Emotion refers to a number of mental states that are relatively short-lived and are associated with an eliciting event. There are four key features of emotions:

1. Emotions are bounded episodes elicited when an event occurs that is of relevance to the organism’s needs, goals or well-being.
2. Emotions prepare the organism to act so as to deal with an event.
3. Emotions affect most or all bodily systems.
4. Emotions establish control precedence over behaviour.

Emotions provide us with essential feedback on the execution of our plans relative to our goals. Emotions have not been studied a lot, because it was first seen as irrational and it is difficult to study. The amygdala (fear), the orbitofrontal cortex (anger) and the cingulate cortex (sadness) are involved in emotions. The insula has been linked to disgust. The default network is a network of brain regions that is active when the person is not focused on the external environment. The salience network is involved in monitoring the external and internal environment to allow detection of salient stimuli.

Emotions are to some extent culture-dependent. Display rules are social conventions governing how, when and with whom emotions may be expressed in society. There are core emotions that are universal. The core emotions are anger, disgust, fear, happiness and sadness. Emotional leakage refers to the unintended expression of emotion or a failure to mask emotion. Masked emotions are associated with more inconsistent expressions and an increased blink rate. The emotional responses someone has when depressed is culturally determined, as being depressed also means not being able to regulate the emotional expression in line with the cultural norms.

Clore and Ortony propose that human emotions are characterized by four components:

1. Cognitive
   Mentally register the significance of the emotion. Appraisal refers to the ways in which people interpret or explain to themselves the meaning of events.
2. Motivational-behavioural
   Our actions in response to the emotion.
3. Somatic
   This involves the autonomic nervous system, which regulates internal organs and the central nervous system, which consists of the brain and the spinal cord. The characteristic of the somatic part of emotion is the physiological responses that occur along with emotion.
4. Subjective-experiential
   This involves the personal experience of the emotion.

There are several theories on the relationship between emotion and cognition. There are two early theories of emotion and cognition:

1. James-Lange theory
   This theory holds that the experience of emotion follows the physiological changes associated with that state. An emotion arises from bodily feedback. Emotion is the perception of bodily changes. The facial feedback hypothesis proposes that feedback from the facial muscles can influence emotional state.
2. Cannon-Bard theory
   This theory holds that the emotional experience and the physiological changes arise concurrently from the stimulus events. The two events are independent.

The catharsis myth is the mistaken idea that aggressive behaviour is an effective means of reducing aggressive feelings. There are also other theories of emotions, based on the James-Lange and the Cannon-Bard theories:

1. Two-factor theory
   This theory holds that two factors create emotion. Physiological arousal and our interpretation of it (e.g: if we see a bear we have the physiological arousal of fear, but our interpretation of the situation causes us to feel the emotion fear). This theory states that physical arousal is necessary in order to feel an emotion.
2. Affective-primacy: Zajonc’s theory
   This theory holds that cognition is not necessary for emotion. Cognition can influence emotion at a later stage of processing, the initial emotional response can be unaffected by cognition. The mere exposure effect refers to the tendency for people to develop a preference for a stimulus with repeated exposure to it. This effect shows that people can develop a preference (some sort of emotional response) without cognition. This theory refers to cognition as conscious cognition.
3. Cognitive primacy: Lazarus’s theory
   This is an appraisal theory, a theory that states that emotions result from our interpretations of, or reactions to, events. This theory holds that cognitive appraisal is fundamental to emotional experience and that you cannot separate out the cognitive aspect of the emotion. He suggested three types of cognitive appraisal: the primary appraisal is an initial assessment of a situation, the secondary appraisal involves an assessment of the resources we have available to us in dealing with the particular situation and reappraisal involves continual monitoring the situation until it’s resolved.

The multi-level theories of emotion propose that both preattentive and conscious cognitive processes are involved in emotion. This states that sometimes we feel an emotion before cognition and sometimes we feel emotion after cognition.

Emotions have an effect on cognition. Attentional bias refers to the tendency for emotional stimuli to capture or draw attention. Emotional content is likely to draw the attention of an individual. This has been demonstrated in the emotional Stroop task. The visual search tasks require an active search of a visual array, usually for a particular object or stimulus feature. Pre-attentive visual search is faster for emotional information compared to neutral information.

Presence of an emotional stimulus heightens contrast sensitivity in perception. Emotion also increases an individual’s field of view. Emotion has an influence on perception.

Memory for emotional events is generally better than for events that do not arouse emotions, but these memories are not error-free. Extreme emotions can have a negative effect on cognition. There is a confidence-accuracy disparity. Confidence is not a useful predictor for the accuracy of a memory. The most common error in memory recall is source error. People tend to misattribute the source of information. The best predictor of later recall accuracy was the strength of the emotional response of the person at the time of the event. Self-monitoring describes the extent to which a person is concerned with self-presentation and how others perceive them. The idea of encoding specificity refers to the idea that memory is facilitated when there is overlap between the conditions at encoding and those at retrieval. Tunnel memory refers to the enhancement of memory of central details with reduced memory for peripheral details. This effect mostly applies to negative events.

Mood congruency refers to the tendency to recall events consistent with the current mood state. This effect is often explained in terms of network models. Network models of memory treat memories as items related in a network which can affect each other through activation. State-dependent memory refers to the facilitation of memory when the mental or physiological state at encoding and retrieval matches. Emotion-congruent memory is stronger for positive emotions than for negative emotions. This does not fit with a network model. Thought congruity is the tendency for thoughts and judgements to be consistent with mood state.