The Behavioural Activation System Essay Example

system and its neocortical projection in the frontal lobe and is sensitive to signals of punishment (Carver and White, 1994). Sensitivity of both systems has traditionally been measured using self-report questionnaires. A person can be understood to be ‘high’ or ‘low’ in strength of either system and these differences are understood to function with the same consistency as traits of personality (Pickering and Smillie, 2008).

An individual, based on the subjective strengths of these two systems, can thus be described in the same way other theories would have classified them as being high or low in extroversion. Across all individuals, different combinations of BIS and BAS strength exist, creating rich variation within the population. The BAS has traditionally been understood to regulate positive affect. However, more recent research has begun to challenge this conceptualisation and suggest that the BAS is not solely, or even predominantly, a mediator of positive affect.

Research has demonstrated BAS strength to be predictive of aggressive emotional experiences, a finding at striking odds with traditional conceptions of the BAS (Harmon-Jones, 2003). The BAS’s more contemporary conceptualisation is as a facilitator of behaviour. Individuals identified as high in trait BAS are considered as being more likely to experience approach motivation, regardless of affective experience (Carver and White, 1994; Sutton and Richard, 1997).Elliot and Thrash (2002) demonstrated levels of BAS to be consistent with high or low achievement motivation towards goals. They posited that this indicates a motivational, and not affective, model of the BAS. The present research looked to demonstrate support for this model of the BAS as an approach mediator by measuring approach motivation within high and low BAS individuals.

Carver and White

(1994) suggested that individuals measured as being high in BAS by their BIS/BAS Scale would be predisposed to high motivation toward goal-directed tasks.This suggests that individuals who are high in BAS will score more highly on a measure of approach motivation to an upcoming task, providing support for the BAS as a motivational system. Examination of the BAS has extended beyond measuring the effect of variations in strength and the effect this has on behaviour. Along with creating a more specific understanding of its role in emotive or approach motivation, locating the BAS within the brain has become a focal point of reserach.Traditionally, an emotive model of hemispheric lateralisation has dominated the literature. Positive affect has generally been understood to be controlled by the left hemisphere and negative affect by the right hemisphere (Schutter, de Weijer, Meuwese, Morgan, and van Honk, 2008; Richard, 1992).

However much like the BAS, more recent research has begun to re-examine hemispheric specificity to be more strongly associated with motivational direction than with positive or negative affect.The motivational direction model of frontal asymmetry suggests that differences between the hemispheres are not specific to affective valence, but are responsible for controlling motivation, as distinct from emotion (Petersen, Shackman, and Harmon-Jones, 2008; Harmon-Jones and Allen, 1998). It is this model which the present research sought to explore. Electroencephalogram (EEG) research has demonstrated greater bilateral frontal cortical activity to be associated with higher scores of BAS sensitivity (Hewig, Hagemann, Seifert, Naumann, and Bartussek, 2006).EEG research has also revealed individuals rated high in BAS to have higher levels of left hemisphere resting alpha activity (Harmon-Jones, 1997). Harmon-Jones (2006) looked to extend understanding of motivational

lateralisation using a hand-contraction task where participants were asked to squeeze a ball in either their left or right hand to direct activation to the contralateral hemisphere.

After the hand-contraction exercise, a measure of approach motivation was taken using self-report measures.Participants who had directed activation towards the left hemisphere were demonstrated to experience higher levels of motivation. This suggests the left hemisphere controls motivation, and that when it is active, individuals are more likely to produce higher scores on approach motivation measures. To examine both the lateralisation of motivational processes and the BAS as a key player in this process, the present research examined BAS levels among participants, and attempted to manipulate cortical activity before measuring approach motivation. Approach motivation has many conceptualisations.

However, previous research does not dictate that any specific concept would not be affected by the independent variables of this methodology. Therefore, a questionnaire was used which measures two concepts of motivation (intrinsic and success) in an attempt to gain as complete a picture as possible of any affects of the independent variables. For the first independent variable, a measure of BAS was taken, and high BAS individuals were hypothesized to demonstrate higher scores of approach motivation generally, as would be consistent with previous research (Elliot and Thrash, 2002).Additionally, the present research looked to manipulate cortical activity by using Harmon-Jones’ (2006) hand-contraction task to direct hemispheric activation as a second independent variable.

This was followed immediately by administration of the measure(s) of approach motivation. Participants were hypothesized to produce higher scores on the measure of approach motivation after squeezing with their right hand than with their left, indicating they felt more motivated towards

an upcoming task.This would be consistent with previous research which demonstrated asymmetry to predict motivational direction (Sutton and Davidson, 1997). Finally, an interaction between these two factors was hypothesized.

Preliminary findings have demonstrated an association between stable differences in asymmetrical activation and individual differences in natural levels of approach motivation (Richard, 1992). This led to the hypothesis that an effect of natural level of BAS sensitivity and activation of the left hemisphere would be demonstrated on scores of intrinsic and success motivation.