appraisal variables, and coping variables were entered in successive steps
(Matthews, Derryberry, et al., 2000). Substantial variance in post-task scores
carries over from pre-task state, but appraisal and coping together add a fur-
ther 13–31% of the variance, depending on the state factor criterion. Across
studies a fairly consistent picture emerges, such that changes in task engage-
ment tend to relate to challenge appraisal and use of task-focused coping,
changes in distress relate to threat appraisal, high perceived workload, failure
to attain performance standards, and emotion-focused coping, and worry
relates to both avoidance and emotion-focused coping. Thus, the cognitive
processes of appraisal and coping provide the primary support for self-
regulation, and concurrently generate changes in cognitive, emotional and
motivational states. State change tells us something about the person’s self-
regulative goals within the constrained performance environment. However,
in line with the ambiguity of the adaptive significance of coping (Zeidner &
Saklofske, 1996), state change does not tell us directly whether those goals
elicit adaptive or maladaptive coping behaviors.
Effects of Stress State on Performance
As previously stated, changes in stress state feed back into changes in infor-
mation processing and performance. Various studies have explored how state
variables relate to objective indices of performance. The majority of studies
have focused on energy and task engagement. These states appear to be
markers for availability of attentional resources. High energy facilitates per-
formance of demanding attentional tasks, but not other types of task
(Matthews, Davies, et al., 2000). Other studies have related distress to impair-
ments of dual-task performance and executive function (e.g., Matthews, Joy-
ner, et al., 1999). There is a large literature on worry in the context of test anx-
iety that suggests high worry impairs high-level verbal processing of the kind
required for performance of academic tests (Sarason & Sarason, 1990;
Zeidner, 1998).
What can we say about effects of stress states on performance from a self-
regulative perspective? Matthews (2001) distinguished two kinds of mecha-
nisms. First, stressors, especially those of a biological nature such as drugs
and infections, may change the basic functioning of neural and cognitive
processes, in some cases (e.g., some toxic agents) without the person being
aware of these changes. A second level of state effects refers to voluntary cop-
ing, driven by attempts to reduce discrepancy between performance goals
and appraisals that one is failing to attain those goals. Figure 6.9 shows how
different kinds of control activity may generate differing coping strategies
that may impact on performance (Matthews & Desmond, 2002). One option
is to increase effort that compensates for task and environmental demands,
or to change strategy qualitatively (task-focused coping). A second option is
- TRAITS, STATES, AND INTELLECTUAL FUNCTIONING 165