1. Wang TINS 2001 Wang Neuron 2002 An integrated microcircuit model of working memory and decision making

2. Lorente de Nó’s reverberatory circuit

3. Roitman and Shadlen 2002

4. Reaction Time Task

5. 2-population excitatory and inhibitory neurons (integrate-and-fire or conductance-based Hodgkin-Huxley neurons) Biologically realistic synaptic kinetics (AMPA, NMDA and GABA A ) Structured network connectivity

6. MT output

7. Reaction Time Simulations

8. Model Data

9. Data by J Roitman, J Ditterich and M Shadlen Reaction time decreases with increasing coherence Weber's Law

10. Integrate-and-Decide (diffusion) Model R Ratcliff (Psychol Rev 1978) J Schall (Nature Rev Neurosci 2001) Mazurek et al (Cereb Cortex 2003)

11. Kong-Fatt Wong

13. c’=6.4% c’=51.2% c’=100%

14. D Munoz and R Wurtz Fixation Target A bursty neuron in superior colliculus But how is threshold-crossing readout by downstream neurons?

15. Bistability: hard threshold detection

16. Chung-Chuan Lo Feedback Inhibition: Bursting

17. A Large-scale Network Model of Decision-Making Cortex Caudate SNr SC

18. LIP Network SC Network

20. Threshold can be effectively modulated by the cortico-striatal synaptic pathway

21. Adjusting the threshold to optimize rewards: Speed-accuracy tradeoff

22. Optimal threshold should be adjustable according to the distribution of coherence levels in the environment

23. End