Tag Archives: seeing

by

Is Seeing Believing?

Isn’t it interesting that some of us can look at a forest and miss the wind riffling through the leaves, while others see the moon as a ‘ghostly galleon tossed upon cloudy seas’? What determines what we see? Does it have to relate to something we’ve seen before -patterns that we recognize? Is our apprehension of reality an expectation? A sorting through the chaos and discarding what we don’t understand -the noise– until something more familiar emerges? Why do we not all see the same thing?

If patterns are what we are evolved to see, if they are what we use to make sense of the world, are there always patterns everywhere? These are things I wonder about, now that I have time to wonder. Now that I am retired, I suppose I can wade more thoughtfully into the turbulence I once found swirling about my days. Clarity is certainly not a common property of old age, but occasionally it descends as softly as a gossamer thread, and then as quickly drifts away leaving only traces of its presence. Doubts about its visit.

Are these mere hints of what the gifted see? Is peering beyond the horizon just a gift, or is it fleeting and unstable unless learned? There was an interesting essay in Aeon, an online offering that touched on the subject of insightful examination, by Gene Tracy, the founding director of the Center for the Liberal Arts at William and Mary in Williamsburg, Virginia: https://aeon.co/essays/seeing-is-not-simple-you-need-to-be-both-knowing-and-naive

‘When Galileo looked at the Moon through his new telescope in early 1610, he immediately grasped that the shifting patterns of light and dark were caused by the changing angle of the Sun’s rays on a rough surface. He described mountain ranges ‘ablaze with the splendour of his beams’, and deep craters in shadow as ‘the hollows of the Earth’. […] Six months before, the English astronomer Thomas Harriot had also turned the viewfinder of his telescope towards the Moon. But where Galileo saw a new world to explore, Harriot’s sketch from July 1609 suggests that he saw a dimpled cow pie.’ And so, the question must be asked, ‘Why was Galileo’s mind so receptive to what lay before his eyes, while Harriot’s vision deserves its mere footnote in history?’ But, as the author notes, ‘Learning to see is not an innate gift; it is an iterative process, always in flux and constituted by the culture in which we find ourselves and the tools we have to hand. […] the historian Samuel Y Edgerton has argued that Harriot’s initial (and literal) lack of vision had more to do with his ignorance of chiaroscuro – a technique from the visual arts first brought to full development by Italian artists in the late 15th century. By Galileo’s time, the Florentines were masters of perspective, using shapes and shadings on a two-dimensional canvas to evoke three-dimensional bodies in space. […] Harriot, on the other hand, lived in England, where general knowledge of these representational techniques hadn’t yet arrived. The first book on the mathematics of perspective in English – The Art of Shadows by John Wells – appeared only in 1635.’

But is it really as fortuitous as that? As temporally serendipitous? Tracy makes the point that, at least in the case of Science, observations are ‘often complex, contingent and distributed.’ And, ‘By exploring vision as a metaphor for scientific observation, and scientific observation as a kind of seeing, we might ask: how does prior knowledge about the world affect what we observe? If prior patterns are essential for making sense of things, how can we avoid falling into well-worn channels of perception? And most importantly, how can we learn to see in genuinely new ways?

‘Scientific objectivity is the achievement of a shared perspective. It requires what the historian of science Lorraine Daston and her colleagues call ‘idealisation’: the creation of some simplified essence or model of what is to be seen, such as the dendrite in neuroscience, the leaf of a species of plant in botany, or the tuning-fork diagram of galaxies in astronomy. Even today, scientific textbooks often use drawings rather than photographs to illustrate categories for students, because individual examples are almost always idiosyncratic; too large, or too small, or not of a typical colouration. The world is profligate in its variability, and the development of stable scientific categories requires much of that visual richness to be simplified and tamed. […] So, crucially, some understanding of the expected signal usually exists prior to its detection: to be able to see, we must know what it is we’re looking for, and predict its appearance, which in turn influences the visual experience itself.’

‘If the brain is a taxonomising engine, anxious to map the things and people we experience into familiar categories, then true learning must always be disorienting. […]Because of the complexity of both visual experience and scientific observation, it is clear that while seeing might be believing, it is also true that believing affects our understanding of what we see. The filter we bring to sensory experience is commonly known as cognitive bias, but in the context of a scientific observation it is called prior knowledge. […] If we make no prior assumptions, then we have no ground to stand on.’

In his opinion, there is a thrust and parry between learning to see, and seeing to learn. I have no trouble with that, but I have to say that Science is only one Magisterium in a world of several. Science is neither omniscient, nor omnispective.

I happened across a friend standing transfixed in the middle of a trail in the woods the other day. A gentle breeze was coaxing her hair across her face, but her eyes were closed and she was smiling as if she had just been awarded an epiphany.

At first I wondered if I should try to pass her unannounced, but I suppose she heard my approach and glanced at me before I had made up my mind. Her eyes fluttered briefly over my face for a moment, like birds investigating a place to perch, then landed as softly as a whisper on my cheek.

“I… I’m sorry, Mira,” I stammered, as surprised by her eyes as her expression. “You looked so peaceful, I didn’t want to disturb you…”

Her smile remained almost beatific, rapturous, but she recalled her eyes to brief them for a moment before returning them to me. “I was just listening to that bird,” she said and glanced into the thick green spaces between the trees to show me where, “when I felt the breeze…” I have to say, I hadn’t noticed anything -I hadn’t even heard the bird. “…And it touched my forehead like a kiss,” she said, and blushed for describing it like that. She closed her eyes and thought about it for a moment. “I can’t think of another word,” she added, and slowly walked away from me with a wink, onto a nearby path.

I don’t think that what she was saying was Science, or even meant to require a proof, and yet I felt far better knowing there are people like her in my world. I think I even felt a brief nuzzle by the wind as I watched her disappear into the waiting, excited fondle of the leaves.

 

 

 

by

Peekaboo

Seeing is believing, my mother used to say when she saw I hadn’t finished the spinach on my plate despite my protestations to the contrary. But what if the belief were to persist in the absence of visual corroboration? Suppose I simply closed my eyes and pointed at the plate? My mother, no solipsist, would merely laugh and tell me it would still be there if I ever chose to open my eyes again. I could never win at that –her open eyes trumped my temporarily closed ones every time. I tried that ruse so many times, I got so I could actually see the spinach and the plate even with my eyes firmly clamped shut.

Perhaps I was a slow child, but it did make me wonder about what seeing actually meant. Was it something that could continue even when I tried to turn it off? In the bedroom at night when the blinds were drawn and the room was black, I could still navigate fairly well -and if I did bump into something, I could usually sense it just before the collision.

People talked about noticing things out of the corners of their eyes –meaning when they weren’t looking at them, I guess- and when I grew older, I learned about the sensitivities and image resolution of different cells in the retina. The cone cells in the macula –which you use when you are actually looking at something- were good for colour discrimination and fine resolution, whereas the rod cells, peripheral to that, were more sensitive to light, but not at resolution.

That weird sensation of thinking someone is looking at you, I assumed, was something detected in that peripheral part of the retina by the rod cells –noticed, but not readily identified, and maybe, therefore, not consciously processed until you turned to focus your cones cells on it. It made sense, but every so often I am thrilled to find others who continue to be intrigued by the process: http://www.bbc.com/future/story/20170512-what-causes-that-feeling-of-being-watched

I had assumed that it was fairly straightforward –light hits the retinal cells in the eyes, the signal travels to the visual cortex in the brain, and then it makes us conscious of what the signal means. But, of course, it’s not quite as simple as that. ‘Once information leaves our eyes it travels to at least 10 distinct brain areas, each with their own specialised functions. […] The visual cortex supports our conscious vision, processing colour and fine detail to help produce the rich impression of the world we enjoy. But other parts of our brain are also processing different pieces of information, and these can be working away even when we don’t – or can’t – consciously perceive something.’

So what would happen if your visual cortex were destroyed by a stroke or trauma of some sort? You’d lose your conscious vision –your cortical vision… but ‘cortically blind is only mostly blind – the non-cortical visual areas can still operate. Although you can’t have the subjective impression of seeing anything without a visual cortex, you can respond to things captured by your eyes that are processed by these other brain areas’ –Blindsight, as a researcher name Larry Weiskrantz called it.

The BBC article reported on a study of a man with just such a condition. They were able to do a functional MRI to watch his brain while faces were presented to his ‘blind’ eyes. ‘The scanning results showed that our brains can be sensitive to what our conscious awareness isn’t. An area called the amygdala, thought to be responsible for processing emotions and information about faces, was more active when TD [the patient] was looking at the faces with direct, rather than averted, gaze. When TD was being watched, his amygdala responded, even though he didn’t know it.’

Exciting stuff. ‘[…]research like this shows that certain functions are simpler and maybe more fundamental to survival, and exist separately from our conscious visual awareness. Specifically, this study showed that we can detect that people are looking at us within our field of view – perhaps in the corner of our eye – even if we haven’t consciously noticed. It shows the brain basis for that subtle feeling that tells us we are being watched.’

The article reminded me of something that happened long ago in my gynaecology practice. At the time it seemed a rather trivial incident, but I suppose the fact that I can even remember it suggests that I found it intriguing nevertheless.

Prisha –I think that was her name- was a young woman whose baby I had delivered, a few years before. She returned every two or three years for her pap smear but I remember being surprised to see her again only a few months after her last visit. A tall, beautiful woman with what seemed to me to be an exquisite taste in saris, it was hard not to notice her in the waiting room whenever she visited. Long black hair that never managed to hide the large gold earrings, and the red bindi in the middle of her forehead marked her as an immediate attraction for whatever children happened to be playing on the carpet with their toys.

That day, however, their attention seemed to be focused on an older lady sitting beside her like a queen. Regal in bearing and bolt upright in posture, she was wearing a dark blue sari with gold trim, and as I recall her snow white hair was tucked away under a lighter blue scarf. I suppose what drew my attention to it was that she sat beside her daughter with her eyes closed even when she talked. A tow-headed little boy with large, blue, curious eyes was standing a few feet away staring at her. He would have been too young to have been Prisha’s son, so I assumed he was just fascinated, as I always was with the saris that Prisha wore. But it was more the older lady that had captured his eyes. As soon as I walked across the room to greet them, the little boy ran back to his mother who was sitting beside the window, but he continued to watch from the corner.

I was welcomed by a big smile as I approached Prisha. “I’m so happy to see you again, doctor,” she said, “but this time it’s my mother, Lakshmi, who needs your help.”

Her mother pursed her lips, but didn’t extend her hand to shake mine as I had expected. Her mouth drooped slightly on one side, but a smile broke through nonetheless.

“She is blind,” Prisha explained, “So I have come to help her, if that is alright with you. She only speaks Hindi, though, so I will also need to translate…”

As Prisha took her mother’s arm and helped her down the corridor to my office, I noticed a distinct limp and obvious weakness on one side.

“Mother had a stroke and lost her vision,” Prisha explained, when we were in the office. She’d settled her mother in a chair beside my desk and pulled another beside it for herself. The two talked for a moment while her mother fussed in her seat. “She says she is very nervous about consulting a man, doctor, but I have just reassured her that I trust you.” She smiled at her mother. “She can see nothing at all now, and with the continuing bit of paralysis, I think she feels particularly vulnerable.”

They chatted to each other in Hindi for a moment, when suddenly her mother’s face changed and I could see her tightening her grip on Prisha’s arm.

“Is there something bothering your mother?” I asked, wondering if perhaps she’d changed her mind about being examined by a man.

Prisha immediately smiled, but I could sense her tension. “She says someone is staring at her…”

I blushed and looked down at the surface of my desk. “I’m sorry, I didn’t mean…”

Prisha shook her head. “No, it’s not you, she says.”

“But…” I was confused. “Didn’t you say she couldn’t see anything?”

Prisha smiled, embarrassed. “Nothing at all. The neurologist says she’s completely blind… But she says she can sometimes feel things,” she continued and then shrugged.

Lakshmi seemed to be staring at the office door –if ‘staring’ is the right word, so I glanced over at it. The door wasn’t completely closed, and through what little space remained I could see a pair of large blue curious eyes examining us like a visitor in the zoo. And then, realizing they were noticed, they disappeared, and the pounding of little feet echoed down the corridor.

Lakshmi’s face relaxed and she said something to her daughter.

“It’s okay now, doctor,” she said, looking at her mother with a bemused expression. “She says the eyes are gone…”

There are more things in heaven and earth, Horatio… Blindsight? I don’t know, but whatever it was, I think I was privy to something special that day so long ago.