Table 1.

Parameters in LIP simulation

Parameter	Value	Justification
MT, baseline firing rate	8 spikes/s	Britten et al., 1993
MT, firing rate to 0% coherence	20 spikes/s	Britten et al., 1993
MT, latency	100 ms	Britten et al., 1993
MT, gain on preferred direction	0.36 spikes/s/%coh	Match to psychophysical data on no-pulse trials
MT, gain on null direction	−0.18 spikes/s/%coh	Match to psychophysical data on no-pulse trials
Magnitude of interneuronal correlation	r = 0.21	Bair et al., 2001
Timescale of interneural correlation	width of CCG at half-height = 9 ms	Bair et al., 2001
LIP, gain on MT signal	5.6	Match to LIP responses on no-pulse trials
LIP, baseline firing rate	48 spikes/s	Match to LIP responses on no-pulse trials
LIP, latency	125 ms	Match to LIP responses on no-pulse trials
Spike rate smoothing, MT	τ = 20 ms	Mazurek et al., 2003; for explanation, see Materials and Methods
Spike rate smoothing, LIP	τ = 100 ms	Mazurek et al., 2003; for explanation, see Materials and Methods
Height of decision bound	68 spikes/s	Match to psychophysical data on no-pulse trials
Effective pulse strength	10% motion coherence	Match to pulse effect on psychophysical data
Postdecision time	Mean = 150 ms	Match to psychophysical data on no-pulse trials

The table shows parameter settings for a simulated bounded integrator used to generate predictions in Figures 9 and 10. The “Justification” column indicates the source of data that was used to set the parameter. For simulation and analysis of a model perfect integrator, see Materials and Methods. For comparison of LIP activity with perfect integration to a decision bound for additional information, see Results. %coh, Percentage coherence; CCG, cross-correlogram. Format follows that for Mazurek et al. (2003).