Washington : Being subject to chronic stress not only clouds your thinking but also impairs memory, new research says. It uncovered a neural (brain cell) mechanism that directly links stress with impaired memory and clouded thinking. Stress hormones are known to influence the prefrontal cortex (PFC), a brain region that controls high level "executive" functions such as working memory and decision making, reports the journal Neuron. "Previous work has shown that chronic stress impairs PFC-mediated behaviours, like mental flexibility and attention, explains study author Zhen Yan, State University of New York, according to a State University statement. Yan and colleagues examined whether repeated stress had a negative influence on glutamate receptors in juvenile rats. Glutamate signalling plays a critical role in PFC function. They found that in response to repeated stress, there was a significant loss of glutamate receptors, which resulted in a deficit of PFC-mediated cognitive processes, such as working memory and decision making.