mutual information to determine relationship between AM input and neuronal firing rate.
- Utilized Victor's bin-less method
- 2 ms of timing jitter reduces mutual information
- Roll off at 500 Hz, which is upper end of natural stimuli
- Used mutual information to determine relationship between AM input and neuronal firing rate.
- To figure out differences/sources of noise and effect on response screw up known signal until mutual info is same. Then compare the output responses.
- Adding noise appeared to increase over-all response but did not reduce precision.
- The IC appears to directly represent the AM signal.
- Inter-aural timing difference and sound intensity have different effects on the filtering of input. ITD does not cause changes in the filtering of the signal.