Method

Participants

Participants consisted of 80 undergraduate and postgraduate students from the University of Sussex. Nineteen were male and sixty-one were female, the age range was from 18 – 35 years with a mean age of 21.12 (sd = 3.48). All participants were volunteers and 76 % participated in order to gain course credits.

Procedure

Participants were required to give their informed consent, after which they were randomly assigned to either a sad (N = 20), happy (N = 20), anxious (N = 20) or angry (N = 20) mood group, this relating to the type of mood induction they would undergo. All participants were asked to listen to an extract of music whilst reading a series of sentences from the computer, they were then asked to read and check a piece of text for errors.

Stage 1

Baseline mood measure: All participants rated their current levels of sadness, happiness, anxiety and anger on separate visual-analogue (VAS) 10-point scales ranging from 0 (not at all sad, anxious etc.) to 10 (extremely sad, anxious etc.). Visual analogue scales of this type have demonstrated both validity and reliability in college students (Stern, Aruda, Hooper, Wolfner, & Morey, 1997) and the general population (Nyenhuis, Stern, Yamamoto, Luchetta, & Arruda, 1997).

Stage 2

Mood Induction: Participants were randomly assigned to either a sad, happy, angry, or anxious mood condition. The combined induction method used herein was based on the work of Mayer, Allen, & Beauregard (1995) and extended by Marzillier & Davey (2005). This used music and guided imagery vignettes to induce specific moods of sadness, anxiety, anger, and happiness.

Participants were informed by written and oral instruction that they were to try and enter into mood X (depending on what mood condition they had been

assigned to). The music was started one minute before the imagery vignettes were shown and was looped to continue during the experiment. Music was played through headphones and the vignettes were shown at 30-second intervals on Microsoft Power Point. To facilitate mood induction for the three negative mood conditions, the blinds were drawn, main lights were turned off and an angle poise lamp produced subdued lighting. During the happy mood induction the overhead lights and lamp were both on and the blinds were open (cf. Davey, Startup, MacDonald, Zara, & Field, 2003).

• Sad mood induction: Participants were asked to listen to Chopin (1839), Opus 28, #6, from Preludes. An example vignette is “You are told by a young relative that she has cancer and has only six months to live”.

• Happy mood induction: Participants listed to Delibes (1870), Mazurka from

Coppelia. An example vignette is “You just got a new job, and it’s even

better than you expected”.

• Anxious mood induction: Participants listened to Ives (1906) Halloween. An example vignette is “You are in your bedroom late at night when you hear someone else enter your apartment. No one else you know has a key”.

• Angry mood induction: Participants listened to Mussorgsky (1867) Night on

Bare Mountain. An example vignette is “Somebody files a false legal claim

against you”.

At the end of the mood induction, participants were asked to complete a second set of mood VAS scales measuring as above, sadness, happiness, anxiety and anger.

Stage 3

Checking task instruction: The checking task and task instruction was based on a task devised by MacDonald & Davey (2005a). Participants were instructed that they would be reading a piece of text that had not been proof read, but which may be used as part of future secondary level maths examinations. Approximately 100 random spelling and punctuation errors had been added to a passage of 41 lines of text taken from Coolican (1994). Participants were

instructed to check for typing, punctuation and grammatical errors and note them on the sheet provided. Participants were also instructed that they should go back and re-check each line for errors and note in tally form the number of times they re-checked each line. These instructions were given both orally and in writing (see appendix E and F for task instructions and task). Participants were then asked to complete a third set of mood VAS as above.

Before starting the checking task, participants were given their ‘stop rule’ instruction. Participants were randomly assigned to either a FL group, or an AM group. The FL group received verbal and written instructions to check the text until they felt that they no longer wanted to continue (see appendix B). The AM group received verbal and written instructions to check the text until they completed the goal of finding and correcting as many errors as possible (see appendix C).

Stage 4

Checking task: Once participants had been asked to start the checking task, the experimenter started the stopwatch and left the room.

Stage 5

Post task: When participants felt that they had completed the task, they informed the experimenter who then noted the total time spent checking. Participants were asked to complete a fourth set of mood VAS (as above). Participants were then debriefed and thanked. To ensure that ethical guidelines were met all who participated received a debrief information sheet with contact details of the university counselling services and the experimenter’s contact details, should they wish to have further information, or withdraw their data from the study (appendix A). Those who had undergone a negative mood induction were offered the option of staying and listening to some happy mood inducing music.