Reaction time changes with the hazard rate for a behaviorally relevant event when monkeys perform a delayed wrist movement task

2008 ◽  
Vol 433 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Yoshiaki Tsunoda ◽  
Shinji Kakei
2016 ◽  
Vol 9 (2) ◽  
pp. 119 ◽  
Author(s):  
Marjan Erfani ◽  
Hedayat Sahraei ◽  
Zahra Bahari ◽  
Gholam Hossein Meftahi ◽  
Boshra Hatef ◽  
...  

<strong></strong><p><strong>BACKGROUND:</strong> Time change (which can lead to sleep duration decrements) can lead to brain dysfunction if repeated. In the present study, cognitive functions of the volunteers were evaluated before and after the time changes in Tehran.</p><p><strong>METHODS:</strong> Eleven, voluntary healthy persons (21±2 year old) were evaluated for their cognitive functions including sustain attention, reaction time, and mental fatigue twenty-one days before the time changes and thirty-eight days after time change using PASAT software. In addition, plasma cortisol level was measured before and after the time changes.</p><p><strong>RESULTS:</strong> After the time changes salivary cortisol concentration increase, but general mental health was decreased. Sustain attention was shortened after time change which was significantly different compared with before the time changes. Reaction time was increased after the time changes in comparison with the before the time changes, but was not statistically significant. In addition, mental fatigue was increased after the time changes.</p><p><strong>CONCLUSION:</strong> It seems that time change may reduce brain cognitive functions which are manifested by general mental health, sustain attention reduction, reaction time as well as mental fatigue.</p>


1979 ◽  
Vol 11 ◽  
pp. 48
Author(s):  
Satoshi Iwase ◽  
Toru Ukai ◽  
Yutaka Kato ◽  
Hideo Saka ◽  
Akio Sato ◽  
...  
Keyword(s):  

Author(s):  
Yuan-chun Huang ◽  
Lan-peng Li ◽  
Zhi-gang Liu ◽  
Hai-yan Zhu ◽  
Lin Zhu

This paper describes an experiment conducted to establish a workload model by employing physiological methods to measure driver workload and fatigue under real working conditions. Experienced healthy metro drivers were selected as subjects; they performed normal schedules during which simultaneous electrocardiogram (ECG) recording was used to assess their levels of fatigue. Then, subjective workload assessment and reaction time tests were conducted during each break interval to monitor the drivers’ physiological and psychological performance. Based on task analysis, driving workload models with time weight parameters of four types of tasks were established and the workload real-time changes during different shifts were evaluated. The results demonstrate that workload tends to increase over time and it is significantly higher during manual driving mode than autonomous mode ( p = 0.015 < 0.05). Driving fatigue occurs earlier in the night shift than in the day shift according to ECG spectrum analysis results. Although the results of reaction time tests show no significance ( p = 0.917 > 0.05), the increase in the number of reaction errors after fatigue driving indicates a reduction in drivers’ cognitive ability. Regression analysis shows a significant regression relationship with a mutual incentive effect between workload and fatigue in three shifts ( R2 > 0.4). These will be used as a future reference for fatigue research and to help develop reasonable schedules to ensure operational safety.


1981 ◽  
Author(s):  
Lj Popović

Changes in reaction time of clot assays are usually expressed only in time units, which fails to indicate the extent of the increase or decrease of the reaction time of the tested specimens against that of the basic sample. Reaction time increases of, e.g. , 6 seconds in tested samples, compared to basic sample reaction times of 12 and 24 seconds respectively, signify an increase twice as large in the first as in the second instance.Changes in reaction time of clot assays can be expressed as the increment or decrement of the reaction time per time unit. This amount of increase or decrease (positive or negative alteration of reaction time, T a ) can be expressed as the quotient of the difference between the reaction times of the tested (T x ) and basic (To) samples and of the basic sample, e.g. in seconds per second, T a =T x -To/To. A test sample reaction time 6 seconds longer than basic sample reaction times of 12 and 2k seconds would mean an increase of 0.5 and 0.25 seconds per second, respectively.Reaction time changes of tested samples against that of the standard sample (T std ) can be calculated in a similar way, T a =T x -T std /T std .It can be assumed that this parameter reflects the intensity of the increase or decrease of reaction time per time unit. The quotient of the tested and basic samples can be considered as the coefficient of the increase or decrease of the total reaction time (CT=T x /To).


1986 ◽  
Vol 24 (5) ◽  
pp. 649-658 ◽  
Author(s):  
Antonio Tartaglione ◽  
Giovanni Bino ◽  
Marcello Manzino ◽  
Luciano Spadavecchia ◽  
Emilio Favale

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10084-10084
Author(s):  
Omar Farooq Khan ◽  
Ellen R. Cusano ◽  
Soundouss Raissouni ◽  
Mica Pabia ◽  
Johanna Haeseker ◽  
...  

10084 Background: The acute impact of chemotherapy on cognition is unknown. This study utilized performance on the psychomotor vigilance task (PVT) and trail-making test B (TMT) to assess CRCI immediately following chemotherapy administration. Methods: Patients aged 18-80 years receiving first-line IV chemotherapy for any stage of breast or colorectal cancer were eligible. Patients with brain metastases, neurologic disorders or allergic reactions to chemotherapy were excluded. Patient symptoms, peripheral neuropathy and Stanford Sleepiness Scale were assessed. A five-minute PVT and TMT were completed on a tablet computer pre-chemotherapy and immediately post-chemotherapy. Paired Wilcoxon Rank Sum tests were used to assess change in median PVT reaction time, TMT completion time, TMT errors and PVT lapses. A priori, an increase in median PVT reaction times by over 20 ms (approximating reaction time changes with blood alcohol concentrations of 0.04 to 0.05 g%) was considered a clinically relevant change. Results: 144 patients (74 breast, 70 colorectal, median age 55.5 years) were tested. Post-chemotherapy, median PVT reaction time slowed by an average of 12.4 ms ( p = 0.01). Post-chemotherapy median PVT times slowed by over 20 ms in 59 patients (40.9%). TMT completion post-chemotherapy was faster by an average of 6.1 seconds ( p < 0.001). No differences were seen in TMT errors ( p = 0.417) or PVT lapses ( p = 0.845). Change in median PVT reaction time was not associated with age, gender, number of prior chemotherapy cycles, peripheral neuropathy grade, self-reported symptoms (anxiety, fatigue or depression). Change in median PVT reaction time was also not significantly associated with use of any specific chemotherapeutic drug or class, including paclitaxel (which includes ethanol as an excipient). Conclusions: Median PVT reaction time was significantly slower immediately after chemotherapy compared to a pre-chemotherapy baseline, and impairment correlating to effects of alcohol was seen in 41% of patients. This effect appears independent of age, self-reported symptoms or prior chemotherapy cycles. Further studies assessing functional impact of immediate-term CRCI are warranted.


2012 ◽  
Vol 18 (4) ◽  
pp. 764-772 ◽  
Author(s):  
Cindy M. de Frias ◽  
Roger A. Dixon ◽  
Richard Camicioli

AbstractWe examined two-wave longitudinal changes in two indicators of neurocognitive speed (i.e., mean rate, intraindividual variability) using one simple and three complex reaction time tasks. Participants included idiopathic Parkinson's disease (PD) patients, with and without incipient dementia, and normal controls. At baseline, there were 45 patients (26 men, 19 women) with idiopathic PD who ranged from 65 to 84 years (M = 71.3; SD = 4.5) and 47 matched controls (27 men, 20 women) who ranged from 65 to 84 years (M = 71.4; SD = 4.9). The 18-month longitudinal sample comprised of 74 returning participants (43 controls; 31 PD patients) who had no cognitive impairment or dementia at both waves. Ten of the 31 PD patients returning for Time 3 had dementia or cognitive impairment. These constituted the PD with incipient dementia (PDID) group. Repeated measures analyses of variance showed that the PD and PDID groups were slower over time on the reaction time tasks, whereas the controls improved their performance over time on all tasks. Inconsistency distinguished the two clinical groups (i.e., the PDID group but not the PD group became more inconsistent over time). Changes in neurocognitive speed and inconsistency may be valid clinical markers of PDID. (JINS, 2012, 18, 1–9)


1972 ◽  
Vol 35 (1) ◽  
pp. 210-210 ◽  
Author(s):  
Walter W. Surwillo

1996 ◽  
Vol 18 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Brian T. Stollery
Keyword(s):  

1981 ◽  
Vol 48 (3) ◽  
pp. 211-218 ◽  
Author(s):  
Birgitta Anshelm Olson ◽  
Francesco Gamberale ◽  
Bertil Gr�ngvist

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