A novel automatic procedure for measuring ocular counterrolling: A computeranalytical method to determine the eye’s roll angle while subjects work on perceptual tasks

In investigations of the perception of space, the consideration of ocular counterrolling-the movement of the eye around its visual axis in response to body movement-is crucially important. The angle of this movement must be known in order for one to determine the precise retinal coordinates of a distal object. Following transformation, this stimulus serves as a reliable cue for visual direction. The otolith organs provide information about body tilt and are responsible for ocular counterrolling. A novel, noninvasive method to measure ocular counterrolling, based on the cross-correlation of digitized video pictures of the eyes, is presented. The resolution attained was ≤ 0.1°. The computer analysis is fully automatic and fast, and it can be performed while subjects work on perceptual tasks. No direct access to the eyeballs is required. Data from 4 subjects showing the counterrolling profile in various body positions are presented.     

Intuitionistic uniformity principles for propositions and some applications

This note deals with the prepositional uniformity principlep-UP: p x N A (p, x) x N p A (p, x) ( species of all propositions) in intuitionistic mathematics.p-UP is implied by WC and KS. But there are interestingp-UP-cases which require weak KS resp. WC only. UP for number species follows fromp-UP by extended bar-induction (ranging over propositions) and suitable weak continuity. As corollaries we have the disjunction property and the existential definability w.r.t. concrete objects. Other consequences are: there is no non-trivial countable partition of;id is the only injective function from to; there are no many-place injective prepositional functions; card () is incomparable with the cardinality of all metric spaces containing at least three elements.     

Integrating velocity,time, and distance information: A developmental study

The development of understanding the relationships between velocity, time, and distance was investigated in three tasks. In each task, values of two dimensions were given, and 5-year-olds, 10-year-olds, and adults had to infer values of the third dimension. These inferences were made in all age groups. The integration rules were found to depend upon age and task. In the distance = time × velocity task, all age groups obeyed the normative multiplication rule. In the time = distance ÷ velocity task, the two older age groups obeyed the normative division rule, but the 5-year-olds shifted to a simpler subtraction rule. In the velocity = distance ÷ time task, which was the most difficult, the two older age groups simplified to use of a subtraction rule, and the 5-year-olds simplified even further to use of a distance-only rule. The knowledge level revealed for young children contrasts sharply with results from previous studies using Piagetian choice tasks, which apparently investigate selective attention to one dimension rather than conceptual understanding of relations.     

Some determinants of task preference and the desire for information about the self

This research examined the influence of task difficulty and diagnosticity (ability information) on task choice and preference. It was found that males preferred diagnostic over non-diagnostic tasks, but among females significant preferences along this variable were not exhibited. Furthermore, the desire to obtain ability-relevant information decreased as a function of prior knowledge about one's ability. Both high and low ability self-perceptions, induced through prior experiences of success and failure, decreased the attraction toward diagnostic in formation. There was no indication that individuals with high ability self-concepts are especially avoidant of further ability-relevant information, as recent literature has suggested. In addition, and contrary to prior findings, difficult tasks were most preferred rather than easy or intermediate tasks, given that diagnosticity is held constant.     

Automatic processes in lexical access and spreading activation.

The semantic priming effect can be reduced or eliminated depending on how the prime word is processed. The experiments reported here investigate this prime task effect. Two experiments used identity and semantic priming tasks to determine whether the prime word is encoded at a lexical level under letter-search conditions. When the prime task was naming, both identity and semantic priming occurred; however, when a letter-search task was performed on the prime word, only identity priming occurred, thus supporting the argument that the search task affects activation of semantic associates rather than lexical access of the prime word. Another experiment demonstrated that this identity priming was the result of lexical processes rather than of letter-by-letter priming. A cross-modal priming technique demonstrated that the letter-search prime task does not actively suppress activation of semantic associates. The implications of these results for automaticity and for proposed mechanisms of priming are discussed.     

The Effect of Attitude Similarity on Task Performance1

It was hypothesized in a two-person situation that students would perform significantly better on intellectual tasks when paired with a liked other than when paired with a disliked other. In a laboratory experiment, 108 male undergraduates performed one of three types of intellectual tasks with an attitudinally similar or dissimilar partner or with a partner about whom the subject had no attitude information. Individuals paired with a similar partner felt affectively more positive than those paired with a dissimilar partner (p < .01). Individuals paired with a similar other performed significantly better on the tasks than those paired with a dissimilar partner (p < .01).