Nothing is whole or part, but thinking makes it so

And last not least, this essay I wrote for the Max Perutz Science Writing Award about my first fMRI project and its philosophical implications. The marriage made in Nirvana between Buddhist mysticism and science, a la Fritjof Capra...

Physics and Buddhism. These seemingly opposite ways of knowledge share one common denominator. The Buddhist doctrine of Pratītyasamutpāda ("dependent origination") says that all within our universe is interconnected and interdependent, every apparent 'thing' depends on everything else, and ultimately on the universe as a whole. Similarly, Niels Bohr, a founding father of quantum physics, argued that "isolated material particles are abstractions, their properties being definable and observable only through their interaction with other systems."

Naturally, if everything is interconnected, nothing is divided. Therefore separate objects cannot truly exist, it's the mind that creates them. Buddha realised this over two millennia before psychologists did, stating that "with Vijñāna as condition, Nāmarūpa arises". Vijñāna is "divided knowing", cognition; Nāmarūpa is "name and form" seen as one. Indeed, what is an object to our minds? It is but its form or features, and its name, a tag binding these together and separating them from the rest of the world.

Cognitive neuroscientists as myself are interested in the neural correlates of mental objects, their "name" and "form", since these help us understand how we structure our visual world, granting us insight into the nature of visual consciousness, the essence of experience. But you may ask, how can you argue that we construct the objects within our visual world if they appear so constant? Let me illustrate our mental malleability with an example:

As you contemplate this page, the very same image enters your eye, but what objects do you see? Now 'tis a paragraph, then a line, a word, a letter even, and if you focus clearly, the traces making up these letters become the objects of your awareness. And as you go back up in this hierarchy, what were once objects become parts thereof, and so on. Thus, a visual object has no objective reality, pardon the pun, but is a subjective matter dependent on occasion, task and mood.



My research is centred on finding, through visual short term memory tests combined with functional Magnetic Resonance Imaging (fMRI), where within the brain we represent visual features and the cage encapsulating them into a single object. fMRI shows that they are kept somewhere in the parietal cortex at the top and back of our head, vital for organising our attention and perception of space. Indeed, it's this attention that is thought to bind features and assign them a tag, constructing objects we can perceive and play with in our mind.

To find where these two components of an object are held separate, I take advantage of an analogy of the above example: I show you a scene made up of coloured discs and ask you to remember them as groups of distinct coloured triangles or as one complex whole. The number of objects depends on how I ask you to remember the discs, since a set of features can only belong to one object at a time. Hence, by comparing brain activity related to memory for the very same discs either as an aggregated whole or a handful of parts, I can find the brain locus where features are glued into single items. Similarly, by changing the number of discs you must remember, I can alter the number of features independently from the number of objects, and locate where these features are kept.



But to what use can this knowledge be brought to bear?

Emerging brain imaging methods let us explore the topography and properties of visual maps in detail, allowing us to predict what a person sees from their brain activity and bringing us ever closer to reconstructing and viewing the content of our inner display. But to truly succeed at reading and comprehending perception we need to be able to image the spectator, the object making homunculus within.

This information can then help us better understand neural conditions arising from parietal brain damage, such as simultanagnosia, whose sufferers cannot perceive more than one object at a time, and often report illusory conjunctions by grouping disparate features into a single object.

The questions on our table are ancient, but the framework of cognitive neuroscience slowly unravels an opening in the thick unknown, promising to illuminate our ignorance and enlighten us. By learning how we structure our external world, we discover how our internal cosmos is built.

So what's the moral? Misquoting Hamlet, "Nothing is whole or part, but thinking makes it so"