Physiology

Some research has been performed in which the physiological changes served as markers of the appraisal process. Whilst Lazarus and colleagues (Lazarus & Alfert, 1964; Speisman et al., 1964) were the first to relate, albeit indirectly, changes in skin conductance activity to appraisal processes, Smith (1989) made important

contributions and found initial support for the idea that physiological changes can be related to a specific dimension. Smith’s most salient findings concerned facial muscle activity (see below) and appraisals of conduciveness. Besides these findings on expression and appraisal, he provides evidence with respect to the contribution of appraised anticipated effort (corresponding to “urgency” in Scherer’s terms) to arousal as indexed by heart rate, with a higher heart rate for high anticipated effort than for low anticipated effort manipulations. However, no effects of the appraisal manipulations on skin conductance level measures were found.

Indeed, research in the domain of affective responses to pictures (e.g. Lang, Bradley,

& Cuthbert, 1990) reports that skin conductance activity, whether magnitude of the responses or the level of skin conductance, is not related to the positive-negative value of information, but instead skin conductance activity is proposed to be a more reliable measure of the arousal that a stimulus elicits. However, as underscored by Scherer (e.g. 1984, 1988), valence cannot always be used synonymously to conduciveness.

Rather, valence often refers to the pleasantness or unpleasantness of a stimulus in itself, regardless of current goals and concerns of a person. To distinguish valence as such from goal/concern-related valence, Scherer introduced the appraisal dimension of Intrinsic Pleasantness (see Scherer, 1984, 1988). Generalisations of studies that reveal effects of “valence” on physiological responding to “conduciveness” thus needs to be regarded with caution.

Despite the absence of effects of valence on skin conductance activity in research using imagery (e.g. VanOyen-Witvliet & Vrana, 1995) or affective pictures (e.g.

Lang, Bradley, & Cuthbert, 1990), which arguably could be related to the valence of

the stimuli being unrelated to a person’s goal-related valence response thus not affecting the person emotionally, a hypothesis on the link between the appraised conduciveness and electrodermal activity can be put forward on the basis of other research. Various parameters of skin conductance activity are well studied, and skin conductance response magnitude is classically used as a reliable indicator of an orienting response, in that response magnitudes increase corresponding to the significance or novelty of a stimulus (e.g. Öhman, Esteves, Flykt, & Soares, 1993;

Dawson, Schell, & Filion, 1990). Possibly due to the potential harmfulness of the event or stimulus, an obstructive event captivates the attention more strongly than conducive events, and thus would show increases in skin conductance response magnitudes (see also Öhman, 1987). Also, Nikula (1991) found that increases in the non-specific skin conductance response rate were associated with thoughts related to current concerns and with emotionally negative connotations. In a similar vein, our own research (Banse, van Reekum, Johnstone, Etter, Wehrle, & Scherer, 1999) indicates increases in skin conductance response rate for obstructive events compared to conducive events.

With regard to the relation between conduciveness and skin temperature, Scherer (1987) predicts peripheral vasoconstriction, reflected in decreasing skin temperature, when the event is appraised as goal obstructive, and vasodilation, reflected in

increasing skin temperature, when the event is appraised as goal conducive. These predictions found partial confirmation in the study of Banse et al. (submitted), where increases in skin temperature were observed for conducive situations in a computer game and slight decreases in skin temperature for obstructive situations, but only when the game situations were relatively unimportant for the player. Equally, a confirmation of Scherer’s (1987) predictions was forthcoming in a study conducted in our lab (van Reekum, Johnstone, & Scherer, 1997) where the a negative skin

temperature slope was significantly related to manipulations of obstructiveness and a positive slope for conduciveness manipulations in a computer game when the player was confronted with such manipulated game situations.

The correlates of coping processes in the autonomic nervous system (in particular the cardio-vascular system) have been well studied by a few different laboratories. Obrist (e.g. 1981, see also Obrist & Light, 1988 for a review) contributed to the research area

with substantial work on the differentiation between passive and active coping strategies employed when confronted with a stressor. The influence of coping processes has also been tested by manipulating task difficulty and measuring the effects of varying difficulty on the ANS, in particular cardiovascular activity (e.g.

Light & Obrist, 1983) and SNS (e.g. Svebak, 1983). More directly pertinent to the appraised coping potential and ANS correlates is work performed by Tomaka and colleagues. Borrowing from Lazarus’ appraisal theory, Tomaka et al. postulate that a threat appraisal occurs when the situation is goal relevant and environmental demands are perceived as exceeding resources or ability to cope. Challenge appraisal occurs when the situation is goal relevant, but the person appraises the situation as within it’s resources or abilities to cope. Tomaka and colleagues (e.g. Tomaka, Blascovich, Kelsey, & Leitten, 1993; Tomaka, Blascovich, Kibler, & Ernst, 1997) found that appraisals of threat were negatively related to cardiac reactivity (e.g. lower heart rate, lower cardiac output, shorter pre-ejection period, and higher peripheral resistance), and that appraisals of challenge were positively related to cardiac reactivity (i.e.

higher heart rate, higher cardiac output, lower resistance). These results were found using a post-hoc allocation of participants to either one of two groups (threat or challenge) on the basis of their reported appraisals of performing mental arithmetic tasks (Tomaka et al., 1993) and by actually manipulating the appraisals through instructions provided before the mental arithmetic tasks (Tomaka et al, 1997).

Pecchinenda and Smith (1996) extended these findings of appraised coping potential and the cardiovascular system with measures of electrodermal activity. They

manipulated the difficulty of various problem-solving tasks, which led to different appraisals of a person’s problem-focused coping potential. Using self-report measures of appraisals to index electrodermal activity, they found that the skin conductance response rate and the slope of skin conductance change were positively correlated with the appraised coping potential. In addition, in a follow-up study (Kirby and Smith, 1996), the response amplitude was found to be negatively correlated with coping potential and actually solving the problem. In a related study, using skin temperature measures, Smith (1994) showed that the slope of skin temperature change was positively correlated with perceived problem difficulty and effort expended on the task. Similar results have been obtained for electrodermal activity and heart rate measures in studies using a computer game to manipulate the player’s coping

potential (Pecchinenda & Kappas, 1998; Pecchinenda, Kappas & Smith, 1997;

Kappas & Pecchinenda, 1999). See Pecchinenda (in press) for a more extended review and discussion of the relation between appraisal, in particular that of coping potential, and autonomic nervous system activity. Thus, various parameters of physiological activity are specifically or differentially related to the appraisal outcomes of coping potential and conduciveness.

Physiology, and perhaps to a lesser extent bodily expression, has also been linked to automatic processing, at least in the early processing stages. As Öhman and

colleagues have shown, pre-attentive processing of stimulus significance is related to increases in electrodermal activity. Physiological changes associated to automatic appraisals might be appraisal-specific or non-specific (i.e. general arousal), and are most probably modified or controlled by higher level appraisals at later processing stages. Unfortunately, the studies reviewed above do not address any levels-issues. As described earlier, pre-attentive processing has been found to at least lead to unspecific physiological activity. It remains to be seen whether the physiology related to

schematic appraisal processing would be specific, as one could infer from appraisal theories (Smith et al., 1996; Scherer, 1986, in press) or unspecific, as suggested by Robinson and Öhman for instance. Based on functional arguments put forward by appraisal theories, and Scherer (1986) in particular, we propose that both schematic and conceptual appraisals produce differentiated physiological activity.