The divergent predictions of 2 models of dual-task performance are investigated. The central bottleneck and central capacity sharing models argue that a central stage of information processing is capacity limited, whereas stages before and after are capacity free. The models disagree about the nature of this central capacity limitation. The central bottleneck model claims that central processin...

Some studies suggest that dual-task processing impairs sequence learning; others suggest it does not. The reason for this discrepancy remains obscure. It may have to do with the dual-task procedure often used. Many dual-task sequence learning studies pair the serial reaction time (SRT) task with a tone-counting secondary task. The tone-counting task, however, is not ideal for studying the cogni...

In this paper we give various equivalent characterizations of upper estimates of heat kernels of regular, conservative and local Dirichlet forms on doubling spaces, from both the analytic and probabilistic points of view. The first part of this paper uses purely analytic arguemtn, while the second part focuses on the probabilistic aspects where the exit time plays an important role.

T here is little doubt that we are witnessing a technological revolution. The question is, does this technological revolution have revolutionary economic consequences? In particular, is economic productivity growing at a much faster rate today, and if so, will it continue to do so in the future? In this article, we review recent literature on the measurement of productivity growth in the United...

Historic urban areas are a significant part of each city not only due to having irreplaceable cultural and social resources, but also due to their attractive patterns of life. They have being threatened by strong development trends. This paper aims to investigate the impacts of redevelopment trends in the historic city of Shiraz, Iran. The paper begins by highlighting historical development in ...

In the psychological refractory period (PRP) paradigm, two unmasked targets are presented, each of which requires a speeded response. Response times to the second target (T2) are slowed when T2 is presented shortly after the first target (T1). Electrophysiological studies have previously shown that the P3 event-related potential component is not delayed during T2 response slowing in the PRP par...

Psychologists often dismiss introspection as an inappropriate measure, yet subjects readily volunteer detailed descriptions of the time and effort that they spent on a task. Are such reports really so inaccurate? We asked subjects to perform a psychological refractory period experiment followed by extensive quantified introspection. On each trial, just after their objective responses, subjects ...

Psychological research has documented again and again marked performance decrements whenever humans perform 2 or more tasks at the same time. In fact, the available evidence seems to suggest that any type of behavior is subject to such limitations. The present experiments employed the psychological refractory period (PRP) paradigm to identify a clear exception to this rule: Unconditioned reflex...

The goal of the present experiment was to test the predictions of Central Bottleneck and Central Capacity Sharing models. According to the Central Bottleneck model, dual task interference, as observed in the PRP paradigm, is caused by an all-or-none bottleneck in information processing. The Central Capacity Sharing model postulates that dual task interference is caused by a capacity limited pro...