Evolving Concepts of Emotion and Motivation

Abstract

This review takes a historical perspective on concepts in the psychology of motivation and emotion, and surveys recent developments, debates and applications. Old debates over emotion have recently risen again. For example, are emotions necessarily subjective feelings? Do animals have emotions? I review evidence that emotions exist as core psychological processes, which have objectively detectable features, and which can occur either with subjective feelings or without them. Evidence is offered also that studies of emotion in animals can give new insights into human emotions. Beyond emotion, motivation concepts have changed over decades too, and debates still continue. Motivation was once thought in terms of aversive drives, and reward was thought of in terms of drive reduction. Motivation-as-drive concepts were largely replaced by motivation-as-incentive concepts, yet aversive drive concepts still occasionally surface in reward neuroscience today. Among incentive concepts, incentive salience is a core motivation process, mediated by brain mesocorticolimbic systems (dopamine-related systems) and sometimes called 'wanting' (in quotation marks), to distinguish it from cognitive forms of desire (wanting without quotation marks). Incentive salience as 'wanting' is separable also from pleasure 'liking' for the same reward, which has important implications for several human clinical disorders. Ordinarily, incentive salience adds motivational urgency to cognitive desires, but 'wanting' and cognitive desires can dissociate in some conditions. Excessive incentive salience can cause addictions, in which excessive 'wanting' can diverge from cognitive desires. Conversely, lack of incentive salience may cause motivational forms of anhedonia in depression or schizophrenia, whereas a negatively-valenced form of 'fearful salience' may contribute to paranoia. Finally, negative 'fear' and 'disgust' have both partial overlap but also important neural differences.

Keywords: addiction; disgust; emotion; fear; history of psychology; psychological method; psychological science; reward.

FIGURE 1

Brain systems of ‘wanting’ versus ‘liking’. Robust and large mesocorticolimbic circuitry can generate intense ‘wanting’ (green), including both mesolimbic dopamine projections and many of its target structures. By comparison, ‘liking’ is mediated by a smaller and relatively fragile set of ‘hedonic hotspots,’ which are distributed across the brain but act as an integrated network.

FIGURE 2

Synergy of cues and internal state in generating intense ‘wanting.’ A Pavlovian cue lever for disgusting Dead Sea saltiness becomes negatively repulsive during learning (left). But in a novel salt-appetite state, the cue becomes immediately ‘wanted’ and attractive, by activating mesocorticolimbic circuitry for incentive salience (Robinson and Berridge, 2013). In Pavlovian-Instrumental transfer (PIT; right), a Pavlovian reward CS+ cue (sound) elicits small peaks of ‘wanting’ during extinction test (bottom). An amphetamine microinjection that releases dopamine in nucleus accumbens selectively magnifies only the CS triggered peaks of cue-triggered ‘wanting,’ without raising baseline effort based on act-outcome expectations or the effect of an irrelevant CS- control sound (Pecina and Berridge, 2013).

FIGURE 3

Motivational salience: positive ‘wanting’ versus negative ‘fear.’ The nucleus accumbens can generate either incentive salience or fearful salience. Microinjections of the same glutamate-blocking drug (DNQX) elicit opposite motivations at different sites. Both incentive motivation and fearful motivation require local mesolimbic dopamine. Many individual sites can be flipped back and forth between generating ‘wanting’ and ‘fear’ by changes in environmental ambience, as described in text. Based on Reynolds and Berridge (2008) and Richard and Berridge (2011).