Neuromyths in Educational Neuroscience

The term ‘neuromyths’ was first coined by an OECD report on understanding the brain. The term refers to the translation of scientific findings into misinformation regarding education. The OECD report highlights three neuromyths for special attention, although several others have been identified by researchers such as Usha Goswami.

    The belief that hemispheric differences relate to different types of learning (i.e. left brain versus right brain).
    The belief that the brain is plastic for certain types of learning only during certain ‘critical periods’, and therefore that learning in these areas must occur during these periods.
    The belief that effective educational interventions have to coincide with periods of synaptogenesis. Or in other words, children’s environments should be enriched during the periods of maximal synaptic growth.

Left Brain versus Right Brain
The idea that the two hemispheres of the brain may learn differently has virtually no grounding in neuroscience research. The idea has arisen from the knowledge that some cognitive skills appear to be differentially localised to a specific hemisphere (e.g. language functions are typically supported by left hemisphere brain regions in healthy right handed people). However, massive amount of fibre connections link the two hemispheres of the brain in neurologically healthy individuals. Every cognitive skill that has been investigated using neuroimaging to date employs a network of brain regions which are spread across both cerebral hemispheres, including language and reading, and thus no evidence exists for any type of learning that is specific to one side of the brain.

Critical Periods
The critical periods neuromyth is an overextension of certain neuroscience research findings primarily from research into the visual system, rather than cognition and learning. Although sensory deprivation during certain time periods can clearly impede the development of visual skills, these periods are sensitive rather than critical, and the opportunity for learning is not necessarily lost forever, as the term ‘critical’ implies. While children may benefit from certain types of environmental input, for example, being taught a second language during the sensitive period for language acquisition, this does not mean that adults are unable to acquire foreign language skills later in life.

The idea of critical periods comes primarily from the work of Hubel and Wiesel. Critical periods generally coincide with periods of excess synapse formation, and end at around the same time that synaptic levels stabilise. During these periods of synaptic formation, some brain regions are particularly sensitive to the presence or absence of certain general types of stimuli. There are different critical periods within specific systems, e.g. visual system has different critical periods for ocular dominance, visual acuity and binocular function as well as different critical periods between systems, for example, the critical period for the visual system appears to end around the age of 12 years, while that for acquiring syntax ends around 16 years.

Rather than talking of a single critical period for general cognitive systems, neuroscientists now perceive sensitive periods of time during which the brain is most able to be shaped in a subtle and gradual fashion. Furthermore, critical periods themselves may be divided into three phases. The first, rapid change, followed by continued development with the potential for loss or deterioration, and finally a phase of continued development during which the system can recover from deprivation.

Although there is evidence for sensitive periods, we do not know whether they exist for culturally transmitted knowledge systems such as educational domains like reading and arithmetic. Further, we do not know what role synaptogenesis plays in the acquisition of these skills

Enriched Environments
The enriched environment argument is based on evidence that rats raised in complex environments perform better on maze tasks and have 20-25% more synaptic connections than those raised in austere environments. However, these enriched environments were in laboratory cages, and did not come close to replicating the intensely stimulating environment a rat would experience in the wild. Furthermore, the formation of these additional connections in response to novel environmental stimuli occurs throughout life, not just during a critical or sensitive period.For example, skilled pianists show enlarged representations in the auditory cortex relating specifically to piano tones, while violinists have enlarged neural representations for their left fingers. Even London taxi drivers who learn the London street map in intense detail develop enlarged formations in the part of the brain responsible for spatial representation and navigation. These results show that the brain can form extensive new connections as the result of focused educational input, even when this input is received solely during adulthood. Greenough’s work suggests a second type of brain plasticity. Whereas synaptogenesis and critical periods relate to experience-expectant plasticity, synaptic growth in complex environments relates to “experience-dependent” plasticity. This type of plasticity is concerned with environment specific learning, and not to features of the environment that are ubiquitous and common to all members of the species, such as vocabulary.

Experience dependent plasticity is important because it does potentially link specific learning and brain plasticity, but it is relevant throughout the lifetime, not just in critical periods. “Experience-expectant plasticity”, suggests that the environmental features necessary for fine tuning sensory systems are ubiquitous and of a very general nature. These kinds of stimuli are abundant in any typical child’s environment. Thus, experience-expectant plasticity does not depend on specific experiences within a specific environment, and therefore cannot provide much guidance in choosing toys, preschools, or early childcare policies. The link between experience and brain plasticity is intriguing. No doubt learning affects the brain, but this relationship does not offer guidance on how we should design instruction.

Bruer also warns of the dangers of enriching environments on the basis of socio-economic value systems, and warns of a tendency to value typically middle class pursuits as more enriching than those associated with a working class lifestyle, when there is no neuroscientific justification for this.

In addition some critics of the Educational Neuroscience approach have highlighted limitations in applying the understanding of early physiological brain development, in particular 'Synaptogenesis' to educational theory.

Synaptogenesis research has primarily been carried out on animals (e.g. monkeys and cats). Measures of synaptic density are aggregate measures, and it is known that different types of neuron within the same brain region differ in their synaptic growth rates. Secondly, the purported ‘critical period’ of birth to three years is derived from research on rhesus monkeys, who reach puberty at the age of three, and assumes that the period of synaptogenesis in humans exactly mirrors that of monkeys. It may be more reasonable to assume that this period of neural growth actually lasts until puberty, which would mean until early teenage years in humans. Periods of intense synaptogenesis are typically correlated with the emergence of certain skills and cognitive functions, such as visual fixation, grasping, symbol use and working memory. However, these skills continue to develop well after the period that synaptogenesis is thought to end. Many of these skills continue to improve even after synaptic density reaches adult levels, and thus the most we can say is that synaptogenesis may be necessary for the emergence of these skills, but it cannot account entirely for their continued refinement. Some other form of brain change must contribute to ongoing learning.

Additionally, the types of cognitive changes usually seen to correlate with synaptogenesis revolve around visual, tactile, movement and working memory. These are not taught skills but rather skills that are usually acquired independent of schooling, even though they may support future learning. How these skills relate to later school learning is, however, unclear. We know that synaptogenesis occurs, and that the pattern of synaptogenesis is important for normal brain function. However, what is lacking is the ability of neuroscience to tell educators what sort of early childhood experiences might enhance children’s cognitive capacities or educational outcomes.

Male Brain versus Female Brain
The idea that a person can have a ‘male brain’ or ‘female brain’ is a misinterpretation of terms used to describe cognitive styles by when attempting to conceptualise the nature of cognitive patterns in people with autism spectrum disorder. Baron-Cohen suggested that while men were better ‘systemisers’ (good at understanding mechanical systems), women were better ‘empathisers’ (good at communicating and understanding others), therefore he suggested that autism could be thought of as an extreme form of the ‘male brain’. There was no suggestion that males and females had radically different brains or that females with autism had a male brain.