Mechanism

The confidence computation subsystem of the semantic agent accepts biological signal inputs derived from the physiological state of a human user interacting with the agent. The signals are not consumed as authoritative outputs in themselves. They are processed into structured state assessments that enter the agent's confidence evaluation function as environmental inputs, modulating the agent's confidence in continuing its current interaction mode. Confidence is the agent's continuously computed assessment of its sufficiency to keep executing, and the biological pathway lets the user's assessed physiological state participate in that assessment alongside the agent's other state inputs.

The biological signals contemplated include heart rate variability, galvanic skin response, facial expression analysis, vocal prosody analysis, keystroke dynamics, gaze tracking patterns, and postural tension indicators. A biological signal interface module receives the raw physiological data, a signal processing module converts that data into normalized feature representations, and a state assessment module produces structured assessments comprising the user's stress level, fatigue level, emotional engagement, and cognitive load. Those structured assessments, not the raw signals, are what the confidence computation module integrates.

Coupling User Stress to Confidence

When the biological signal interface detects elevated user stress, indicated by increased heart rate variability, elevated galvanic skin response, or tense vocal prosody, the agent's confidence in continuing the current interaction mode decreases. The disclosure grounds this reduction in a concrete risk rationale: an agent interacting with a stressed user faces an elevated risk of producing adverse outcomes, because the user may be less receptive to the agent's output, more likely to misinterpret the agent's actions, or more likely to experience negative consequences from an interaction that proceeds at normal pace under abnormal emotional conditions.

Because confidence is the variable the confidence governor gates execution against, a stress-driven confidence reduction feeds the same authorization machinery that governs the agent's other adverse inputs. The biological signal does not act as an independent veto or alarm; it lowers a graded confidence value that the governor then evaluates against the agent's execution authorization threshold.

Coupling User Fatigue to Confidence

When the biological signal interface detects elevated user fatigue, indicated by decreased keystroke velocity, increased error rates, reduced gaze fixation stability, or vocal monotony, the agent's confidence in the user's ability to meaningfully engage with the agent's output decreases. This confidence reduction may trigger a transition to a reduced-intensity interaction mode in which the agent simplifies its output, reduces the frequency of decision requests directed to the user, and defers complex or consequential actions until the user's fatigue indicators improve.

The fatigue pathway therefore changes how the agent acts rather than only whether it acts. The agent remains engaged with the user but adapts the form and pace of the interaction to the user's assessed capacity, deferring the actions whose cost of misunderstanding is highest until the fatigue indicators recover.

Coupling User Disengagement to Confidence

When the biological signal interface detects user disengagement, indicated by gaze aversion, prolonged inactivity, reduced response latency variance suggesting automatic rather than considered responses, or postural relaxation consistent with attention withdrawal, the agent's confidence in the user's continued attention to the interaction decreases. In response the agent may pause its current operation, issue a re-engagement prompt, or transition to a holding pattern that preserves state until the user re-engages.

The holding pattern preserves the interaction's accumulated state rather than discarding it, so that when the user's attention returns the agent can resume from where it paused. Disengagement, like stress and fatigue, is read as a reason to lower confidence in proceeding at normal intensity, not as a terminal failure of the task.

Privacy-Preserving Constraints

The biological signal coupling is subject to privacy-preserving constraints. Raw biological data is not stored in the agent's memory or lineage. Only the structured state assessments, the stress level, fatigue level, and engagement level, are recorded, and these assessments are recorded at a temporal granularity that prevents reconstruction of the underlying physiological signals.

The biological signal interface operates as a one-way transducer: physiological data flows in, structured assessments flow out, and no reverse channel exists through which the agent can request or compel additional physiological data from the user. This one-way property is structural to the interface, which means the agent's ability to influence its own confidence through this pathway is limited to consuming the assessments produced for it, not to soliciting more physiological data.

Signal Flow

The pathway from physiology to confidence is staged. The biological signal interface receives raw physiological data from the human user. A signal processing module converts that raw data into normalized feature representations. A state assessment module then produces the structured state assessments comprising stress level, fatigue level, emotional engagement, and cognitive load indicators. Those assessments are delivered to the confidence computation module, where they are integrated as environmental inputs to the confidence evaluation function and modulate the agent's confidence value based on the user's assessed physiological state.

Each stage performs a defined narrowing: raw signals become features, features become a small set of named state assessments, and those assessments become a contribution to a single computed confidence value. The staging is what lets the privacy constraint hold, since by the time a value reaches memory or lineage it is already an assessment rather than a physiological trace.

Composition With the Confidence Governor

The biological pathway is one source of environmental input among several. Confidence is computed from the agent's own state inputs, including capability sufficiency, resource availability, internal integrity state, affective modulation state, and experiential memory, together with task state inputs, and the user-state assessments enter as additional environmental inputs to that same evaluation function. The confidence value the function produces is then gated by the confidence governor, which authorizes or suspends execution according to whether confidence remains above the authorization threshold.

Because the coupling expresses itself entirely through the confidence value, it inherits the governor's existing behavior rather than introducing a parallel control path. A reduction driven by user stress, fatigue, or disengagement is treated by the governor in the same way as a reduction driven by resource scarcity or a capability gap, and every change to the confidence field is recorded in the agent's lineage, so the contribution of the user's assessed physiological state to any execution decision remains auditable after the fact.

Disclosure Scope

The biological signal coupling described here, comprising the biological signal interface, signal processing, and state assessment stages that convert physiological data into structured assessments of user stress, fatigue, emotional engagement, and cognitive load, the integration of those assessments as environmental inputs to the confidence evaluation function, the reduced-intensity interaction mode and holding-pattern responses, and the privacy-preserving one-way transducer that records only assessments and not raw signals, is disclosed in the cognition filing (U.S. Application No. 19/647,395 and its international counterpart). This article describes that disclosed mechanism.

The scope extends to the enumerated and unenumerated biological modalities, including heart rate variability, galvanic skin response, facial expression analysis, vocal prosody, keystroke dynamics, gaze tracking, and postural tension, provided they are reduced to structured state assessments before entering the confidence computation. It does not extend to configurations that consume raw physiological signals as authoritative outputs, that store raw biological data in memory or lineage, or that provide a reverse channel through which the agent can compel additional physiological data from the user, all of which the disclosed mechanism structurally excludes.