{'fraction_non_alphanumeric': 0.027287319422150885, 'fraction_numerical': 0.006955591225254147, 'mean_word_length': 5.824817518248175, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Interactions between behavior and the cardiovascular system.

• That environmental events of a stressful nature can elicit profound cardiovascular responses hardly requires documentation, and a sizable literature has evolved treating anecdotal and correlational observations of acute and chronic cardiovascular effects of stress. For example, humans exposed to combat (1), natural disasters (2), and chronic occupational stress (3) are reported to show various sustained alterations in cardiovascular function, including hypertension. Analogously, animal studies indicate cardiovascular effects consequent to environmental manipulations such as crowding, chronic territorial conflict (4), and imposition of stressful behavioral tasks (5, 6). Based on such observations, environmental or behavioral factors have been imputed various degrees of importance in the etiology of cardiovascular pathology (7), and it has even been suggested that acute emotional episodes can precipitate ventricular fibrillation and sudden death (8). In this context, there has been recent interest in the possible value of behavioral manipulation for the control and management of cardiovascular disease (e.g., 9, 10). However, much of the foundation for hypotheses relating behavior and cardiovascular activity derives from correlational observations, and it is only in recent years that systematic experimental efforts have been undertaken to explore possible relationships more precisely. It is the intent of this review to highlight recent developments in this area. Our focus is on controlled laboratory models; we have not attempted to review the more observational literature that contributed so importantly to the historical inception of this field. Our goal is to examine the degree to which we are able (1) to produce cardiovascular change with behavioral manipulation, (2) to spec-