Textbox 1- Cognition and executive function taxonomy The term “cognition” is a broad expression of mental domains related to brain processes connected to assimilating and understanding external stimulation [14] and “the ability to hold, process and manipulate information in the mind” ([15], p.5). One major important set of cognitive processing is described by the term “executive function” (EF), which is also referred to as cognitive control [10]. According to the definition of Diamond [10], EF is an umbrella term for a collection of mental processes regarding the ability to concentrate, focus and adequately react to external stimuli. Based on this it is of general agreement that EFs are subdivided into three core elements inhibition, working memory and cognitive flexibility [10].  1. Inhibition describes the ability to control attentional resources, e.g. connected to behaviour, thoughts or emotions. Inhibition enables an individual to selectively focus on an external stimulus to be processed, while suppressing other stimuli.   ° Inhibitory control is often measured by testing one’s selective attention which requires the ability to correctly discriminate two incongruent stimuli, e.g. the Stroop, the Flanker Test or tasks involving a go/no-go instruction.  2. Working memory (WM) involves holding and manipulating information in mind, e.g. using stored information to solve an ongoing problem. Linked to a variety of neuronal subsystems, WM enables the analysis and clustering of information while selectively focusing on information stored in mind. Testing WM often requires reordering stored information, e.g. repeat a selection of numbers in another order, which is for example used in complex span-backwards tasks, e.g. the n-back task.   ° Verbal fluency tasks require the ability to hold information in mind, while performing a mental process, e.g. the spontaneous production of words.   ° Arithmetic tasks refer to tasks solving mathematical problems, e.g. counting backwards or multiplying.  3. Cognitive flexibility describes the ability to change perspectives according to external demands and an adequate reaction. Flexibility is often investigated via task switching (set-shifting) tasks. This requires the ability to randomly shift between various required stimulus-respond set, e.g. during the Wisconsin Sorting Card test [15]. Other basic cognitive functions regarding reaction time and speed of cognitive processing [16]:  1. Processing speed is referred to as the simple reaction time between an external stimulus and a behavioural response occurrence, which can be tested by the finger-tapping speed as a reaction of a visual stimulus.  2. Visuospatial abilities are connected to the processing and memory of visual as well as spatial stimuli. Common test for visuospatial planning abilities are the Clock-Drawing-Test or the Spatial Span test.