First carpenter-like experiment

Subject: Myself

80% of stimuli at right-hand side, 20% at left-hand side.
Time between stimuli follows a uniform distribution between 0.5 and 1.5 seconds (just like Carpenter)
Keys used: 1=left, 2=right (in the numerical keypad).

200 trials. 199 correct, 1 confused the side of the second stimulus.

>> load(‘c:\hipertec\decisionmaking\Resultados\APE_20090513T174355_sesgo08.mat’)
>> [correctos,procesados]=salida2procesados(salida);

Scale in the 4th box is multiplied times 10^-3.
One timing of the first stimulus has an abnormally high uncertainty (box 3). However, it is still lower than needed:
errorbar(1:199,correctos.t_entrestim(:,1),correctos.t_entrestim(:,2),’.’)

The strange point is the one with appreciable errorbars, still very small compared with the overall scale.

Accuracy of reaction times is also high enough:
>> errorbar(1:199,correctos.t_reaccion(:,1),correctos.t_reaccion(:,2),’.’)

Although all results are valid, I would say that accuracies were higher last day. Probably this is due to having other programs open (especially firefox). In the following, one should do the experiments with all other programs closed.

Overall reaction times show the skewness:
>> hist(correctos.t_reaccion(:,1))

Separating right and left stimuli, skewness is mantained, and the expected shift occurs.
>> subplot(2,1,1)
>> hist(correctos.t_reaccion(correctos.dcha,1))
>> subplot(2,1,2)
>> hist(correctos.t_reaccion(~correctos.dcha,1))

The correlation between reaction time and interval between both stimuli is clear, both for the global dataset and when separating the two kinds of stimuli:

>> ploterr(correctos.t_reaccion(:,1),correctos.t_entrestim(:,1),correctos.t_reaccion(:,2),correctos.t_entrestim(:,2),’.’)
>> xlabel(‘Reaction time (s)’)
>> ylabel(‘Time b/w stimuli (s)’)

>> ploterr(correctos.t_reaccion(correctos.dcha,1),correctos.t_entrestim(correctos.dcha,1),correctos.t_reaccion(correctos.dcha,2),correctos.t_entrestim(correctos.dcha,2),’.’)
>> hold on
>> ploterr(correctos.t_reaccion(~correctos.dcha,1),correctos.t_entrestim(~correctos.dcha,1),correctos.t_reaccion(~correctos.dcha,2),correctos.t_entrestim(~correctos.dcha,2),’r.’)

 

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