What is Cognitive Neuroscience about?

The field of cognitive neuroscience is a new field and has emerged from the field of neuroscience, the biomedical field, and cognitive science, which studies mental processes. For example, cognitive science studies basic functions such as perception and motor processes, but also studies emotions and thoughts. Various methods are used to study the function of the brain, such as looking at the effect of brain damage, monitoring single neurons or by temporarily deactivating parts of the brain and looking at the effects of this deactivation.

What are cognitive functions?

Cognitive functions include a number of processes through which humans and other animals perceive the outer world (external stimuli). Perceiving the outer world is done by focusing attention on important information and memorizing this, which ultimately leads to the creation of thoughts and actions. Some describe cognition as the processes influenced by the mind, but this concerns only subjective conscious experiences. However, cognitive functions can also work on a subconscious level. Therefore, most researchers do not prefer this description.

What can be said about the history of cognitive neuroscience?

Philosophers explored cognition by drawing conclusions from introspection and reasoning. In the nineteenth century, the first scientists studied cognition by behavioral observation or by experimental manipulation. Many of these methods are still in use as of today. At the beginning of the twentieth century, behaviorism came into existence. This field of behaviorism had an emphasis on controlled experiments in which objective external stimuli are linked to measurable behavior. For example, it was studied how different stimuli could influence the behavior of individuals. These studies were often conducted on animals, because animals were believed to have the same learning processes as humans. Then, the results of these experiment were generalised to humans. To date, some of these techniques are still in use, such as the stimulus-response learning technique. Even though behaviorists ignored cognitive functions, they laid the foundation for an objective, experimental approach within psychology.

What were some other developments?

In the mid-twentieth century, there were other developments. For example, many researchers used the workings of a computer as a metaphor for the workings of the mind. For example, Miller concluded that complex stimuli are, due to memory processes, encoded in the brain into smaller parts. Also, the behaviorist view on behavior was criticed. For example, Chomsky argued that behaviorism was not able to explain how children develop language. He argued that cognitive models should be used to explain how sensory input leads to behavioral output. Cognitive models do include psychological and internal processes. Thus, cognitive models look at psychological constructs for explaining certain phenomena. However, cognitive models do not search for causes in the brain.

What is the neuroscience?

The neuroscience studies how the nervous system is organized and how it functions. In the early nineteenth century, it was already known that damage to the brain can lead to changes in cognition. Phrenologists created a map of the skull, and they attributed various functions and traits to different locations in the skull. However, later it was discovered that the shape of the skull did not have any relation to the underlying structure (the brain) itself. However, this still laid the basis for the recognition that different parts of the brain are responsible for different forms of processing. This is called the localization of function. Later, at the end of the nineteenth century, neurons were discovered and it was shown that these neurons are the cause of cognitive processes. By means of action potentials, signals are transported along axons. Also, neurotransmitters are used by neurons to stimulate other cells. These neurotransmitters are released by synapses which are located in the neuronal axons. It is said that depression is a disorder which is the result of a dysfunction in neurotransmitters. 

What is the cognitive neuroscience?

Cognitive neuroscientists link cognitive processes that influence behavior to underlying brain functions. Part of cognitive neuroscience is to relate activated parts of the brain to psychological processes, although this is not all of it. In one study, brain activity was measured. This showed that there are filters for what enters one’s attention, and this process happens at the beginning of processing and also at a later moment. In cognitive neuroscience, it is also important to examine individual differences in cognition. This contributes to a better understanding of the (neuronal basis) of cognition.

What methods are used in cognitive neuroscience?

In cognitive neuroscience, multiple methods are used. This has two advantages, namely:

1. Convergence: This refers to combination of different experimental studies to reinforce the results found. When the design of a study differs, but the results stay the same, it is more plausible that the results found are correct. 
2. Complementarity: Using various methods can serve as a complementation. For example, functional magnetic resonance imaging (fMRI) measures blood and oxygen levels and single unit recording shows how neurons transmit information. Methods such as transcranial magnetic stimulation (TMS) can temporarily alter brain functions and therefore demonstrate causal relationships. Combining these techniques may yield a more nuanced image of the studied variable.

Also, all techniques have their strengths and weaknesses. Therefore, combining different methods and techniques can lead to better results.

What are meta-analysis?

Meta-analysis are used to merge information from (a lot of) different studies. Since many studies in cognitive science contain relatively few participants, performing meta-analysis improves the power and the precision of results. 

There are three approaches for conducting meta-analysis:

1. A qualitative meta-analysis: This involves collecting studies that examine the same cognitive functions and then looking for similarities between results.                                
2. Quantitative meta-analysis: this involves comparing fMRI activations from different studies to study of the brain regions involved in certain functions. In addition, subtle functional differences within a brain region can be demonstrated by using this approach.                               
3. Semantic meta-analysis: combines studies based on underlying concepts. The relationship between different concepts can thus be demonstrated, and complex cognitive functions can also be divided into basic cognitive functions.