Motivation and emotion/Textbook/Emotion/Mood
Emotion and Mood
Mood and emotion are experienced everyday by every individual. This field is commonly studied in psychology. An understanding of the causes and effects of mood and emotion is important in interpreting how an individual will behave and react.
This chapter will be explored through focus questions. The first looks at the difference between emotion and mood. Followed by whether positive and negative moods are polar opposites. After this different sections of the brain, the anterior cingulate cortex, the amygdala and the hippocampus, will be explored through mood and emotion. This section will also look at the effects of mood and the brain in Alzheimer's disease and schizophrenia. The section on the brain will be followed by what mood and emotion effects. Depressive and manic mood disorders, risk-taking behaviour and prosocial behaviour will also be examined in this section. Then substances that effect mood and emotion, such as alcohol, nicotine, cannabis and MDMA (ecstacy), will be discussed. This chapter will conclude with a look at the PANAS, a measurement of mood.
What is the difference between emotion and mood?
Reeve, 2009, notes three main difference between mood and emotion; cause, action specificity and time. Emotions are caused by significiant life events whereas moods emerge from ill defined, often unknown, causes. Emotions influence behaviours while mood influences cognitions. Finally, emotions are short lived events that last seconds or minutes. On the other hand, moods are mental events that can last hours or days. In short, emotions are less enduring than moods. Moods are also different from personality traits and temperament, as these last even longer than moods.
There are also more classes of emotion than mood. Moods tend to be noted as either positive or negative (Reeve, 2009) whereas Ekman and Davidson's (1994: cited in Reeve, 2009) noted six basic emotions; fear, anger, disgust, sadness, joy or happiness and interest. These six basic emotions can also be noted as either positive or negative. Fear, anger, disgust and sadness are negative emotions and joy/happiness and interest are positve emotions.
Mood also differs from affect. Mood is an overall state of being, normally refered to as either positive or negative. Whereas affect is the experience of emotions. Affect is more commonly seen than moods, normally through facial or vocal expressions or body gestures (Watson, Clark & Tellegan, 1988). Affect is generally seperated into two groups; normal affect, for example positive and negative emotions, and pathological affect (see table below; Watson, Clark & Tellegan, 1988).
|States of Affect|
|Normal Affect||Pathological Affect|
|Positive Emotion||Negative Emotion|
|Joy/ Happiness||Fear||Major Depression|
THINK ABOUT IT
When someone asks 'how are you,' do you refer to your mood or emotion?
Are Positive and Negative Moods Polar Opposites?
The emotional equivalent of a positive mood is most commonly stated as happiness and sadness for a negative mood (Reeve, 2009). This may lead individuals to believe that they are polar opposites. However, these are correlated together and have different psychological correlates (Cook, Spring, McChargue & Hedeker, 2004). For these two mood states to be polar opposites their effects on behaviours would also have to be opposite. It is generally thought that individuals are more creative when in a positive mood, but many famous masterpieces have been created while the artist was in a self-reported negative mood, such as most of Vincint Van Gogh's work (Montgomery, Hodges & Kaufman, 2004). Also, individuals tend to report tasks easier when in a positive mood than a negative mood. For example, smokers find it easier to quit when in a positive mood than a negative mood (Cook, et al, 2004). This is not to say that individuals in a negative mood cannot quit smoking. Examples of how positive and negative moods effect behaviour and how behaviour effects moods will be explored throughtout this chapter.
THINK ABOUT IT
Have you ever been waiting for something that you were both excited and apprehensive about? It could be a date or job interview. If positive and negative moods were opposite, would you be able to experience both at the same time?
What Does Mood and Emotion Do in the Brain?
A lot of the research on mood and emotion in psychology is based around what areas of the brain correlate to mood and/or emotion. The two main areas of the brain that have been correlated with mood and emotion are the anterior cingulate cortex, the amygdala and the hippocampus.
How are the Anterior Cingulate Cortex and Mood and Emotion Linked?
One part of the brain that has been linked to mood and emotion is the anterior cingulate cortex. The anterior cingulate cortex (ACC) is located around the corpus callosum and is the frontal area of the cingulate cortex (see right; Alexopoulous, Gunning-Dixon, Latoussakis, Kanellopoulos & Murphy, 2008; Barrett, Pike & Paus, 2004). The ACC is connected to the limbic structures of the brain (Alexopoulous, et al, 2008) and regulates emotional responses, as well as autonomic and visceral responses (Alexopoulous, et al, 2008; Barrett, Pike & Paus, 2004). This area of the brain has also been linked to response error and, in turn, response error has been linked to mood and cognitive changes in depression (Alexopoulous, et al, 2008). Response error refers to how an individual responds to error. Dysfunction of coginitive division in the ACC can be seen when an individual has an abnormal response to error (Alexpoulous, et al, 2008). Abnormal response to error is found more in individuals with negative affect before the response than those with positive affect before the response (Alexopoulous, et al, 2008). This abnormal response could be a drastic increase in negative affect, including crying or signs of depression (Alexopoulous, et al, 2008). Research has also found the ACC to be involved in normal affect, such as sadness, as well as pathological affect, such as major depression (Barrett, Pike & Paus, 2004). Depression and induced negative affect increase activity in the ACC (Barrett, Pike & Paus, 2004). Therefore, mood and emotion have been linked to activation of the anterior cingulate cortex.
How are the Amygdala and Mood and Emotion Linked?
Another part of the brain that effects mood and emotion is the amygdala. The amygalae are found in the temperal lobes of the brain. Each lobe has one amygdala; a group of nuclei shaped like an almond (Derntl, et al, 2009; Hamann, Ely, Hoffman & Kilts, 2002; Tranel, Gullickson, Koch & Adolphs, 2006). Strong evidence has linked the amygdala to negative or aversive emotions, such as fear (Derntl, et al, 2009; Hamann, Ely, Hoffman & Kilts, 2002; Tranel, Gullickson, Koch & Adolphs, 2006). However, little research has looked into, or found evidence of, a link between positive emotions and the amygdala (Hamann, Ely, Hoffman & Kilts, 2002). Hamann, Ely, Hoffman and Kilts (2002) showed participants positive and negative photographs while said participants underwent a Positron emission tomography (PET) scan. This study looked at how neural correlates of positive and negative emotions affect the amygdala. The results of this study found negative emotions create bilateral amygdala activation and positive emotions to create left amygdala and prefrontal cortex activation. However, Derntl and colleages found bilateral activation in both positive and negative emotional states. Damage to the amygdala interfers with processing emotional signals, such as facial expression and negative emotions like fear, anger and sadness (Derntl, et al, 2009; Tranel, Gullickson, Koch & Adolphs, 2006). Therefore, mood and emotion have been linked to the amygdala.
How are the Hippocampus and Mood and Emotion Linked?
The final part of the brain that effects mood and emotion to be discussed is the hippocampus. As the picture on right depicts, the hippocampus is located near the amygdala in the limbic system (Richardson, Strange & Dolan, 2004). Many studies have found a link between fear and hippocampus activation (see Richardson, Strange & Dolan, 2004), as well as links to other psychopathological disorders. Individuals with Alzheimers disease tend to have disruptions in the hippocampus (Richardson, Strange & Dolan, 2004). Also, individuals who suffer from schizophrenia tend to have smaller hippocampi than individuals who do not suffer from this disorder (Richardson, Strange & Dolan, 2004). Alzheimers disease and schizophrenia influence sufferers' mood and emotions as well (Richardson, Strange & Dolan, 2004).
How are Alzheimer's Disease and Mood and Emotion Linked?
Diagnostic criteria: Alzheimer's Disease
Multiple cognitive deficits manifested by both memory impairment and at least one of the following disturbances; aphasia, apraxia, agnosia or disturbance in executive functioning (APA, 2008, p157)
Alzheimers disease is a disorder that is noted in the Diagnostic and statistical manual of mental disorders IV (DSM-IV) as dementia of the Alzheimer's type (p154) and is a cognitive disorder (American Psychiatric Association [APA], 2008). This disease has been associated with social withdrawal and depression that are thought to be due to sufferers frustration in diminishing memory and cognitive abilities (Lancioni, et al, 2009). Although there tends to be a decline in general mood as individuals enter retirement age and older, sufferers of Alzheimer's disease have higher rates and longer periods of negative moods than others their age (Lancioni, 2009). Currently there is no cure for this disease. However, there are pharmacological treatments, such as antioxidants, acetylcholinesterase inhibitors and the N-menthyl-D-aspartate receptor-antagonist and memantine, which can also effect an individual's mood (Lancioni, 2009).
How are Schizophrenia and Mood and Emotion Linked?
Diagnostic criteria: Schizophrenia
Presence of at least two of the following disturbances for a significant portion of time in a 1-month period; delusions, hallucinations, disorganised speech, grossly disorganised or catatonic behaviour, or negative symptoms such as affective flattening, alogia, or avolition (APA, 2008, p312)
The typical onset of Schizophrenia is between the late teens and mid-30s (APA, 2008). Studies have found that gray matter in the brains frontal, temporal and limbic lobes decreases in sufferers of schizophrenia over time (Smieskova, et al, 2009). Like Alzheimer's disease, schizophrenia has high comorbidity with major depression (Martin, Allan, Fleming & Atkinson, 2008). There is also a high comorbidity between schizophrenia and nicotine dependence, which also effects mood (see below; Martin, Allan, Fleming & Atkinson, 2008). Nearly all sufferers of schizophrenia experience mood disturbance (Martin, Allan, Fleming & Atkinson, 2008). Mood disturbance can include abnormal reactions to stimuli as well as rapid mood swings or unprevoked mood swings (Martin, Allan, Fleming & Atkinson, 2008).
THINK ABOUT IT
These are not the only parts of the brain or disorders that effect the brain that also effect mood.
What does Mood and Emotion effect?
It might not come as a surprise that individuals in a positive mood smile more than individuals in a negative mood (Vrugt & Vet, 2009). However, there are many other things that mood and emotion effect. Although there are five common mood disorders (see above), only three will be discussed in this chapter. Depression is a significantly depressed or irritable mood whereas bipolar I and II are disorders that alternate between depressed and manic moods. Both depression and bipolar I and II have effects on mood and emotion. Risk taking behaviours also increase with an increase in positive moods. The final effect on mood and emotion to be discussed is prosocial behaviour, such as helping behaviour and altruism.
How does Mood and Emotion effect Mood Disorders?
Diagnostic criteria: Major Depressive Episode
Presence of at least five of the following disturbances during the same 2-week period that represents change from previous functioning with either a depressed mood or loss of interest or pleasure; significnt weight loss or weight gain, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue, feelings of worthlessness, diminished concentration or recurrent thoughts of death (APA, 2008, p356)
Firstly, depression can lead to psychomotor retardation such as changes in speech and motor activity, which can cause an individual frustration and a negative mood state (Barrett, Pike & Paus, 2004). The age of onset for major depressive disorder is lowering, and so it is hard to say what is the mean age of onset (Durand & Barlow, 2010). Depression normally follows a significant life stressor, such as the loss of a loved one (Patten, 2009). Individuals with depression normally experience negative moods and more negative emotions, such as anger and sadness, than positive emotions (Wadsworth, Moss, Simpson & Smith, 2005). Depression can also effect eating and sleeping patterns as well as self-esteem (APA, 2008). The most commonly prescribed antidepressant medication is selective serotonin reuptake inhibitors (SSRIs; Wadsworth, Moss, Simpson & Smith, 2005). Although depression has a significant effect on mood, individuals taking SSRIs have reported their belief that on SSRIs they can no longer experiences moods, either positive or negative (Wadsworth, Moss, Simpson & Smith, 2005).
Diagnostic criteria: Manic Episode
Presence of at least three of the following disturbances during at least a 1-week period of abnormal and persistent elevated, expansive or irritable mood; inflated self-esteem, decreased need for sleep, more talkative than usual, flight of ideas, distractibility, increase in goal-directed activity or excessive risk taking (APA, 2008, p362)
Bipolar I and II both consisted of depressive and manic episodes. The difference between these two disorders is that sufferers of bipolar I experience full depressive and manic episode whereas bipolar II sufferers alternate between depressive and hypomanic episodes. Hypomanic episodes are less severe than manic episodes (Durand & Barlow, 2010). Individuals during manic episodes have elevated positive moods and emotions (APA, 2008). These individuals are also easily distracted and more likely to partake in risk taking behaviours than individuals not suffering from bipolar (APA, 2008). These two disturbances can lead to harm of the sufferer (Durand & Barlow, 2010).
How does Mood and Emotion effect Risk Taking Behaviour?
Unlike individuals experiencing a manic episode, the majority of individuals are more likely to partake in risk taking behaviours when in a negative mood than a positive mood (Chuang & Chang, 2007). A lot of literature has looked into large risk taking behaviours, such as gambling and risky business ventures (Chuang & Chang, 2007). However, Chuang and Chang (2007) looked into everyday risk taking behaviours and mood. The experiment consisted of 82 students, 38 men and 44 women ranged in age from 21 to 53, enrolled in a executive master of business administration course. The experimenters enduced a positive mood in half of the participants and a negative mood in the remaining half and then given 13 scenarios with differing risk taking behaviours. One scenario looked at buying a new pair of shoes. Chuang and Chang (2007) noted that this involves social and economic danger; social due to the influence of friends and society and econimic due to the price of the shoes. This experiment found that individuals with a negative mood take more risk in everyday life than those in a positive mood.
Much like the name suggests, a convience sample is when the participants of an experiment are selected using conveient means. In the Vrugt and Vet (2009) experiment, this was done by approaching every passer-by on a street until an equal number of men and women had participated.
The final thing that mood and emotion effect to be discussed is prosocial behaviour. Experiments on the effect of mood on prosocial behaviour have been conducted for years (see Latane & Darley, 1968). Prosocial behaviour has two main forms; helping behaviour and altruism. Helping behaviour is when an individual deliberately and voluntarily behaves in a way that will benefit other individuals. This behaviour may also benefit the individual who performed the behaviour (Crisp & Turner, 2010). As helping behaviour must be deliberate, this definition excludes accidental help; such as dropping money that another individual later finds (Crisp & Turner, 2010, p283-4). This definition also excludes behaviours that might seem to be helping others but are mostly selfish, such as companies giving money to charities, as this would also help their public image (Crisp & Turner, 2010, p284). Altruism, on the other hand, is a behaviour that is not expected to help the individual who is being altruistic (Crisp & Turner, 2010).
A Dutch experiment by Vrugt and Vet (2009) looked into prosocial behaviour. A convience sample of 240 male and 240 female passers-by were approached by a male or female experimenter who was either smiling or had a neutral expression and asked to help by participating in an investigation. This experiment found smiling experimenters were more likely to receive a smile from participants and women smiled more often than men. The results also showed a positive correlation between participants who smiled and those who accepted to participate in the investigation. Also, that a smiling male experimenter elicited more helping behaviour from female participants than any other combination of experimenter/ participant genders. Vrugt and Vet (2009) state that participants who were in a positive mood, defined as smiling, were more likely to participate in the investigation.
THINK ABOUT IT
When studying, do you learn more if you are in a positive or negative mood? Are you more interested in meeting new people when you are in a good mood or a bad mood? What about doing new things? Think of examples from your own life of how your behaviours differ depending on your mood. Do you notice a difference in your eating behaviours? Do you eat more or less? Do you eat more of one type of food than another? Sale of chocolate tends to go up in Winter months in most countries around the world. This tends to be positively correlated with increased rates of depression. However there is still a great debate over which is the cause of which (see Strandberg, Strandberg, Pitkälä, Salomaa & Miettinen, 2008).
What Effects Mood and Emotion?
How does Alcohol Effect Mood and Emotion?
In Australia alcohol tends to be used as a legal, typically reliable way to alter mood (Lindsay, 2009). Alcohol is a depressant, which decreases central nervous system activity (Durand & Barlow, 2010). Relaxation and a reduction in physiological arousal are the typical effects of depressants (Durand & Barlow, 2010). At first the effects of alcohol tend to be seen as a stimulant, with people experiencing a lowering of inhibition. However, alcohol has been linked to negative mood and emotions (Durand & Barlow, 2010). High rates of alcohol intake have been linked to aggression, property damage, sexual assaults and attempted suicides (Jennison, 2004). Excessive drinking has also been associated with risky sexual behaviour and unplanned pregnancy (Jones & Gregory, 2009).
How does Nicotine Effect Mood and Emotion?
Nicotine withdrawal has been linked to negative mood and emotions, such as anger, as well as depression (Durand & Barlow, 2010). This may suggest that nicotine increases mood. However, ther is a strong positive relationship between nicotine dependence and major depressive episodes (Durand & Barlow, 2010). Cook and colleagues' (2004) study deprived 35 smokers, aged between 18 and 65 years (M = 17.5) who smoked at least ten cigarrettes a day for the past year, of nicotine for a 48 hour period (Cook, et al). Each participant's mood was tested six times in the 48 hour period using the Profile of Mood States questionnaire. This questionnaire consisted of 65 questions rated on five point Likert scales (0= not at all; 4 = extremely) (Cook, et al). Postive moods were noted as activation, elation, enthusiasm, happiness, jubilation and peppiness. Negative moods were noted as distress, hositility, nervousness, scorn, gloominess, tension, depression and anger. Cook and colleagues found that cigarette craving is due to a decrease in positive mood rather than an increase in negative mood. This study also found that smokers who partake in pleasurable activities during the nicotine deprevation have lower rates of cigarette cravings than those who do not.
How does Cannabis Effect Mood and Emotion?
Cannabis, commonly known as marijuana, is currently the most frequently used hallucinogen (Durand & Barlow, 2010). Hallucinogens effect the way an individual perceives the world by distorting sight, sound, taste, smell and feelings (Durand & Barlow, 2010). Cannabis has different effects on different people (Durand & Barlow, 2010). Individuals under the influence of cannabis tend to experience mood swings and typically normal experiences are thought to be extremely funny (Durand & Barlow, 2010). Most users report increased positive mood and emotions. However, this can change to paranoia if taken in larger doses (Durand & Barlow, 2010).
How does MDMA (Ecstasy) Effect Mood and Emotion?
Methylenedioxymethamphetamine (MDMA) otherwise known as ecstasy, was fist synthesised in Germany in 1912. Recreational use rose sharply in the 1980s (Durand & Barlow, 2010). MDMA is an amphetamine, which is a stimulant drug (Durand & Barlow, 2010). Caffeine and nicotine are also stimulants (Durand & Barlow, 2010). Amphetamine use induces a positive mood and feelings of elation and vigor as well as reducing fatigue. However, amphetamine withdrawal induces feelings of depression and tiredness (Durand & Barlow, 2010). In fact, both amphetamine use and withdrawal have been linked to sleep and eating behaviour disturbances (Roiser & Sahakian, 2004).
THINK ABOUT IT
Are you typically in a positive or negative mood when you are sick? When you are stressed? Or anxious about something? How does your mood change when something unexpected happens to you? What happens when someone cuts you off in traffic? What happens when someone compliments you? What happens when you see Santa Claus at the shopping centre?
What is the PANAS?
POSITIVE AFFECT: *interested *excited *strong *enthusiastic *proud *determined *alert *inspired *attentive *active NEGATIVE AFFECT: *distressed *upset *guilty *scared *hostile *irritable *ashamed *nervous *jittery * afraid
The Positive Affect Negative Affect Schedule (PANAS) is a 20-item self report measure of mood states on a 5-point Likert scale (1= very slightly or not at all, 5= extremely) (Watson, Clark & Tellegan, 1988). Items are divided into positive or negative, with ten items in each category. A score between 10 and 50 is possible in both categories. The mean score for positive affect is 35.7 (SD = 6.2) and for negative affect is 19.5 (SD 6.0) (Watson & Clark, 1994). This measure is used with one of seven different time instuctions; at the moment, today, in the past few days, in the past week, in the past few weeks, in the past year, or in general (Watson, Clark & Tellegen, 1988). A longer version, the PANAS-X, contains not only positive and negative affect but also fear, hostility, guilt, sadness, joviality, self-assurance, attentiveness, shyness, fatigue, serenity and surprise (Watson & Clark. 1994). The PANAS-X is a 74-item self report measure on the same 5-point Likert scale as the original (Watson & Clark, 1994). Both measures were constructed so each item held high factor loading on the selected scale, such as positive affect, and near-zero factor loadings on all other scales (Watson, Clark & Tellegan, 1988). An example of the PANAS can be found here (see the bottom of the fourth page).
Mood and emotion are related and have similar cause and effects. Emotions are short-lived reactions to life events that influence behaviours, whereas moods are mental events from ill defined causes that influence cognition and can last for hours or days. Moods are generally defined as either positive or negative. Positive moods have been found to have a positive influence on creativity in people, yet this does not mean that individuals in negative moods cannot be creative. Positive and negative moods are not polar opposites dispite them commonly being identified as such. Instead these two moods are correlated and have different psychological correlates. A person can be experiencing both positive and negative moods simultaneously.
The brain plays an important role in mood and emotion. The anterior cingulate cortex shows cognitive changes when an individual is depressed. A relationship has also been found between this area of the brain and normal affect and pathological affect. Futhermore, bilateral amygdala activation is seen during positive and negative moods. The amygdala and the hippocampus have also been linked to negative emotions, such as fear. Changes in the hippocampus can be seen in sufferers of both Alzheimer's disease and schizophrenia. There is a comorbidity between Alzheimer's disease and depression, as well as schizophrenia and depression. The medications perscribed to lessen the effects of Alzheimer's disease and schizophrenia can also effect mood and emotion.
In this chapter, four main areas were discussed in relation to what mood and emotion have an effect on. The first two were depression and mania. Depression decreases positive moods and increases negative moods and emotions. Whereas mania elevates positive moods and decreases negative moods. Mania has been linked to risk taking behaviour. However, individuals who do not suffer from mania have higher rates of risk taking behaviour when in a negative mood than a positive. Prosocial behaviour was the final discussion point in this section. Positive mood states increase prosocial behaviour such as helping behaviour and altruism.
After the effects of mood and behaviour, the effects on mood and behaviour were explored. Alcohol is a depressant that increases rates of anger and aggression. Nicotine use and withdrawal have also been linked to anger. Cannabis is a hallucinogen that distorts users' experiences of feelings as well as causes mood swings. The final drug discussed was MDMA or ecstacy. MDMA creates positive moods while in an individual's system. However, withdrawal from the drug can cause intense negative mood states.
The final topic explored in this chapter was the measure of mood, the positive and negative affect schedule (PANAS). This version is a 20 item self report questionnaire that measures mood in one of seven time periods. A longer version of this measurement, the PANAS-X, using 74 items across 13 categories is also available. Emotions and moods are experienced on a daily basis and have a marked effect on an individual's experience of the world.
- Depression (Textbook chapter)
Alexopoulous, G. S., Gunning-Dixon, F. M., Latoussakis, V., Kanellopoulos, D. & Murphy, C. F. (2008). Anterior cingulate dysfunction in geriatric depression. International Journal of Geriatric Psychiarty, 23, 347-355. DOI: 10.1002/gps.1939
Barrett, J., Pike, G. B. & Paus, T. (2004). The role of the anterior cingulate cortex in pitch variation during sad affect. European Journal of Neuroscience, 19, 458-464. DOI: 10.1111/j.1460-9568.2003.03113.x
Chuang, S. C. & Chang, C. L. (2007). The effects of mood and openness-to-feeling trait on choice. Social Behavior and Personality, 35, 351-358. Retrieved from: http://web.ebscohost.com.ezproxy1.canberra.edu.au/ehost/pdfviewer/pdfviewer?vid=8&hid=14&sid=a58ea5d3-ee1b-4b7e-b0e6-0ba8e37743c3%40sessionmgr13
Cook, J. W., Spring, B., McChargue, D. & Hedeker, D. (2004). Hedonic capacity, cigarette craving, and diminished positive mood. Nicotine and Tobacco Research, 6, 39-47. DOI: 10.1080/14622200310001656849.
Crisp, R. J. & Turner, R. N. (2010). Essential Social Psychology: Second Edition. Sage Publications Ltd: London, England.
Derntl, B., Habel, U., Windischberger, C., Robinson, S., Kryspin-Exner, I., Gur, R. C. & Moser, E. (2009). General and specific responsiveness of the amygdala during explicit emotion recognition in females and males. BMC Neuroscience, 10, 1-14. DOI: 10.1186/1471-2202-10-91
Hamann, S. B., Ely, T. D., Hoffman, J. M. & Kilts, C. D. (2002). Ecstasy and agony: Activation of the human amygdala in positive and negative emotion. Psychological Science, 13, 135-141. Retrieved from: http://web.ebscohost.com.ezproxy1.canberra.edu.au/ehost/pdfviewer/pdfviewer?vid=7&hid=14&sid=a58ea5d3-ee1b-4b7e-b0e6-0ba8e37743c3%40sessionmgr13
Johnston, B. A., Campling, G. M., Griffiths, D. & Cowen, P. J. (1993). Attenuation of some alcohol-induced mood changes and the desire to drink by 5-HT3 receptor blockade: A preliminary study in health male volunteers. Psychopharmacology, 112, 142-144. Retrieved from: http://www.springerlink.com/content/y02517p63u211708/
Jennison, K. M. (2004). The short-term effects and unintended long-term consequences of binge drinking in college: A 10-year follow up study. The American Journal of Drug and Alcohol Abuse, 30, 659-684. DOI: 10.1081/ADA-200032331
Jones, S. C. & Gregory, P. (2009). The impact of more visible standard drink labelling on youth alcohol consumption: Helping young people drink (ir)responsibly? Drug and Alcohol Review, 28, 230-234. DOI: 10.1111/j.1465-3362.2008.00020.x
Lancioni, G., Singh, N., O'Reilly, M., Zonno, N., Flora, A., Cassano, G., de Vanna, F., et al. (2009). Persons with mild and moderate Alzheimer's disease use verbal-instruction technology to manage daily activities: Effects on performance and mood. Developmental Neurorehabilitation, 12, 181-190. DOI: 10.1080/17518420903029493
Latané, B. & Darley, J. M. (1968). Group inhibition of bystander intervention in emergencies. Journal of Personality and Social Psychology, 10, 215-221.
Lindsay, J. (2009). Young Australians and the staging of intoxication and self-control. Journal of Youth Studies, 12, 371-384. DOI: 10.1080/13676260902866520
Martin, C. R., Allan, R., Fleming, M. & Atkinson, J. (2008). Mood and smoking in schizophrenia. Journal of Psychiatric and Mental Health Nursing, 15, 722.727. Retrieved from: http://web.ebscohost.com.ezproxy1.canberra.edu.au/ehost/pdfviewer/pdfviewer?vid=5&hid=14&sid=a58ea5d3-ee1b-4b7e-b0e6-0ba8e37743c3%40sessionmgr13
Montgomery, D., Hodges, P. A. & Kaufman, J. S. (2004). An exploratory study of the relationship between mood states and creativity self-perceptions. Creativity Research Journal, 16, 341-344. Retrieved from: http://web.ebscohost.com.ezproxy1.canberra.edu.au/ehost/pdfviewer/pdfviewer?vid=1&hid=14&sid=04db8ae8-911a-4d53-bf8f-4af80248b606%40sessionmgr4
Patten, S. B. (2009). Accumulation of major depressive episodes over time in a prospective study indicates that retrospectively assessed lifetime prevalence estimates are too low. BMC Psychiatry, 9, 1-4. doi: 10.1186/1471-244X-9-19
Reeve, J. (2009). Understanding Motivation and Emotion: (5th ed.). Hoboken, NJ: Wiley.
Richardson, M. P., Strange, B. A. & Dolan, R. J. (2004). Encoding of emotional memories depends on amygdala and hippocampus and their interactions. Nature Neuroscience, 7, 278-285. DOI: 10.1038/nn1190
Roiser, J. P. & Sahakian, B. J. (2004). Relationship between ecstasy use and depression: A study controlling for poly-drug use. Psychopharmology, 173, 411-417. DOI: 10.1007/s00213-003-1705-6
Smieskova, R., Fusar-Poli, P., Allen, P., Bendfeldt, K., Stieglitz, R. D., Drewe, J., Radue, E. W., et al. (2009). The effects of antipsychotics on the brain: What have we learnt from structural imaging of schizophrenia? - A systematic review. Current Pharmaceutical Design, 15, 2535-2549. DOI: 1381-6128/09
Strandberg, T. E., Strandberg, A. Y., Pitkälä, K., Salomaa, R. S. & Miettinen, T. A. (2008). Chocolate, well-being and health among elderly men. European Journal of Clinical Nutrition, 62, 247-253. DOI: 0954-3007/08
Tranel, D., Bullickson, G., Koch, M. & Adolphs, R. (2006). Altered experience of emotion following bilateral amygdala damage. Cognitive Neuropsychiatry, 11, 219-232. DOI: 10.1080/13546800444000281
Vrugt, A. & Vet, C. (2009). Effects of a smile on mood and helping behavior. Social Behavior and Personality, 37, 1251-1258. DOI: 10.2224/sbp.2009.37.9.1251
Wadsworth, E. J. K., Moss, S. C., Simpson, S. A. & Smith, A. P. (2005). SSRIs and cognitive performance in a working sample. Human Psychopharmacology, 20, 561-572. DOI: 10.1002/hup.725
Watson, D. & Clark, L. A. (1994). The PANAS-X Manual for the Positive and Negative Affect Schedule - Expanded Form. Retrieved from: http://www.psychology.uiowa.edu/faculty/clark/panas-x.pdf
Watson, D., Clark, L. A. & Tellegan, a. (1998). Development and validation of brief measures of positive and negative affect: The PANAS scale. Journal of Personality and Social Psychology, 54, 1063-1070. DOI: 0022-3514/88/$00.75