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Psychophysiology of Resilience to Stress 121

It is not yet clear to what extent individual personality diff erences may
affect anticipatory response to negative events. Anxiety is correlated with some

physiological measures during anticipation, but findings in this area of inquiry

are mixed. In a study that directly examined the personality traits of resil-
ience (as measured by the ego-resiliency scale, ER89; Block & Kremen, 1996)
and anticipatory anxiety, trait resilience did not correlate with physiological
arousal or with expression of negative emotions during anticipation (Tugade &

Fredrickson, 2004). This study employed a “recovery paradigm” ( Fredrickson
& Levenson, 1998) in which participants anticipated delivering a speech, which
they believed would be evaluated by their peers. While study participants
prepared their speeches, experimenters measured their cardiovascular reactiv-
ity as represented by heart rate, diastolic/systolic blood pressure, fi nger pulse
amplitude, and pulse transmit time to the finger and the ear. They found that

trait resilience did not correlate with cardiovascular reactivity or with reports
of anxiety as documented during speech preparation (Tugade & Fredrickson,

2004). In summation, these findings suggest that trait resilience and, more
generally, anxiety may not play a significant role in emotional arousal that

occurs during anticipation of a negative event that is certain to occur.
It may be the case that personality variables play a more signifi cant role
when anticipating uncertain events. For example, it is well known that when
faced with uncertainty, optimistic individuals tend to expect good things to
occur (Scheier & Carver, 1985), whereas individuals who tend toward defen-
sive pessimism expect the worst (Norem & Cantor, 1986). Individuals who
score high on resilience measures also tend to be optimistic (Block & Kre-

men, 1996). Thus, it is reasonable to expect that when faced with the uncer-
tain prospect of a negative event, resilient individuals may be more inclined
to consider that the negative event may not occur. A neuroimaging study
directly tested the effect of trait resilience during anticipation of an uncer-

tain event (Waugh, Wager, Fredrickson, Noll & Taylor, 2007). Participants

were fi rst identified and grouped as high resilient (upper quartile) or low
resilient (lower quartile) based on their scores on the ER89 (Block & Kremen,
1996). They were then shown one of the two cues. One cue was a safety cue,

which indicated that a neutral picture would always follow. The other cue

was a threat cue, which indicated that either a negative or a neutral picture

would follow. The true probability (0.50) of neutral versus negative stimulus

presentation was unknown to the study participants. The results showed that
in response to the threat cue, low-resilient participants experienced much
greater activation of the lateral orbitofrontal cortex (LOFC) than did their
high-resilient counterparts (Waugh, Wager et al., 2007). Activation of the
orbitofrontal cortex has previously been reported during anticipation of
punishment (O’Doherty, Kringelbach, Rolls, Hornak & Andrews, 2001) and
is also correlated with degree of uncertainty regarding the occurrence of
anticipated events (Critchley, Mathias & Dolan, 2001). Hence, the fi ndings

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