Page 147 - Biobehavioral Resilence to Stress

124 Biobehavioral Resilience to Stress

member may be quite stressful due to low perceived control. However, indi-
viduals’ emotional reaction during the anticipation phase may be less severe if
they have confidence in their own ability to cope with the unavoidable loss.

Reported effects of confidence upon emotional and physiological

responses are best explained by the biopsychosocial theory of arousal
regulation (Blascovich, 1992; Blascovich, Tomaka & Zanna, 1996; Tomaka,
Blascovich, Kelsey & Leitten, 1993; Tomaka, Blascovich, Kibler & Ernst,

1997). This theory holds that when faced with a demanding task or situation,
human beings perform two appraisals, the comparative results of which will

influence their psychological orientation to the task. First, they appraise the
perceived demand of the task as conceptualized in terms of the amount of
effort it will require, its inherent uncertainty, and its associated risks or costs.

Second, human beings appraise their own perceived coping resources. If per-
ceived coping resources match or exceed the perceived demands of the task
or situation, the human subject will orient to the task as a challenge. If per-
ceived coping resources are inadequate to the perceived demand, the human
subject will orient to the task or situation as a threat (Blascovich, 1992).
Resulting orientation to a demanding task will, in turn, predict physi-
ological response as indexed by four measures of cardiovascular reactivity
(heart rate, ventricular muscle contractility, cardiac output, peripheral
resistance). Heart rate reflects the human operator’s level of task engagement

but does not typically differentiate challenge versus threat orientation to the

task. Ventricular contractility (the degree to which the muscles in the heart
are contracting) is typically increased in response to challenge, which also
coincides with increased cardiac output and reduced total peripheral resis-
tance. Taken together, these data suggest that when people feel challenged,
their body responds by increasing sympathetic-adrenomedullary (SAM)
activity, which is typically associated with improved cardiac performance
and decreased feelings of stress (Tomaka et al., 1993). By contrast, when
people feel threatened, they experience increased pituitary-adrenocortical
(PAC) activity, which is associated with reduced cardiac performance and
increased feelings of stress (Tomaka et al., 1993).
To address the question of causality, Tomaka et al. (1997) independently
manipulated appraisal or orientation and physiological response patterns.
They provided participants with explicit instructions to manipulate their

orientation to the task and found that participants’ cardiovascular response
patterns were consistent with those described above. However, when the
investigators independently manipulated cardiovascular response patterns
by having participants pedal (versus sit) on a stationary ergometer (Study 2)
or immerse their hand into cold (versus warm) water (Study 3), participants’

orientation to the task was unaff ected. Thus, it appears that cognitive appraisals
that generate threat versus challenge orientations to demanding tasks also
produce subsequent cardiovascular reactivity patterns (Tomaka et al., 1997).

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