Certainty Now Uncertain

Abstract

The material bases of information—paper, computer discs—usually scale with information quantity. Large quantities of information usually require large material bases. Conventional wisdom has it that human long-term memory locates within brain tissue, and might be expected to scale with brain size which, in turn, depends on cranial capacity. Large memories, as in those with savant syndrome, should always require large heads. Small heads, as in microcephalics, should always scale with small memories. Neither of these predictions is invariably true. Brain tissue size also depends on ventricle size, which can remain large in some survivors of childhood hydrocephaly, occupying 95% of cranial volume. Yet some of these have normal or advanced intelligence, indicating little impairment of long-term memory. This paradox strongly challenges the scaling hypothesis. The scope of possible explanations (plasticity, redundancy) should not exclude extracorporeal information storage, for which ‘cloud computing’ appears an apt metaphor. It is intriguing to suppose that this view might relate to the cosmic level of subjectivity, deduced by Romanes from Clifford’s “kindred consciousness,” which inspires the modern “Theory of Mind” debate.

But what about such a proposition as “I know I have a brain?” Can I doubt it? Grounds for doubt are lacking! Everything speaks in its favour, nothing against it. Nevertheless it is imaginable that my skull should turn out empty when it was operated upon.

Ludwig Wittgenstein [1]