Why does raw meat give me a hard-on?" This is Michael, chopping sirloin ready for the stir-fry. Typically, he is going to the trouble of preparing a good lunch: beef in hoi-sin sauce. He's bought some beer, too. We're drinking straight from the can. Amy, his girlfriend, sits at the kitchen table, reading a magazine. "Michael," she says, without looking up. Michael slides the diced beef into the wok where it sizzles in the hot oil. "Easy, Amy. Only a twitch." He winks at me. Then he drops what he is doing and strides out of the room. "Have a listen to this," he calls over his shoulder and soon the place is awash with cascades of sound-brittle arpeggios, tumbling fragments of melody. He returns, head tilted back. "Koto," he says. "Japanese. Astonishing." From this angle the dent in his head, about three inches up from the right eyebrow, is more noticeable.
Next day I'm over at Stuart's. We sit in his stuffy front room. An ornate black clock-his early retirement present-clings to the wall like a huge fly. Stuart locks me in his gaze. He is about to say something, but doesn't, quite. It is a long pause. Eventually he speaks. "I don't love you any more," he says. "Do I, love?" The words are intended for his wife, Helen, who sits beside him. "No, love," she replies. "So you say." There is silence again, except for the tick of the insectoid clock. The dent in Stuart's head is above the left eyebrow.
Michael had climbed the tree to retrieve an entangled kite. He needn't have bothered because the kite drifted down of its own accord. But he was high up by then. In her dreams, Amy recalls how abruptly his voice was stifled by the creak and crack of a branch and the wind-whipped silence of the freefall as his body cleared the boughs. Concealed within the meadow grass was a spur of rock. The fall fractured his skull and released a flash flood of bleeding into the right frontal lobe. "I thought his number was up," the surgeon told me. He had said as much to Amy as she kept vigil over the comatose body. "No point beating about the bush," he'd said. But, after three days, Michael came back to life-with a different number.
Stuart's twist of fate was a motorway pile-up. A bolt snapped and blasted like a bullet from the vehicle in front. It came through the windscreen, through his forehead and tore deep into the left frontal lobe. Despite the immediate displacement of some brain matter, loss of consciousness was brief, as is sometimes the case with penetrating missile wounds. He told the paramedics he was fine and had better get home now, but they saw the brain stuff gelling his hair and put him in the ambulance. Within an hour, the surgeons were working to extract the foreign body from the interior of his head, a process also requiring the disposal of adjacent brain tissue. Part of Stuart went with it.
By these means, Mother Nature has neatly created mirror-image brain lesions. As a neuropsychologist, my role is to examine the consequences. Stuart now has trouble getting started. Helen encourages him out of bed in the morning, points him in the direction of the bathroom, has his clothes ready, and gets him breakfast before she goes to work. She leaves him lists of things to do around the house and puzzle books to fill the hours. But when she returns, she often finds him where she left him, sitting in silence. She'll go over and hug him and he'll return the embrace, but it's perfunctory. He doesn't love her any more. It's the plain truth. She accepts it. Stuart is not to blame. What he feels towards Helen is what he feels towards all other people, including himself: indifference. The absence of emotion frees him to declare the truth. He can read people's moods and motivations, but lacks the emotional charge of empathy. I ask what he feels about the little girl who was abducted and murdered last year. He knows it was a dreadful thing. They should hang the murderer or chop his balls off but, no, it doesn't make him "feel" anything very much. Then, he says, it's funny, but he never used to believe in capital punishment.
Michael has trouble stopping. Amy has to rein him in. He'll talk to strangers in the street, he'll tell them they're beautiful, or their children are, or their pets. He wants to touch. He wants to celebrate. Beggars bring a tear to his eye. He once gave a man his coat and a ?10 note. Empathy is hair-triggered but more complex social calculations befuddle him. When he first came home from the rehab centre his tastes were plain. Amy said he lived on fish fingers and Led Zeppelin. He said it was like going back in time. He'd always liked these things and now he didn't feel he should pretend otherwise. Fine, Amy said. But she wouldn't tolerate the porn videos. Like Stuart, Michael no longer feels the need to dissimulate.
"How do you feel in yourself, Stuart?" I ask. "Alright." "Are you miserable?" "No." "Are you happy?" "I don't think so." He turns to Helen. "Am I happy?" Helen looks at me, I look at Stuart; the question goes round in a circle.
Michael saw me off at the front door. Amy gave a wave from down the hall. Michael was close to tears. He pulled me to him and kissed me on the cheek. For an instant, I thought he was going to say he loved me.
