Cognitive complexity study

To validate the relationship between the cognitive complexity of a task and the cognitive skill required to sueeessfully perform that task, a further study will examine the pattern of eue acquisition for tasks fliat are structured to embody a high or low level of cognitive complexity. Cues represent features of an environment that have some meaning or association for flie receiver and may be visual, auditory, olfactory, or tactile in form (Ratcliff and McKoon, 1995). Previous research has identified that an operator s pattern of cue acquisition will vary as a function of the demands of the task (e.g., Bellenkes, Wickens and Kramer, 1997 Wiggins et al., 2002 Underwood, 2005). 

Animal studies support he human evidence of neurobehavioral toxicity from prenatal exposure to low levels of lead. In an extensive review of the literature, Davis et al. (1990) discussed similarities between human effects and those in animals. The authors concluded that qualitatively "... the greatest similarities between human and animal effects involve cognitive and relatively complex behavioral processes such as learning." They further reported that quantitative relationships for PbB levels across species that cause developmental neurobehavioral effects are 10-15 pg/dL in children, <15 pg/dL in primates, and <20 pg/dL in rodents. 

Adult subject studies can be divided into two broad categories response to basic sensory stimulation and response to more complex cognitive tasks. Recently, there have also been reports applying the NIR spectroscopy to brain computer interface research [18] and studyinh the correlation of hemodynamic response to computational cognitive models [94]. 

Data from the few available case reports and the numerous animal studies strongly suggest that disulfoton exposure may cause mild to severe neurological effects in humans. Although disulfoton-associated memory loss has not been reported in humans, there should be concern that occupational exposure and exposure at hazardous waste sites may interfere with the performance of cognitive and complex tasks. 

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