Bipolar disorder is characterized by mood alterations that include manic or hypomanic, depressive and mixed episodes, intermingled with intervals of euthymic remission (DSM-5, 2014). Patients show significant attentional deficits (Cullen et al., 2016; Palazzo et al., 2017), even after controlling for mild residual symptomatology (Clark et al., 2002) and pharmacological treatment (Thompson et al., 2005; Goswami et al., 2009). In tasks in which participants have to monitor a continuous stream of stimuli to detect a pre-specified target, euthymic patients show a decrease in target sensitivity and slowed response latencies (Bora et al., 2005; Clark et al., 2002; Sepede et al., 2012). The primary aim of the present study is to investigate the Attentional Boost Effect (ABE) in a sample of euthymic patients. Considering that the ABE represents a trade-off between attentional competition and attentional facilitation (Mulligan et al., 2014; Prull, 2019; Swallow & Jiang, 2010, 2013), we expect euthymic patients to exhibit a reduced advantage for images encoded with target stimuli. Swallow and Jiang (2010) showed that, when the attentional requests needed to detect the targets were slightly increased, the negative effects of attentional competition exceeded the positive effects of attentional facilitation, thus resulting in the elimination of the ABE. If the maintenance of a fast and accurate performance in the target detection task requires more attention resources in euthymic patients than in healthy controls (as suggested by previous studies: eg. Bora et al., 2005; Sepede et al., 2012), then the ABE should be reduced or eliminated in the patient group. Moreover, to investigate whether the effect is modulated by participants' age, we will divide both the patients¿ and the healthy controls' samples into two sub-groups: the young group (participants between 18 and 35 years) and the adult group (participants between 36 and 60 years).
The present study will provide a significant contribution to a better understanding of the Attentional Boost Effect phenomenon, particularly as regard memory, attention and age dependency. The study will also pave the road to further research to investigate the neural mechanisms underlying ABE both in healthy people and patients affected by Bipolar Disorder. The involvement of patients with a diagnosis of Bipolar Disorder is a crucial feature of the study both from the point of view of basic knowledge and in a therapeutic perspective. Considering that patients with a Bipolar Disorder diagnosis might experience social and cognitive functions difficulties, it appears important to understand the existence of ABE in these patients and thus to envisage the possibility to positively modulate patients¿ cognitive and attentional abilities.