621670.fig.009a
(a)
621670.fig.009b
(b)
Figure 9: These are the same results shown in Figure 7 but focussing on the conditional expectations of the hidden states and neuronal causes over the first 128 (3.22 second) time bins. Left panel: the hidden states are overlaid on periods (grey bars) of visual motion. These hidden states correspond to flow-inducing signal, flow, volume, and deoxyhaemoglobin (dHb). It can be seen that neuronal activity, shown in the right panel, induces a transient burst of signal (blue), which is rapidly suppressed by the resulting increase in flow (green). The increase in flow dilates the venous capillary bed to increase volume (red) and dilute deoxyhaemoglobin (cyan). The concentration of deoxyhaemoglobin (involving volume and dHb) determines the measured response.