Emotion is defined as the condition of physiological arousal as well as the cognition suitable to the state of arousal (Schachter and Singer, 1992), whereas cognition refers to both conscious and unconscious mental processes which includes memory, perception, attention, problem solving and so on. Research and theory on emotion and cognition in psychology, psychotherapy and psychopathology are examined to illustrate the usefulness of emotion in human functioning and the role cognitive processes plays in the symptoms and maintenance of affective disorders (Rapaport, 1971).

Cognitive Psychologists tends to carry out research on emotion and cognition by ethically manipulating participant’s emotional states. This is done by using various techniques including the use of films or music to alter participant’s moods. Other techniques involves using naturally occurring states or asking participants to recall past traumatic or stressful events that has happened to them. Emotion and cognition are unavoidably linked in such a way that cognition works to maintain affective goals, while emotion works as a response to cognition (Greenberg, 2008). Hence, this article will be exploring the effects of emotion on cognition in regards to attention and memory.

Studies has shown that negative emotion causes narrowing of attention (Kesinger et al, 2005). Researchers have also used the study of affective disorders such as anxiety to investigate the way in which emotions influences cognitions (Mineka & Sutton, 1992 as cited by Kulas, Conger & Smolin, 2003). Anxiety is a motivational as well as an apathetic state which occurs during threatening situations and it is very useful within cognitive psychology (in the field of cognition and performance) because it is usually linked with adverse effects on cognitive tasks and performance (Eysenck, 2007). According to attentional control theory (Eysenck et al, 2007) anxiety increases the designation of attention to stimulus which are threat related, which implies that anxiety minimizes attentional focus on current task unless it has to do with stimulus which are threatening. Hence, anxious individuals selectively allocate their attentional resources to stimulus which are threat related whether external or internal (Eysenck, 2007). It has been further assumed that anxiety also hinders attentional control even in the absence of threat-related or task-irrelevant stimuli. When individuals perceive they are under threat and experiences anxiety, it then becomes harmful to retain a high attentional control, rather the best strategy becomes to re-direct attentional resources, thereby minimizing attentional control in regards to any ongoing task (Eysenck et al, 2007).

Previous research conducted to investigate how cognition is influenced by emotions was done using emotional Stroop task. Klein (1964) evidence showed that non-colour words can produce notable interference in a colour naming task, he proposed that the interference was as a result of an increase in attention to specific words (Kulas, Conger & Smolin, 2003). Other researchers such as foa et al (1991) have revised the original Stroop task by altering the coloured words and changing it to emotionally charged words which are relevant to the participants (rape victims), and they found out that participants showed a prolonged response time interval for colour naming of words related to rape than other word types. Words related to anxiety have emotional meaning, therefore attention is directed to those words leading to attentional bias’’ which interferes with the colour naming task. Vrena et al (1995) made use of modified Stroop task in addition to recognition and free recall task. They assumed that if threat-related words were being avoided, then participants should therefore have a poorer recognition and recall of emotional words. Instead, participants were better at recalling threat words compared to neutral words, which shows increased attention to words which are anxiety-relevant rather than avoidance. However, Calvo and Avero (2005) studies on effects of trait anxiety on attention to threat-related pictures discovered that 58% of the studies found attentional bias linked with high anxiety whereas the remaining 42% was non-significant. The main point that needs to be emphasized about this statement is that there is more suitable evidence for an attentional bias in attention at an early stage than a later stage of attentional allocation (Calvo and Avero, 2005).

Negative emotion also affects memory for peripheral information and this can be as a result of neglect. If attention is aimed towards emotional stimulus, non-emotional information will not receive as much focused attention and hence the likely hood of being encoded will be reduced (Compton, 2003). Even if encoding takes place, neutral information might not be deeply processed or rehearsed thereby making long-term memory storage less likely to take place (Finkenaur et al, 1998 as cited by Levine et al, 2009). At retrieval people are more likely to focus on information they consider to be of more importance to their well-being, which leads to the provision of retrieval cues for information which are emotional. There are reduced retrieval cues accessible for neutral information to the level that memory and attention processes are of limited capacity, then processing is dominated by emotional information which leaves less resources for peripheral details (Levine et al 2009). Baddeley (1972) conducted a study whereby some servicemen were placed on a flight and they were made to believe an emergency has taken place, and findings from this study showed that emergency hinders the ability to remember and recall detailed instructions (Christianson, 1992).

Positive stimuli can also hinder memory and this has been investigated in a study where researchers assessed people’s memory for both peripheral and central information in negative and positive neutral anime film. For neutral film, people expressed enhanced memory for comical and erotic events but showed limited memory for peripheral details in positive film (Moyer 2002 as cited by Reisberg & Heuer, 2004). Easterbrook’s (1959) cue utilization hypothesis has shown that increased level of emotional arousal causes narrowing of attention. Details which are temporally and spatially linked with emotional item are given more attention and remembered later, whereas information that is not of major relevance to that item has a higher possibility of been forgotten ( Easterbrook, 1959 as cited Kensinger, Garoff-Eaton & Schacter, 2007). Individuals are more likely to exhibit a poor recognition of information in the periphery especially if an item which is emotional was included in the scene than if items present were only non-emotional (Kensinger et al, 2005). Similar effect is believed to be the basis of weapon-focus ‘’ effect, as individuals who witnessed a crime is most likely to remember the perpetrator’s weapon rather than the vehicle, face or clothing of the perpetrator (Loftus et al, 1987) as the witness’s’ attention is more focused on the weapon at the crime scene.

According to eyewitness testimony literature, it is often assumed that emotional stress hinders memory and hence, the negative emotional events are less likely to be remembered accurately than neutral events. Memory impairment can be caused by stress. With regards to acute stress, varieties of elicitors such as trauma, public speaking and so on has been proven to impair memory (working memory) and retrieval (Het, Ramlow, & Wolf, 2005). Effects of stress (acute) on memory seems to vary and this depends on the type of memory processes involved (consolidation and encoding versus working memory and retrieval), the amount of stress hormones released, as well as the type of information to be remembered, (Levine et al, 2009). Various forms of emotion regulation such as expressive suppression and distraction can also hinder memory for emotional events. for example people who repress behavioural display of emotion either habitually or by following experimental instructions have been reported to have worse memory for emotional related events than those who do not apply such regulatory strategy (Richards and Gross, 2000). Hence emotion regulation strategy that directs attention away from emotional events hinders memory for such event.
Early attempt to investigate the effect of emotion on memory was illustrated by Sigmund Freud by making use of Psychoanalytical approach in his work (clinical) on his patients (hysterical patients). Freud discovered that people often repress anxiety provoking and unacceptable memories from their consciousness in order to prevent emotional confrontation. According to Freud case studies, the in ability to remember negative emotional experience is as a result of limited accessibility instead of limited availability to the experience. Freud’s idea of repression has successfully generated evidence to support the fact that some relevant details are well preserved for traumatic events. However, Freud Psychoanalytical approach faces some major criticism because it is difficult to test for the reliability of his findings, as Freud’s analysis were obtained from patients whose real life experiences cannot be known precisely, hence it is difficult to know which memory was repressed or not.

In conclusion, emotions play a very important role in human cognition and functioning. Studies have shown that emotion narrows attention which in turn leads to an impairment in memory. Hence, detailed information which are temporally and spatially linked with emotional item are given more attention and remembered later, whereas information that is not of major relevance to that item has a higher possibility of been forgotten.