Conflict Resolution as Near-Threshold Decision-Making: A Spiking Neural Circuit Model with Two-Stage Competition for Antisaccadic Task
Fig 3
The reaction time and percentage correct associated with the decision layer.
The decision layer is capable of producing the mean reaction time and the percentage correct observed in prosaccade and antisaccade tasks if the input levels are properly selected. We measured A the percentage of correct decisions and B the mean reaction times of the decision layer under various input levels from the upstream Dir and Inv neurons. Although the two types of neurons receive the same visual stimulus, their firing rates can be adjusted differently by varying their baseline inputs, which are indicated in the abscissa (for Dir) and in the ordinate (for Inv). The region above the diagonal line (where the input from the inverted pathway is stronger than that from the direct pathway) corresponds to the antisaccade condition and the region below corresponds to the prosaccade condition. A decision is counted as correct when the firing rate of the neural population driven by Dir or Inv hits a present decision threshold (50Hz) first in the prosaccade or antisaccade condition, respectively. The reaction time is the time interval between the onset of the input and the decision. We identified specific baseline input levels (green circles for prosaccades and red circles for antisaccades) which produce the mean reaction time and the percentage correct that match the typical values observed in monkey experiments. These specific baseline inputs were used to determined the strength of the top-down influence in the proposed model.