Awareness in memory: being explicit about the role of sleep

Sleep is crucial to the 'off-line' consolidation of procedural memory. A recent study by Robertson et al. shows that this might hold true only if the task is trained explicitly, that is, with the subject being aware of the task structure. These new data add to emerging evidence that sleep-related memory consolidation involves an interaction between different memory systems.     

Does imminent threat capture and hold attention?

According to models of attention and emotion, threat captures and holds attention. In behavioral tasks, robust evidence has been found for attentional holding but not for attentional capture by threat. An important explanation for the absence of attentional capture effects is that the visual stimuli used posed no genuine threat. The present study investigated whether visual cues that signal an aversive white noise can elicit attentional capture and holding effects. Cues presented in an attentional task were simultaneously provided with a threat value through an aversive conditioning procedure. Response latencies showed that threatening cues captured and held attention. These results support recent views on attention to threat, proposing that imminent threat captures attention in everyone.     

The effect of the September 11 terrorist attacks on suicide and deliberate self-harm: a time trend study

Suicide rates may be affected by world news. Our objective was to investigate the possible impact of the terrorist attacks of September 11, 2001, on suicidal behavior in the Netherlands. There was evidence of an increase in rates of suicide and deliberate self-harm in the weeks immediately following the attacks. These findings contrast with Durkheim's (1897) original suggestion that suicide rates decline in times of war and outside threat but are in line with findings of increases in suicidal behavior after media coverage of lethal violence.     

Parent-adolescent disagreement regarding psychopathology in adolescents from the general population as a risk factor for adverse outcome

This study investigated whether parent-adolescent disagreement regarding adolescents' behavioral and emotional problems predicted adverse outcome. A Dutch sample of 15- to 18-year-olds was prospectively followed across a 4-year interval. The Child Behavior Checklist (CBCL: T. M. Achenbach, 1997) and Youth Self-Report (YSR; T. M. Achenbach, 1991b) were administered at initial assessment, and the following signs of poor outcome were assessed 4 years later: police/judicial contacts, expulsion from school/job, suicidal ideation, unwanted pregnancy, suicide attempts, deliberate self-harm, referral to mental health services, report of having a behavioral or emotional problem, and feeling the need for professional help without actually receiving help. Twenty CBCL syndrome scores, 23 YSR syndrome scores, and 16 discrepancy scores were significant predictors of poor outcome. It was concluded that to determine the prognosis of psychopathology in adolescents, discrepancies between informants may be important.     

On the selective relation of frontal cortical asymmetry and anger-out versus anger-control

The model of anterior asymmetry and emotion proposes an asymmetric representation of approach and withdrawal systems in the left and right anterior brain regions. Within this framework, 3 different concepts have been related to anterior asymmetry: affective valence, motivational direction, and behavioral activation. The aim of the present study was an empirical investigation into the relation between anterior cortical activity and questionnaire measures related to the 3 dimensions positive versus negative affect, approach versus withdrawal motivation, and behavioral activation versus inhibition. Subjects with relative greater left than right frontal cortical activity showed higher anger-out scores and lower anger-control scores. These results support the hypothesis that motivational direction is related to frontal asymmetry (approach-left and withdrawal-right). Furthermore, subjects with greater bilateral (left and right) frontal cortical activity showed higher behavioral activation scores. This finding might suggest that behavioral activation is related to approach and withdrawal motivation.     

The timing of meals

In most individuals, food intake occurs as discrete bouts or meals, and little attention has been paid to the factors that normally determine when meals will occur when food is freely available. On the basis of experiments using rats, the authors suggest that when there are no constraints on obtaining food and few competing activities, 3 levels of interacting controls normally dictate when meals will start. The first is the genetically determined circadian activity pattern on which nocturnal animals tend to initiate most meals in the dark. The second is the regularly occurring changing of the light cycle: These changes provide temporal anchors. The third relates to the size of the preceding meal, such that larger meals cause a longer delay until the onset of the next meal. Superimposed on these 3 are factors related to learning, convenience, and opportunity.     

Reduction of left visual field lexical decision accuracy as a result of concurrent nonverbal auditory stimulation

To investigate whether concurrent nonverbal sound sequences would affect visual-hemifield lexical processing, lexical-decision performance of 24 strongly right-handed students (12 men, 12 women) was measured in three conditions: baseline, concurrent neutral sound sequence, and concurrent emotional sound sequence. With the neutral sequence, Naveteru, Roy, Ovelac, and Steinling (1992) had observed a right greater than left cerebral blood flow, and an opposite pattern with the emotional sequence. In the present study, the neutral sound sequence induced a significant accuracy reduction for lexical decisions to stimuli presented in the left visual field. It is hypothesized that RH activation in response to neutral sounds interferes with the limited lexical processing resources of that hemisphere.     

Perception of biological motion: A stimulus set of human point-light actions

We present a set of stimuli representing human actions under point-light conditions, as seen from different viewpoints. The set contains 22 fairly short, well-delineated, and visually “loopable” actions. For each action, we provide movie files from five different viewpoints as well as a text file with the three spatial coordinates of the point lights, allowing researchers to construct customized versions. The full set of stimuli may be downloaded fromwww.psychonomic.org/archive/.     

Parallel allocation of attention prior to the execution of saccade sequences

In a series of 5 experiments, the allocation of attention prior to the execution of saccade sequences was examined by using a dual-task paradigm. In the primary task, participants were required to execute a sequence of 2 endogenous saccades. The secondary task was a forced-choice letter identification task. During the programming of the saccade sequences, letters were briefly presented at the saccade goals and at no-saccade locations. The results showed that performance was better for letters presented at any of the saccade goals than for letters presented at any of the no-saccade locations. The results support a spatial model that assumes that prior to the execution of a saccade sequence, attention is allocated in parallel to all saccade goals. ((c) 2003 APA, all rights reserved)     

Perception of surface reflectance of 3-D geometrical shapes: influence of the lighting mode

We examined in three experiments whether the perception of surface reflectance in 3-D geometrical shapes is influenced by the mode of lighting, the level of surface reflectance, the number of polyhedral faces, and the regularity of polyhedral shape. As stimuli, we used simulations of regular polyhedra in a 2AFC constant-stimuli procedure to measure how large variations in the reflectance needed to be for observers to be able to tell whether the whole surfaces were uniform or non-uniform. In almost all the cases observers were more successful in discriminating non-uniform polyhedra in the hemispherical diffuse lighting conditions than in the collimated lighting conditions. The different levels of reflectance had no effect on the discrimination of non-uniformity. Second, as the number of faces of the shape increased, discrimination thresholds became lower, indicating that the interpretation of reflectance variations was better when a shape had many faces. Finally, the regularity of the shape, such as the central symmetry, was not an important factor. These results suggest that the interpretation of surface reflectance is more precise when surfaces have less variance in relative strengths between the face luminance values; these surfaces were the ones obtained under hemispherical diffuse lighting.