Category Archives: Science

Arts, Philosophy, Science

Philosophy: The blank slate

INNATE IDEAS

Intro: In An Essay Concerning Human Understanding, John Locke rebutted the rationalists’ argument that we are born with innate ideas, and so laid the foundations for modern empiricist thought.

“No man’s knowledge here can go beyond his experience.” – John Locke (1689)

British empiricism

Central to the philosophy of John Locke (1632–1704) is the idea that there is no such thing as innate knowledge: at birth, the mind is what he called a tabula rasa, or “blank slate”. When we observe new born babies, he said, it is clear that they do not bring ideas into the world with them. It is only as we go through life that ideas come into our minds, and these ideas are derived from our experience of the world around us. This idea stood in marked contrast to much contemporary thinking, particularly the ideas of Descartes and Leibniz, who argued that we are born with innate ideas and that our reason, rather than our experience, is our primary means of acquiring knowledge.

Locke’s idea was not new – it had been defended by Francis Bacon and Thomas Hobbes, and even went back to Aristotle. However, Locke was the first philosopher to give a comprehensive defence of empiricism – the idea that experience is our principle source of knowledge. That is not to say that Locke dismissed the importance of reasoning in our acquisition of knowledge. He believed, too, that each of us is born with a capacity for reasoning, and that the right education is critical to a child’s intellectual development.

Learning the world

Locke claimed that there are two kinds of idea – ideas of sensation and ideas of reflection – and that the latter are made out of the former. In Locke’s words, the objects of the world “cause” ideas of sensation to form in our minds. We then organise these ideas into ideas of reflection:

Blank Slate – At birth, a baby brings no ideas into the world; its mind is completely blank. This means that everything that it will know will come from the world around it. For this reason, Locke claimed that the child should be exposed to the best ideas possible.

Ideas of Sensation – According to Locke, the objects of the world cause ideas of sensation in the infant’s mind. These simple impressions form in the way that light forms images on photographic film: it is a mechanical process that requires no effort on the child’s behalf.

Ideas of Reflection – As the child grows older, it builds ideas of reflection out of its ideas of sensation. From its interactions with other people, and its simple understanding of the qualities of a ball, for example, it can create the idea of “football”. From that, and other simple ideas, it forms the more complex ideas of “teamwork” and “competition”.

Primary and Secondary Qualities

According to Locke, we can only receive information about the world through our senses. This information, he claimed, is of two kinds, and concerns what he called the primary and secondary qualities. An object’s primary qualities, such as its height or mass, are objective, and exist independently of whoever is observing it. However, its secondary qualities, such as its colour or taste, may differ between observers. A ball, for example, may appear grey or multicoloured to two different observers, but both will agree on its size.

Primary Qualities – For Locke, the primary qualities of a thing are its length, breadth, height, weight, location, motion, and overall design.

Secondary Qualities – The secondary qualities of a thing are its colour, taste, texture, smell, and sound. These qualities depend on the perceiver’s senses.

NEED TO KNOW

. Although Locke denied the existence of innate ideas, he claimed that we have innate capacities for perception and reasoning

. In the 19th century, the notion of innate ideas resurfaced. Scholars questioned whether behavioural traits come from “nature or nuture”

. In the 20th century, Noam Chomsky extended Locke’s idea that we have an innate capacity for reasoning. Chomsky claimed that all humans have an innate ability to acquire language.

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Environment, Research, Science

Migrating animals: How do they find their way?

ETHOLOGY

Intro: The ability by some animals to find their way when migrating over long distances intrigues and amazes us. The puzzle of how they do this is difficult to solve and we are only really just beginning to find answers

SOME of the migratory habits of animals are truly astonishing, not least because without our own navigational aids, our compasses and our GPS systems, we very easily get lost ourselves. Arctic terns leave their northern breeding grounds in and around the Arctic Circle towards the end of the summer to fly south all the way to the Antarctic coast, arriving in time for the onset of summer in the southern hemisphere, and then fly all the way back to the Arctic to breed the following spring. If the terns flew directly between their two destinations, this would involve journeys totalling over 32,000 km (20,000 miles), but they actually adopt much more convoluted routes, increasing the distances they cover by tens of thousands of miles. Yet after covering such enormous distances, the terns often return to the exact spot where they bred the previous year.

Atlantic salmon spend most of their adult lives in the ocean before returning to the same river where they were born, and usually to the same stretch of that river, to spawn. Some monarch butterflies are involved in a circular migration – which takes several generations to complete, travelling from southern Canada to overwintering sites in central Mexico while every year, millions of Christmas Island crabs travel from the forest in the interior of their Indian Ocean island to the coast to breed. Several species of frogs and toads engage in similar annual mass migrations, and sea turtles such as loggerheads and leatherbacks give the impression of being engaged in a lifelong migration, swimming for what can be thousands of kilometres between breeding grounds on beaches and feeding grounds in the distant ocean.

Navigating animals

These birds, fish, butterflies, crabs and turtles provide a few examples from among the thousands of species of animals that engage in migratory behaviour of one sort or another. Charles Darwin thought that animals, and to some extent humans as well, possessed an instinctive ability to orientate themselves in their surroundings, which they could use to navigate by dead reckoning, but he could not be any more specific about how this ability worked. Beginning in the 1910s, the Austrian animal behaviourist Karl von Frisch carried out experimental research on honeybees, which showed that their primary means of navigation involved using the position of the Sun to orientate themselves, but that they could also detect and follow the pattern of ultraviolet light in blue skies, which is caused by polarisation and is invisible to human eyes. On cloudy days, Frisch found that the bees could also make use of the Earth’s magnetic field to find their way when the Sun and polarised light were not visible. He would also be the first to describe the so-called waggle dance that the bees engaged in as a means of communicating the location of a source of nectar they had found to other bees in a hive.

Since Frisch’s work, which earned him a Nobel Prize in 1973, other animals, such as sea turtles, have also been found to be able to detect the Earth’s magnetic field. Homing pigeons, which can return to their own lofts after being released hundreds of kilometres away, appear to use the magnetic field as one of a range of navigation techniques. Attempts have been made to discover how pigeons detect the magnetic field, which is actually very weak, and while we do not know for certain, one theory suggests they somehow make use of particles of magnetite, a highly magnetic mineral of iron oxide found in the upper part of their beaks. Even so, it remains a mystery how the navigational information that may be gained in this way is passed to the brain and processed.

Homing pigeons can switch between different methods of navigation as circumstances dictate, sometimes following known landmarks, such as coastlines, rivers and roads, while at others navigating by the Sun and stars. When it is too dark or cloudy for them to see the sky, they can fall back on finding their way by following the magnetic field. Researchers at the University of Texas who monitored the brain activity of pigeons while they were subjected to a moving magnetic field came to the conclusion that, as well as having compasses in their heads, the pigeons somehow constructed maps in their brains as they went along, so when they ended up in a place they had never been before they could head straight for home. We may like to think of ourselves as rather more intelligent than pigeons, but, for all our superior brainpower, we can’t do that.

Alternative theories

Research into the ability of European robins to use the Earth’s magnetic field to navigate suggests that the mechanism involved may work at a subatomic, or quantum, level. If this proves to be the case, then it would go some way to explaining how animals can detect and make use of the natural magnetic field, which is far too weak to provide enough energy to power any molecular chemical reactions. Magnetoreception, as this ability is known, appears to function through the eyes of the robin, so it is possible that light provides the energy required to activate so-called radical pairs, subatomic charged particles that are small enough to be influenced by the low levels of magnetism and may create some form of navigational signal that is then passed to the robin’s brain via the optic nerve.

See also:

. Book Review – ‘Greenery: Journeys In Springtime’

. Science Book

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Arts, Books, Psychology, Science

Book Review: The Complete Guide to Memory

LITERARY REVIEW

Intro: If you want to strengthen your mind, a new compendium exploring the mechanics of memory may be the place to start

IT IS all too easy to forget how much we rely on our memory and how quickly things can go south when it falters. Although the march towards forgetfulness is often presented as a foregone conclusion, it doesn’t have to be that way. That’s according to Dr Richard Restak in The Complete Guide to Memory, a short but comprehensive compendium of everything we know about memory and how we might improve it.

So-called brain training has been in vogue for decades in the form of sudoku puzzles or apps that promise to help you defy the cognitive decline of ageing, but there is little evidence for this.

Despite his book’s subtitle – The science of strengthening your mind – Dr Restak’s gambit is slightly different. He is a neuroscientist, author of more than 20 books on the human brain, and with decades of experience of patients with memory problems. Here he argues that by performing certain tasks to boost your memory, other mental faculties that rely on it will improve and you might ease the impact of old age.

Of course, memory isn’t one thing, but an interconnected series of brain structures and processes that interact with stimuli and consciousness in myriad ways. To understand how to improve it, an understanding of these processes is helpful, so Restak devotes a sizeable chunk of this book to teasing out the nuances of memory.

This includes episodic, semantic and procedural memory, how working and long-term memory differ, and how these are, in turn, formed from different stimuli, such as internal and external speech or visual information. It can feel like a whirlwind tour, and unless you take Restak’s advice to be attentive and intentional about remembering, the neuroscience will likely wash over you.

But understanding how different kinds of memories are made and stored does help make sense of the sections that follow, on how our brains use memory in daily life and what happens when these processes falter or start to go wrong.

The book is at its most enjoyable when Restak blends case study and personal anecdote to explore memory and what happens when faculties start to disengage.

Somewhat distressingly, the chapter devoted to memory’s malfunctions is almost as five times as long as the chapter that describes it working as intended – but, apart from rare brain injuries or traumatic events, these cognitive vulnerabilities are instructive.

For instance, knowing that advertisers and political campaigners tend to recycle and repeat the same catchphrases to evoke a sense of familiarity, and so prime you to remember them, could fortify you against manipulation in the future – or encourage you to use those same repetitious techniques for things you would like to remember.

The main way to improve all forms of memory, the author says, is to actively practise certain techniques, ideally daily. Some are as simple as attending to things more closely to expand long-term memory, while others are more involved, such as exercises and games that include memorising sequences of cards or numbers to boost working memory.

For all its emphasis on brain structure, the guide can feel frustratingly unstructured. Some curiosities, like the brain’s tendency to more easily recall interrupted tasks (the Zeigarnik effect) or that you remember things better when you see them on large screens, seem random and underexplored, with only a few paragraphs devoted to each and little about how you should incorporate them into your life.

Then there are its more eye-catching claims – for example, that memory exercises could help prevent memory decline in Alzheimer’s disease. Some might say that these rely too much on Dr Restak’s clinical experience and suffer from a lack of balanced discussion, essential for a book that has “avoid memory loss” on the cover and mentions Alzheimer’s on the first page.

Critical reviewers will likely still be pondering over the book’s anti-dementia credentials, although a few weeks of the daily memory exercises emphasised may well lead to a small boost in recall and help those who use them to feel more present.

The Complete Guide to Memory by Dr Richard Restak is published by Penguin Life, 208pp

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