. (2015). Handedness and behavioural inhibition system/behavioural activation system (BIS/BAS) scores: A replication and extension of Wright, Hardie, and Wilson (2009). Laterality, 20(5), pp. 585-603. doi: 10.1080Laterality, 20(5), pp. 585-603. doi: 10. /1357650X.2015 This is the accepted version of the paper.This version of the publication may differ from the final published version. Handedness has been of interest to neuropsychologists for over a century, largely because of its association with asymmetry of hemispheric function (Beaton, 2003; Ocklenburg, Best, Arning, Peterburs & Güntürkün, 2014). In many, probably most, cognitive and behavioural studies lefthanders are excluded with the intention of minimising heterogeneity with respect to the cerebral representation of function or behaviour. Recently, however, a strong plea has been made to include left-handers in these studies as they "represent a substantial portion of the human population and therefore left-handedness falls within the normal range of human diversity" (Willems, Van der Haegen, Fisher & Francks, 2014). If this plea is heeded, then in studies involving left-handers it will be necessary to understand how, if at all, they differ from right-handers (see also Hancock & Bever, 2013). Permanent repository linkPutative cognitive differences between left-and right-handers have long been of interest (see Beaton, 1985;Willems et al., 2014) but differences related to other aspects of behaviour, such as alcohol consumption (Bakan, 1973;London, 1987;1990 but see Denny, 2011, smoking (Harburg, Feldstein & Papsdorf, 1978), sleep duration (Hicks, Pellegrini & Hawkins, 1979) and dream frequency (Schredl, Beaton, Henley-Einion & Blagrove, 2013;2014) have also been reported. Coren (1994) considered that left-and right-handers differ in temperament and personality. One aspect of personality/behaviour that has received considerable attention is anxiety.On the basis of a questionnaire administered to a group of 14-17 year old girls attending a classifying centre at what was then called an "approved" school (i.e. for adolescents with emotional and behavioural difficulties), Orme (1970) found that a greater proportion of 23 left-handers (defined by writing hand) showed high levels of emotional instability as compared with 277 right-handers. This study was criticised by Hicks & Pellegrini (1978) Dillon (1989) reported a significant correlation among 34 male but not 44 female college students between scores on a questionnaire assessing students' worries and scores on a General Laterality Scale. Using the Edinburgh Handedness Inventory (EHI), Merkelbach, de Ruiter and Olff (1989) compared the handedness of 77 anxiety disorder patients with handedness in a healthy control 6 group and found no evidence of a relationship between left-handedness and clinically diagnosed anxiety.In a recent study Lyle, Chapman and Hatton (2013) Previously they had found (Wright, Hardie & Wilson, 2009) that left-handers reported themselves to have higher BIS scores than right-hande...

Frontal EEG asymmetry has been investigated as a physiological metric of approach motivation, with higher left frontal activity (LFA) suggested to reflect approach motivation. However, correlations between LFA and traditional metrics of approach motivation (e.g., scores from the behavioral inhibition system/behavioral approach system [BIS/BAS] survey) are inconsistent. It is also not clear how LFA correlates to approach motivation on an observable, behavioral level. Here, we tested correlations between BIS/BAS scores, LFA, and performance in the Effort Expenditure for Rewards Task (EEfRT). In our sample (n = 49), BIS/BAS results did not correlate to LFA values (resting or task states), and were also unrelated to EEfRT performance variables. We found evidence of significant and distinct correlations between LFA and EEfRT performance. Resting-state LFA positively correlated to effort expenditure on lower utility trials, where reward size and/or probability were suboptimal. Task-onset LFA captured in the first 5 min of the task was related to overall behavioral performance in the EEfRT. High task-onset LFA correlated to high trial completion rates, high-effort trial selection percentages, and overall monetary earnings. One interpretation of these initial findings is that resting-state LFA reflects approach tendencies to expend effort, but that this extends to suboptimal situations, whereas task-state LFA better reflects effortful approach toward high-utility goals. Given the relatively small sample size and the risk of Type I/II errors, we present the study as exploratory and the results as preliminary. However, the findings highlight interesting initial links between LFA and EEfRT performance. The need for larger replication studies is discussed.