effect of parameters on neural accumulators psych 239 david sutoyo & shyam srinivasan
Post on 22-Dec-2015
217 views
TRANSCRIPT
Effect of parameters on Neural Accumulators
Psych 239
David Sutoyo & Shyam Srinivasan
Effect of Parameter dt Aim: To study the effect of reducing dt,
does it make a difference?
Why? In reality, the time step is not discretized
So, dt->0 is closer to reality
dt = 10
RT Distribution for Error Responses
0
1
2
3
4
5
6
320 513.3333333 706.6666667 More
Time
Frequency
Frequency
Histogram
0
5
10
15
20
25
30
330
414.4444444498.8888889583.3333333667.7777778752.2222222836.6666667921.11111111005.555556
More
Bin
Frequency
Frequency
dt = 5
RT Distribution for Correct Responses
0
5
10
15
20
25
335
436.6666667538.3333333
640
741.6666667843.3333333
945
1046.6666671148.333333
More
Time
Frequency
Frequency
RT Distribution for Error Responses
0
1
2
3
4
5
6
370 538.3333333 706.6666667 More
Time
Frequency
Frequency
dt = 2
RT Distribution for Correct Responses
0
5
10
15
20
25
358
469.3333333580.6666667
692
803.3333333914.6666667
1026
1137.3333331248.666667
More
Time
Frequency
Frequency
RT Distribution for Error Responses
0
1
2
3
4
5
6
7
396 542 688 More
Time
Frequency
Frequency
dt = 1
RT Distribution for Correct Responses
0
2
4
6
8
10
12
14
16
18
20
348
436.7777778525.5555556614.3333333703.1111111791.8888889880.6666667969.44444441058.222222
More
Time
Frequency
Frequency
RT Distribution for Error Responses
0
1
2
3
4
5
6
7
8
396 566 736 More
Time
Frequency
Frequency
dt = .5
RT Distribution for Correct Responses
0
2
4
6
8
10
12
14
16
18
20
336.5
421.2222222505.9444444590.6666667675.3888889760.1111111844.8333333929.55555561014.277778
More
Time
Frequency
Frequency
RT Distribution for Error Responses
0
1
2
3
4
5
6
403 573.375 743.75 914.125 More
Time
Frequency
Frequency
dt = .25RT Distribution for Correct Responses
0
5
10
15
20
25
30
359.25501.75644.25786.75929.251071.751214.251356.751499.25More
Time
Frequency
Frequency
RT Distribution for Error Responses
0
1
2
3
4
5
6
7
368.75 598.8333333 828.9166667 More
Time
Frequency
Frequency
dt = .125
RT Distribution for Error Responses
0
1
2
3
4
5
6
418.75 581.7916667 744.8333333 More
Time
Frequency
Frequency
RT Distribution for Correct Responses
0
5
10
15
20
25
323.5
419.3194444515.1388889610.9583333706.7777778802.5972222898.4166667994.23611111090.055556
More
Time
Frequency
Frequency
Activation < 0
• In our model, the activation of neural accumulator can take a negative value
• Biologically, that doesn’t really make sense
• Does it make a difference?
Lat. inhibition = 0.01, no zeroing
Lat. inhibition = 0.01, zeroing
Lat. Inhibition = 0.01
Lat. Inhibition = 0.05, no zeroing
Lat. Inhibition = 0.05, zeroing
Lat. Inhibition = 0.05