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D Zakay

Publications and source records attributed to D Zakay.

16 recordsLinked to original sources
PubMed1996

The relativity of unrealistic optimism.

The influence of the interaction between the valence of a future event and its perceived controllability on the degree of unrealistic optimism (UO) was tested. It was hypothesized that participants, while comparing themselves to an unknown comparison-target, will assign higher occurrence probabilities for positive-controllable events, and lower occurrence probabilities for negative events to themselves, than respective probabilities assigned to a vague comparison-target. It was further hypothesized that in the case of positive-uncontrollable events the probabilities assigned to oneself might be equal or even lower than those assigned to a comparison-target. These hypotheses were supported in a study in which 62 high school students assigned occurrence probabilities to 12 relevant future events representing 4 categories of events, i.e., positive events perceived as controllable or uncontrollable, and negative events perceived as controllable or uncontrollable. The findings are discussed in terms of cognitive and motivational processes.

Adult↗
PubMed1994

Attention reduces perceived brightness contrast.

The effects of attention on brightness perception was investigated in four experiments. In the first three, subjects estimated the brightness of a briefly presented small grey square by selecting a number that corresponded to one of four possible squares varying on a lightness-darkness dimension. In the last experiment, subjects matched the brightness of two peripheral squares, one attended and one unattended. When the stimulus appeared on a white background (Experiments 1, 2, and 4a) it was judged as brighter when attention was directed to its location than when attention was diverted to another location. When the stimulus appeared on a dark background (Experiments 3 and 4b), the opposite pattern of results was obtained: the attended stimulus was judged as darker than the unattended one. These results show that attention reduces the perceived contrast between the stimulus and its background, suggesting that attention enables subjects to provide a more veridical judgement of stimulus brightness by limiting processing resources to the square itself, at the expense of the surrounding background. As attention produced a directional brightness effect rather than just an improvement in report accuracy, the results can be attributed to early perceptual processing effects, hence providing support for early selection views of attention.

Adult↗
PubMed1994

The role of segmentation in prospective and retrospective time estimation processes.

In five experiments, we investigated the effects of the segmentation level of an interval on its perceived duration. A prospective paradigm and an absolute time estimation method were used in two experiments, and in two others we used a retrospective paradigm and a comparative estimation method. A positive relationship was obtained between segmentation level of the estimated interval and its perceived duration under retrospective-comparative conditions for both auditory and tactual stimuli, but no relationship was found under prospective-absolute conditions. The paradigm, estimation method, and segmentation level were jointly manipulated in the fifth experiment. The impact of segmentation was significant under retrospective (both absolute and comparative) and close to significant under prospective-comparative conditions. These findings suggest that high-priority events are perceived and coded as contextual changes and that the impact of segmentation on time estimation is mediated by memory processes.

Adult↗
PubMed1993

The roles of non-temporal information processing load and temporal expectations in children's prospective time estimation.

Children in the pre-operational phase were asked to prospectively estimate the duration of a thirty-second interval. Estimated intervals were either filled by a task demanding non-temporal information processing, or were 'empty'. Children were either expecting a prize after the termination of the to-be-estimated interval, or were not expecting such a prize. Prospective time estimates were highest when a prize was expected and the to-be-estimated interval was 'empty', and lowest when a prize was not expected and the to-be-estimated interval was filled by the task. Accuracy was highest when a prize was expected and a non-temporal task required. These findings were accounted for by an attentional model of prospective time estimation. The similarity between children and adults' prospective time estimation processes was discussed.

Attention↗
PubMed1993

Time estimation methods--do they influence prospective duration estimates?

The validity of an attentional model of prospective time estimation was tested in three experiments. In the first experiment two variables were manipulated: (1) nontemporal information processing load during the estimated interval, and (2) time estimation method, ie production of time simultaneously with the performance of a second task, or reproduction of time immediately upon termination of a task whose duration has to be measured. As predicted, a positive relationship between produced time length and information processing load demanded by a simultaneous task, and a negative relationship between reproduced time length and information processing load during the estimated interval, were found. The results were replicated in a second experiment in which verbal estimates of time were also measured and the objective duration of the estimated interval was varied. The pattern of results obtained for verbal estimates was similar to that obtained for reproduced ones. The results of a third experiment indicated that produced and reproduced times were positively correlated with clock time. The results are interpreted as supporting an attentional model of prospective time estimation.

Adult↗
PubMed1993

Relative and absolute duration judgments under prospective and retrospective paradigms.

A dual-process contingency model of short duration judgment is proposed and tested. The first process, or P(t), is a timer that uses cognitive capacity to keep track of units of time. If capacity is directed toward other tasks, P(t) will record fewer units and produce lower time judgments than when capacity is not directed toward other tasks. This timing process is most likely to affect performance when people know in advance (prospective judgments) that time judgments will be required and when absolute, rather than relative, judgments are made. The second process, or P(m), which is used for retrospective and relative judgments, judges duration on the basis of the number of remembered high priority events (HPEs) occurring during the interval. When this process is used, time judgments increase with the amount of HPEs that can be retrieved at the moment of judgment. Two experiments are reported. Tactual stimuli were presented, and nontemporal information processing load (simple or complex stimuli), type of judgment (absolute or relative), and judgment paradigm (prospective or retrospective) were manipulated. The results obtained support the proposed dual-process contingency model.

Adult↗
PubMed1992

The role of attention in children's time perception.

This study tested the role of attention in 7- to 9-year-old children's time estimation. Based on an attentional model of time estimation, it was hypothesized that prospective estimates of short intervals are a function of the degree to which a child is occupied with the passage of time and is focusing his or her attention on estimating the exposure time of a stimulus. Two experiments with two different manipulations on attentional focus were conducted. Eighty children were exposed to two types of light bulbs, one a big bulb kindled with high intensity and the other a small one kindled with low intensity. The light bulbs were kindled for different intervals ranging from 3 to 10 s. In both experiments children estimated the lighting time of the bulbs in each condition by a reproduction method. In the first experiment prospective time estimates were found to be significantly longer than retrospective ones. In the second experiment children gave shorter time estimates when their attention was attracted away from the time estimation task than when it was not. In both experiments the attentional hypothesis was supported. In addition, support for the "more is more" hypothesis was obtained. Implications for understanding children's time perception processes are discussed.

Attention↗
PubMed1985

The influence of temporal and spatial variation on tactile identification of letters.

This study was designed to show that variation in stimulation has an influence on tactile perception similar to that in the visual modality. Thirty-two subjects were required to identify Hebrew letters by the tactile sense. Identification time was found to be significantly (p less than .01) shorter when subjects could feel the letters both with temporal variation (i.e., vibrations) and spatial variation (i.e., allowing the subjects to move their fingers over the letters) than when the letters were stable. The longest identification time was found when both temporal and spatial variation were absent. The effects of the two types of tactile variation were found to be compensatory, and a possible explanation for that is offered. Possible implications of these results regarding the use of tactile perception in man-machine systems are discussed.

Adult↗