Preferred gaze direction and the vergence system at rest]

In two experiments the effects of binocular vergence, head tilt, and prolonged gaze inclination on the preferred vertical gaze direction were studied. Concurrently, dark vergence was measured to test a hypothesis on the effect that binocular vergence has on the preferred vertical direction of gaze. The previously reported influence of observation distance on the preferred gaze inclination was replicated. When the head was tilted backward, the preferred gaze inclination was lower and the effect of observation distance was reduced; when the head was tilted forward, the preferred gaze inclination was higher and the effect of observation distance was increased. After prolonged upward or downward gaze inclination the preferred vertical gaze direction was shifted up or down, respectively, while the effect of observation distance remained constant. Overall the change of the preferred vertical direction of gaze upon binocular fixation of near stimuli was accompanied by a reduced discrepancy between convergence and the resting state of the vergence system; additional implications of the hypothesis on the relation between individual resting vergence and the effect of observation distance on the preferred inclination of gaze could not be substantiated.     

The influence of movement cues on intermanual interactions

In two experiments, we studied intermanual interactions in bimanual reversal movements and bimanual aiming movements. Targets were presented on a monitor or directly on the table on which the movements were produced. Amplitudes for each hand were cued symbolically or spatially either in advance of an imperative signal or simultaneous with it. In contrast to findings of Diedrichsen et al. (Psychological Science, 12, 493–498, 2001), reaction times for different-amplitude movements were longer than for same-amplitude movements both for symbolic and spatial cues presented on the monitor and directly on the table. However, with symbolic cues the effect of the relation between target amplitudes was considerably stronger than with spatial cues, no matter where the cues were presented. Intermanual correlations of amplitudes, movement times, and reaction times were smaller with different than with same target amplitudes, and this modulation was more pronounced when targets and cues were presented on the monitor than when they were presented on the table. The findings are taken to suggest that the basic reaction-time disadvantage of different-amplitude movements results from interference between concurrent processes of amplitude specification. Additional factors like interference between concurrent processes of mapping cues on movement characteristics may add strongly to it.     

Speeded detection and increased distraction in fear of spiders: evidence from eye movements

Anxiety patients exhibit attentional biases toward threat, which have often been demonstrated as increased distractibility by threatening stimuli. In contrast, speeded detection of threat has rarely been shown. Therefore, the authors studied both phenomena in 3 versions of a visual search task while eye movements were recorded continuously. Spider-fearful individuals and nonanxious control participants participated in a target search task, an odd-one-out search task, and a category search task. Evidence for disorder-specific increased distraction by threat was found in all tasks, whereas speeded threat detection did not occur in the target search task. The implications of these findings for cognitive theories of anxiety are discussed, particularly in relation to the concept of disengagement from threat.     

Models for response-response compatibility: The effects of the relation between responses in a choice task

A simple model is presented that consists of a stimulus-discrimination module and a motor-programming module. The motor-programming module is intended to account for RR-compatibility effects in different types of task. In combination with the stimulus-discrimination module, it is applied to a choice-RT task in which subjects have to perform rapid movements with the left or right hand in response to a left or right signal. The spatio-temporal patterns of the movements that have to be performed with the one or the other hand can be same or different. In the model the relation between the responses is mapped on the strength of inhibitory crosstalk between concurrent processes of motor programming. The stimulus-discrimination module implements a variant of an accumulator model or a random-walk model, and the transmission of information to the programming module can be continuous or discrete. Data that were generated by a model with discrete transmission were inconsistent with available experimental data. With continuous transmission, RR-compatibility effects can result from inhibitory crosstalk during concurrent processes of motor programming after presentation of the response signal and/or from the limiting effect of crosstalk on the level of pre-programming.     

Induced motion and oculomotor capture

Three experiments investigating the basis of induced motion are reported. The proposition that induced motion is based on the visual capture of eye-position information and is therefore a subject-relative, rather than object-relative, motion was explored in the first experiment. Observers made saccades to an invisible auditory stimulus following fixation on a stationary stimulus in which motion was induced. In the remaining two experiments, the question of whether perceived induced motion produces a straight ahead shift was explored. The critical eye movement was directed to apparent straight ahead. Because these saccades partially compensated for the apparent displacement of the induction stimulus, and saccades to the auditory stimulus did not, we conclude that induced motion is not based on oculomotor visual capture. Rather, it is accompanied by a shift in the judged direction of straight ahead, an instance of the straight ahead shift. The results support an object-relative theory of induced motion.     

Intermanual cross-talk effects in unimanual choice reactions

Intermanual interactions originate at different levels of motor control. Interactions during specification of movement characteristics should affect reaction time for choice between left-hand and right-hand movements. In two experiments combinations of short and long target amplitudes for reversal movements of the left and right hand were cued with variable precueing intervals. Upon presentation of the response signal a unimanual left-hand or right-hand movement had to be produced. Reaction time was faster when same target amplitudes were precued than when different target amplitudes were. At short precueing intervals the longer reaction time with different target amplitudes (early effect) was accompanied by an amplitude assimilation: Short amplitudes were too long, and long amplitudes were too short. At longer precueing intervals the longer reaction time with different target amplitudes (late effect) was accompanied by a higher choice accuracy. These findings are taken to indicate a transient parametric coupling of amplitude specifications, which produces the early and the late effects by way of different mechanisms-namely different degrees of advance specification and generalized de-coupling, which affects the process of choice between hands.     

Forced choice reaction time paradigm in children with separation anxiety disorder, social phobia, and nonanxious controls

Cognitive distortions refer to cognitive processes that are biased and therefore yield dysfunctional and maladaptive products (e.g., interpretation bias). Automatic aspects of information processing need to be considered and investigating these aspects requires forms of assessment other than self-report. Studies focussing on the specificity of cognitive biases across different types of anxiety disorders in childhood are rare. Thus, a forced choice reaction time paradigm with picture stimuli was used to assess the interpretation bias in anxious children online. The study investigated disorder-specific interpretation bias in 71 children with separation anxiety disorder (SAD), 31 children with social phobia, and 42 children without mental disorders, aged 5–13 years. Results indicated that children with SAD rated ambiguous separation pictures as significantly more unpleasant and more arousing than nonanxious children. However, no support was found that children with SAD and social phobia interpret ambiguous separation or social pictures in a more negative way than nonanxious children. Furthermore, no group differences were found in reaction times to all picture categories.     

Whose “Storm and Stress” Is It? Parent and Child Reports of Personality Development in the Transition to Early Adolescence

The present study investigated Big Five personality trait development in the transition to early adolescence (from the fifth to eighth grade). Personality traits were assessed in 2,761 (47% female) students over a 3‐year period of time. Youths’ self‐reports and parent ratings were used to test for cross‐informant agreement. Acquiescent responding and measurement invariance were established with latent variable modeling. Growth curve models revealed three main findings: (a) Normative mean‐level changes occurred for youths’ self‐report data and parent ratings with modest effects in both cases. (b) Agreeableness and Openness decreased for self‐reports and parent ratings, whereas data source differences were found for Conscientiousness (decreased for self‐reports and remained stable for parent ratings), Extraversion (increased for self‐reports and decreased for parent ratings), and Neuroticism (remained stable for self‐reports and decreased for parent ratings). (c) Girls showed a more mature personality overall (self‐reports and parent ratings revealed higher levels of Agreeableness, Conscientiousness, and Openness) and became more extraverted in the middle of adolescence (self‐reports). Personality changes modestly during early adolescence whereby change does not occur in the direction of maturation, and substantial differences exist between parent ratings and self‐reports.