It has been assumed that cognitive development – the development of attention, learning, memory, language, reasoning, and conceptual development – can only commence outside the womb. However, recent research shows that cognitive development in many respects begins even inside the womb.

Some of the advances in understanding foetal learning were made possible by techniques developed in the field of cognitive neuroscience. Cognitive psychology and cognitive neuroscience differ in their measurement techniques and aims, despite being related. Cognitive psychology explains cognition via concepts and ideas held in the mind – cognitive representations.  It’s believed that these representations are discreet and symbolic.

Which neural imaging methods are used for developmental data?

Due to technical progress, we can now display images of active areas in the brain during a certain action. We can now see what the brain does when it is, for example, solving a problem. Brain research in children can currently be carried out using three techniques:

• Electroencephalography (EEG): Sensitive electrodes are placed on the skull. These electrodes detect the electrical brain activity. A disadvantage of this technique is that localization is very difficult. However, the technique is very accurate.

• Functional magnetic resonance imaging (fMRI): an fMRI scan measures the changes in blood flow in the brain. When an increased blood flow to a certain brain area is observed, this means that the water distribution changes. The fMRI gives a blood oxygenation level dependent (BOLD) value. The technique is less accurate than EEG, but the localization is much better.

• Magnetoencephalography (MEG): a direct measure of the magnetic fields that are created by the electrical signaling of neurons. These fields are not distorted as they pass through the head, thereby enabling measurements with high spatial and temporal resolution. These magnetic fields from the brain are estimated to be one billion times smaller than the magnetic field generated by the electricity in a lightbulb. They are measured with highly sensitive equipment which is very costly to run, and combines the temporal information with MRI scans to localize the activity.

• Functional near-infrared spectroscopy (fNIRS): the quantity of hemoglobin in the brain tissue is examined. This indicates changes in oxygen supply. Thus changes in blood supply can also be measured. The localization is better than the EEG-technique and the fNIRS is more accurate than an fMRI scan. Also, with this technique, a child does not have to lie in a noisy magnet, as is the case with an fMRI scan. The disadvantage is that the accuracy is not as good as EEG and the location capacity not as good as fMRI.

How do the foetal and neonate brain develop?

Most known neurological examinations have been carried out in adults. So, we know most of the systems that have already been developed with regard to linguistic, perceptual and reasoning tasks. Yet research is increasingly being conducted among children. We know that most brain cells develop before birth (around the seventh month of pregnancy most neurons are present). The environment in the womb can affect later cognitive development. For example, excessive alcohol consumption has an irreversible negative effect on brain development, which affects future arithmetic cognition.

After birth, brain development mainly consists of the growth of connections between neurons. This is called synaptogenesis. This makes the child's brain twice as large in the first year of life. Information is passed between brain cells via low voltage electrical signals (via the synapses).

The primary sensory systems are the first to develop. The higher-level association areas mature later. One of the last areas of the brain going through the maturation process is the prefrontal cortex.

What are two core developmental questions?

1. What is developing? This question is investigated by observing the cognitive abilities of children during a certain time. Because of this we know that the sensory- and motor cortex develop earlier than language- and spatial areas and that the prefrontal cortex develops last, far into adolescence and early adulthood. The order of brain development corresponds very well with Piaget's stages of development.

2. Why does development pursue its observed course? To formulate an answer to this question, we need causal reasoning for observed cognitive changes. Experimental research is suitable for this. In the future we will also receive causal explanations from neuroscientific research.

How does the domain-general differ from domain-specific explanation of cognitive development?

Traditionally, there are two explanatory systems for explaining cognitive changes in children. The first system focuses on the idea that fundamentals of learning or reasoning are applied to all cognitive domains. This is called the domain-general explanation of cognitive development. The second system states that the development of cognition arises bit by bit, at different times across different domains. According to this view, cognitive development is domain-specific.

The knowledge that we have influences our cognition. The two explanatory systems described above are both structured differently, but they are not mutually exclusive. This book describes that some types of learning match with the first explanatory system and others with the second. The book focuses more on the first developmental question (what is developing?) and less on the second question (why does development pursue its observed course?). The reason for this is that findings on the first question are generally certain, while opinions on the second question may differ.

How do children learn and what are constraints on learning?

Infants and toddlers can learn in many different ways. Some examples are learning by imitation, learning by analogies and explanation-based learning. The last-mentioned learning method is asking "why?" questions. Because of the focus on causal information, children can explain, predict and ultimately control events.

Deductive reasoning starts at an early age. Deductive reasoning is reasoning based on examples. In n cases, event X leads to Y. In n cases, event A leads to B. You can investigate this by, for example, changing A to X and seeing if B changes to Y.

Inductive reasoning is observed even at a younger age. We reason inductively when we draw conclusions that are not necessarily deductively valid. We generalize on the basis of a well-known example.

Both in domain-general as well as in domain-specific explanation systems causal deduction can be observed. However, the ability of making causal implications appears to be domain-general.

What is the difference between innate versus acquired accounts of cognition in children?

In addition to the explanatory models as mentioned earlier, there is also the nature-nurture debate. Should development be explained in terms of genes or in terms of an enriched environment? Research has shown that even structures that rely heavily on genetic influences can be altered based on environmental influences. Gene expression is therefore controlled by the environment. This also means environment within us, such as brain tissue. An important question within cognitive developmental psychology is how genes and environment interact with each other, thus creating development.