Struct DeltaModulation 

pub struct DeltaModulation {
    pub gain_factor: f64,
    pub target: LayerTarget,
    pub source: DeltaModulationSource,
}

Delta modulation parameters for SSM state injection.

Brain analog: noradrenergic gain control (Aston-Jones & Cohen 2005). Delta (dt) in Mamba’s selective scan controls state update speed:

• Higher delta → state updates more from current input (reactive, focused)
• Lower delta → state preserves more history (inertial, exploratory)

Hidden Attention (ACL 2025) proves: delta modulation = modulating implicit attention’s temporal decay.

Safety bounds (Mamba Modulation, NeurIPS 2025):

• Uniform 2-3× scaling across all layers = catastrophic
• Layer-selective 0.7-1.3× = safe (Lyapunov-stable regime)
• ~25% state norm change at mid-layers = catastrophic forgetting (HiSPA 2026)

Fields

gain_factor: f64

Multiplicative scale factor for delta (dt) parameter.

• 1.0 = no modulation (pass-through).
• > 1.0 = attend more to current input (phasic, focused).
• < 1.0 = preserve more history (tonic, exploratory).

Clamped to [0.5, 2.0] by compute_delta_modulation().

target: LayerTarget

Which layers to target for modulation.

source: DeltaModulationSource

What cognitive signal drove this modulation (for debugging/tracing).

Trait Implementations

impl Clone for DeltaModulation

fn clone(&self) -> DeltaModulation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DeltaModulation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DeltaModulation

fn default() -> Self

No modulation — pure pass-through. Used as fail-open fallback (P5).

impl<'de> Deserialize<'de> for DeltaModulation

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for DeltaModulation

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.