Perceptual Coherence : Hearing and Seeing

Transformation of Sensory Information Into Perceptual Information 33
Table 2.2 Spikes Resulting From the Presentation of Tones Composed of
One to Four Frequency Components
Time
Frequency 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
F 1 X X X X X X
F 2 X X X X X X X
F 3 X X X X X X X X X X
F 4 X X X X X X
Spike * * * *
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
F 1 X X X X X X X X X
F 2 X X X X X X X
F 3 X X X X X X X
F 4 X X X X X X X
Spike * * * *
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
F 1 X X X X X X
F 2 X X X X X X
F 3 X X X X X X X X X
F 4 X X X X X X X X
Spike * * * * * *
46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
F 1 X X X X X X X X X
F 2 X X X X X X
F 3 X X X X X X X
F 4 X X X X X X X
Spike * * * * *
a realistic stimulus input, and then calculating the output of the simulated
receptive field. We then correlate the simulated response to that of the actual
neural receptive field using the identical input.
Suppose we manipulate the receptive field, moving the inhibitory region
relative to the excitatory region, as shown in figure 2.3 by 20 ms. Assume
that only the F 2 and F 3 frequencies are presented, each at 100 units.
In the gray region, the probability of response is .25 (resting rate); in the
black inhibitory region the probability is 0.1; and in the white excitatory
region the probability is .9. Now imagine that we are measuring the output
of the cell starting at the onset of the tones. The response rates are shown
in table 2.4.
At the tones onset, the cell fires at its base rate to any frequency.
Then from 10 ms to 20 ms, F 2 hits the excitation region before F 3 hits the