# Tele-Assessment of Executive Functions in Young Adults with ADHD: A Pilot Study
## 5 Materials and Methods
### Measures  
To tele-assess EF components, four classical paradigms from the TeleFE platform were used (three experimental tasks and one ecological task). For all tasks, participants sat 30-50 cm from the PC screen. The screen size was usually 11 inches (range 9-13). The stimulus size was calibrated before the assessment began by matching a 1 EUR coin with its image on the screen. Go/NoGo task. The Go/NoGo task is designed to assess the response inhibition (RI) or a person's capacity to suppress impulsive actions in favor of those that align with the task rules [83; 84]. During the task, the participant is presented with a geometric shape--either a yellow or blue circle or triangle--displayed at the center of the screen. The task comprises four blocks, each containing 50 trials (35 Go trials and 15 NoGo trials). The conditions are structured as follows:  
* Block 1: Go stimuli are yellow; NoGo stimuli are blue. * Block 2: Go stimuli are blue; NoGo stimuli are yellow. * Block 3: Go stimuli are circles; NoGo stimuli are triangles. * Block 4: Go stimuli are triangles; NoGo stimuli are circles. Each stimulus appears for 500 milliseconds. If the participant presses the spacebar within this window, the stimulus disappears immediately. Otherwise, it remains on the screen until the end of the 500 ms, followed by a neutral black screen (interstimulus interval: 500, 750, or 1000 ms) and then the next stimulus. The measures derived from the task are as follows:  
* Go CR (Correct Responses): the average number of accurate responses to the Go stimuli. * NoGo CR (Correct Rejections): the average number of correct inhibitions in response to the NoGo stimuli. * Go RT (Reaction Time): the average response time to the Go stimuli (calculated only if the accuracy on the Go trials exceeds 20%). The interpretation of the metrics:
* NoGo CR serves as a direct index of the inhibitory control accuracy. * Go RT reflects the processing speed of the inhibitory control. Flanker task. This task assesses two key executive functions: interference control (CI), defined as the ability to suppress responses to irrelevant information, and cognitive flexibility (FC), or the capacity to adapt behavior according to two distinct rule sets depending on the stimulus features [85; 86; 87]. In the task, five horizontally aligned arrows appear on the screen. The participant is instructed to identify the direction of the target arrow while ignoring the others. The task is divided into three blocks:  
* Block 1 and Block 2 each consist of 8 practice trials and 40 test trials. * Block 3 includes 64 test trials. In Block 1, all arrows are blue; in Block 2, all are orange; and in Block 3, half are blue and half are orange. Each block includes 50% congruent trials (all arrows point in the same direction) and 50% incongruent trials (the central arrow points in the direction opposite to the flanking arrows). * In Block 1 (central target condition), the participant must press the 'S' key if the central arrow points left and 'L' if it points right. * In Block 2 (peripheral target condition), the response is based on the direction of the flanking arrows. * In Block 3 (mixed-rule condition), the response depends on the color of the arrows: blue arrows require a response based on the central target; orange arrows require a response based on the peripheral targets. Each trial begins with a fixation cross displayed at the center of the screen for 600-1200 ms, followed by a blank screen lasting 600 ms. Then, the stimulus array is presented for up to 1500 ms. A response is considered valid if made between 200 ms after stimulus onset and before its disappearance. For the single-rule blocks (Blocks 1 and 2), there are general measures:  
* CI accuracy: the accuracy related to interference control, derived from the performance in incongruent trials in the first two (single-rule) blocks of the Flanker task. * CI RT: the speed related to the interference control, calculated based on reaction times in incongruent trials from the first two blocks of the Flanker task.