p030tbl01.02 The What and Where cortical processing streams obey complementary laws.  These laws enable the What stream to rapidly and stably learn invariant object categories without experiencing catastrophic forgetting, while the Where stream learns labile spatial and action representations to control actions that are aimed towards these objects.<BR>||  <TABLE border="1"><TR><TD><B>WHAT</b></td><TD><B>WHERE</b></td></tr><TR><TD>spatially-invariant object learning and recognition</td><TD>spatially-variant reaching and movement</td></tr><TR><TD>fast learning without catastrophic forgetting</td><TD>continually update sensory-motor maps and gains</td></tr><TR><TD>IT InterferoTemporal Cortex</td><TD>PPC Posterior Parietal Cortex</td></tr></table><TABLE border="1"><TR><TD></td><TD><B>What</b></td><TD><B>Where</b></td></tr><TR><TD><B>matching</b></td><TD>excitatory</td><TD>inhibitory</td></tr><TR><TD><B>learning</b></td><TD>match</td><TD>mismatch</td></tr></table>