Computer-based tasks.

Six computer-based tasks were created to assess emotion recognition skills and non- emotion processing across three presentation types (static faces, non-verbal

vocalisations, and single words).

2.2.1.1 Emotion recognition tasks. In Chapter 1 several methodological

inconsistencies in the field that may account for the between-study differences in emotion recognition ability in OAs were discussed. Such methodological differences limit our ability to make cross-study comparisons. Thus, to enable meaningful

comparisons across the three experiments in Phase 1 the emotion recognition tasks were designed to be as procedurally similar to each other as possible. Specifically, the emotion experiments in Phase 1 had similar methods: the same emotion types (happy, sad, fear, anger, disgust, and neutral); the same number of response options (six); the equivalent number of trials per category (six per emotion type); and a 4000 ms response time per trial. Further, the visual appearance of the task was matched, as far as possible,

across experiments; on each task the response labels were presented underneath the stimuli (a sound icon was presented on the screen during the auditory task).

Finally, the tasks were also designed to avoid possible response bias as far as possible. A response bias is when a participant responds to a task or questionnaire in a systematic way rather than in the manner that is required by the task (Paulhuss, 1991). For example, participants may press a response key more often than other response keys depending on their position in a scale. To control for the effects of such a response bias, the position of the emotion labels were counterbalanced and this was achieved by

creating several versions of the tasks and varying the position of the response labels across each version. The exception to counterbalancing was the neutral category, as this served to act as a control in the task so the neutral label did not change position.

2.2.1.2 The non-emotion tasks. In addition to the three emotion tasks, each

experiment in Phase 1 included a corresponding non-emotion task (i.e., static faces, short non-verbal sounds, and single words). The inclusion of a non-emotion task that is similar in design and procedure to the emotion task is a novel feature of the research in Phase 1. Orgeta and Phillips (2008) call for research to incorporate non-emotion tasks alongside emotion tasks to determine whether findings in the field reflect deficits in emotion processing or a more general processing impairment. Thus, in the current research, and to be comparable to the emotion tasks, the non-emotion tasks measured non-emotion processing of faces, short sounds, and single words. The tasks were as procedurally comparable to the emotion task as possible; the non-emotion tasks had the same number of trials, response options, and time limit as the emotion tasks. The similarity in methodology was to match task demands across the emotion and non- emotion tasks as far as possible; thus, enabling meaningful comparisons.

For each task the participants were required to attend to and perceive the

to the stimuli, form a categorical judgement, discriminate between six options, select a label, and enter a motor response via a response box. Therefore, not only were the demands the same on each trial but the similarities in the number of trials and the time limit ensured that the task demands between the emotion and non-emotion tasks were as matched as far as possible. The tasks were only dissimilar in the content type (emotion or non-emotion). The similarities between the emotion and the non-emotion tasks enables meaningful conclusions to be made regarding whether the findings on the emotion task can be best explained by emotion processing or general processing ability. For example, if the emotion task is more difficult for both age groups (a main effect of content type) than the non-emotion task then any age-related emotion recognition differences are likely to be due to processing of the emotion stimuli. In contrast, if OAs are less accurate than YAs on both the emotion and non-emotion task (a main effect of age group) then it is probable that OAs have a more general processing deficit that is not limited to emotion processing.

Some researchers have included non-emotion tasks in their studies to investigate the influence of task demands on the emotion recognition task performance. For

example, Circelli, Clark, and Cronin-Golomb (2013) used landscapes (canyon, city, forest, mountain, shore, town, and tropical) as a non-emotion task. The procedure between the emotion and landscape tasks were similar, as participants had to make categorical judgements between seven choices and each task consisted of 10 trials per category. OAs and YAs performed as equally well as each other on the landscape task suggesting that poorer recognition ability of fearful facial expressions in the same OAs, compared to YAs, is unlikely to result from task demands. However, faces portray social cues that arguably are not reflected in landscapes, thus age-related differences in emotion recognition could be attributed to age-related differences in face processing ability (Kiffel, Campenella, & Bruyer, 2005; McKone, Kanwisher, & Duchaine, 2007).

It is, therefore, important that non-emotion tasks test the ability to make non-emotion judgements from stimuli that are as similar as possible to those used in the emotion task.

There is evidence, however, that face-processing ability is not related to age- related emotion recognition differences. Suzuki, Hoshino, and Shigemasu (2007) used a face identification task where participants were required to select from the given options which face was the same as the target face. The findings suggest that emotion recognition accuracy for specific emotion types did not significantly correlate with accuracy on the face-matching task for either YAs or OAs. Whilst correlational analysis does not imply causation the findings suggest that it is unlikely that the age- related emotion recognition deficits are related to face processing abilities. However, there were a few procedural differences between the tasks that have the potential to confound the interpretation of the findings. For instance, the emotion task had 48 trials, as such, had slightly higher task demands than the non-emotion task, which had 30 trials. It is possible that age-related deficits may reflect higher fatigue effects in the emotion task than the non-emotion task. Therefore, to enable meaningful comparisons between the emotion and non-emotion tasks the current research used tasks that were, as far as possible, procedurally alike and used similar stimuli. The specific choice of stimuli for the non-emotion tasks is discussed in more detail in Chapters 3-5, however, static faces displaying neutral expressions, short animal sounds, and words related to parts of the body were used as non-emotion stimuli.

2.2.1.3 Pilot study. All of the computer-based tasks were piloted to ensure good

content validity, in that each stimulus is a good measure of the target behaviour (Burns, 1996) (see Appendix 2.2). For the current tasks content validity was determined by how accurately the participants chose the correct label for each target emotion or non- emotion stimulus. Strictly speaking in the current pilot study the ability to detect the target above that of chance was 17% (1/6 chance = 17% accuracy). This criteria,

however, is lenient so content validity was set at 50% accuracy. Furthermore, the pilot study also assessed whether the emotion and non-emotion tasks differed in accuracy, as it is possible that participants found one of the tasks easier than the other despite the tight methodological controls between the emotion and non-emotion task. Any difference in task difficulty would reduce the ability to make informative comparisons between the two.

Fourteen volunteers (two males and 12 females) responded to a request for participants. Participants were aged between 39 years and 71 years of age (M = 47.14 years; SD = 10.41 years). In general the tasks had good content validity and any stimulus that failed to meet the criteria were replaced by a suitable stimulus used in the practice trials. In all two emotion words, two non-emotion sounds, and two emotion sounds were replaced. As a result of the changes the tasks were considered to have good content validity. Furthermore, there were no differences in accuracy between the emotion and non-emotion tasks on the face and sound tasks (both ps > .05); thus, neither task appeared to be easier than the other. However, the non-emotion words task had higher accuracy than the emotion word task, t(12) = 3.57, p = 0.004 (out of a maximum of 36 the mean accuracy was 30.15 [SD = 2.4] for emotion words and 33.15 [SD = 1.40] for non-emotion words). Therefore, the non-emotion word task might be easier than the emotion task and this needs to be considered when comparing findings on the emotion and non-emotion word tasks.

2.2.2. Standardised tasks.