  We use the edge of the quantum Hall sample to study the possibility for
counter-propagating neutral collective excitations. A novel sample design
allows us to independently investigate charge and energy transport along the
edge. We experimentally observe an upstream energy transfer with respect to the
electron drift for the filling factors 1 and 1/3. Our analysis indicates that a
neutral collective mode at the interaction-reconstructed edge is a proper
candidate for the experimentally observed effect.
