Effects of a Brief Mental Exercise on Emotional Processing

Participants are presented with individual pictures of facial expressions of emotions. Each presented face displays one of six basic emotions (anger, disgust, fear, happiness, sadness, or surprise). Each emotional expression is presented at different levels of intensity which have been created by combining shape and texture features of the two extremes "neutral" (0%) and "full prototypical emotion" (100%) to varying degrees. Examples of neutral facial expressions are presented as well. Participants are instructed to correctly classify each facial expression as angry, disgusted, fearful, happy, sad, surprised or neutral both as quickly and as accurately as possible. Responses are made by pushing one out of seven labelled keys on a response box. Hit rates, false alarm rates, and reaction times for correct classifications are measured separately for each emotion.

Participants are presented with positive and negative personality descriptors and are asked to classify the valence of each word. These words describe either extremely agreeable/positive characteristics (e.g. "cheerful", "honest", "optimistic") or extremely disagreeable/negative characteristics (e.g. "domineering", "untidy", "hostile") and are presented individually in the centre of the screen. Participants are instructed to imagine themselves overhearing someone describing them with each of the words and to indicate as quickly and accurately as possible whether they would like or dislike to be described with each of the words. Responses are made by pressing a correspondingly labelled key on a button box. Reaction times for correct classifications are measured separately for positive and negative words.

Pictures of positive and negative emotional stimuli (happy and fearful facial expressions) are presented individually together with a matched neutral stimulus (neutral face). On each trial, one stimulus is shown above and the other below a central fixation point. Subsequently, a probe appears behind one of the stimuli and participants have to correctly classify the probe as quickly and as accurately as possible. Stimuli can be masked (i.e. presented very briefly and followed by a jumbled face) or unmasked (i.e. presented for a longer period without a subsequent masking stimulus). Reaction times for correct responses are recorded and vigilance scores are calculated for masked and unmasked positive and negative stimuli by subtracting reaction time data from trials when the probe appeared in the same position as the emotional stimulus (congruent trials) from trials when the probe appeared in the opposite position to the emotional stimulus (incongruent trials).

Following a delay period after the emotional categorisation task (about 15 min), emotional recall memory is assessed. Participants are asked to recall and write down as many words as possible from the emotional categorization task. Numbers of correctly and incorrectly recalled positive and negative words are measured.

Following the emotional recall task, emotional recognition memory is assessed by presenting participants with the original personality descriptors plus an equal number of matched distractor words (50% positive, 50% negative). Participants are asked to indicate for each word as accurately and as quickly as possible whether they recognise it from the emotional categorization task. Numbers of correctly and incorrectly recognised items as well as reaction times for correct recognitions are measured separately for positive and negative words.

Salivary cortisol is assessed prior to and after completion of the 7-day exercise period. For each assessment, participants have to provide five saliva samples taken in their own home (0, 15, 30, 45, and 60 minutes after awakening).

Center for Epidemiologic Studies Depression Scale Revised. Standard questionnaire to assess symptoms of depression. Total score ranging from 0 to 60 with higher scores indicating higher levels of depressive symptoms.

Authentic Happiness Inventory. Questionnaire developed to assess authentic happiness levels. Scores ranging from 0 to 120 with higher scores indicating higher happiness levels.

State-Trait Anxiety Inventory. Standard questionnaire for subjectively felt anxiety. Two scores: (1) State anxiety: ranging from 20 to 80 (higher scores indicating higher state anxiety levels). (2) Trait Anxiety: ranging from 20 to 80 (higher scores indicating higher trait anxiety levels).

Zersen's Befindlichkeits-Skala. Standard questionnaire for subjectively felt mood and energy levels. Total score ranging from 0 to 112. Subscores: Mood (ranging from 0 to 94) and Energy (ranging from 0 to 18). Sum of subscores for mood and energy provide total score. Higher scores represent worse subjective mood and energy

Positive and Negative Affect Schedule. Standard questionnaire for subjectively felt positive and negative affect. Two scores: (1) Positive score: ranging from 10 to 50 (higher score representing greater extent of positive affect). (2) Negative score: ranging from 10 to 50 (higher score representing greater extent of negative affect).

Beck Depression Inventory. Standard questionnaire for assessment of depression severity. Scores ranging from 0 to 63 with higher scores indicating greater depressive severity.

Visual Analogue Scales of different subjective states (anxious, alert, happy, sad, angry, disgusted, afraid). Minimum = 0 mm ("Not at all") , Maximum = 96 mm ("Extremely"). Greater scores represent greater extent of felt emotions.

Written records of positive events will be coded according to theme. Prevalence of each theme will be analysed.