  We observe a dramatic reduction in the degree of spin-polarization of a
two-dimensional electron gas in a magnetic field when the Fermi energy moves
off the mid-point of the spin-gap of the lowest Landau level, $\nu=1$. This
rapid decay of spin alignment to an unpolarized state occurs over small changes
to both higher and lower magnetic field. The degree of electron spin
polarization as a function of $\nu$ is measured through the magneto-absorption
spectra which distinguish the occupancy of the two electron spin states. The
data provide experimental evidence for the presence of Skyrmion excitations
where exchange energy dominates Zeeman energy in the integer quantum Hall
regime at $\nu=1$.
