Inhibitory control test (ICT)

This test is a computer program measuring attention and inhibitory control. Bajaj et al. [29] proposed the ICT for the diagnosis of patients with liver cirrhosis and created a computer program. The test is freely available on the Internet. During the test, the patient is shown a sequence of letters on the computer screen, displayed in 500 millisecond intervals. The patient’s task is to respond to a specific sequence of letters. In total, the program consists of 212 ‘targets’ (X displayed after Y and vice versa) and 40 ‘lures’ (X after X and Y by Y). The patient must press the button when X follows Y (or vice versa Y after X) but refrain from responding when X is displayed after X or Y after Y. The program automatically calculates the numbers and rates of correct and incorrect lure and target responses and response times. Before performing 5 test runs, the patient performs one training run [30]. The whole test takes about 15-20 minutes and does not require special training for the investigator. The free test was downloaded from the website: https://www.chronicliverdisease.org/disease_focus/ICT/. In the ICT study, the percentage of correct responses and the lures/target accuracy rate was taken into account in the diagnosis of MHE based on PHES.