Identifying mood- and age-related differences in attentional biases in dysphoria : an eye-tracking study : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Palmerston North, New Zealand

Previous research has indicated that individuals who experience depression selectively attend to negative information for greater periods of time than non-depressed individuals. This negative bias may reflect difficulty disengaging from negative stimuli that is not seen in non-depressed individuals. While there has been a high level of researcher interest in this arena, no studies have investigated the presence of a negative bias in older adults. Accordingly, the present study employed eye tracking techniques to investigate differences in negative biases between dysphoric (n = 27; 14 younger adults; 13 older adults) and non-dysphoric (n = 29; 14 younger adults; 15 older adults) participants by presenting competing emotionally valenced stimuli. In an additional stage of the experiment, the presence of an interpretation bias was investigated whereby participants rated the previously viewed images for perceptions of ‘mood’. Results from the eye tracking task were mixed, with partial support being found for a negative bias in dysphoric participants. Similarly, partial support was found for the hypothesis that non-dysphoric participants would attend to positive stimuli for greater periods of time than dysphoric participants. No age-related differences were found in the non-dysphoric group when attending to sad and happy images. However, when attending to sad images, younger dysphoric participants showed greater average glance durations than older dysphoric participants. Results from the rating task were also mixed. No evidence of a negative interpretation bias was found in the dysphoric group. Similarly no evidence of a positive interpretation bias was found in the nondysphoric group. Consistent with previous research, older non-dysphoric participants provided more positive ratings for happy images compared to younger non-dysphoric participants. Although overall results are not consistent with previous research, methodological issues in the present study may go some way to explain these inconsistencies. Limitations in using eye tracking techniques on older adults offer one possible explanation. Further, the sub-clinical level of dysphoria in the present sample suggests that negative biases are most evident at severe, clinical levels of depression