Perception of danger signals: the role of control

How does the perceptual system process stimuli that signal aversive outcomes or dangers? Considering the functional links between perception, attention, and action regulation, we posit that when people can avoid the aversive consequences, sensitivity of the perceptual system to danger signals should be enhanced, whereas it should be reduced when there is no such option. To test this prediction, we used a search task in which tachistoscopically presented conjunctions of features had to be detected. Parameters of sensitivity and response bias were analyzed drawing on procedures from signal detection theory. Although the experimental procedure rewarded correct responses, the predicted asymmetry emerged. For stimuli that were linked to a negative consequence (loss of points in the experimental game), perceptual sensitivity was enhanced when participants had the opportunity to neutralize the loss in a second task; an opposite pattern emerged when they had no such opportunity.     

Artificially induced valence of distractor words increases the effects of irrelevant speech on serial recall

In a game context, nonwords either were artificially associated with negative valence or were in some sense neutral or irrelevant. Subsequently, participants memorized target words in silence or while attempting to ignore the negatively valent, irrelevant, or neutral auditory distractor nonwords. The presence of distractor nonwords impaired recall performance, but negative distractor nonwords caused more disruption than neutral and irrelevant distractors, which did not differ in how much disruption they caused. These findings conceptually replicate earlier results showing disruption due to valence with natural language words and extend them by demonstrating that auditory features that may possibly be confounded with valence in natural language words cannot be the cause of the observed disruption. Explanations of the irrelevant speech effect within working memory models that specify an explicit role of attention in the maintenance of information for immediate serial recall can explain this pattern of results, whereas structural models of working memory cannot.     

Inflation of conditional predictions

The authors report 7 experiments indicating that conditional predictions--the assessed probability that a certain outcome will occur given a certain condition--tend to be markedly inflated. The results suggest that this inflation derives in part from backward activation in which the target outcome highlights aspects of the condition that are consistent with that outcome, thus supporting the plausibility of that outcome. One consequence of this process is that alternative outcomes are not conceived to compete as fully as they should. Another consequence is that prediction inflation is resistant to manipulations that induce participants to consider alternative outcomes to the target outcome.     

Automatic vigilance for task-related information: Perseverance after failure and inhibition after success

In three experiments, the influence of failure and success on persistent automatic vigilance task-related information was investigated. Participants first had to work on a series of synonym selection problems for which negative and positive feedback was given independently of their performance. In the second part of the experiments, words from the synonym selection problems were presented as distractors in a dual task with speeded responses. Interference effects of the distractors served as a measure of automatic vigilance for the previous synonym selection problems that was unbiased by strategic processes. Interference effects were stronger for words from failure tasks than for words from success tasks. Comparing the success and failure conditions against a neutral baseline suggested that this difference was due to both a perseverance of automatic vigilance for failure tasks and an inhibition of cognitive accessibility after success.     

The influence of an external symbol system on number parity representation, or What’s odd about 6?

The aim of this study was to investigate whether language-specific properties influence mental number processing. German Sign Language (DGS) numbers differ from those in spoken German not only in terms of modality but also in their basic language structure. A group of 20 congenitally deaf German signers participated in a number parity (odd/even) judgment task with DGS and printed German number words. The results indicated that two-handed DGS number signs are processed in a decomposed way. This language-specific effect also generalized to another linguistic number notation, German number words, but not to Arabic digit notation. These differences are discussed with respect to two possible routes to number parity.     

Memory for fact, fiction, and misinformation: the Iraq War 2003

Media coverage of the 2003 Iraq War frequently contained corrections and retractions of earlier information. For example, claims that Iraqi forces executed coalition prisoners of war after they surrendered were retracted the day after the claims were made. Similarly, tentative initial reports about the discovery of weapons of mass destruction were all later disconfirmed. We investigated the effects of these retractions and disconfirmations on people's memory for and beliefs about war-related events in two coalition countries (Australia and the United States) and one country that opposed the war (Germany). Participants were queried about (a) true events, (b) events initially presented as fact but subsequently retracted, and (c) fictional events. Participants in the United States did not show sensitivity to the correction of misinformation, whereas participants in Australia and Germany discounted corrected misinformation. Our results are consistent with previous findings in that the differences between samples reflect greater suspicion about the motives underlying the war among people in Australia and Germany than among people in the United States.     

Language effects in magnitude comparison: small, but not irrelevant

It is assumed that number magnitude comparison is performed by assessing magnitude representation on a single analog mental number line. However, we have observed a unit-decade-compatibility effect in German which is inconsistent with this assumption (Nuerk, Weger, & Willmes, 2001). Incompatible magnitude comparisons in which decade and unit comparisons lead to different responses (e.g., 37_52 for which 3<5, but 7>2) are slower and less accurately responded to than compatible trials in which decade and unit comparisons lead to the same response (e.g., 42_57, for which 4<5 and 2<7). As overall distance was held constant, a single holistic magnitude representation could not account for this compatibility effect. However, because of the inversion property of the corresponding German two-digit number words ("einundzwanzig" ), the language-generality of the effect is questionable. We have therefore examined the compatibility effect with native English speakers. We were able to replicate the compatibility effect using Arabic notation. Thus, the compatibility effect is not language-specific. However, in cross-linguistic analyses language-specific modulations were observed not only for number words but also for Arabic numbers. The constraints imposed on current models by the verbal mediation of Arabic number comparison are discussed.     

Evidence of separable spatial representations in a virtual navigation task

Three experiments investigated spatial orientation in a virtual navigation task. Subjects had to adjust a homing vector indicating their end position relative to the origin of the path. It was demonstrated that sparse visual flow was sufficient for accurate path integration. Moreover, subjects were found to prefer a distinct egocentric or allocentric reference frame to solve the task. "Turners" reacted as if they had taken on the new orientation during turns of the path by mentally rotating their sagittal axis (egocentric frame). "Nonturners," by contrast, tracked the new orientation without adopting it (allocentric frame). When instructed to use their nonpreferred reference frame, both groups displayed no decline in response accuracy relative to their preferred frame; even when presented with reaction formats based on either ego or allocentric coordinates, with format unpredictable on a trial, both groups responded highly accurately. These findings support the assumption of coexisting spatial representations during navigation.