Lexical Decision Task

• Depressed people will be slightly slower at identifying the lexicality of negative words with respect to positive or neutral words due to attention to (or ``rumination on'') the negativity of such words, unless the words are specifically depressotypic for them. That is, were a word specifically depressotypic for a depressed person, the feedback from affective nodes (or from the amygdala to the hippocampus) is predicted to re-excite exactly this cognition. Thus it is predicted that depressed people will react faster to depressotypic negative words than to neutral, positive or nondepressotypic negative words.
  
• As noted above, different predictions for performance on the lexical decision task are predicted based on how much the ruminative cycle (the proposed hippocampus-amygdala loop) may be expressed with respect to other perceptual mechanisms. For conditions in which a relatively long SD is allowed, it is predicted that relatively few information processing biases may be observed whereas for shorter SD's above some perceptual threshold, more biases may be observed. Importantly, the perceptual threshold for the task short enough to engage information processing biases but long enough to allow positive identification of the stimulus must be empirically determined. As most published affective lexical decision task studies have employed near infinite SD's, and a handful of others have used very short SD's (near 50ms) with relatively small results, it will be important to bracket a reasonable middle ground.