Constant versus variable response signal delays in speed—accuracy trade-offs: Effects of advance preparation for processing time

In two experiments, we used response signals (RSs) to control processing time and trace out speed—accuracy trade-off (SAT) functions in a difficult perceptual discrimination task. Each experiment compared performance in blocks of trials with constant and, hence, temporally predictable RS lags against performance in blocks with variable, unpredictable RS lags. In both experiments, essentially equivalent SAT functions were observed with constant and variable RS lags. We conclude that there is little effect of advance preparation for a given processing time, suggesting that the discrimination mechanisms underlying SAT functions are driven solely by bottom-up information processing in perceptual discrimination tasks.     

Children's understanding and experience of mixed emotions

Though some models of emotion contend that happiness and sadness are mutually exclusive in experience, recent findings suggest that adults can feel happy and sad at the same time in emotionally complex situations. Other research has shown that children develop a better conceptual understanding of mixed emotions as they grow older, but no research has examined children's actual experience of mixed emotions. To examine developmental differences in the experience of mixed emotions, we showed children ages 5 to 12 scenes from an animated film that culminated with a father and daughter's bittersweet farewell. In subsequent interviews, older children were more likely than younger children to report experiencing mixed emotions. These results suggest that in addition to having a better conceptual understanding of mixed emotions, older children are more likely than younger children to actually experience mixed emotions in emotionally complex situations.     

Evidence for parallel semantic memory retrieval in dual tasks

In this dual-task study, we applied both cross-talk logic and locus-of-slack logic to test whether participants can retrieve semantic categories in Task 2 in parallel to Task 1 bottleneck processing. Whereas cross-talk logic can detect parallel memory retrieval only in conditions of categorical overlap between tasks, the locus-of-slack approach is independent of such restrictions. As was expected, using the cross-talk logic, we found clear evidence for parallel retrieval of semantic categories when there was categorical overlap between tasks (Experiment 1). Locus-of-slack-based evidence for parallel semantic retrieval was found, however, both in conditions with (Experiment 1) and in those without (Experiment 2) categorical overlap between tasks. Crucially,however, increasing the demand for resources required to switch from Task 1 to Task 2 eliminated even the locus-of-slack-based evidence for parallel memory retrieval during the psychological refractory period (Experiment 3). Together, our results suggest that parallel retrieval is not bound to conditions of categorical overlap between tasks but, instead, is contingent upon resources needed for switching between tasks (e.g., Oriet, Tombu, & Jolicoeur, 2005).     

Temporal dynamics of masked word reading

The repercussions of unconscious priming on the neural correlates subsequent cognition have been explored previously. However, the neural dynamics during the unconscious processing remains largely uncharted. To assess both the complexity and temporal dynamics of unconscious cognition the present study contrasts the evoked response from classes of masked stimuli with three different levels of complexity; words, consonant strings, and blanks. The evoked response to masked word stimuli differed from both consonant strings and blanks, which did not differ from each other. This response was qualitatively different to any evoked potential observed when stimuli were consciously visible and peaked at 140ms, earlier than is usually associated with differences between words and strings and 100ms earlier than word-consonant string differences in the visible condition. The evoked response demonstrates a qualitatively distinct signature of unconscious cognition and directly demonstrates the extraction of abstract information under subliminal conditions.     

Subjective reports of stimulus,response, and decision times in speeded tasks: How accurate are decision time reports?

Four experiments examined how accurately participants can report the times of their own decisions. Within an auditory reaction time (RT) task, participants reported the time at which (a) the tone was presented, (b) they decided on the response, or (c) the response key was pressed. Decision time reports were checked for plausibility against the actual RTs, and we compared the effects of experimental manipulations on these two measures to see whether the reported decision times showed appropriate effects. In addition, we estimated the amount of error associated with individual decision time reports by checking how often participants’ decision time reports were implausibly early (i.e., before stimulus onset) or late (i.e., after response), and by using several quantitative models. Overall, the results suggest that decision time reports are not very accurate but they may be usable for some purposes.