The huge paintings, up to 5ft by 8ft, are not as revealing as they look. The hidden clue is that they were inspired by an emergency operation to remove a brain abscess that Anderson underwent at the age of 17. He nearly died.
If that had happened to you, you might feel an urge to demonstrate to people that the life force is still with you. You might want to actually show it to them by pulling it out of your head, like a vivid membrane. Denied an explanation, however, the first-nighters at the show's opening last week decided that the red extrusion was not a metaphor but a pair of women's tights. Which, indeed, they are.
Anderson persuaded his girlfriend to buy them from Marks and Spencer in Sauchiehall Street, Glasgow. They are large-size, the last pair in the shop. To make the self-portraits he strips, then pulls the tights over his head, and confronts himself in a mirror - removing the tights whenever he needs to see clearly to paint.
Self-confrontation is central to the process. That operation left emotional scars. "I felt I had to face what I was most scared of - that is, how I'm perceived by others. Although I did it for myself, I realised that I was painting for an audience."
Hence not only the vulnerable self-exposure of nakedness, but the relaxed and confident pose. He made sure to paint big, larger than life, and to place himself centre-stage. "I wanted the image to be essential, basic. It was not until I stripped off that the dynamics of what I was doing started to work. I began to feel vital, empowered."
But his confidence sagged on opening night. Apprehensive - justifiably, as it turned out - he arrived an hour-and-a-half late.
A couple in their thirties told him they found the "distortions" disturbing. The wife said the images seemed to follow her when she visited other parts of the gallery. She did not want to stay too long because of their impact.
Half a dozen others had a go at him in the same way - an unusual response at an opening, where the standard drill is to face the centre of the room, ignore the artist, drink as much wine as possible, and gossip. "I was surprised," says Anderson. "It had never occurred to me that there might be open criticism."
Did the first-nighters sense another hidden vein in his work? Witchcraft, perhaps?
While in hospital, he was given a copy of John Baptista Porta's Natural Magic of 1558. It speaks of creating new living creatures out of putrefaction, the basis of life. The earlier paintings in Anderson's series are dark. The figures, putrid-looking, emerge from a primordial blackness. Only in the later ones does the vivid red triumph.
"Porta's book has an amazingly New Age feel about it. It discusses mental techniques for healing. Although I did the self-portraits instinctively, I afterwards came to realise that I was trying to paint out badness, such as the abscess. Painting was like making spells or affirmations. I wanted something positive to happen. I wanted to produce something beyond the normal body. What I show coming out of my head is a living thing."
Or, could the first-nighters' discomfiture have been due to the fact that the paintings, although figurative, are loaded with conceptual content? The action of the figure is ritualistic and its nakedness, Anderson points out, "is the most powerful state to be in for spell-making - there should not be any added ingredients".
Even the technical accomplishment of the painting has, despite its anatomical accuracy, an ethereal quality. The outlines seem to be out of register - "like an aura, an extra dimension", says Anderson. The effect results from applying layer after layer of oil paint diluted with Shellac and Damer varnish, which show through one another, like watercolour. "That's how we're made ourselves," says Anderson, "in layers."
After four years at Glasgow School of Art, he came away with a lower second degree. He says staff changes had brought in more and more tutors who preferred conceptual to figurative art. But he stuck doggedly to figurative painting and drawing. No figurative painter in his year was awarded a degree higher than a lower second. "You could say I'm not driven by fashion," he says.
Prices: pounds 450 to pounds 3,000. To 26 September at Well Hung Gallery, 39 Ledbury Road, Notting Hill, London, W11 (0171-727 1357)