Figure 1.

Illustration of how dopamine-driven reduction of the precision of the “start-gun” may influence accuracy of interval timing. The gray sinusoids in four panels depict oscillators in the theta range in two example trials (the first two columns). The first row depicts oscillatory process when dopaminergic receptors are not impaired. In this case the oscillators are perfectly synchronized. The second row depicts oscillators in the condition with impaired dopamine receptors. In this condition the onset of the oscillators are jittered, corresponding to the less precise “start-gun” mechanism. The amplitude of each oscillator is represented by the size of gray circle. Columns of matrices represent n, and n + 1 trial, respectively. Both matrices in each row depict the amplitude pattern at 200, and 450 ms that correspond to the dotted lines in the panels showing the oscillators. The amplitude/phase pattern between trials (columns of each matrix) is more dissimilar in the second row, because of the larger variability in the onset of the oscillators. Thus, if a particular amplitude/phase pattern has to be detected, the detection process will be more variable, causing larger variability in the state of oscillators around the criterion time. The right column depicts the spread of time estimations caused by jitter in the reset latency of ongoing oscillatory process.