Affective Attentional Bias Training In Depression: An Eye-Tracking Study

The existence of a negative affective bias in depression has been consistently supported throughout literature and has been identified as one of many factors that are associated with depressive symptomatology. A negative affective bias in depression refers to the fact that individuals with depression or depressive symptoms are more likely to focus on negative stimuli and less likely to pay attention to positive stimuli. Typically, this bias is most prominent and consistent in relation to sad stimuli, as opposed to other negatively valenced stimuli, such as anger or fear. Affective bias has been found to play a role in both the onset and maintenance of depressive disorders, and extends to information interpretation, memory, and attention.

Such findings regarding the influence of this negative affective bias on depressive symptoms has spurred further research that aims to reduce or 'correct' this bias in an attempt to improve mood state and reduce depressive symptoms. This research has generally focused on the use of dot-probe attention bias modification (ABM) paradigms, which are forms of cognitive bias modification that attempt to 'train' attention towards positive stimuli and away from negative stimuli through a manipulation of the dot-probe. ABM paradigms have found success in a number of studies, and have been shown to be effective in decreasing the attentional bias for negative information, increasing attention for positive stimuli, and decreasing depressive symptoms leading to improvements in mood. Thus, ABM research represents a promising avenue for treating depressive symptoms through the elimination of the negative affective bias.

However, the diverse methodology, stimuli, and design of existing research has led to conflicting and inconsistent results, with some studies being either unable to manipulate attention at all or failing to significantly improve mood. The use of the dot-probe paradigm as a means of modifying or training behaviour has been contested, with some findings suggesting that it is unable to induce either a positive or a negative attention bias. Moreover, single-session dot-probe paradigms in particular often fail to achieve any significant effects, which may be a result of insufficient durations to produce a change in attention. Additionally, designs that use negatively valenced emotions other than sadness may be weakened due to the fact that an attentional bias towards negative emotions other than sadness in depression has not been consistently demonstrated. Finally, it is common for similar studies to make use of either dysphoric populations or undergraduate populations with varying degrees of non-clinical depressive symptoms. Oftentimes, such studies fail to produce robust effects, which may be a result of an affective bias being less pronounced in non-clinical populations, or a result of a floor effect, in which less-depressed participants with lower initial depressive scores do not experience statistically significant changes. It would be premature to dismiss the effectiveness of attention modification training for affective biases in depression without addressing, clarifying, and improving upon such potential weaknesses in design and implementation.

The proposed novel attention bias modification study seeks to administer a novel training paradigm that utilizes a reward-based, naturalistic, free-viewing design. It is expected that the design of this study will improve upon past research in four ways: 1) by overcoming the limits of the dot-probe through a free-viewing paradigm; 2) by utilizing only stimuli that represent 'sadness' and no other negatively valenced stimuli; 3) by providing multiple training sessions to induce a meaningful effect on attention; and 4) by providing treatment to individuals with MDD who might be more likely to benefit from ABM for a negative affective bias.

This study will take place over five sessions over approximately two weeks: a pre-training assessment, three sessions of affective bias or sham training, and a post-training assessment. Participants will be asked to complete a brief, at-home measure of mood state on each day between pre- and post-assessments. Participants will be told that the study involves attention and learning, but to preserve blinding, they will only be told that the study is specifically an "attention training" study.