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Differential classical conditioning selectively heightens response gain of neural population activity in human visual cortex


  • This research was supported by National Institute of Mental Health Grants R01 MH084932-02, R01 MH097320, the Ministerio de Ciencia e Innovación Grant I + D + i PSI2009-07066 awarded to A.K. and an American Psychological Association Dissertation Award by Science Directorate to I.S.


Neutral cues, after being reliably paired with noxious events, prompt defensive engagement and amplified sensory responses. To examine the neurophysiology underlying these adaptive changes, we quantified the contrast-response function of visual cortical population activity during differential aversive conditioning. Steady-state visual evoked potentials (ssVEPs) were recorded while participants discriminated the orientation of rapidly flickering grating stimuli. During each trial, luminance contrast of the gratings was slowly increased and then decreased. Right-tilted gratings (CS+) were paired with loud white noise but left-tilted gratings (CS−) were not. The contrast-following waveform envelope of ssVEPs showed selective amplification of the CS+ only during the high-contrast stage of the viewing epoch. Findings support the notion that motivational relevance, learned in a time frame of minutes, affects vision through a response gain mechanism.