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.     

Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident

This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information.     

Group decision making in hidden profile situations: dissent as a facilitator for decision quality

The effect of diversity in individual prediscussion preferences on group decision quality was examined in an experiment in which 135 three-person groups worked on a personnel selection case with 4 alternatives. The information distribution among group members constituted a hidden profile (i.e., the correct solution was not identifiable on the basis of the members' individual information and could be detected only by pooling and integrating the members' unique information). Whereas groups with homogeneous suboptimal prediscussion preferences (no dissent) hardly ever solved the hidden profile, solution rates were significantly higher in groups with prediscussion dissent, even if none of these individual prediscussion preferences were correct. If dissent came from a proponent of the correct solution, solution rates were even higher than in dissent groups without such a proponent. The magnitude of dissent (i.e., minority dissent or full diversity of individual preferences) did not affect decision quality. The beneficial effect of dissent on group decision quality was mediated primarily by greater discussion intensity and to some extent also by less discussion bias in dissent groups.     

Persistent complex subliminal activation effects: first experimental observations

A strong recent focus on unconscious processes has increased interest in subliminal stimulation and other experimental activation technologies. Five experiments using male and female university students (N = 365) were carried out to compare 5-ms exposures of "mommy and I" stimuli with 5-ms control stimulation. Measures of self-mother similarity and other variables taken 7-14 days after exposure were more strongly correlated among experimental participants. Such complex, persistent effects may follow when powerfully activating stimuli administered under wholly unconscious conditions provokes schematic processing of social information and behavioral confirmation. These scientifically exciting and ethically problematic findings imply a need for further reduction of the role accorded to conscious volition and control in psychology.     

Memories of mother,complementarity and shame: predicting response to subliminal stimulation with "Mommy and I are one"

A poorly understood finding with potentially wide-ranging implications is that subliminal stimulation with "Mommy and I are one" affects behavior. In this study (n= 62), "Mommy and I are one" lowered implicit mood (p= 0.0015) in comparison with a neutral stimulus ("People are walking"). The effect was most pronounced in shame-prone participants with less positive memories of their mother, and low self-mother complementarity (interaction p= 0.0044). Effects of a potentially shame-inducing stimulus ("I am completely isolated") were not significant (ps > 0.11). The results concerning less positive memories of mother replicate previous findings. We suggest that activation of unconscious associative networks explains the data. Though more research is needed, the cognitive content of these networks may involve representations of self-with-mother; for some, the affective content could involve shame.     

The perceived onset time of self- and other-generated actions

Awareness of actions is partly based on the intentions accompanying them. Thus, the awareness of self- and other-generated actions should differ to the extent that access to own and other's intentions differs. Recent studies have found a brain circuit (the mirror-neuron system) that represents self- and other-generated actions in an integrated fashion. This system does not respond to actions made by nonagents, such as machines. We measured the estimated onset time of actions that subjects either executed themselves or observed being executed by someone else or by a machine. In three experiments, the estimates of the machine actions always differed from those of self- and other-generated actions, whereas the latter two were indistinguishable. Our results are consistent with the view that intentions are attributed to others but not to machines. They also raise the interesting possibility that people attribute intentions to themselves in the same way as they do to others.     

A diffusion model analysis of adult age differences in episodic and semantic long-term memory retrieval

Two experiments investigated adult age differences in episodic and semantic long-term memory tasks, as a test of the hypothesis of specific age-related decline in context memory. Older adults were slower and exhibited lower episodic accuracy than younger adults. Fits of the diffusion model (R. Ratcliff, 1978) revealed age-related increases in non-decisional reaction time for both episodic and semantic retrieval. In Experiment 2, an age difference in boundary separation also indicated an age-related increase in conservative criterion setting. For episodic old-new recognition (Experiment 1) and source memory (Experiment 2), there was an age-related decrease in the quality of decision-driving information (drift rate). As predicted by the context-memory deficit hypothesis, there was no corresponding age-related decline in semantic drift rate.     

Domain specificity in experimental measures and participant recruitment: an application to risk-taking behavior

We challenge the prevailing notion that risk taking is a stable trait, such that individuals show consistent risk-taking/aversive behavior across domains. We subscribe to an alternative approach that appreciates the domain-specific nature of risk taking. More important, we recognize heterogeneity of risk profiles among experimental samples and introduce a new methodology that takes this heterogeneity into account. Rather than using a convenient subject pool (i.e., university students), as is typically done, we specifically targeted relevant subsamples to provide further validation of the domain-specific nature of risk taking. Our research shows that individuals who exhibit high levels of risk-taking behavior in one content area (e.g., bungee jumpers taking recreational risks) can exhibit moderate levels in other risky domains (e.g., financial). Furthermore, our results indicate that risk taking among targeted subsamples can be explained within a cost-benefit framework and is largely mediated by the perceived benefit of the activity, and to a lesser extent by the perceived risk.     

How something can be said about telling more than we can know: on choice blindness and introspection

The legacy of Nisbett and Wilson’s classic article, Telling More Than We Can Know: Verbal Reports on Mental Processes (1977), is mixed. It is perhaps the most cited article in the recent history of consciousness studies, yet no empirical research program currently exists that continues the work presented in the article. To remedy this, we have introduced an experimental paradigm we call choice blindness [Johansson, P., Hall, L., Sikström, S., &; Olsson, A. (2005). Failure to detect mismatches between intention and outcome in a simple decision task. Science, 310(5745), 116–119.]. In the choice blindness paradigm participants fail to notice mismatches between their intended choice and the outcome they are presented with, while nevertheless offering introspectively derived reasons for why they chose the way they did. In this article, we use word-frequency and latent semantic analysis (LSA) to investigate a corpus of introspective reports collected within the choice blindness paradigm. We contrast the introspective reasons given in non-manipulated vs. manipulated trials, but find very few differences between these two groups of reports.     

Looking for foes and friends: perceptual and emotional factors when finding a face in the crowd

In a face-in-the-crowd setting, the authors examined visual search for photographically reproduced happy, angry, and fearful target faces among neutral distractor faces in 3 separate experiments. Contrary to the hypothesis, happy targets were consistently detected more quickly and accurately than angry and fearful targets, as were directed compared with averted targets. There was no consistent effect of social anxiety. A facial emotion recognition experiment suggested that the happy search advantage could be due to the ease of processing happy faces. In the final experiment with perceptually controlled schematic faces, the authors reported more effective detection of angry than happy faces. This angry advantage was most obvious for highly socially anxious individuals when their social fear was experimentally enhanced.