Implicit measures

Hostility: Word Completion Task (WCT; Anderson, Carnagey & Eubanks, 2003)

The WCT is a novel implicit cognitive assessment for the measure of a hostility bias. The WCT comprises a list of 98 words with one or more letters missing, and requires the respondent to fill in the missing letters to form a completed word. The missing letters are strategically presented so that for each item in the list more than one

100 word can be formed. For example, one item is presented as: “explo_e” which may be completed as “explore” or “explode”. Participants were advised not to spend too long on any one item and complete as many words in the list as they can. Participants’

responses were then coded into the following categories: aggressive words, neutral words, ambiguous words, and non-words. A hostile bias score was then derived by dividing the number of aggressive word completions by the total number of completions. Forty-nine of the items in the list can yield an aggressive word when completed.

Rumination: Emotional Stroop Task

Several relevant studies have used variants of the emotional Stroop task, in which individuals are required to name the colour of stimuli rather than paying attention to its affective meaning (Williams, Mathews & MacLeod, 1996). It is believed that rumination involves selective attention processes that favour a particular type of affective input. As such, difficulties in disengaging from this particular attention is inferred from slower colour-naming latencies for a given type of affective stimulus, for instance, one with a hostile meaning. A study that has used a task of this type found that individuals higher in trait anger displayed a delayed colour-naming performance when the stimulus was a hostile word (Smith & Waterman, 2005).

Development of an emotional Stroop task for this study involved selection, assessment and ordering of the words to be included. Thirty anger-related words which represent the emotional stimulus words and 30 neutral-related words in the task were taken from John (1998). These words have norms established by ratings of emotional content. Emotionality ratings ranged from 1 to 7; the higher rating number indicated an increased emotion invoking word. All 30 angry words had an average rating from 6.51 (e.g., hate) to 3.74 (e.g., friction). All 30 neutral words had average rating from 1.20 (e.g., tray) to 1.52 (e.g., indirect). These words were arranged in 5 blocks, with 6 emotional words and 6 neutral words in each block (See Figure 5.2.). Each block was tested using analysis of variance for word length, emotional intensity and frequency to ensure they were all equal. Four colours were used (Blue, Green, Red and Yellow) and assigned to each word, whilst, ensuring that a different colour in the previous trial was not the same when the new block of words followed in the sequence of the task. All blocks were balanced to ensure that an equal amount of each colours were used. In

101 addition to the emotional words and neutral words, 18 congruent (the word presented in a matching colour) and 18 incongruent (the word presented in a non-matching colour) trials were included in the Stroop paradigm.

Block 1 Block 2 Block 3 Block 4 Block 5

Green Violent Yellow Angry Vicious

Red Bitter Blue Evil Cruel

Blue Attack Green Assault Spite

Yellow Annoy Red Enemy Critical

Red Stubborn Yellow Ranting Mean

Blue Fist Green Bold Rebel

Green Margin Killing Lens Salad

Blue Wrist Cross Whatever Porch

Red Weekly Quarrel Juice Jacket

Yellow Bag Provoke Wagon Pen

Blue Butter Awkward Zone Somehow

Red Bread Stern Total Resident

Hate Lock Red

Hostile Maple Blue

Rage Sandwich Yellow

Mad Quarter Green

Inflict Library Red

Friction Replace Blue

Tray Yellow Red

Context Green Blue

Zero Red Yellow

Vitamin Blue Green

Heel Yellow Blue

Indirect Green Green

The design of the task was arranged in the following order: Block 1 – Congruent, Incongruent, Emotional and Neutral. Block 2: Emotional and Neutral. Block 3:

Incongruent, Emotional, Neutral and Congruent. Block 4: Emotional and Neutral. Block 5: Emotional, Neutral, Congruent and Incongruent. In total, this arrangement consisted of 96 trials within the task.

The Emotional Stroop task was administered via a laptop computer using a purpose designed Microsoft Windows program. The program generated and presented the trials in the task, and recorded the audible responses and the response time for

102 each trial. All words appeared in one of four colours on a black background for 700ms for each trial. Participants were instructed to name the colour of the word as quickly as possible, rather than reading the word. Response time recordings were defined at the onset of speech. Recordings of correct and incorrect trials were also retrieved. A rumination score was derived by the average emotional word response time minus the average neutral word response time (Larsen, Mercer & Balota, 2006; Wentura,

Rothermund & Bak, 2000).

Effortful Control: Wisconsin Card Sorting Test-64: Computer Version 4 (WCST; Heaton, 1990)

The WCST is primarily used to assess for perseveration and abstract thinking, but it is also considered as a measure of executive function because of its reported sensitivity to frontal lobe dysfunction. The use of the WCST in this study to measure the concept of effortful control required the respondent to develop and maintain an

appropriate problem-solving strategy, across changing stimulus conditions in order to achieve a future goal. The WCST provides objective measures for overall success and identifies particular sources of difficulty on the task such as: inefficient initial

conceptualisation, perseveration, failure to maintain a cognitive set, and inefficient learning across stages of the test.

The test was structured with four stimulus cards that incorporate three stimulus parameters: colour, form, and number. Respondents were required to sort cards

according to different principles and to alter their approach during test administration. In order to complete the task, it was ensured that respondents had normal or corrected vision and hearing, to be able to comprehend the instructions and to visually

discriminate the stimulus parameters.

The administration of the test was conducted on a laptop computer. Respondents were advised that their task was to match each of the cards that appear on screen to either one of the four key cards. The software automatically informed the respondent whether the choice they made in matching the card was correct or incorrect on each trial. There were 128 cards/trials in total. Completion time of the test usually varies between individuals. A report of the respondents’ performance of the test was produced

103 with raw score to normalised standard, percentile and T-score conversions.

Perseveration scores were used to indicate patient’s effortful control in this study (Serper et al, 2008).