Indexed on: 20 Feb '09Published on: 20 Feb '09Published in: Psychophysiology
Prepulse inhibition of startle (PPI) represents an automatic mechanism that reflects sensorimotor gating and early attention processes. PPI neither is the consequence of conscious behavioral modulation nor does it depend on learning and conditioning. However, pairing of weak tones and aversive startle stimuli during PPI testing may induce associative learning. Thus, in the present study (n=60) we tested whether prepulses may be subject to aversive conditioning. Eyeblink EMG and electrodermal responses to intense (100 dB) acoustic stimuli, presented either alone or preceded by weak tones (prepulses, 50 ms, 70 dB, SOA=120 ms), were measured. We found that after strong contingent pairing of weak tones with startle stimuli (PPI paradigm) intense versions of these tones induced significantly larger eyeblink and skin conductance responses than did never paired control tones. We conclude that during PPI testing, prepulses may be subject to aversive conditioning.