MAP

function wholeNerveCAP  = UTIL_CAPgenerator...

    (ANresponse, dt, BFlist, numANfibers, plotCAP)

%

% Generates a compound action potential by convolving an impulse repsonse,

% as defined by Mark Chertoff (2004, JASA), with the response of the

% auditory nerve.

%

%

% -e(-k*time)*SIN(2*PI()*f*time)

%

% mu(t) = e^-kt * sin(omega*t)

% omega = 2 * pi * f

%

%

% Robert T. Ferry

% 01st May 2008

%

%

nChannels=length(BFlist);

[r nSpikeEpochs]=size(ANresponse);

wholeNerveCAP       = [];

channelCAP          = [];

e                   = exp(1);

k                   = 1000;

impulseDuration     = 0.01;

impulseFrequency    = 750;

impulseTime         = dt:dt:impulseDuration;

impulseResponse     = -e.^(-k*impulseTime).*sin(2*pi*impulseFrequency*impulseTime);

impulseResponse=impulseResponse-mean(impulseResponse);

% WholeNerveCAP

ANoutput = sum(ANresponse, 1);

convolvedWholeNerveCAP = conv(ANoutput, impulseResponse(1,:));

% truncate

convolvedWholeNerveCAP=convolvedWholeNerveCAP(1:nSpikeEpochs);

% apply measurement time constant

sampleRate=1/dt;

upperFreq=sampleRate/4;

lowPassCutOff=40;

wholeNerveCAP = UTIL_Butterworth(convolvedWholeNerveCAP, dt, lowPassCutOff, upperFreq, 1);

% or do not do this

% wholeNerveCAP = convolvedWholeNerveCAP;

% Plot output?

CAPtime = dt:dt:dt*length(wholeNerveCAP);

if (plotCAP == 1)

    figure(9)

    subplot(3,1,1), plot(impulseTime, impulseResponse)

    title('Impulse response')

    xlabel('Time (s)'), ylabel('Amplitude (Pa)')

    xlim([0 max(impulseTime)]), ylim([-inf inf])

    subplot(3,1,2), plot(CAPtime, wholeNerveCAP)

    title(['AN CAP (whole-nerve)  '   num2str(length(BFlist)) ' channels' num2str(numANfibers) ' fibers/ch'])

    xlabel('Time (s)'), ylabel('Amplitude (Pa)')

    xlim([0 max(CAPtime)]), ylim([-inf inf])

end