Attentional boost effect: research based on source memory and emotional materials

The attentional boost effect (ABE) refers to the phenomenon that stimuli which appear with targets in a detection task are better remembered than those that appear with distractors. Previous studies have consistently reported a robust ABE in item memory, but inconsistent conclusions have been drawn for source memory. Additionally, regarding the impact of emotional stimuli on the ABE, conclusions have also been inconsistent. The aim of this research was to clarify these inconsistencies. In Experiment 1, participants were asked to memorize different emotional background words (primary task), monitor the symbols above the words, press the spacebar when encountering the “+” (secondary task), and remember the size of the emotional background stimuli (as a source feature). Results revealed that the ABE of negative stimuli was stronger in item memory. For source memory, an ABE was observed only for large fonts. In Experiment 2, participants performed the same task as in Experiment 1, except for recalling the color of emotional stimuli instead of their size. Results indicated a stronger ABE for emotional stimuli in item memory, with no ABE observed in source memory. These findings suggest: (1) Item and source memory are regulated by distinct cognitive processes, leading to differential effects of emotionality on ABE in both types of memory. (2) Contrary to previous literature, emotional stimuli, such as negative words, do not consistently diminish the ABE.