Mindfulness meditation practices can be conceptualized as a set of attention-based, regulatory, and self-inquiry training regimes cultivated for various ends, including the training of well-being and psychological health. This panel discusses conceptual issues related to the construct of mindfulness in psychological research and reviews recent, nonclinical work in this area. Instead of proposing a single definition of mindfulness, we favor the view of mindfulness training as a continuum of practices embedded within a variety of axiological frameworks. We map mindfulness-related states and traits into a well-defined multidimensional phenomenal matrix that can readily be expressed into a neurocognitive framework. This phenomenal and neurocognitive matrix of mindfulness is presented as a heuristic to guide formulation of next generation research hypotheses from both cognitive/behavioral and neuroscientific perspectives. We review selected findings on mindfulness research. Lastly, we identify significant gaps in the literature and outline promising new directions for research.