Self-Report Inventories The following inventories and task were administered at Time 1 and Time 2 in order to explore the potential relationship between measures of affect, metacognitive processing, and executive function:
The Beck Depression Inventory. The Beck Depression Inventory (BDI; Appendix D) is a 21-item self-report questionnaire designed to assess dysphoric mood in adolescents and adults (Beck, Rush, Shaw, & Emery, 1979; Beck & Steer, 1987). Respondents indicate the extent to which they have experienced each of the 21 affective, cognitive, behavioural and somatic symptoms of depression over the last 7 days by rating each item on a 3-point scale, ranging from 0 to 3 in severity. The BDI is scored by summing the ratings of the 21 items. It is the most commonly used instrument for assessing the severity of depression in both clinical and normal populations (Beck, Steer, & Garbin, 1988). The reliability (Reynolds & Gould, 1981), concurrent validity (mean correlation between .72 and .73), discriminant validity, and internal consistency (Cronbach's â•¬â–’ between .81 and .86 ) of the inventory have been well established (Beck et al., 1988).
The Beck Anxiety Inventory. The Beck Anxiety Inventory (BAI; Appendix E) is a 21-item self-report questionnaire designed to assess the major cognitive, affective, and physiological symptoms associated with DSM III-R (APA, 1987) anxiety disorders (Freeston, Ladouceur, Thibodeau, Gagnon, & Rheaume, 1994) and discriminate anxiety from depression (Beck, Epstein, Brown, & Steer, 1988). Respondents indicate the extent to which they have experienced each of the listed 21 psychological and physical symptoms of anxiety over the last 7 days by rating each item on a 4-point scale, ranging from 0 ("Not at all") to 3 ("Severely - I could barely stand it"). The BAI is scored by summing the ratings of the 21 items. The scale has demonstrated excellent reliability, and high convergent and discriminant validity with other widely used measures of anxiety and depression (Beck et al., 1988), as well as high internal consistency and a median item-total correlation of .60 and a correlation of .48 with the BDI (Freeston, Ladouceur, Thibodeau, Gagnon, & Rheaume, 1994).
The Positive and Negative Affect Schedule. The Positive and Negative Affect Schedule (PANAS; Appendix F) consists of two 10-item scales, designed to assess positive and negative affect, respectively (Watson & Clark, 1988). Respondents indicate the extent to which they are experiencing each of the 20 feelings and emotions at the moment of testing by rating each item on a 5-point scale, ranging from 5 ("Extremely") to 1 ("Very slightly or not at all"). The PANAS is scored by summing the ratings of the 10 items on each subscale, providing two overall scores: one for positive affect and another for negative affect. The scales are largely uncorrelated and are stable over time (Watson, Clark & Tellegen, 1988). Internal consistency coefficients range from .84 to .90, and test-retest reliabilities from .39 to .71 (Watson, Clark & Tellegen, 1988).
The Ruminative Responses Scale. The Ruminative Responses Scale (RRS; Appendix G) is a subscale of the Response Styles Questionnaire (RSQ; Nolen-Hoeksema & Morrow, 1991). It consists of 22 self-report items designed to assess ruminative coping style, each describing reactions to mood which are self-focused (e.g. "Why can't I handle things better"), symptom-focused (e.g. "think about your feelings of fatigue and achiness"), and consequence-focused (e.g. "I won't be able to do my job if I don't snap out of this"). Respondents rate each item on a 4-point Likert-type scale, ranging from 1 ("Almost never") to 4 ("Almost always"). The RRS is scored by summing the ratings to the 22 items; higher scores indicate more rumination. Good test-retest reliability and internal consistency have been established (Nolen-Hoeksema & Morrow, 1991; Nolen-Hoeksema, Parker & Larson, 1994), and it has been shown to be nonredundant with depression-scale items (Treynor, Gonzales & Nolen-Hoeksema, 2003).
The Mindful Attention Awareness Scale. The Mindful Attention Awareness Scale (MAAS; Appendix H) is a 15-item self-report scale designed to assess individual differences in trait mindfulness - that is, the degree of sustained attention to, and awareness of, what is occurring in the present moment (Brown & Ryan, 2003; Appendix). Respondents rate each item on a 6-point Likert-type scale, ranging from 1 ("Almost always") to 6 ("Almost never"). The MAAS is scored by summing the ratings to the 15 items; higher scores indicate more mindfulness. Although the scale is extremely new, it has demonstrated a high degree of stability, reliability, and convergent and discriminant validity (Brown & Ryan, 2003).
The Digit Span Backward (DSB) subscale of the Wechsler Adult Intelligence Scale, 3rd edition (WAIS III). The Digit Span Backward (DBS; Appendix I) subscale provides a measure of working memory (The Psychological Corporation, 1997). Respondents are presented with strings of random digits, beginning with a 2-digit string (e.g. 2-4, read out to them as "two-four"), and progressing to an 8-digit string (e.g., 9-4-3-7-6-2-5-8), with two trials at each level. They then repeat the numbers in the reverse order to which they were presented (e.g. "four-two" in the first example, above). Incorrect responses gain a score of 0 and correct responses gain a score of 1 (the maximum score is 14). Testing ceases when participants (1) get both trials of a single level incorrect, or (2) successfully complete all sequences. The average reliability coefficient is reported to be greater than .90 (The Psychological Corporation, 1997).
Internal Switching Task The delay between the presentation of each word on the screen and the participants' pressing of the spacebar to update to the next word was recorded automatically as a choice reaction time (RT) by DMDX v.3.0.4, an application which allows RTs to be measured to millisecond accuracy (Forster & Forster, 2003). The independent variable was whether each successive word was of the same or a different semantic category from the one immediately preceding it, representing "nonswitch" and "switch" conditions, respectively. The order of the stimulus words was randomized in terms of both length and frequency, although they were presented in an identical order for each participant. The 80 words in the neutral condition (Appendix J) were presented in blocks of 18, 19, 21 and 22 words, respectively. The 80 words in the affective condition (Appendix K) were presented in blocks of 18, 22, 19 and 21 words, respectively.
The following tasks were administered at T1 and T2 in order to explore the potential relationship between measures of affect, metacognitive processing, and executive function:
Neutral Condition. A total of 80 English words were used, belonging to two semantic categories, food and household objects. The frequency of these words was balanced based on the corpus by Leech, Rayson and Wilson (2001), and the number of letters in each word was balanced between the two semantic groups.
Affective Condition. A total of 80 English words were used, again belonging to two semantic categories, this time positive affective words and negative affective words. Selection was based on ratings in the Affective Norms for English Words (ANEW) by Bradley and Lang (1999). Again, the words were balanced for both length and frequency.