Category Archives: Science

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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Arts, Philosophy, Science

Philosophy: Facts and ideas

REASON AND EXPERIENCE

Intro: Like John Locke before him, David Hume believed that our knowledge derives primarily from experience. However, he also argued that we can never know anything about the world with certainty

Natural assumptions

David Hume (1711–1776) was primarily interested in epistemology (the nature of knowledge), rather than metaphysics (the nature of the universe). In An Enquiry Concerning Human Understanding, he set out to examine the way that human psychology determines what we can and cannot know, and in particular what we can and cannot know for certain.

Although an empiricist – that is, he believed that experience is our primary source of knowledge – Hume conceded that many propositions, such as mathematical axioms, can be arrived at by reason alone and cannot be doubted: to doubt that 2+2=4 is to fail to understand its meaning. However, he argued that such truths tell us nothing about the world: they simply express relationships between ideas. To gain knowledge about the world we need experience, but Hume argues that such knowledge can never be certain. We are therefore caught on the prongs of a fork: on the one hand, we have certainty about things that tell us nothing about the world; on the other hand, our knowledge about the world is never certain.

Hume argues that it is human nature to make assumptions about the world, especially that it is predictable and uniform. We assume, for example, that when a brick is thrown at a window the brick “causes” the window to smash. However, Hume argues that all we know for certain is that throwing a brick at a window is regularly followed by the window smashing. We never perceive causes, he says, but only a “constant conjunction” of events – that is, the regular occurrence of certain events following others. We only imagine a “link” between them.

Hume is not saying we are wrong to make assumptions – life would be impossible without them. Rather, he is suggesting that we should recognise the extent to which assumptions govern our lives, and not confuse them with the truth.

Relations of ideas

Statements of this kind are necessary truths, which means that they cannot be contradicted logically. For example, it is not possible to say that the angles of a triangle do not add up to 180 degrees, or that 2 plus 2 does not equal 4. We can be certain of such truths, but they tell us nothing about the world: they merely express relationships between ideas.

Hume’s fork

For Hume, there are two kinds of truth: “relations of ideas” and “matters of fact”. The former are true by definition, while the latter depend on the facts. Philosophers call this distinction “Hume’s fork”.

Matters of fact

Statements of this kind are contingent, which means that their truth or falsehood depend on whether or not they represent the facts. For example, it is not illogical to deny the statements “It is snowing” or “I have a cat”. Their truth depends simply on the current state of the weather and whether I own a cat or not.

“Custom, then, is the great guide of human life.” – David Hume, An Enquiry Concerning Human Understanding (1748)

THE PROBLEM OF INDUCTION

Hume argued that general statements such as “The Sun rises in the east” are logically unjustified because we cannot prove that the Sun will not rise in the west tomorrow. This also means that scientific claims, such as “The Moon orbits the Earth”, are unjustified because we may discover, for example, that the Moon may also behave in a different way tomorrow. Such statements are known as “inductions”, because they use the inductive method of reasoning – that is, they make general claims based on a limited number of particular cases or events. There are different types of inductive argument which will be examined in detail in a future entry.

NEED TO KNOW

. According to Hume, the difference between mathematics and the natural sciences is that mathematical truths are what he calls “relations or ideas”, or necessary truths, whereas scientific truths are contingent, or conditional, “matters of fact”.

. Half a century before Hume, Gottfried Leibniz made a similar distinction between truths of reasoning and truths of fact. Leibniz was an accomplished mathematician. He invented calculus (which Isaac Newton was also instrumental in) and was characterised as an optimistic philosopher. He believed that God is supremely perfect, and that ours is the best possible world – one in which the modern “monads” exist in harmony. The word “monad” is derived from the Greek word monas, meaning “unit”, which Leibniz borrowed to describe the fundamental units of existence. He distinguished “truths of reasoning” from “truths of fact”.

. Immanuel Kant and later philosophers distinguished between analytic statements, whose truth can be established by reasoning alone, and synthetic statements, which are verified by reference to the facts.

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Arts, Philosophy, Science

Philosophy: The Scientific Revolution

RENAISSANCE

Intro: Although the Renaissance was primarily an artistic and cultural movement, its emphasis on free thinking challenged the authority of religion, and paved the way for an unprecedented age of scientific discovery

Tradition undermined

THE Scientific Revolution began with the publication in 1543 of Nicolaus Copernicus’s De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), which presented evidence contradicting the notion of a geocentric universe. A description of this is given at the end of this article.

That same year, Andreas Vesalius published De humani corporis fabrica (On the Fabric of the Human Body), which overturned many orthodox ideas in anatomy and medicine. What followed was a profound change in the approach to enquiry into the natural world. Conventional wisdom, including the dogma of the Church, was no longer blindly accepted, but challenged. Even the work of Aristotle, who had initiated the idea of natural philosophy based on methodical observation, was subject to scientific scrutiny.

At the forefront of this scientific revolution were philosophers such as Francis Bacon, whose Novum Organum (New Instrument) proposed a new method for the study of natural philosophy – systematically gathering evidence through observation, from which the laws of nature could be inferred. But there was also a new class of thinkers and scientists, including Nicolaus Copernicus, Johannes Kepler, and Galileo Galilei. Galileo challenged dogma more than most by proving that the Earth orbits the Sun, and fell foul of the Church for his efforts.

The discoveries made by these scientists, and the methods they used, laid the foundations for the work of Isaac Newton in the following century, and also influenced philosophers such as Descartes, Spinoza, and Leibniz, who helped to shape the ideas of the Age of Enlightenment.

One Cause Only

Central to Aristotle’s philosophy was the concept of the “four causes” (see article). The new scientific methods of the 16th and 17th centuries rejected these, especially the concept of a “final cause”, or purpose. Instead it was proposed that there are only “efficient causes” in nature – i.e. physical causal triggers. Although this is closer to the modern idea of cause and effect, the idea had first been proposed by the Atomists some 2,000 years earlier (see article).

Laws of nature

The theories of Copernicus and his contemporaries heralded a new era of scientific discovery. Religious authority was undermined, but so too was the orthodox concept of the laws that governed the universe, which were based on Aristotelean cosmology and physics. In this new atmosphere of scientific enquiry, conventional assumptions were replaced with laws of nature derived from empirical evidence of observation and experiment.  

The New Method

Induction

Bacon described a method of scientific enquiry using the process of induction, inferring a general rule from particular instances. For example, the rule that water boils at 100C can be inferred because this is the case in every instance.

Experimentation

Often, it is not enough simply to observe in order to come to a scientific conclusion. The scientific method pioneered by Islamic philosophers involves conducting controlled experiments to get reproducible results.

Galileo Galilei once said: “In science the authority of thousands of opinions is not worth as much as the reasoning of one individual.”

Sunspots – The detailed study of sunspots made by Galileo and others showed that these are inherent features of the Sun. These observations contradicted the Aristotelean idea of the perfection of objects in the heavenly spheres.

Gravity – Although it may only have been a thought experiment, Galileo dropped two balls of different weights from the Tower of Pisa to show that they fell at the same speed. This refuted Aristotle’s assertion that heavy objects fall faster than lighter ones.

Elliptical orbits – Once it was proven that the Earth orbits the Sun, the orbits of the planets could then be explained. Kepler discovered that the orbit of Mars was not circular, but an ellipse, and concluded that all the planets had elliptical orbits.

THE GEOCENTRIC UNIVERSE

Outside the orbit of the Moon lies the celestial region in which the Sun, the planets, and the stars move in orbits at various distances from the Earth. Unlike the sublunary region, the celestial region is made from an incorruptible substance, which Aristotle calls the “quintessence”, or fifth element. According to Aristotle, the natural movement of the earthly elements is up or down, towards or away from the centre of the Earth. By contrast, the natural movement of things in the celestial region is circular. What’s more, earthly elements tend towards a position of rest, while celestial movement is unceasing. Thus, Aristotle reasoned that the stationary Earth, although imperfect, is at the centre of the cosmos.

Beyond the Moon’s orbit, Aristotle identified 55 concentric spheres to which the celestial objects are attached. As they radiate away from the Earth, the outer spheres draw closer towards perfection, stretching into spiritual realms that have no material existence. The universe, for Aristotle, is a perfect form, and cannot have come into being at any one time: it is eternal, unchanging.

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