Comparable cardiovascular responses to orthostasis in controls and AD subjects suggest intact reflex control of circulation. AD subjects had blunted HR responses to public speaking; this is consistent with the attenuated cortisol responses observed in this sample and in previous studies. This suggests a possible alteration in limbic system regulation of hypothalamic and brainstem responses to psychological stress. Cardiovascular responses of AD subjects that are inconsistent with subjective accounts of tension and anxiety suggest a disconnection between perception of threat and resulting physiologic responses in AD subjects.

Comparable cardiovascular responses to orthostasis in controls and AD subjects suggest intact reflex control of circulation. AD subjects had blunted HR responses to public speaking; this is consistent with the attenuated cortisol responses observed in this sample and in previous studies. This suggests a possible alteration in limbic system regulation of hypothalamic and brainstem responses to psychological stress. Cardiovascular responses of AD subjects that are inconsistent with subjective accounts of tension and anxiety suggest a disconnection between perception of threat and resulting physiologic responses in AD subjects.