Grandma–Ding!

This year marks the fortieth anniversary of the publication of Philip Roth’s novel Portnoy’s Complaint. In 1969, the book also became fodder for one of the oddest ideas in neuroscience: the grandmother cell. What if a neuron in your head only responded to the sight of your grandmother? For a long time, many neuroscientists have dismissed it out of hand. And yet the idea will not quite die.

Earlier this year a psychologist published an intriguing review of the grandmother cell, arguing that we sho