Bergen Sleep and Chronobiology Network

Cognitive tests

Cognitive tests are used in research studies to assess cognitive performance and functioning. For each project, a test battery adapted to the study in question is developed.

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Psychomotor Vigilance Task (PVT)

PVT is a simple RT-test that measures vigilance and sustained attention. PVT is the gold standard for measuring behavioral alertness in sleep loss/sleep deprivation studies. There are minimal aptitude requirements and limited learning effects, hence the PVT is suitable for repeated administration. The duration of the standard PVT is 10 minutes, but shorter duration, e.g., 5 min, can also be used.

Digit Symbol Substitution Test (DSST)

DSST is sensitive to changes in cognitive functioning, but has low specificity in terms of which cognitive domain it measures. Processing speed and complex attention have been proposed. The duration is usually between 90-120 seconds.

Working Memory Scanning Test

Designed to measure encoding to working memory as well as the ability to maintain and search information in working memory. The duration can be adjusted and also depends on the test person, but minimum 6-7 minutes is common.

Task Switching Test

Measures the ability to quickly change between different tasks. Calculation of «switch cost» provides a measure of how long time the test person needs to reconfigure cognitive processes needed to solve the new task. Considered a basic executive function.

Reversal Learning Test

Provides a measure of cognitive control and flexibility, and the ability to adapt and adjust to changes. These are hallmark characteristics of executive function. The test is based on a go/no go paradigm that requires speeded responses to particular stimuli (go) and withhold responses to other stimuli (no go). The test person must use feedback to learn the correct response set in the beginning of the test, and after reversal feedback must be used to update and adjust the response set.

Visual search

Visual search is used to measure selective attention. During the test, one is first instructed to find a given target stimulus (a symbol). Images are then presented where there are also distractor stimuli among a potential target stimulus. The distractor stimuli have the same visual properties as the target stimulus and are intended to make it challenging to find the target stimulus. The number of distractor stimuli increases linearly over the trials, increasing the challenge of finding the target stimulus. The target stimulus is present in 50% of the cases and the participant is instructed to decide as quickly and precisely as possible whether the target stimulus is present by pressing "j" for yes and "x" for no. In the first half of the test, the participant must find a horizontal red line among the distractors which are green horizontal/vertical or red vertical lines. In the last half, a black digital number 2 must be located among other digital numbers 5. This is a self-paced test, where precision can be sacrificed for total time spent.

Attentional Network

Attentional Network is a measure of executive functioning. During the test, the participant is presented with 5 arrows/symbols. The participant must focus on the arrow in the middle and decide whether it points to the right or the left. In some cases, all the arrows point in the same «<<<<< / >>>>>» or different «<<<>>» direction. The answer is given by pressing "c" for left and "m" for right. The arrows can also appear either at the top or bottom of the screen. This is indicated by the cue symbol *, which flashes at the top or bottom of the front. It is also possible to manipulate the cue symbol to be misleading, so that the test directs the participant's attention in the wrong direction. The test lasts for 180 trials.

Game of Dice

Game of dice measures risk taking. In the game, you start with NOK 10,000, and the aim is to be left with as much money as possible after 18 attempts. You can lose/win money by taking low/high risk bets on a die that is rolled every attempt. You can either bet on four dice (win/lose NOK 1000), three dice (win/lose NOK 2000), 2 dice (win/lose NOK 5000) or 1 dice (win/lose NOK 1000). You can choose which dice you want to bet on.


"No"/"no-go" measures cognitive inhibition, i.e., the ability to withhold a response. In the test, the participant is first shown four different stimuli. Two of these stimuli are roughly the same but are of different magnitudes. E.g., one large star, one small star, one large triangle and one small triangle. It is then specified that one of these stimuli is "no-go", where no response is to be given. The others are "go", where you must react as quickly as possible. Responses are given by pressing "space" as soon as one of the "go" stimuli is seen. In the test, you have up to 2000 ms to give an answer, before the next trial starts. In total, the test lasts for 180 trials.

Grooved pegboard

Grooved pegboard measures fine motor skills and does not take place on a computer. The participant is presented with a pegboard with 25 holes. The holes in the board are small and all have a notch. For every hole, there is a metal peg that fit exactly into the hole. The peg have to be rotated (because of the notch) so that it fits into the hole. In the test, the participant must pick up one peg at a time and place it in the hole. The amount of time it takes to fill all the holes and how many times you unintentionally lose the peg out of your hand are measured. The test is taken once with the dominant hand and once with the non-dominant hand. The hand you are not using must rest in your lap during the entire test.