This programme was ostensibly about "blindsight," a rare condition that allows certain blind people to "see" what is happening. A man known as "G Y" was injured at the age of eight and his primary visual cortex (the part of the brain thought to be essential for receiving visual stimuli) completely destroyed. Yet "G Y" is able to recognise certain visual images: he thinks he is only guessing, yet time and again he can identify the situation or the movement of objects passed in front of his eyes. And, amazingly, as this happens, his pupils change shape.
The neuro-scientists can't yet explain it, but they are getting there. There are, it seems, nine other pathways from the eye to the brain, all of them old in evolutionary terms, which can convey messages without their owner's awareness. By similar means, the deaf can sometimes hear, the numb feel and drivers know where they are in relation to their surroundings, though their conscious minds may be miles away, even - as mine was that terrifying day - in the mythic Arcadia that is Ambridge. Most strangely, the less hard we try to make these methods work, the better they do.
Now. Could you honestly say that such an instructive and stimulating programme was symptomatic of the dumbing-down from which we are all supposed to be suffering? If you listen, really listen, to enough radio, you know the truth: there are some astonishingly un-dumb programmes out there.
Of course, there is also a fair amount of rubbish, the stuff that we critics regularly and despairingly sweep up, some of it noisome, toxic material, some just untidy or grubby. Also, the political problems faced by those who make programmes are not insignificant - caused, generally, when bureaucrats, knowing little about the practicalities but a lot about consulting dubious focus groups, impose rules that are irrelevant, unworkable or silly. The recent, pointless censoring of the harmless Double Vision (R4) is a prime example.
Yet despite or because of all this, it is important to celebrate the excellent, which survives to distract, provoke and entrance a weary world. It really does. Take Seamus Heaney. Or rather, leave him just where he was last Sunday, Viewing the Century on R3. And force anyone who complains about the intellectual weakening of radio to listen to this kind of thing. Heaney's subject was provoked by something Auden wrote in his elegy for W B Yeats: "for poetry makes nothing happen." He went on to prove, triumphantly, the irony of that line.
In one grand sentence, he dismissed all the things he could have said about how poetry has changed the way we look at things - from the trenches, through resistance to totalitarianism, to the acceleration of cultural, sexual and racial awareness. His talk became, instead, a series of elegies, linked to Auden's, rising to a powerful lament for Ted Hughes and culminating in his own, for Joseph Brodsky. Brodsky said that human beings are put on earth to create civilisation. Heaney asserted, with great authority, that poets have been true to that purpose.
And so has R3. Forget, if you can, the irritations of Petroc Trelawney and his kind. Think instead of last weekend, when the exalted and spiritual voice of Olivier Messiaen dominated the air, followed, on Saturday, by Opera on 3 - a live, intensely moving performance of Lucia di Lammermoor from the Metropolitan Opera in New York - followed in turn by the intellectual aerobics of The Brains Trust. Or tune in to World Music, listen to the "Song of the Slandered Woman" and lament the loss of other Maori chants, which once accompanied tattooing, canoe-paddling, "degrading others" and sorcery - and then talk about dumbness, if you dare.
If you still wonder where it's all going, Piers Plowright offered some ideas in a typically eclectic melange of opinions and examples he called The Future of Radio (R4). There were memories, such as the huge delight of listening to pirate stations under teenage eiderdowns (long before duvets had been invented). There were great radio moments of the last few years: Hugo Gryn bearing witness, furiously, to the truth about Auschwitz on The Moral Maze; the first few moments of Lee Hall's miraculous monologue Spoonface Steinberg; that powerful performance of the Verdi Requiem at the Proms, at which both Princess Diana and Georg Solti were saluted.
Various speakers spoke of their visions of a digital future rich in microchips, when we might be able merely to imagine what we want to hear in order to hear it. But I believe it was Frank Delaney who uttered the dire warning that we must never allow ourselves to think that, unless something's popular, it's not important. His great fear is the interminable proliferation of cheap and fatuous phone-ins and he argued that the private individual response to a shared event is a central purpose of radio.
And it is also the purpose of music. Yet the privacy of Private Passions (R3) is sometimes, usefully, invaded by conversation. The painter, John Burningham, spoke of the difficulty faced by an artist who tries to differentiate between dawn and sunset, a problem gloriously surmounted by Richard Strauss in Burningham's ninth choice - a recording that went straight onto my shopping list. Here is his selection:
"Erlkonig" (Schubert, arr. Liszt), Leslie Howard
"At the Jazz Band Ball" (La Rocca), Bix Beiderbecke
"O del mi amato ben" (Donaudy), Gigli
Third cello suite in C (Bach)
"J'attendrai" Tino Rossi
The Coolin (trad) Felix Doren
"Una voce poco fa" (Rossini), Luisa Tetrazzini
"Besame mucho" (Velasquez), Quentin Verdu
An Alpine Symphony (Strauss), Berlin Philharmonic
"Deh vieni ... " (Mozart), Ingvar Wixell