Bushnell P J
Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
Behav Processes. 1999 Jun;46(2):141-50. doi: 10.1016/s0376-6357(99)00030-3.
Animal models of human cognitive processes are being developed for investigating the neurobiological mechanisms of these processes and for identifying potential therapies for intoxication and neurodegenerative diseases. One promising method involves assessment of sustained attention in rats by use of a discrete-trial signal detection task. Several psychophysical and procedural factors have been identified in the literature that affect sustained attention in normal human subjects. Three key parameters that affect the level of performance, and whether that performance level deteriorates over time, include the quality of the signal, the event rate, and the type of task employed (simultaneous or successive discrimination). These three parameters were manipulated in this study to assess the degree of similarity in the behavior patterns engendered in rats by this signal detection task, in relation to the behavior observed in humans performing a variety of sustained attention tasks. Signal quality was manipulated by varying the increment in the intensity of a lamp (duration=300 ms), and event rate was varied among values of 4, 7, and 10 trials/min. The 'standard' detection task was used as a simultaneous discrimination and a successive discrimination task was designed in which a dim light flash was defined as a non-signal event and any of three brighter flashes were signal events. Accuracy of signal detection was quantified by the proportion of correct detections of the signal [P(hit)] and the proportion of false alarms [P(fa), i.e., incorrect responses on non-signal trials]. P(hit) fell with decreasing signal intensity, increasing event rate, and was lower in the discrimination task compared to the detection task. P(fa) increased with increasing event rate, but only in the detection task. A decrement in P(hit) across trial blocks was observed in the discrimination task primarily, and was most evident with a high event rate and dim signals. These data confirm that these tasks assess process(es) in rats that are very similar to those considered as sustained attention in humans.
人类认知过程的动物模型正在被开发，用于研究这些过程的神经生物学机制，以及识别中毒和神经退行性疾病的潜在治疗方法。一种有前景的方法是通过使用离散试验信号检测任务来评估大鼠的持续注意力。文献中已经确定了几个影响正常人类受试者持续注意力的心理物理学和程序因素。影响表现水平以及该表现水平是否随时间恶化的三个关键参数包括信号质量、事件发生率和所采用任务的类型（同时或相继辨别）。在本研究中，对这三个参数进行了操作，以评估该信号检测任务在大鼠中产生的行为模式与在执行各种持续注意力任务的人类中观察到的行为之间的相似程度。通过改变灯强度的增量（持续时间 = 300毫秒）来操纵信号质量，事件发生率在4、7和10次试验/分钟的值之间变化。“标准”检测任务用作同时辨别，还设计了一个相继辨别任务，其中暗光闪烁被定义为非信号事件，三个较亮闪烁中的任何一个为信号事件。信号检测的准确性通过信号正确检测的比例[P(命中)]和误报比例[P(误报)，即非信号试验中的错误反应]来量化。P(命中)随着信号强度降低、事件发生率增加而下降，并且在辨别任务中比检测任务中更低。P(误报)随着事件发生率增加而增加，但仅在检测任务中如此。在辨别任务中主要观察到跨试验块的P(命中)下降，并且在高事件发生率和暗光信号时最为明显。这些数据证实，这些任务评估的大鼠中的过程与被认为是人类持续注意力的过程非常相似。
