Experiment matlab help

petersternfeld

Hello everybody, I'm working on a cognitive science experiment and needed a little help writing some matlab code. Its a basic listening experiment where the participant hears a tone at a frequency of 800 hz followed by a string of 30 tones that vary in frequency. The subject uses a slider that starts at the middle (800hz) and moves it to the relative location up or down on the slider that they think corresponds to the new frequency. So if the next tone was 900 hz, they would move the slider up, say halfway. If it was 775 hz they will pull the slider to a little under the original halfway mark.

I have some basic code for a slider but was wondering how I could first put lines on the side displaying intervals on the slider (if the middle is 800, have a long line denoting this as well as shorter lines marking 4 - 50 hz intervals both up and down). I also have basic code for collecting data but it doesn't seem to be working. I have a 2 x 32 matrix, the two rows representing two trials for the experiment and the first two columns denoting which subject number and which trial number respectively. For every sound, I would like the program to record where the slider is (with respect to the middle line of the slider) and save that number into the exp_data file. If anyone can take a look at this code and offer some advice, it would be greatly appreciated. Thanks!



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clear all; close all;

background = figure('NumberTitle','off','Toolbar','None','MenuBar','none', ...
'Name','Experiment','Color',[0 0 0],'Units','normalized','Position',[0 0 1 1]);
%instructions;

inst = {'Thank you for participating in this experiment!' ;
'';
'Please read these instructions very carefully!!';
'' ;
''
'Click OK when you are ready to begin.';%these are the instructions
};
inst2 = {'Part One of this experiment is now complete.' ;
'';
'The experimenter will give you instructions for the second part of the experiment';

'';
%these are the instructions
};
instruction = msgbox(inst,'Instructions'); %calls an instruction message box
uiwait (instruction) %Tells the system to wait until the instruction box is closed


outbutton=uicontrol('style','radio','units','normalized',...
'position',[0 0 1 1],'string','Same','fontsize',20, 'visible','off');

outslider = uicontrol('style','slider','parent',background,'units','normalized','sliderstep',[0.1 0.1], ...'position',[0.45 0.35 0.1 0.3],'backgroundcolor',[1 1 1]); %create a slider

set(outslider,'value',0.5); % set a slider value in the middle

numtrials=30;

fs=8192;
dur=0.5;
isi=2;
t=[0:1/fs:dur];


fname = 'exp_data.mat';
if exist(fname,'file')
disp('load file');
load(fname);
partno = size(expdata,1)/2 + 1;
else
currentf=800;
f=[600 600 650 650 700 700 750 750 775 775 785 785 800 800 800 800 800 800 815 815 825 825 850 850 900 900 950 950 1000 1000];
rand('seed',123456);
stimorder1=randsample(length(f),30);
stimorder2=randsample(length(f),30);
expdata = [];
partno = 1;
end

z1=sin(2*pi*t*currentf);

for niter = 1:4
sound(z1,fs);
pause(dur+isi*2);
endfor j=1:numtrials


set(outbutton,'value',0); drawnow();
%pause(.1); %pause(isi/6);
z=sin(2*pi*t*f(stimorder1(j)));


waitforbuttonpress

set(outbutton,'visible','on');

stimorder = stimorder1;
for niter = 1:2
sound(z,fs);

pause(dur+isi);

data(j)=get(outbutton,'value');
data2(j)=get(outslider,'value'); % get a slider value


end
expdata = [expdata ; [ partno niter data ] ];
if niter == 1
instruction = msgbox(inst2,'Instructions #2'); %calls an instruction message box
uiwait (instruction) %Tells the system to wait until the instruction box is closed

waitforbuttonpress

for niter = 1:4
sound(z1,fs);
pause(dur+isi*2);
end
end

waitforbuttonpress

stimorder = stimorder2;
end

save(fname,'f','currentf','stimorder1','stimorder2','expdata');

close(background);
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Kwitko

Moved to Matlab help forum