Decisions require careful weighing of the risks and benefits associated with a choice. Some people need to be offered large rewards to balance even minimal risks, whereas others take great risks in the hope for an only minimal benefit. We show here that risk-taking is a modifiable behavior that depends on right hemisphere prefrontal activity. We used low-frequency, repetitive transcranial magnetic stimulation to transiently disrupt left or right dorsolateral prefrontal cortex (DLPFC) function before applying a well known gambling paradigm that provides a measure of decision-making under risk. Individuals displayed significantly riskier decision-making after disruption of the right, but not the left, DLPFC. Our findings suggest that the right DLPFC plays a crucial role in the suppression of superficially seductive options. This confirms the asymmetric role of the prefrontal cortex in decision-making and reveals that this fundamental human capacity can be manipulated in normal subjects through cortical stimulation. The ability to modify risk-taking behavior may be translated into therapeutic interventions for disorders such as drug abuse or pathological gambling.

Children aged 6 to 13 yr. were given verbal and non-verbal fluency tasks as well as the Vocabulary and Block Design subtests of the W I S C R. The results, providing normative data, showed that the fluency tasks are age-, but not sex-depe~dent, and are only modestly correlated to one another and to standard measures of intelligence.

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Imaging work has begun to elucidate the spatial organization of emotions; the temporal organization, however, remains unclear. Adaptive behavior relies on rapid monitoring of potentially salient cues (typically with high emotional value) in the environment. To clarify the timing and speed of emotional processing in the two human brain hemispheres, event-related potentials (ERPs) were recorded during hemifield presentation of face images. ERPs were separately computed for disliked and liked faces, as individually assessed by postrecording affective ratings. After stimulation of either hemisphere, personal affective judgements of face images significantly modulated ERP responses at early stages, 80-116 ms after right hemisphere and 104-160 ms after left hemisphere stimulation. This is the first electrophysiological evidence for valence-dependent, automatic, i.e. pre-attentive emotional processing in humans.

In this study the regional cerebral glucose utilization and the neuropsychological performance of patients with amyotrophic lateral sclerosis (ALS) was investigated. Special attention was given to neuropsychological tests thought to mirror frontal lobe dysfunction. The regional cerebral glucose utilization was studied in 18 patients using high-resolution positron emission tomography. Clinically all patients displayed upper and lower motor neurone signs. In ALS patients glucose metabolism was significantly reduced in the frontal and in the entire cortex compared with controls; no changes were seen in the cerebellum. Comprehensive neuropsychological assessment of ALS patients compared to a pair matched control group revealed mild frontal dysfunction which in part significantly correlated with reduced glucose metabolism in the cortex and subcortical structures. We conclude that in patients with ALS, glucose consumption is decreased in parts of the brain other than the motor cortex accompanied by mild neuropsychological deficits based on the tests employed in this study.

the self. 10 The investigation of out of body experiences and related mechanisms at the temporo-parietal junction might thus allow us to improve our neuroscientific models of self and corporeal awareness. Although many other cortical areas are involved in self processing, recent neuroimaging studies indicate a key role for the temporo-parietal junction. This is not only true for out of body experiences but also for many aspects of body and self processing, such as the integration of multisensory bodily information, the visual perception of the body, the perception of biological motion, and the distinction between self and other. 3 11 12 The experimental investigations of these multi-sensory and cognitive mechanisms in out of body experiences and related illusions, in combination with neuroimaging and behavioural techniques, will further our understanding of the central mechanisms of self and corporeal awareness-much as previous research was successful with respect to understanding the central mechanisms of phantom limbs. 9

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Performance on extra‐sensory perception (ESP) and on subjective random generation (SRG) has been shown independently to differ along a number of personality dimensions. One of the variables known consistently to influence ESP performance but not studied yet in SRG experiments is belief in the paranormal. We report three experiments on subjective randomness as a function of belief in ESP: (1) a retrospective analysis of randomness in multiple choice answers of a telepathy experiment revealed that believers in ESP (‘sheep’) avoided repetitive responses significantly more than non‐believers (‘goats’); (2) in an experiment where subjects had to produce random strings of the digits 1−6, sheep avoided repetitions significantly more than goats; (3) in an experiment where subjects had to compare equiprobable short random sequences, sheep underestimated the number of mathematically expected repetitions significantly more than goats. In all three experiments a stronger bias against the incidence of direct repetitions was found for subjects believing in ESP than for those denying its possibility. This may indicate that believers are more prone to an illusion of causality in the face of everyday coincidences. We suggest that effects of subjective probability and, particularly, of subjective randomness should be considered in future studies concerned with individual differences in ESP scoring.