Neurocognitive mechanisms of cognitive control: the role of prefrontal cortex in action selection, response inhibition, performance monitoring, and reward-based learning

Convergent evidence highlights the differential contributions of various regions of the prefrontal cortex in the service of cognitive control, but little is understood about how the brain determines and communicates the need to recruit cognitive control, and how such signals instigate the implementation of appropriate performance adjustments. Here we review recent progress from cognitive neuroscience in examining some of the main constituent processes of cognitive control as involved in dynamic decision making: goal-directed action selection, response activation and inhibition, performance monitoring, and reward-based learning. Medial frontal cortex is found to be involved in performance monitoring: evaluating outcome vis-a-vis expectancy, and detecting performance errors or conflicting response tendencies. Lateral and orbitofrontal divisions of prefrontal cortex are involved in subsequently implementing appropriate adjustments.     

Lying to insurance companies: the desire to deceive among physicians and the public

This study examines the public's and physicians' willingness to support deception of insurance companies in order to obtain necessary healthcare services and how this support varies based on perceptions of physicians' time pressures. Based on surveys of 700 prospective jurors and 1617 physicians, the public was more than twice as likely as physicians to sanction deception (26%versus 11%) and half as likely to believe that physicians have adequate time to appeal coverage decisions (22%versus 59%). The odds of public support for deception compared to that of physicians rose from 2.48 to 4.64 after controlling for differences in time perception. These findings highlight the ethical challenge facing physicians and patients in balancing patient advocacy with honesty in the setting of limited societal resources.     

Sequential modulations of logical-recoding operations in the Simon task

The Simon effect consists of faster responses to the color (or another nonspatial feature) of spatially corresponding stimuli than to spatially noncorresponding stimuli. Recently, several studies observed the Simon effect after corresponding predecessor trials, but not after noncorresponding predecessor trials. To explain these sequential modulations, Stürmer et al. (2002) proposed a mechanism modulating the ability of stimulus position to automatically activate a response. The present study investigated which events are effectively triggering this mechanism in a variant of the Simon task, in which both stimuli and responses varied in color (participants wore colored gloves) as well as in horizontal position. In the same-color task (e.g., green stimulus-green response), a normal Simon effect showed up after corresponding trials, but no effect occurred after noncorresponding trials. In the alternate-color task (e.g., green stimulus-red hand), no effect occurred after spatially corresponding trials, whereas an inverted Simon effect was found after noncorresponding trials. Additional analyses showed that repetition (or alternation) effects did not affect the results. The results are discussed in terms of a conflict-monitoring account (Stürmer et al., 2002), and in terms of a feature-integration account (Hommel et al., 2002).     

Is traumatic amnesia nothing but psychiatric folklore?

Some psychotherapists believe that certain experiences are so overwhelmingly traumatic that some victims become incapable of remembering their worst trauma except under special circumstances (e.g. therapy) many years later. Unfortunately, clinicians who endorse this concept of traumatic amnesia often misinterpret the very studies they adduce in support of it. More specifically, they misinterpret other, unrelated memory phenomena as evidence for traumatic amnesia, such as ordinary forgetfulness, psychogenic amnesia, organic amnesia, incomplete encoding of traumatic experiences, non-disclosure of remembered trauma, and simply not thinking about something for a long time. The purpose of this article is to dispel confusions rampant in this literature.     

Increasing false recognition rates with confirmatory feedback: a phenomenological analysis

During a simulated witness interrogation, participants were encouraged to confabulate an account consistent with false information concerning a videotaped event. The interviewer verbally affirmed some false responses. Previous research has shown that, a week later, participants often recognize confabulated events that were affirmed by the experimenter as being from the video. What is unclear is whether confirmatory feedback encouraged a change in the mental representation of the confabulated events to fit the original event or confirmation might have merely encouraged a change in beliefs about the event. To further understand the mechanisms that underlie the confirmatory feedback effect, participants were asked to judge the phenomenological experience associated with false recognition.     

Biomedical, ethical, and moral issues being forced by advanced medical technologies

Technology is rampant, exponentially growing beyond the bounds normally comprehensible by the human mind. Many of these technologies are so fundamentally disruptive that they challenge the very practice of science. Discoveries once unimaginable except in science fiction are appearing at such a rapid rate that there is no time to evaluate their moral and ethical implications in a deliberate and measured fashion. Genetic engineering, human cloning, tissue engineering, intelligent robotics, nanotechnology, suspended animation, regeneration, and species prolongation are but a few that will revolutionize what it means to be human and what the ultimate fate of the species may be. Unless these issues are addressed at this time, we shall face the consequences of an uncontrolled and unprepared future.