Advance directives, substituted judgment, and the best-interest standard all have limitations that constrain their usefulness in making medical decisions for patients who cannot choose for themselves.
The practice of banking sperm from adolescents about to undergo chemotherapy is not universal, which lends support to the argument that parental consent be required for the intervention.
Our ability to infer mental states from fMRI scans is still rudimentary, but the time may be approaching when neuroimaging can be used to indicate witnesses’ reliability in court proceedings.