Signs perception

Martens, M. H. (2000). Assessing road sign perception a methodological review. Transportation Hum. Fact, 2(4), 347-357. 

If we now attempt to summarize the results of the different studies on sign perception and recall, the most obvious conclusion is that different methods yield widely different results. The most likely factor that distinguishes the different methods is that they utilize different skills. When we are not actively searching for a specific target, such as a sign, the likelihood of perceiving it is based on what is called "object conspicuity", the degree that it is visually... 

Drory, A. and D. Shinar (1982). The effects of roadway environment and fatigue on sign perception. J. Safe. Res., 13,25-32. 

Since MW correlates with molecular size, the negative sign of its coefficient indicated indeed that larger molecules have lower permeation rates. The positive coefficient of LA indicated that lipoaffinity enhances the permeation rate, and the negative coefficient of TPSA was in agreement with the perception that hydrophilicity reduces the permeation rate. 

PCP and ketamine are dissociative anesthetics. They can induce analgesia without loss of consciousness. The individual appears awake but will not remember the experience, and vital signs such as respiration and heart rate are not impaired. The drugs distort perceptions of sight and sound, and produce feelings of detachment and dissociation from the environment and self. Persons abusing PCP exhibit very bizarre behavior and may become violent. 

Smolenski and Plucinski [13] examined the effect of sunlight and found that signs of decomposition are perceptible after only 40 hr of irradiation. A sample so irradiated shows a somewhat lower ignition temperature. 

However, these drugs are now more commonly— and more accurately—called neuroleptics or antipsy-chotics. As opposed to medications prescribed for sedation, the neuroleptics often produce signs of neurological dysfunction, such as extrapyrimidal effects (involuntary movements such as Parkinson-like tremors and other abnormal movements). The term antipsy-chotics is sometimes used because these drugs are generally used to treat symptoms of paranoia, psychosis, or serious distortions in the perception of reality, such as hallucinations or delusions. The neuroleptics are not typically drugs of abuse. 

For decades researchers have looked at whether intoxication with certain drugs could mimic the signs and symptoms of schizophrenia. Amphetamines increase dopamine release and can induce some positive symptoms like paranoia. Lysergic acid diethylamide (LSD) affects 5-HT receptors but tends to induce visual perception changes and not frank hallucinations. Phencyclidine (PCP), however, induces a state in healthy controls that seems very similar to schizophrenia. This includes thought disorder and negative symptoms... 

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