Affective priming - is it only affect that primes?

A target word is classified faster as pleasant or unpleasant if preceded by a prime that matches the target word’s valence. This affective priming phenomenon is currently popular as an implicit measure of stimulus valence. The present set of experiments investigated whether rated stimulus arousal will affect target classification as well. In three experiments, word targets were preceded by prime stimuli that differed in rated arousal and valence. The basic priming effect was replicated in all experiments, however, priming was largest after high arousal unpleasant and low arousal pleasant primes, and reduced after low arousal unpleasant and high arousal pleasant primes. This finding emerged for picture and word primes and does not reflect the effect of differences in stimulus complexity. The difference in the effectiveness of the primes was not affected by SOA and seemed to hold across a wide range (50-200 ms for words and 200-500 ms for pictures). The present results suggest that some failures to find affective priming may not reflect on prime valence, but on prime arousal. Moreover, it suggests that increases in stimulus arousal have differential effects for the processing of pleasant and unpleasant stimuli.

Attention vs. emotion: Affective learning and the startle reflex

The eye-blink startle reflex can be modulated by attentional and emotional processes. The reflex is facilitated during stimuli that engage attention. A linear pattern of emotional modulation has also been consistently demonstrated: the reflex is facilitated during unpleasant stimuli and attenuated during pleasant stimuli. However, during anticipation of pleasant or unpleasant stimuli it is unclear whether emotion or attention drives startle reflex modulation. This study used a differential learning procedure to investigate whether startle modulation during anticipation of a salient stimulus reflected emotional or attentional processes. In acquisition, a CS+ was paired with a pleasant or unpleasant US and a CS- was presented alone. In extinction, blink startle magnitude was measured during CS+ and CS-. Post-acquisition valence ratings and affective priming showed that CS+ had acquired the same affective value as the pleasant or unpleasant US with which it was paired. No differences in modulation of blink startle reflexes during pleasant CS+ and unpleasant CS+ were found throughout extinction. Blink startle facilitation occurred during CS+ but not CS- across the first third of extinction. Thus, attentional rather than emotional processes appeared to facilitate blink startle during anticipation of salient stimuli.

The good and the bad: Acquisition of likes and dislikes in affective learning

Affective learning, the acquisition of likes and dislikes, was investigated in two experiments using verbal ratings and affective priming as indices of affective change. In both experiments, neutral geometric shapes were paired with pleasant or unpleasant pictures in a picture-picture conditioning procedure to acquire positive and negative valence. Experiment 1 found the acquisition of positive valence; however, this valence change was lost after extinction training. Experiment 2 used more salient pictures as unconditioned stimuli. Positive and negative valence was acquired during paired presentations and retained across extinction training. The results of Experiment 2 are consistent with dual process accounts, which claim that evaluative conditioning is distinct from Pavlovian conditioning because it is resistant to extinction.