The concept of arousal is at the core of Neurofeedback (NF) training principles and is a central feature of many clinical assessment strategies. There are many different types of arousal states in humans, with NF focusing on elements of neurophysiological arousal, as a function of brainwave patterns measured by an electroencephalogram (EEG).
NF training aims to improve the symptoms of both under-arousal and over-arousal.
Examples of each are included in the table below.
There are different ways of measuring arousal. Physiologically our arousal level is considered in relation to our sleep/wake cycle. Difficulties with managing arousal can be seen in people to fall asleep in low stimulation environments when they sit still (under-arousal) or have issues with falling asleep when in bed (over-arousal). Typically when we aim to regulate arousal we work over the sensory-motor strip as C3, C4, or Cz (see below 10-20 system). It is very important to distinguish between cortical over-arousal (i.e., brain waves with very high frequency) and behavioural over-arousal (symptom based) as often people can present as being cortically under-aroused yet behaviourally over-aroused. There are several hypotheses as to why this occurs. Martjin Arns discusses what he terms ‘Vigilance Auto-stabilisation Syndrome’ . This is when people with high levels of slow wave move around and fidget in order to activate their brains which are ‘sluggish’.
Training for Arousal Levels
Training for Over-Arousal:
Sample training protocol: Training for Over Arousal (Rewarding SMR 12-15 Hz)
If your child has symptoms of over-arousal, we will be aiming to reduce the over-arousal through training your child in SMR. SMR is the Sensory Motor Rhythm in which is 12-15Hz noted over the sensory-motor strip. This corresponds to C3, Cz &C4 in the picture below. Typically when we train SMR we place sensors at C4 (right hemisphere) or Cz. Whilst we start at 12-15Hz we need your feedback to know whether your child responds appropriately to this setting. 12-15Hz is still quite an activating level and may over-activate your child. Dependent upon your feedback we may start to shift their training 0.5Hz up or down to modify the protocol. If we find that your child is too sleepy we will shift it to 12.5-15.5Hz. If we find you child too activated we will shift it down to 11.5-14.5Hz. We will continue shifting based on your feedback. For children who have any obsessive or cognitive flexibility issues we tend to train them at Cz rather than C4. Slightly stronger effects are seen at C4, however there are benefits from training more centrally for children who get fixated, stuck or obsessed due to the different brain regions treated.
Training for Under-Arousal:
Sample training protocol: Training for Over Arousal (Rewarding Low Beta 15-18 Hz)
If your child has symptoms of under-arousal we will be aiming to increase arousal levels through training your child in Low Beta, which is 15-18Hz. We train for under-arousal typically at Cz and C3 (left hemisphere). Whilst we start at 15-18Hz we need your feedback to know whether your child responds appropriately to this setting. 15-18Hz can be very activating and may over-activate your child. Dependent upon your feedback, we may start to shift the training 0.5Hz up of down to modify the protocol. If we find your child is too activated we will shift it to 14.5-17.5Hz or even lower. If we find you child is not activated enough we may even shift the training higher (15.5-18.5Hz). We will continue shifting based on your feedback. For children who have any obsessive or cognitive flexibility issues we tend to train them at Cz rather than C3. Slightly stronger effects are seen at C3, however there are benefits from training centrally for children who can get fixated or cognitive stuck.
Mixed- Arousal Training Protocol:
This protocol aims at training for individuals who experience symptoms related to both over-arousal and under-arousal.
Many children we train have both symptoms of under- and over-arousal. In these cases, we divide the training up accordingly to the frequency of symptoms. Typically we always start with first training symptoms of over-arousal, as if we activate someone who is already over-aroused we can induce anxiety as a side effect. We usually first train the over-arousal symptoms and then slowly introduce some activation. We then build the activation whilst monitoring for side effects. For these children it can take a while to arrive at the desired protocol that addresses all symptoms adequately. This type of training is more complex as not only does the level of training need to be determined for two different protocols (Hz), but also the relative time spent on each protocol needs to be evaluated. This is based on completed feedback from parents (and where possible teachers). Again the importance of you monitoring your child is evident.
The default mode network (DMN), (also default network, or default state network), is a network of interacting brain regions known to have activity highly correlated with each other and distinct from other networks in the brain. The default mode network is most commonly shown to be active when a person is not focused on the outside world and the brain is at wakeful rest, such as during daydreaming and mind-wandering. But it is also active when the individual is thinking about others, thinking about themselves, remembering the past, and planning for the future. The network activates “by default” when a person is not involved in a task. Though the DMN was originally noticed to be deactivated in certain goal-oriented tasks and is sometimes referred to as the task-negative network, it can be active in other goal-oriented tasks such as social working memory or autobiographical tasks. The DMN has been shown to be negatively correlated with other networks in the brain such as attention networks. Evidence has pointed to disruptions in the DMN with people with Alzheimer’s and autism spectrum disorder.