Vigilance (psychology)

Vigilance, also vigility (Latin Vigilantia " alertness ", " cunning " ), sustained attention or alertness called, in the physiology and psychology states of sustained attention. Alertness is an aspect of consciousness.

Tangible wake states

In causal- functional view vigilance means the average excitation level of the central nervous system, that is, a topological -temporal integration of brain activity at each Vigilanzstadien. These correspond to tangible wake states. They can be arranged as a quantitative levels Vigilanzreihe which has two poles:

• High arousal, such as when Schreck
• Dreamless deep sleep. This definition excludes sleep states in the Vigilanzbegriff with a.

Between stages, which can be passed through both ascending and descending, such as critical of attention, relaxation, dozing, light sleep with loss of the spatio-temporal orientation and dream activity between these two extreme activity states. The phenomenological descriptive assessment of Vigilanzzustandes can be contrasted with a number of electrophysiological findings that correspond to the existence of certain stages of wakefulness.

In neurology, the following terms for Vigilanzminderungen be used:

• Somnolence ( = sleepy, but easily woken up )
• Sopor ( = deep sleep, only by strong stimuli ( eg pain ) woken up )
• Coma ( = not woken up )

The vigilance sustained attention capacity of the patient is measured by a vigilance task in the sleep laboratory, which is executed on the computer. Evaluated here is the patient's ability to respond appropriately in monotonous and prolonged situations to rare stimuli. The vigilance test typically takes 25 to 60 minutes. Narcolepsy patients often do not respond because of their daytime sleepiness, delayed, inaccurate or fall asleep during the test.

Sustained Attention

Stressed to the operational aspect, it means vigilance the state of operational readiness of the organism to react critically to random, near-threshold, infrequent events. The Vigilanzbestimmung in this sense is done by recording the response times and errors of observation in the context of activities that require ongoing attention that is called vigilance. In this sense, vigilance means capacity for sustained attention.

Meeting this monitoring requirement sets a certain psychophysiological state ahead already. Sleep stages are excluded in this definition. Donald B. Lindsley (1960 /61) distinguishes three stages of wakefulness based on electroencephalogram ( EEG) guiding principles: the relaxed waking state, the state of waking attention and the strong excitation:

• The relaxed waking state ( relaxed wakefulness ) is characterized by low voltage, irregular, low-frequency background activity in brain image with closed eyes.
• The state of waking attention ( alert attentiveness ) has μVolt a synchronous background activity of the EEG from eight to twelve seconds in duration with eyes closed with a voltage of 30 to 200, and occipital preference (see alpha rhythm).
• In a state of high arousal (strong emotion excited ) there exists an asynchronous brain current image, that is, it come in different voltage EEG frequencies 14-30 Hz before, which have only small deflections. The voltage remains typically below 50 microvolts. The degree of this condition is specified as arousal.

The first two stages of this activity classification merit the term passive wakefulness with and without relaxation, which an active wakefulness has to face.

Control

The activation of the brain, initially in the ascending reticular system ( ARAS ) in the brainstem (part of the reticular formation ). There are formed (noradrenaline, dopamine, serotonin) as messengers monoamines. This enabled both the hypothalamus ( the hormonal control centers ) and the thalamus, which in turn activates the cerebrum. This is subject to the activity of the ARAS of the circadian rhythm. Both innate rhythm donors and environmental factors play a crucial role. The information about the brightness of the environment is managed by the suprachiasmatic nucleus, which has direct links to both the reticular formation, as well as to the hypothalamus and thalamus has. Another important factor is the measurement of the activity on ascending and descending long tracts ( pyramidal tract and loop path ). This one can stay awake longer with appropriate activity.