Effects of Emotions on Selective Attention and Control

Introduction

Emotions consist of multiple components that include subjective feelings, a behavioural reaction, cognitive appraisal and accompanying physiological reactions (Cacioppo et al., 1993). William James (1894) regarded emotions as adaptive behavioural and physiological response tendencies that are called forth directly by evolutionarily significant situations. Carver and Scheier (1990) have viewed emotion as the readout of a system that monitors the rate at which the discrepancy between a goal and reality is being decreased. According to them, positive emotion signals a rate of discrepancy reduction that is faster than expected; negative emotion signals a rate that is slower than expected.

Certain contrasting positions have been taken with respect to the relationship between cognitive processes and emotion. While some claim emotions to be completely independent of cognition (Zajonc, 1980), others posit that cognitive appraisals are invariably necessary for the production of emotion (Lazarus, 1991). Recently the view that cognitive processes are closely related to emotion has been steadily gaining ground (Izard, 1993; Rolls, 1990, 2005). The close interaction of cognition and emotion makes it difficult to dissociate the two sets of processes (Halgren, 1992). Theories of emotion differ regarding whether emotional evaluation of events is considered to be automatic or a conscious process (Damasio, 1994; Ekman, 1992; LeDoux, 1993; Thompson, 1988).

In order to determine a goal for one's action, every type of cognitive operation needs to be involved. According to Rolls (2005) cognitive operations produce emotions at three levels. The first is the implicit level, where an unlearned reinforcer may lead to emotions. The second level is where a (first order) syntactic symbol processing system performs computation to implement planning for the identification of a rewarding or punishing [Page 133]outcome. The third level is the higher order linguistic thought level where thinking about and evaluating the operations of the first order linguistic processor may result in a reinforcing outcome. Another way in which cognition influences emotion is through cognitive states at the level of language that modulate subjective and brain responses to affective stimuli. De Araujo et al. (2005) showed that a word label influences the pleasantness ratings and the activations of the secondary olfactory cortex located in the orbitofrontal cortex (where the reinforcing value of rewards and punishers is initially represented). This type of top-down modulation occurs in a way that is analogous to the top-down attentional effects (Rolls and Deco, 2002). This fits in with arguments for reciprocal links between emotion and attention (Vuilleumier, 2002).

Attentional processes have been characterized in terms of three different functions subserved by different attentional networks (Jackson et al., 1994). The alerting network (involving right fronto-parietal areas) functions to maintain an organism's readiness to react to stimuli by suppressing background neural noise through the inhibition of irrelevant mental activity. The orienting network (involving posterior parietal lobe and thalamus) functions to motorize special neural operations needed to bring attention to the relevant visual location (visual search) and thus bind signals. The executive network (involving anterior cingulate, left lateral frontal lobe and basal ganglia) coordinates multiple specialized neural processes, for example, target detection to direct behaviour. The anterior cingulate helps in target detection by boosting activation of signals for feature selection in the extrastriate regions (Posner and DiGirolamo, 1998). These functions of the attentional system facilitate activities in different brain regions to increase performance. Given the putative interactions between emotion and attention, we first discuss the interaction between emotions and selective attention in the next section. This is followed by a discussion on emotions and executive control.

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