What FCE Measures

FCE measures short-task functional execution. It records how a person responds under time, control, attention, and accuracy demands.

“FCE measures execution signals, not identity, diagnosis, or cause.”
Response speed Inhibitory control Divided attention Motor precision Consistency
Open instrument

The measured domain

FCE does not attempt to measure a person in general. It measures a narrower domain:

  • how quickly they initiate responses
  • how reliably they inhibit responses when required
  • how stable execution remains when attention is split
  • how accurately they perform repeated motor actions
  • how consistent their performance is across repeated trials

What counts as a signal

FCE records observable performance signals such as:

  • reaction time
  • misses
  • false alarms
  • false starts
  • variability across trials
  • accuracy and normalized error

These are execution signals. They are not diagnoses or conclusions by themselves.

Primary measurement domains

  • Response speed — how quickly a valid response is initiated after a signal appears
  • Response control — whether a response is made only when it should be made
  • Inhibitory control — whether action can be withheld on non-response trials
  • Divided attention stability — whether performance holds when a second demand is added
  • Motor accuracy — how close repeated actions are to the intended target
  • Consistency — how stable performance remains across trials, not just how good the average looks

Why consistency matters

Average performance is only part of the picture.

Two sessions can have similar average speed but very different consistency. One may be stable and repeatable. Another may be uneven, noisy, or error-prone.

This is why FCE looks at both level and variability.

What FCE does not measure here

  • general intelligence
  • knowledge
  • personality
  • motivation in any broad psychological sense
  • medical diagnosis
  • biological cause

FCE is narrower than that. It measures short-task execution under defined conditions.

How the four tasks map to the measured domain

  • Reaction Time → response speed and consistency
  • Go / No-Go → response control and inhibition
  • Divided Attention → response control under dual demand
  • Precision → motor accuracy and motor consistency

Interpretive boundary

Even when FCE measures these domains clearly, the result is still a structured signal, not a full explanation.

For limits and non-goals, continue to Scope & Limits.

FCE measures execution signals under controlled conditions. The relationship between these signals and real-world performance outcomes is not yet formally validated and should not be assumed.