Thomas M. Hess, Claire M. Growney, and Erica L. O'Brien
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Psychology. Please check back later for the full article.
The assessment of cardiovascular (CV) responses associated with behavioral phenomena has long been an important component of psychological research seeking to better understand the physiological underpinnings of behavior. Within the field of gerontology, there has historically been much interest in CV responses. Much of this work has focused on blood pressure as an important reflection of CV functioning that is relatively simple to assess. An examination of the gerontological literature reveals at least three different ways in which researchers have used blood pressure to examine aging-related processes. One approach is to use blood pressure as a measure of health, either in terms of the level of functioning of the CV system or as a reflection of various disease-related processes, and examine its relationship to other aspects of functioning. For example, blood pressure has been frequently examined in relation to cognitive decline. A second approach has been to examine blood pressure reactivity as a reflection of physiological responses to stress. Aging has been associated with higher levels of reactivity to the emotionally evocative, and thus an examination of normative changes in reactivity may be useful in understanding the impact of aging on the ability to deal with stress. Reactivity is also potentially useful in understanding the impact of stress on health, with high levels of reactivity along with high frequency of such incidences being associated with negative health outcomes. In the field of gerontology, the additional burden associated with elevated levels of reactivity in later life is of particular interest. Finally, recent work has also focused on blood pressure as a measure of an individual’s attempts to actively cope with challenging situations, broadly defined. Building off the active coping model of Obrist, blood pressure responses in a given situation are viewed as direct reflections of active coping as the cardiovascular system is energized to provide the resources needed by the body and nervous system to deal with a given situation. The level of response has been shown to reflect both the difficulty of the task and the individual’s motivation, and thus is a relatively reliable indicator of (a) an individual’s engagement in a particular task and (b) the resources necessary to perform that task. Recent work on aging has focused on the utility of this measure as a reflection of the costs associated with cognitive engagement and the extent to which variation in these costs might predict both between-individual and age-related normative variation in participation in cognitively demanding—but potentially beneficial—activities.
Dyslexia, or a reading disability, occurs when an individual has great difficulty at the level of word reading and decoding. Comprehension of text, writing, and spelling are also affected. The diagnosis of dyslexia involves the use of reading tests, but the continuum of reading performance means that any cutoff point is arbitrary. The IQ score does not play a role in the diagnosis of dyslexia. Dyslexia is a language-based learning disability. The cognitive difficulties of dyslexics include problems with recognizing and manipulating the basic sounds in a language, language memory, and learning the sounds of letters. Dyslexia is a neurological condition with a genetic basis. There are abnormalities in the brains of dyslexic individuals. There are also differences in the electrophysiological and structural characteristics of the brains of dyslexics. Hope for dyslexia involves early detection and intervention and evidence-based instruction.
Idan Shalev and Waylon J. Hastings
Stress is a multistage process during which an organism perceives, interprets, and responds to threatening environmental stimuli. Physiological activity in the nervous, endocrine, and immune systems mediates the biological stress response. Although the stress response is adaptive in the short term, exposure to severe or chronic stressors dysregulates these biological systems, promoting maladaptive physiology and an accelerated aging phenotype, including aging on the cellular level. Two structures implicated in this process of stress and cellular aging are telomeres, whose length progressively decreases with age, and mitochondria, whose respiratory activity becomes increasingly inefficient with advanced age. Stress in its various forms is suggested to influence the maintenance and stability of these structures throughout life. Elucidating the interrelated connection between telomeres and mitochondria and how different types of stressors are influencing these structures to drive the aging process is of great interest. A better understanding of this subject can inform clinical treatments and intervention efforts to reduce (or even reverse) the damaging effects of stress on the aging process.