Sweating the small stuff: A meta-analysis of skin conductance on the Iowa gambling task.

To systematically examine the role of anticipatory skin conductance responses (aSCRs) in predicting Iowa Gambling Task (IGT) performance. Secondly, to assess the quality of aSCR evidence for the Somatic Marker Hypothesis (SMH) during the IGT. Finally, to evaluate the reliability of current psychophysiological measurements on the IGT. Electronic databases, journals and reference lists were examined for inclusion. Data were extracted by two reviewers and validated by another reviewer, using a standardised extraction sheet along with a quality assessment. Two meta-analyses of aSCR measures were conducted to test the relationship between overall aSCR and IGT performance, and differences in aSCR between advantageous and disadvantageous decks. Twenty studies were included in this review. Quality assessment revealed that five studies did not measure anticipatory responses, and few stated they followed standard IGT and/or psychophysiological procedures. The first meta-analysis of 15 studies revealed a significant, small-to-medium relationship between aSCR and IGT performance (r= .22). The second meta-analysis of eight studies revealed a significant, small difference in aSCR between the advantageous and disadvantageous decks (r= .10); however, publication bias is likely to be an issue. Meta-analyses revealed aSCR evidence supporting the SMH. However, inconsistencies in the IGT and psychophysiological methods, along with publication bias, cast doubt on these effects. It is recommended that future tests of the SMH use a range of psychophysiological measures, a standardised IGT protocol, and discriminate between advantageous and disadvantageous decks.

Performance Under Stress: An Eye-Tracking Investigation of the Iowa Gambling Task (IGT).

Stress pervades everyday life and impedes risky decision making. The following experiment is the first to examine effects of stress on risky decision making in the Iowa Gambling Task (IGT), while measuring inspection time and conscious awareness of deck contingencies. This was original as it allowed a fine grained rigorous analysis of the way that stress impedes awareness of, and attention to maladaptive financial choices. The extended Cognitive Reflection Task (CRT) further afforded examination of the impact of impaired reflective thinking on risky decision making. Stressed participants were slower to avoid the disadvantageous decks and performed worse overall. They inspected disadvantageous decks for longer than the control condition and were slower in developing awareness of their poor deck quality compared to the control condition. Conversely, in the control condition greater inspection times for advantageous decks were observed earlier in the task, and better awareness of the deck contingencies was shown as early as the second block of trials than the stress condition. Path analysis suggested that stress reduced IGT performance by impeding reflective thinking and conscious awareness. Explicit cognitive processes, moreover, were important during the preliminary phase of IGT performance-a finding that has significant implications for the use of the IGT as a clinical diagnostic tool. It was concluded that stress impedes reflective thinking, attentional disengagement from poorer decks, and the development of conscious knowledge about choice quality that interferes with performance on the IGT. These data demonstrate that stress impairs risky decision making performance, by impeding attention to, and awareness of task characteristics in risky decision making.

Contrast class cues and performance facilitation in a hypothesis-testing task: evidence for an iterative counterfactual model.

Hypothesis-testing performance on Wason's (Quarterly Journal of Experimental Psychology 12:129-140, 1960) 2-4-6 task is typically poor, with only around 20% of participants announcing the to-be-discovered "ascending numbers" rule on their first attempt. Enhanced solution rates can, however, readily be observed with dual-goal (DG) task variants requiring the discovery of two complementary rules, one labeled "DAX" (the standard "ascending numbers" rule) and the other labeled "MED" ("any other number triples"). Two DG experiments are reported in which we manipulated the usefulness of a presented MED exemplar, where usefulness denotes cues that can establish a helpful "contrast class" that can stand in opposition to the presented 2-4-6 DAX exemplar. The usefulness of MED exemplars had a striking facilitatory effect on DAX rule discovery, which supports the importance of contrast-class information in hypothesis testing. A third experiment ruled out the possibility that the useful MED triple seeded the correct rule from the outset and obviated any need for hypothesis testing. We propose that an extension of Oaksford and Chater's (European Journal of Cognitive Psychology 6:149-169, 1994) iterative counterfactual model can neatly capture the mechanisms by which DG facilitation arises.

Dual-goal facilitation in Wason's 2-4-6 task: what mediates successful rule discovery?

The standard 2-4-6 task requires discovery of a single rule and produces success rates of about 20%, whereas the dual-goal (DG) version requests discovery of two complementary rules and elevates success to over 60%. The experiment examined two explanations of DG superiority: Evans' (1989) positivity-bias account, and Wharton, Cheng, and Wickens' (1993) goal-complementarity theory. Two DG conditions were employed that varied the linguistic labelling of rules (either positively labelled Dax vs. Med, or mixed-valence "fits" vs. "does not fit"). Solution-success results supported the goal-complementarity theory since facilitation arose in both DG conditions relative to single-goal tasks, irrespective of the linguistic labelling of hypotheses. DG instructions also altered quantitative and qualitative aspects of hypothesis-testing behaviour, and analyses revealed the novel result that the production of at least a single descending triple mediates between DG instructions and task success. We propose that the identification of an appropriate contrast class that delimits the scope of complementary rules may be facilitated through the generation of a descending instance. Overall, our findings can best be accommodated by Oaksford and Chater's (1994) iterative counterfactual model of hypotheses testing, which can readily subsume key elements of the goal-complementarity theory.