Evidence for the Bypass of the Response-Selection Bottleneck in Tasks with Reflexive Responses in Younger and Older Adults

This study investigated dual-task processing in younger and older adults using a psychological refractory period procedure. The first task was to name the color framing a picture; the second task was to either press a button or tilt their body in the direction of the tilt of the picture. In the body-tilt condition, electromyography was used to determine the reaction time. The stimulus-onset asynchrony (SOA) between the onset of the color and tilting of the picture varied from 50 to 1000 ms. In contrast with the response selection bottleneck model, which claims that processing of a second task cannot be completed until the first task is finished, the mode of response for the two tasks directly impacted the ability to avoid the bottleneck. In the body-tilt condition the increase in reaction time to the second task with decreasing SOA was less than in the button press condition, suggesting that processing of the second task could begin before processing of the first task was completed. This was true for both younger and older adults. Contrary to previous findings that older adults cannot engage in simultaneous processing of two tasks, evidence was found that older adults, like younger adults, could bypass the cognitive bottleneck if the second task has a reflexive component

Ideomotor-Compatible Tasks Partially Escape Dual-Task Interference in Both Young and Elderly Adults

Under most circumstances, it is not possible to carry out central processing for 2 tasks at the same time; effectively there is a bottleneck. Nevertheless, in 2 experiments it is demonstrated here that both younger and older adults are able to partially bypass the bottleneck in a psychological refractory period procedure, even without extensive training, when the 2nd of the 2 tasks is a saccade or a body tilt in the direction of rotation of a visual stimulus. Consistent with earlier research, the findings showed that younger adults can bypass when the second task has ideomotor-compatible stimuli and responses. Most strikingly, they demonstrated that bypass can also occur in older adults. Overall, the findings are inconsistent with any categorical claim that younger adults can bypass the dual-task bottleneck whereas older adults cannot. The construct of ideomotor-compatible tasks may comprise 2 quite different classes of experimental procedures

Energy levels of Z = 11−21 nuclei (IV)

Compilation of experimentally determined properties of energy levels of Z = 11−21 nuclei with special emphasis on nuclear spectroscopy