"It's so convincing, isn't it?" Adrian's voice came to Zoe a little bit distantly, as though the smooth and resonant clicking sound that filled the room was falling onto his dulcet tones like a soft blanket of snow and muting him ever so slightly. "No matter how much you try to tell yourself that it's just an illusion, it never fails to trick the eye. As much as we like to believe persistence of vision is a purely psychological phenomenon, it's actually working on a real, physical property of the brain. We can't resist it no matter how hard we try. The smooth and seamless flow of images becomes a perfect, inescapable reality right there in front of us, doesn't it?"
Zoe nodded absently, her brow furrowing slightly as she attempted to defy his confident predictions by capturing a single picture with her gaze as it went by. But no matter how hard she focused on the black-and-white silhouette of the woman's face on the other side of the viewing slit, it resolutely failed to resolve into a sequence of images. Instead she watched the woman bobbing back and forth, back and forth on the thick shaft between her lips in an obvious depiction of a blowjob. Trust Adrian to find an example of pornography that predated even the silent film.
Not that Zoe was a prude. If anything, she felt a little determination to stare a bit harder at the simulated fellatio, simply to prove to her rich friend's rich friend that he wasn't going to shock her or get under her skin just by showing her a crude drawing of a woman sucking cock. She knew Adrian was trying to get her goat--not maliciously, maybe, not out of cruelty, but out of that slightly childish urge to assert dominance she'd come to recognize as typical among the young and wealthy and bored. They didn't have anything to do but try to get one over on each other, and Adrian was trying to remind her he was her social superior. She wasn't going to let him get away with it. She was going to push back against all the subtle pressure he brought to bear and--
"They call it tricking the eye," Adrian continued, startling Zoe ever so slightly as she realized she'd allowed herself to focus on the moving image and the soft, gentle clicking sound to the exclusion of Adrian's presence in the room. "But really it's the brain that gets fooled. The signals the optic nerve send back to the brain come so fast that it's overwhelming, each one writing over the other so fast that we don't have time to think. Perception and will get confused, muddied, unable to cope with the flow of information until it's simply easier to give up and allow reality to become something it's not."
He chuckled. "And all from turning this little crank. It's like I'm making you see what I want you to see, isn't it, my little Zoetrope?" Zoe almost rolled her eyes at the thuddingly obvious joke--they'd already had the part of the conversation where Adrian patronizingly explained to her that her name and the name of the antique device he was showing off merely shared a common root, a condescension that stung a little bit harder because Zoe had to admit that she genuinely didn't know until he told her. She'd assumed the inventor named it after his wife or his daughter or something. It was a little embarrassing being corrected about something as fundamental as her own name.
"But of course it's your own brain that's creating that persistent illusion, making it seem as though there's movement in front of you even though each image stays perfectly still in its order on the cylinder." Zoe's brow furrowed a little deeper as she tried to isolate the sensation stealing over her from the soft clicking sound and the hush of Adrian's study and the constant flickering motion in front of her. It was an odd feeling, a kind of stultifying tranquility that she recognized from playing puzzle games on her smartphone or following the motion of a lava lamp--like she could find herself at any moment losing track of time completely and letting the endless repetitive loop of the woman's lips on a silhouetted cock flow endlessly past her eyes.
Adrian's voice didn't help matters. He kept it pitched low, using the reverent tones of a librarian in the presence of a First Folio as he continued to turn the crank and describe the process. "It's funny, because the brain is hardwired to follow moving images, simply as a survival instinct--movement means prey, movement means predators, movement is something we naturally focus on and pay close attention to, and so tricking the eye into tricking the brain means we're being bamboozled into staring at a sequence of still pictures in the belief that they're vitally important to our survival. And because they keep moving...."
He sped up the motion a little, causing the woman in the viewing slit to go into a sudden frenzy of lust. "There's never a point where that residual instinct to follow the motion can relax and let go and tune the pictures out. They keep flowing smoothly and evenly into the eyes, into the brain, overwriting perception and thought despite our best efforts to resist and captivating us with the constant, endless illusion of movement. That's why you can't look away right now, Zoe. Your brain is telling you to keep staring, keep watching, keep that loop of cocksucking devotion right there in front of you and millions of years of evolution have conspired to make it utterly fascinating in the literal sense of the word."
Zoe wanted very much to roll her eyes at that. But she was surprised to discover that they absolutely refused to move from the little slit in front of her and the looping motion of the woman's sucking mouth. Surprise became astonishment as she slowly turned her head, the effort of overcoming her own lassitude unexpectedly difficult, only to find that her gaze remained utterly fixed on the image in front of her. It was as though her pupils were magnetized, locked tight on the silhouetted lips and the silhouetted cock they were pleasuring. "I.... uhhh...." she mumbled, realizing vaguely that she hadn't spoken a word in what felt like several minutes.
"That kind of fixation is another property of the physical brain," Adrian went on, his words filling the thoughtless pause left behind as Zoe tried to think of anything to say beyond that slurred, bewildered mumble and utterly failed. "We talk about willpower a lot, we ascribe moral properties to the ability to shake free from that irresistible fascination and call people 'weak' for struggling against it and failing, but the fact of the matter is the mind has simply evolved over millions of years to develop that ability to focus its consciousness on a single important point of sensory input to the exclusion of all else. The fact that you can't look away, Zoe, only tells me that you're very good at paying attention. You should be proud of that." She felt a warm glow of pride at Adrian's words despite herself. It felt nice to be praised. And Adrian did have a very comforting voice.