2. Mood

2.3. Natural mood vs. Induced mood

The study of the interaction between affective and cognitive functioning based on natural occurring moods can be made by selecting individuals who have been diagnosed as depressed or anxious or who present (more or less stable) dysphoric or anxious traits. The clinical diagnosis of depression or anxiety is usually made as a result of psychiatric interviews and specific questionnaires – e.g., the Schedule for Affective Disorders and Schizophrenia (SADS; Spitzer & Endicott, 1978), or the Hamilton Rating Scale for Depression (HRS-D; Hamilton, 1967). The most common procedures propose to the subjects to complete questionnaires of self-evaluation, such as the Center for Epidemiologic Studies – Depression Scale (CES-D; Radloff, 1977) or the Beck Depression Inventory (BDI; A. T. Beck, Ward, Mendelson, Mock, & Erbaugh, 1961) which assess mainly depressive tendencies, or the State Trait Anxiety Inventory (STAI, Spielberger, Gorsuch, & Lushene, 1983) for state anxiety. The CES-D and BDI allow the assessment of non-clinical depressive subjects. Their depressive state is diagnosed as

more or less severe depending on their score. Most of the research involving natural mood differences is related to individuals who are not clinical depressed, but who present elevated scores on depression scales (Kendall, Hollon, Beck, Hammen, & Ingram, 1987) – i.e., dysphoric individuals (e.g., Brinkmann &

Gendolla, 2007). To avoid difficulties inherent in choosing a “natural mood sample” (e.g., low number of depressive or dysphoric subjects in the general population, ethical issues), mood induction appears as the best alternative. Mood manipulation can induce both negative and positive affective states.

Additionally, it is not necessary to induce intense mood states; usually mood states of medium intensity are sufficient to produce effects in many experimental settings.

The present research program uses induced mood for manipulating mood states. Therefore, procedures and measures of mood induction will be presented, with a stronger focus on the procedures and measures used in the experiments of our research program.

2.3.1. Mood induction: Procedure 2.3.1.1. Simple procedures

A review of the literature reveals a large number of experimental procedures to induce mood changes in a controlled manner. These induction procedures are extremely diverse (Blaney, 1986; M.

Martin, 1990; Gerrards-Hesse, Spies & Hesse, 1994; Westermann, Spies, Stahl & Hesse, 1996) and can be defined as strategies aimed at causing in an individual an ephemeral, artificial, and controlled affective state. Mood induction intends to be the experimental and artificial reflex of naturally occurring moods.

The meta-analysis of Abele (1995), M. Martin (1990), Gerrards-Hesse et al. (1994), Thayer (1989), and Westermann et al. (1996) list a large number of procedures used to induce positive or negative moods.

In addition, some procedures have been created or adapted to try to induce other affective states such as anxiety, anger, disgust or fear (Bodenhausen, Sheppard & Kramer, 1994; Mayer, Allen & Beauregard, 1995). However, as noted by Corson (2002), due to the reduced amount of studies regarding these other affective states, a coherent image cannot yet be drawn. Among the main techniques used to induce positive and negative moods we encounter:

- film excerpts presentation (more detailed in the paragraph below);

- music, reported for the first time by Sutherland, Newman and Rachman (1982);

- autobiographic recall, developed by Brewer, Doughtie, and Lubin (1980), from the work Mosak and Dreikurs (1973); a modified version (not only recall, but having 10 min to write in detail a

happy or sad event, according to the mood condition) was introduced by Ric and Krauth-Gruber (2000);

- the «Velten Mood Induction Procedure» (Velten, 1968);

- hypnosis (Bower, 1981 ; Friswell & McConkey, 1989);

- guided imagery (Miller et al., 1987);

- experiences of success or failure or little rewards (Isen, Daubman, & Nowicki, 1987;

Nummenmaa & Niemi, 2004);

- changes in forehead blood temperature (Zajonc, Murphy, & Inglehart, 1989);

- exposure to specific stimuli: photographs (Fox, 1996) or odors (Ehrlichman & Halpern, 1988).

The present thesis uses a single simple procedure of mood induction: movie clips presentation.

The screening of film clips is a widespread technique, because it has the advantage of being simple to use and it poses fewer ethical problems than other procedures, since participants are daily exposed to emotionally loaded images via television. Moreover, many studies have highlighted the effectiveness of this method on the induction of positive and negative moods (e.g., Gendolla & Krüsken, 2002a, 2002b, 2002c; Silvestrini & Gendolla, 2007), but also other affective states (Dalle & Niedenthal, 2003; Gouaux, 1971; Gross & Levenson, 1995 ; Hänze & Hesse, 1993; McHugot, Smith & Lanzetta, 1982; Philippot, 1993; Rottenberg, Ray & Gross; 2004, S. M. Smith & Shaffer, 1991).

2.3.1.2. Composed procedures

In an attempt to increase the efficiency of the mood induction, some researchers have combined several types of existing induction procedures (Gerrards-Hesse et al., 1994). The success of such procedures is to bind a first induction, which monopolizes the attention, to a second manipulation that helps to create a congruent atmosphere in the background. For example, the procedure of Velten (1968) was successively associated with hypnosis (Natale & Hantas, 1982), with music (A. Mathews & Bradley, 1983; Mayer, Gayle, Meehan & Haarman, 1990) and with an imagination proceeding (Richardson &

Taylor, 1982). Other researchers have developed an induction process involving a task of guided imagery and music (Mayer et al., 1995). As stated before, the present research program does not apply a composed procedure of mood induction. It uses the presentation of movie excerpts as a simple procedure of mood manipulation.

2.3.2. Mood induction: Measures

Mood induction efficiency can be evaluated according to three distinct indicators: a) behavioral and cognitive indices, b) physiological indices, and c) self-report measures. To assess mood we applied verbal manipulation checks, via self-report questions. The physiological measures used in the present research program serve as indices of effort and not as indicators of mood inductions.

A brief presentation of each mood manipulation assessment indicator is presented below, with a special focus on the self-report measures.

2.3.2.1. Behavioral and cognitive indices

In this case, the evaluation of induced affective states is based on the detection of cognitive and behavioral patterns usually associated with those induced affective states. The most frequently used behavioral index remains the psychomotor delay which is operationalized by the writing speed (D. M.

Clark, 1983) – slowness is usually indicative of negative affect. Similarly, the presence of facial expressions can indicate a particular affective state (Ekman, Friesen & Ancoli, 1980).

2.3.2.2. Physiological indices

The physiological element of affective states can be objectively measured, which is not possible with subjective and behavioral components (Doron & Parot, 2007). Heart rate, blood pressure, respiratory rate, body temperature, changes in eye movements, pupillary dilation, electrodermal response, and muscle contractions (especially facial electromyography) are all indicators that can be used to denote the presence of an affective state (Cacioppo & Petty, 1983; Wagner & Manstead, 1989).

However, variations of these psychophysiological indices do not accurately indicate the presence of a particular affective state (Gerrards-Hesse et al. 1994; Schachter & Singer, 1962).

2.3.2.3. Self-report measures

Self-evaluation measures with assistance of scales remain the most common method for evaluating the effectiveness of mood induction. Literature outlines a wide set of self-reports and Lickert-type scales including the Nowlis Mood Adjective Checklist (Nowlis & Green, 1957; Nowlis, 1965), Profile of Mood State (POMS; McNair, Lorr, & Droppelman, 1981), Multiple Affective Adjective Checklist-Revisited (MAACL; Zuckerman & Lubin, 1985), Visual Analogue Mood Scale (Vamsi; Teasdale & Dent, 1987), Brief Mood Introspection Scale (BMIS; Mayer & Gaschke, 1988), Positive and Negative Affect Scale (PANAS; Watson, Clark & Tellegen, 1988), Differential Emotions Scale (DES; Izard, Dougherty, Bloxom &

Kotsch, 1974; Philippot, 1993), Implicit Positive and Negative Affect Test (IPANAT; Quirin, Kazén, Rohrmann, & Kuhl, 2009) or the University of Wales Institute of Science and Technology (UWIST) Mood Adjective Checklist (MACL) developed by Matthews, Jones and Chamberlain (1990).

A reduced version of this latter scale (from now on referred simply as UWIST) is the self-report measure used in the present research program. The UWIST is a survey instrument consisting of 42 adjectives that a subject must rate on seven-point scales (ranging from 1 – ”not at all true" to 7 –

”completely true") accordingly to how well each item describes his or her mood at that moment. The UWIST measures the affective state based on the two-dimensional affect representation – Russell’s (1980) affect circumplex model. In this model, each specific affect is characterized along two dimensions: “valence", which indicates how pleasant or unpleasant the emotional state is, and

“arousal", which characterizes how activated or deactivated the person feels. For example, feeling bored would imply a low-activation, unpleasant, affective state, whereas feeling excited would imply a highly activated, pleasant, affective state. Despite the intuitive nature of the survey, the accuracy of the valence/arousal representation of affect is not universally accepted in the psychological literature (Ekman & Davidson, 1994). The scores for eight categories that correspond to different sectors in the affect circumplex are calculated based on UWIST responses: (1) Pleasant (happy, pleased, content), (2) Unpleasant (miserable, troubled, unhappy), (3) Activated (aroused, alert, hyperactivated), (4) Deactivated (sleepy, still, quiet), (5) Pleasant-Activated (interested, excited, strong, enthusiastic, proud, inspired, determined, attentive, active), (6) Pleasant-Deactivated (relaxed, at rest, serene, calm, at ease), (7) Unpleasant-Activated (distressed, upset, guilty, scared, hostile, irritable, ashamed, nervous, jittery, afraid), and (8) Unpleasant-Deactivated (tired, sluggish, droopy, dull, drowsy, bored). Due to some limitations associated with research on affective states – such as the specific process for eliciting affect, insufficient mood intensity in a laboratory setting, or the purity of emotional experience (i.e., experiencing only one emotion at a time) – the UWIST often serves as a useful first-order approximation.

Previous studies from our laboratory have successfully applied a reduced version of the UWIST hedonic tone scales, focusing on eight adjectives: four of the positive hedonic tone scale (happy, joyful, contented, cheerful) and four of the negative hedonic tone (sad, frustrated, depressed, dissatisfied). The long list of 42 adjectives does not meet the purposes of our experiments, since this extensive list would draw too much attention to the mood manipulation and thus uncover our intentions of a masked mood manipulation. The present research work departs – as well as other more recent research from the Geneva Motivation Lab (e.g., Silvestrini & Gendolla, in press-a) – from this eight adjectives and uses a

simplified version of four adjectives: two positive (joyful, cheerful) and two negative (sad and depressed) – the ones that evidenced higher internal validity.

Despite the broad use of self-report measures – due to their savings in terms of time and money – these instruments also have some constraints. These issues will be addressed later, in section 4.9. of this Theoretical part.

Dans le document Mood and mental effort : informational mood impact on cardiovascular reactivity and the context-dependency of moods (Page 22-27)