A Wall Street Journal article describes a study that refutes the claim that mental activity is itself a defense against cognitive decline.

Usually we talk about neuroscience marketing here, i.e., improving marketing using brain science (aka neuromarketing). But, to engage in a verbal contortion, what about marketing brain improvement with science? That’s exactly what proponents of brain fitness systems are trying to do. The confluence of demographics and research suggest continued and rapid growth in the field. [...]