The appetitive motivation scale and other BAS measures in the prediction of Approach and Active Avoidance

Abstract

The Appetitive Motivation Scale (Jackson & Smillie, 2004) is a new trait conceptualisation of Gray’s (1970, 1991) Behavioural Activation System. In this experiment we explore relationships that the Appetitive Motivation Scale and other measures of Gray’s model have with Approach and Active Avoidance responses. Using a sample of 144 undergraduate students, both Appetitive Motivation and Sensitivity to Reward (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire, SPSRQ; Torrubia, Avila, Molto, & Ceseras, 2001), were found to be significant predictors of Approach and Active Avoidance response latency. This confirms previous experimental validations of the SPSRQ (e.g., Avila, 2001) and provides the first experimental evidence for the validity of the Appetitive Motivation scale. Consistent with interactive views of Gray’s model (e.g., Corr, 2001), high SPSRQ Sensitivity to Punishment diminished the relationship between Sensitivity to Reward and our BAS criteria. Measures of BIS did not however interact in this way with the appetitive motivation scale. A surprising result was the failure for any of Carver and White’s (1994) BAS scales to correlate with RST criteria. Implications of these findings and potential future directions are discussed.

Introduction

Gray, 1970, Gray, 1982, Gray, 1991 Reinforcement Sensitivity Theory (RST) is a model of personality with a basis in approach-avoidance motivational processes. The major dimensions of this model are Anxiety and Impulsivity. Anxiety is presumed to have a causal basis in the activity of the Behavioural Inhibition System (BIS; Gray, 1982), although the focus of the present paper is the Behavioural Activation System (BAS; Fowles, 1980), which is Gray’s proposed basis for Impulsivity. Gray (1970) and Gray, Owen, Davis, and Tsaltas (1983) originally suggested that the functioning of the BAS is responsible for motivation by and reactions to conditioned appetitive stimuli (reward). Recent revisions to the theory (Gray & McNaughton, 2000) indicate that the distinction between conditioned and unconditioned stimuli is not as important as originally considered, and as such the BAS mediates responses to all appetitive stimuli. It has therefore been suggested that the BAS may be a particularly important dimension of personality, with broader relevance to individual differences than has previously been supposed (Jackson & Francis, 2004; Jackson & Smillie, 2004).

An often overlooked feature of the BAS concerns the arbitrary nature with which this appetitive system was related to trait impulsivity (Diaz & Pickering, 1993; Pickering & Gray, 2001). Gray’s (1970) model was first proposed as a theory of the neuropsychology of anxiety, couched in aversive motivational processes related to activity of the BIS. At the trait level, Gray represented BIS-mediated anxiety within Eysenck’s (1967) ‘Extraversion–Neuroticism’ personality spaces, at an anticlockwise rotation from Neuroticism. Since anxiety was presumed to reflect aversive motivation, it was supposed that an equivalent rotation of Extraversion might reflect manifestations of appetitive motivation, and at the trait level have some descriptive correspondence to impulsivity (Gray et al., 1983). It is not entirely clear, however, to which kind of impulsivity the BAS is related (e.g., Pickering & Gray, 2001; Quilty & Oakman, 2004). Presently, there is no agreed psychometric representation of Gray’s dimensions (Corr, 2001; Slobodskaya, Knyazev, Safronova, & Wilson, 2003), particularly for dispositional reactivity of the BAS (Pickering, 1997). For instance, Carver and White (1994) produced three possible psychometric conceptualisations of the BAS (Reward Responsiveness, Drive, and Fun-Seeking) on the basis that there was no consensus regarding how the BAS is to be measured. Reward Expectancy, as measured by the Generalised Reward and Punishment Expectancies Scale (GRAPES; Ball & Zuckerman, 1990) provides a cognitive interpretation of RST and conceptualises BAS reactivity as heightened general expectancy of attaining rewards. Conversely, Sensitivity to Reward, as measured by the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ; Torrubia, Avila, Molto, & Caseras, 2001), conceptualises BAS reactivity as the extent to which individuals instinctively approach specific and unrelated appetitive situations.

We have recently suggested that existing representations of dispositional BAS reactivity fail to emphasise the motivational features of this system (Jackson & Smillie, 2004). To address this issue we developed a new measure called the Appetitive Motivation scale, which conceptualises BAS reactivity in terms of motivations by or reactions to appetitive stimuli. Psychometric validation indicated strong convergence with relevant RST measures, and also with broader personality measures, such as the scales of the Eysenck Personality Questionnaire (EPQ). As Pickering (in press) and Depue and Collins (1999) note, the dimension in Eysenck’s system which corresponds most closely to the BAS is Extraversion, and indeed this was the strongest correlate with our Appetitive Motivation Scale. A weaker positive correlation was found with Psychoticism, and a low (negative) to zero correlation was found with Neuroticism. While this suggests that our scale may be a valuable contribution to RST research, with particular respect to clarification of the ‘BAS-related trait’ (Pickering & Gray, 2001), further validation is clearly required. We are of the opinion that, for a measure to genuinely reflect the functioning of the BAS, it must correspond to BAS-mediated behaviour using a suitable experimental paradigm. This is because the general trait to which the BAS has been related (i.e., impulsivity) has many and varied conceptualisations which tend to correlate highly despite having quite different theoretical bases (Miller, Joseph, & Tudway, 2004; Parker & Bagby, 1997; Whiteside & Lynam, 2001). As such, any given impulsivity-type measure may have descriptive similarity to Gray’s conceptualisation of the BAS-related trait, but show little relationship with appetitively motivated behaviour.

Gray, 1987, Gray, 1991 described two major kinds of appetitive behaviour which are mediated by the BAS. The first of these is termed Approach, which concerns behaviour directed towards reward. In a classic animal learning paradigm, a rat trained to run towards a goal-box containing food would comprise an instance of approach behaviour. The second BAS-mediated behaviour is termed Active Avoidance, which involves making an action or response in order to avoid punishment (i.e., to approach relief Fowles, 1987). While it is descriptively useful to distinguish between Approach and Active Avoidance, the two responses are different manifestations of the same underlying process, and the only meaningful difference between them are the contexts within which they are executed (Fowles, 1987; Gray, 1987). As such, indices of Approach and Active Avoidance should have a very similar relationship with a measure of appetitive motivation or BAS. It is this prediction which shall be tested empirically in the present research.

Now, based upon our description of BAS-mediated behaviour, we see that appetitive motivation is not elicited simply by positive stimuli, but more accurately by the presentation of positive stimuli or the omission/termination of negative stimuli. Similarly, and although we do not consider the BIS in great detail here, aversive motivation is not elicited simply by negative stimuli, but more accurately by the presentation of negative stimuli or the omission/termination of positive stimuli. The fact that both positive and negative stimuli have the potential to activate the BAS and the BIS creates difficulty for devising a purely appetitive task. This is because a reward stimulus may elicit Approach, but also have some association with failure to attain the reward; similarly, a relief stimulus may elicit Active Avoidance, but also have some association with failure to successfully avoid punishment. This issue is not unrelated to the role of reward-expectancies, as discussed by Gray (1987) and Corr (2002a). Specifically, a stimulus will be perceived as rewarding only if it matches or exceeds expectancy of reward, otherwise it serves as a punisher. It can be seen, therefore, that even a paradigm designed to exclusively activate the BAS may also potentially engage the BIS.

Simultaneous BAS/BIS activation is a pertinent issue for experimental investigations of RST as it has the potential to cause significant problems with research criteria (see Pickering et al., 1997 and Pickering & Gray, 2001 for discussion). This is because the BAS and BIS have mutual inhibitory outputs, such that BIS activity will directly antagonise functioning of the BAS, and therefore reduce appetitively motivated responses (Gray & Smith, 1969; Pickering, 1997). It is this state of affairs which has led to Corr, 2001, Corr, 2002b formation of a Joint Subsystems Hypothesis of RST. Traditionally, due to the physiological separability of the BAS and BIS, appetitive motivation or reward reactivity has been linked only to the functioning of the BAS, while aversive motivation or punishment reactivity has been linked only to the functioning of the BIS. However, Corr, 2001, Corr, 2002b suggests that, under certain experimental conditions, the mutual inhibitory links between the BIS and BAS result in appetitive motivation being strongest in those with a more active BAS and less active BIS, while aversive motivation will be strongest in those with a less active BAS and more active BIS. From this we can make the prediction that measures of BAS will be strongly related to Approach and Active Avoidance at low levels of BIS, but that this relationship will be diminished at higher levels of BIS.

In the present research we develop an experimental paradigm, based upon response latencies to reward (Approach) and relief (Active Avoidance), in order to continue validation of the Appetitive Motivation scale. It is expected that this measure, along with other well-known measures of the BAS, will predict faster responses to our Approach and Active Avoidance operations. Measures of BIS should not be related to response latency for either of these responses, however, they may antagonise their relationship with BAS scales. Therefore, we anticipate that at higher levels of anxiety the relationship that BAS scales have with active avoidance and approach will be weaker.