The timing rule of fear conditioning contradicts the Hebbian coincidence rule because simultaneous CS–US pairing is less efficient than CS onset preceding the US with co-termination tens of seconds later¶

Claim · All claims
Evidence · 1 study · review r2 · q2
Currency · newest study 2016 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Simultaneous CS–US presentations are less efficient at driving fear learning than protocols in which CS onset precedes the US and the two co-terminate tens of seconds later, contradicting the Hebbian rule given rapid adaptation of LA firing. → Nair 2016

Evidence¶

Nair 2016¶

Nair, S. S., Paré, D. and Vicentic, A. (2016). Biologically based neural circuit modelling for the study of fear learning and extinction. npj Science of Learning. https://doi.org/10.1038/npjscilearn.2016.15

q2 · i? · review · r2

The review states this as an established behavioural finding from the fear conditioning literature, citing single-unit recording studies showing CS-evoked LA firing adapts quickly so that LA firing has almost returned to baseline when the US occurs.

"it is well established that simultaneous CSs and USs are actually less efficient at driving fear learning than when CS onset precedes the US and the two co-terminate tens of seconds later."

Discussion¶

Related Claims¶

• STC associative interactions occur across intervals of hours, extending the temporal contiguity needed for association well beyond the tens of milliseconds typical of Hebbian associativity — a broader claim this one bears on
• Experimental work indicates basolateral amygdala cells activated by appetitive CSs mainly encode behavioural output, not CS identity, challenging amygdalo-centric feedforward accounts — related
• The Hebbian CS–US convergence model of lateral amygdala plasticity is inconsistent with the timing and brevity of LA CS responses — possibly the same claim (merge candidate)