We like to divide people into left-brained, right-brained, but this is inaccurate, says Biddy Passmore. It is better to think of the brain as a complex and sophisticated organ, where both sides work together
Good with words? You must be left-brained, Madam. Happier with numbers? You must be right-brained, Sir. Such facile categorisation of brain-types and sexes makes intuitive sense. It plays along with the prejudice that people fall on two sides of a great divide: words or numbers, arts or science and that the former are female strengths and the latter, male. And it is true that some tasks can be associated with extra activity predominantly in one hemisphere or the other. Brain activity connected with language, for instance, is considered to be concentrated in the left hemisphere.
But defining someone as left-brained or right-brained, which some texts* encourage teachers to do, makes no more sense than saying they are visual, auditory or kinesthetic learners (see last week's The TES Magazine). And for the same reason: that the brain is a highly sophisticated organ, with many networks on both sides communicating with each other in a complex way.
In the words of the commentary, Neuroscience and Education: "No part of the brain is ever normally inactive in the sense that no blood flow is occurring. Furthermore, performance in most tasks, including learning, requires both hemispheres to work together in a sophisticated parallel fashion. There is no reliable evidence that (dividing pupils into left-brained and right-brained) is helpful for teaching and learning."
Commercial educational programmes, such as Brain Gym and those under the broad heading of "accelerated learning", stress the need for balance between the left and right sides of the brain. "Remember," says one,** "that the synergy generated in creating new pathways between left and right results in all-round improvement."
"In fact," retorts Neuroscience in Education with scorn, "except in the rare case of brains which have been lesioned (injured), pathways exist permanently between the left and right hemispheres, most notably via the corpus callosum. At present, there is no scientific evidence to suggest we can voluntarily create new ones."
Teachers should leave preconceptions about their pupils' brains at the classroom door. If you must, think of lobes not hemispheres (see box, opposite). But better to think in the round. Go at the subject from as many angles and using as many methods as possible, to fire as many neural networks in your pupils' brains as you can
*Hoffman, E (2002) Introducing Children to their Amazing Brains. Middlewich: LTL Books Ltd **Smith, A. (1996) Accelerated Learning in the Classroom, Bodmin: Network Educational Press Ltd
HOW DOES THE BRAIN WORK?
The two hemispheres of the brain, left and right, are joined by a mass of fibres known as the corpus callosum. Each hemisphere is further divided into four lobes: the frontal, parietal, occipital and temporal. Each lobe is associated with cognitive function (see Figure A).
The frontal lobe is involved with reasoning and movement. The temporal lobe is associated with memory and hearing. The parietal lobes integrate information from different sources and are associated with mathematical skills. The occipital lobes are critical regions for visual processing.
The cortex is the wrinkled surface. It is more wrinkled in humans than other species, thought to reflect our greater reliance upon higher level thought processes. Some parts exist well below the outer surface. One notable example is the cingulate cortex, the anterior part of which becomes active when we engage in a wide variety of tasks. It also appears to have a significant role in the allocation of attention.
The adult brain contains about 100 billion cells or neurons (see Figure B). Each neuron consists of a cell body, to which are connected dendrites and an axon. The terminals at the end of the axon make contact with dendrites of other neurons and allow connections, or synapses, to form between neurons. Thus complex neural networks can be created.
Neurons communicate using electric signals, which pass down the axon and are transmitted across the synaptic gap using chemicals called neurotransmitters.
Adapted from Neuroscience and Education: Issues and Opportunities, download on www.tlrp.org