CARNEY2015 - Brainstem processing

Usage:

[ic_sout_BE,ic_sout_BS,cn_sout] = carney2015(an_sout, BMF, fs)
[ic_sout_BE,ic_sout_BS,cn_sout, keyvals] = carney2015(an_sout, BMF, fs)
[..] = carney2015(an_sout, BMF, fs, varargin)

Input parameters:

`an_sout`	auditory nerve output [time CF]
`BMF`	best masking frequency (Hz)
`fs`	sampling frequency (Hz)

Output parameters:

`ic_sout_BE`	output of the band-enhanced cell [time CF]
`ic_sout_BS`	output of the band-suppressed cell [time CF]
`cn_sout`	cochlear nucleus output [time CF]
`keyvals`	parameters used in calculations, as key-value pairs: keyvals.t_cn : time vector for plotting CN responses, see arg_carney2015 for the list of other parameters

Description:

This function implements the LPBR model from Carney et al. (2015), which is an extension of the SFIE model from Nelson and Carney (2004). As in the Nelson and Carney (2004) model, it calculates the output ic_sout_BE of the BP IC cell. Further, it also calculates the output ic_sout_BS which is the output of the band-supressive IC cell. Further, the output cn_sout of the CN cell is provided.

Additional input parameters:

`'tau_ex_cn',texc`	CN excitation time constant (in s), see Eq. 2 in Nelson et al. (2004)
`'tau_inh_cn',tic`	CN inhibition time constant (in s)
`'cn_delay',D`	CN disynaptic inhibition delay (in s)
`'Sinh_cn',Sc`	CN excitatory strength
`'afamp_cn',ac`	CN alpha function area --> changes RATE of output cell
`'tau_ex_ic',texc`	IC excitation time constant (in s), see Eq. 2 in Nelson et al. (2004)
`'tau_inh_ic',tic`	IC inhibition time constant (in s)
`'ic_delay_inh',D`	IC inhibition delay (in s)
`'afamp_ic',ai`	IC alpha function area --> changes RATE of output IC BE cell
`'Sinh_ic',Si`	IC inhibitory strength
`'inh_str_bs',isb`	IC inhibitory strength, BS cell, see Carney et al. (2015)
`'tau_inh_bs',tib`	IC inhibition, from BE to BS cell
`'ic_delay_bs',idb`	IC local delay from BE to BS cell (in s)
`'Aex',ae`	rate Scalar for BS cell

References:

L. Carney, T. Li, and J. McDonough. Speech coding in the brain: Representation of vowel formants by midbrain neurons tuned to sound fluctuations. eNeuro, 20(2), 2015.