Several tasks within Soma use strict scoring parameters, response thresholds, and task-specific rules that can occasionally cause confusion when athletes first start using them. In most cases, unusual results are not caused by a technical issue but are a reflection of how the athlete interacted with the task. This article explains the most common issues we see, how these tasks are scored, and what to look for when reviewing data.
Before You Begin
All Soma tasks have undergone extensive internal testing and have been used across thousands of sessions in both applied performance environments and peer-reviewed research studies. Collectively, these tasks have accumulated well over 1,000 hours of testing, validation, and real-world use. From time to time, coaches or athletes may question a result that appears unusual. In the vast majority of cases, a review of the session data shows that the outcome can be explained by factors such as task familiarity, attentional lapses, missed sequences, mental fatigue, pacing issues, or misunderstanding of the task instructions rather than a technical issue. For this reason, we always recommend reviewing Lapse Count, Reaction Time, Accuracy, and overall trends before assuming a problem with the task itself. What may initially appear to be an error is often valuable information about how the athlete performed during that session.
Mackworth Clock
The Mackworth Clock measures attention and concentration over time. The most common issue is that athletes respond too slowly. When an athlete is too slow, they miss the target and then accidentally respond to the next movement instead. This causes accuracy to drop, lapses to increase, and reaction times to become slower.
If an athlete is struggling with the Mackworth Clock, the first thing to check is the Lapse Count. In most cases you will find high lapse counts, lower accuracy, and reaction times around 520-600 ms or higher. This is extremely common, especially when athletes are new to the task. In the majority of cases, the athlete is simply unable to keep pace with the task rather than there being an issue with the software or scoring.
Double Mackworth Clock
The Double Mackworth Clock works exactly the same way as the standard Mackworth Clock. The difference is that it is significantly more demanding because the athlete must monitor two streams at the same time. If an athlete is struggling, check the Lapse Count first, followed by Reaction Time and Accuracy. In most cases you will find high lapse counts, slower reaction times, and reduced accuracy. As with the standard Mackworth Clock, this is usually a sign that the athlete is struggling to keep up with the task demands.
PVSAT and PASAT
The PVSAT and PASAT require athletes to continuously remember and process numbers. The most common issue is that the athlete loses track of the sequence. Once this happens, accuracy drops quickly, multiple mistakes often occur in a row, and the athlete can struggle to recover for the remainder of the task. This does not necessarily mean the athlete is performing poorly. It usually means they lost the sequence and could not get back into rhythm. For these tasks, accuracy is normally the first metric you should review. Even elite athletes can find the higher levels difficult, particularly over longer durations.
PVT and PVT-B
The PVT and PVT-B measure reaction time and vigilance. One of the most important metrics in these tasks is Lapse Count. A lapse is simply a very slow response and is often one of the strongest indicators of mental fatigue. More lapses generally mean the athlete is mentally fatigued, less attentive, less alert, or struggling to maintain concentration. If you see a sudden increase in lapses, it is usually worth looking deeper into the athlete’s data and monitoring trends over time.
What Is a Lapse?
A lapse is a response that is slower than a predefined threshold. Soma uses the following thresholds:
PVT = 500 ms
PVT-B = 355 ms
Mackworth Clock = 650 ms
Any response slower than these values is counted as a lapse.
Why Are Lapses Important?
Lapses are often one of the strongest indicators of mental fatigue. An athlete may still have a reasonable average reaction time while showing a large increase in lapses. This tells us that attention is becoming less stable and less consistent. For this reason, coaches should always review lapse count alongside reaction time and accuracy rather than relying on a single metric. Looking at all three together will usually provide the clearest picture of what is happening.
Why Does Mean Reaction Time Sometimes Show Zero?
Occasionally you may see a mean reaction time of zero. This does not mean the task failed or that there is an issue with the system. It simply means every response was slower than the lapse threshold.
For example:
Every PVT response was slower than 500 ms.
Every PVT-B response was slower than 355 ms.
Because there were no valid reaction times below the cutoff threshold, the system cannot calculate a mean reaction time and therefore returns zero. When this happens, focus on the lapse count rather than the reaction time. The lapse count contains the important information and will tell you far more about what occurred during the session.