Information integration in judgements of time to contact

Time to contact (TTC) is specified optically by tau, and studies suggest that observers are sensitive to this information. However, TTC judgements also are influenced by other sources of information, including pictorial depth cues. Therefore, it is useful to identify these sources of information and to determine whether and how their effects combine when multiple sources are available. We evaluated the effect of five depth cues on TTC judgements. Results indicate that relative size, height in field, occlusion, and motion parallax influence TTC judgements. When multiple cues are available, an integration (rather than selection) strategy is used. Finally, the combined effects of multiple cues are not always consistent with a strict additive model and may be task dependent.     

Lack of positive experiences and positive expectancies mediate the relationship between BAS responsiveness and depression

The anhedonic symptoms of depression have been linked to a lack of incentive responsiveness, which is a function of the Behavioral Activation System (BAS). Using structural equation modeling within the context of a cross-sectional design, we found that a lack of positive experiences and positive expectancies mediated the BAS-depression link among an undergraduate sample (N = 171). We tested the specificity of this model across four alternative models substituting negative experiences, negative expectancies, threat sensitivity, and symptoms of anxiety for their theoretical counterparts in the original model. In each case, the alternative model did not fit the data as well as our original model. This pattern of results is consistent with the position that a lack of positive experiences and positive expectancies uniquely mediate the relationship between the BAS and anhedonic symptoms of depression.