  The positive-parity nucleon spectrum is studied in 2 + 1 flavour lattice QCD
in an attempt to discover novel low-lying energy eigenstates in the region of
the Roper resonance. In this work, we employ standard three-quark interpolating
fields and introduce new local five-quark meson-baryon operators that hold the
possibility of revealing new states that have been missed in previous studies.
Motivated by phenomenological arguments, five-quark interpolators based on the
$\sigma{N}$, $\pi{N}$ and $a_0{N}$ channels are constructed. Despite the
introduction of qualitatively different operators, no novel energy levels are
extracted near the regime of the Roper resonance.
