This video on the left caused a stir when it was posted on Tumblr before Christmas. It's Mariah Carey's version of All I Want For Christmas I You, converted to MIDI, which is a digital way of recording sound. MIDI sequencing makes the song sound like the music to a cheesy '80s video game and removes the human voice. Or does it? Lots of listeners contacted the blog to say they could hear Mariah's ghostly voice, singing along in the background. Can you?

It gets odder. The file was passed on to Diana Deutsch, a cognitive psychologist in California, and she listened to it and heard... nothing! Ah, but Prof. Deutsch had never heard the original version, you see.

The "ghostly Mariah" is an example of top-down processing. This is where the brain uses information it already has as a sort of "template" to understand the world around it. So, if you've heard the song before you have a template for how it's supposed​ to sound and your brain uses that to "fill in the gaps" in the MIDI version you're listening to.
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This is why some people can hear the non-existent vocals but others can't; their expectations shape their perceptions.

So Season 9 of Doctor Who ended with the Doctor (Peter Capaldi) getting his mind wiped, forgetting all about Clara Oswald (Jenna Louise Coleman), except for the hole left in his memories. It was an elegant climax, a nice echo of Season 4's downbeat conclusion, where Donna Noble (Catherine Tate) lost all her memories of being the Doctor's companion. This time round, the Doctor is the one with amnesia, giving Clara a much more optimistic and generous send-off in a TARDIS of her own - sorry to all the Clara-haters who wanted to see her stay dead; you're just going to have to accept it.

The exact mechanic by which the memory-wipe happens is a "neuro blocker" but it's really what film and TV writers call a Maguffin - an object that moves the plot along; it doesn't matter how it works. Nonetheless, "neuro" suggests it works by altering brain structures and we know that altering brain structures removes memories. The tragic case of H.M. came about when surgery on H.M.'s brain removed his hippocampus, taking with it memories of the last decade of his life and the ability to create new ones. A brain virus did something similar to Clive Wearing and Sir Colin Blakemore's case study on Clive Wearing reveals that he too suffered damage to the hippocampus.

The Doctor's amnesia is much more specific than H.M. or Clive Wearing - or the blanket memory wipe he gave to Donna Noble. The Doctor remembers that there was a Clara, he just can't remember the details. This sort of distinction was identified by Endel Tulving as episodic and semantic memory. Semantic memory is the memory of meanings and relationships: the Doctor remembers he had a companion, he remembers how she fitted into his life. What he lacks are the episodic memories, the particular details of her appearance and actions.

(With delicate irony, writer Stephen Moffat has the Doctor explain this to Clara herself, who is disguised as a waitress and talks to him and laughs at what he says.)

A similar thing happened to Clive Wearing, who remembers that he is a father, but cannot remember his children's names. He remembers that he loves Deborah, his wife, but cannot remember where she is.

Season 9 introduced another aspect of the psychology of memory with the character of Ashildr (Maisie Williams), a Viking girl who becomes immortal. Ashildr outlives her husband and children and everything she every knew. Over the centuries, she masters every skill but is consumed with boredom and loneliness. She forgets most of her past, her old name and her family. She keeps a journal to remind herself of things, but tears out the pages when the memories they bring back are too painful. The only pages she leaves intact are the ones describing her long-dead children - but that is so that she will remember not to have any more.

Students studying Long Term Memory are told that its duration and capacity are "unlimited". However, we only think this because very few humans build up more than a century of memories. There might be a liit to LTM's duration/capacity, it's just that no one has reached it yet. But what might happen if you did?

Maybe LTM does have a duration - say, 150 years? If that were the case, then when someone passed their 151st birthday, they'd lose memories from their first year of life. No great loss, you might say. But when you hit 160 and you can't remember anything before the age of 10, that's a bit more alarming. Someone reaching 170 wouldn't remember their schooldays, at 180 you'd have forgotten your wedding, by 200 you might have forgotten your children and your parents. Scary.

If LTM has a limited capacity, then eventually it becomes "full" and you just can't add more. This is worse, because you'd be left in the same position as H.M., unable to make new memories and forgetting everything 30 seconds after it happens.

Ashildr doesn't seem to be as badly off as that. She seems to be able to choose to forget stuff, either because it's painful (like memories of family) or burdensome.

The idea of selective amnesia - choosing which stuff to forget and which to remember - is part of a big debate in the psychology of memory. Sigmund Freud pioneered the idea of motivated forgetting (he called it "repression") where we forget episodes that are disturbing, frightening or shameful. However, repressed memories aren't gone forever: they can turn up again, years down the line, as painful "flashbacks". This is a controversial idea because psychologists like Elizabeth Loftus argue that these "recovered memories" are really just imaginative reconstructions - it's quite possible they never really happened.

It is interesting that 'Me'/Ashildr doesn't forget skills. Using her immortal life to perfect her abilities, she doesn't forget how to fight or speak anguages or build reality-bubbles.

Psychologists call this procedural memory and it does indeed seem to operate separately from episodic and semantic memory. For example, Clive Wearing still remembers how to conduct music and play the piano. H.M. remembered how to play tennis, even though he had forgotten learning it and (because he learned after his brain damage) didn't know that he knew how to do it.

That's a perk to being immortal - you can get really good at stuff. Obviously, you can get to the final boss fights on all your favourite video games. You can learn to play electric guitar like Hendrix or surf or speak Finnish or become Tenth Dan in karate.

In Greek mythology, Tithonus was given eternal life by the gods, but they fogot to give him eternal youth as well. Silly gods, but poor Tithonus, who aged into a rotting zombie but could never die. The psychology of memory gives me a great idea for a short Science Fiction or Horror story. Imagine if a character did become immortal, through drugs or by becoming a vampire or whatnot. They would spend a long time enjoying themselves and become awesome at everything... but then, the sting in the tail! Their LTM is still finite and runs out. They carry on living (or being a vampire) but forget everything they ever knew - or turn into a creature with H.M.'s problem, unable to remember any new stuff and just living moment by moment. Imagine a vampire like that, that knows that it is hungry for blood and has forgotten it was ever a person - and forgets 30 seconds after you try to remind it! Creepy.

Now that all the obedience stuff is posted up in Social Psychology, I can turn my attention to what's really vexing me: The Lord of the Rings. Specifically, Gollum. So just why, psychologically-speaking, does Gollum serve Frodo so eagerly. And why does he betray him at the end? What can the psychology of obedience tell us about this?

Milgram's Agency Theory suggests we all enter "agentic states" in the presence of authority figures. We can resist this "agentic shift" if the authority figures commands us to do things that go strongly against our wishes, but the "moral strain" this produces is uncomfortable. It's easier to let yourself become an agent, then you can hold the authority figure responsible for anything you do at their command.
This seems to fit Gollum pretty well. Frodo orders Gollum to take him to Mordor, which Gollum doesn't want. Moral strain ensues. In the 2002 film of The Two Towers, director Peter Jackson cleverly plays out Gollum's strain (delightfully acted by Andy Serkis) as a mental battle between "nice" Smeagol and "nasty" Gollum.
But what makes Frodo an authority figure in the first place? It's the Ring, of course. Milgram noticed how "symbols of authority" turned an ordinary Biology teacher, Jack Williams, into the stern Experimenter who must be obeyed: a white lab coat, a clip board, the advanced science of the shock generator, the prestigious setting of Yale University. When Milgram took away some of these symbols, in Variation #10, which was set in a run-down office that had no connection with Yale, then obedience dropped from 65% top 45.5%.
In Tolkien's world, the Ring is the ultimate symbol of authority - although Aragorn's reforged sword Anduril which enables him to command the dead men of Dunharrow in The Return of the King, runs it a close second.

It's not quite that clear though, is it? Because Gollum does disobey... he abandons the hobbits in Shelob's lair.
Milgram could explain this, up to a point. Obedience isn't always blind obedience and agents still have wishes of their own as well. In Variation #7, Milgram had Mr Williams phoning in his orders. The participants still obeyed, but they sneakily flicked lower-voltage switches than the ones they were supposed to, if they thought no one was observing them. This is a bit like Gollum: they were obeying, but they tried to subvert the orders, twisting them to their own wishes while still "going along with" the authority figure.
If we bring in Social Impact Theory, it gets a bit clearer, because Impact Theory looks at how many people are giving the orders and how many are receiving them. Throughout most of the story, Frodo and Sam gang up on Gollum: there are two of them and one of him, which increases the Social Force of Frodo's orders. Once the hobbits get to Cirith Ungol, Gollum has backup in the form of a giant spider.  Frodo's authority doesn't have the social impact it once had and Gollum is free to rebel openly.

... said Giles to Xander in a great episode of Buffy the Vampire Slayer. My original plan was to build a psychology website entirely around Geek interests. So, I'd explain Gollum's obedience to Frodo in terms of Agency Theory and explore Luke Skywalker's Oedipus Complex; I'd look at intergroup conflict between vampires and werewolves or Purebloods and Mudbloods; I'd examine how the Doctor forgot about Clara in terms of semantic and episodic memory.
And I might still do that. Oh yes. I think I shall.
But first, I'll just get this site up as a conventional set of study resources for students (and teachers, why not?) following Edexcel's new (2015) Specification for A-Level Psychology.
Because the Spec is new, there's a lack of stuff out there, especially for the contemporary studies and some of the more outre theories. There are a couple of textbooks but, since they were penned before the spec was quite finalised, they err on the safe side by including wa-a-a-ay too much. No doubt 2nd editions will roll off the press with a bit more exam focus. Until then, I'm setting myself the task of resourcing this course. I'm trying to include a bit more information than students strictly need - you you've got choices to make - but not so much that it overwhelms.
I'm following the APRC (Aims, Procedures, Results, Conclusions) and GRAVE (Generalisability, Reliability, Application, Validity, Ethics) mnemonics approved by Edexcel, but adding a few of my own. I'm indebted to Ali Abbas whose excellent INSET has thrown so much light on this course. Get this guy into your school to talk about Psychology. And Lord of the Rings.