Dominance of processing levels

The discussion of bottom-up and top-down appraisal interactions still does not address the question of how the different processing levels dominate or prevail in the

generation of an emotional response. What are the conditions for automatic processing outcomes to prevail and when are automatic processing outcomes overruled? In the section described above, we have seen that the prefrontal cortex is presumed to play an important role in mediating such a process. But when and how does such prefrontal activity come into play? Some twenty-five years ago, Posner and Snyder (1975) described the issue of the relative dominance of the outcomes of either processing type, in particular for the case that these conflict. The authors hypothesised that automatic processing outcomes, being faster, will dominate when a fast response is required, i.e. within 200 to 300 milliseconds after stimulus onset. Conscious processes, taking longer to develop and being attention-resource intensive, will override the response initiation of the automatic level when given enough time to develop. Time is thus proposed to be the crucial factor in the overriding of automatic processes by strategic or conscious ones; if not enough time is allotted, automatic processes will prevail in response determination.

This hypothesis of time being the crucial factor in overriding of automatic processing has been empirically tested by Neely (1977), using a lexical decision task in which primes were used that were either semantically related to target words (e.g. “bird” as prime with “sparrow” as target) or semantically unrelated to target words (e.g.

“building” as prime with “arm” as target). Furthermore, the participants were instructed that for some prime words, such as “bird” they should expect a

semantically related word, whereas for others, such as “building” they should expect a semantically unrelated word. Thus for each trial, the prime could potentially affect the processing of the target word either through semantic association or through

expectancy. According to Neely, the process of semantic priming is highly learned and automatic, whereas the process of expectancy priming is recently learned and controlled. Importantly, for a certain number of trials, the two types of priming were in conflict – either the target was semantically associated to the prime, but

unexpected, or the target was expected but not semantically associated to the prime.

By varying the stimulus onset asynchronies¹ (SOAs), thus manipulating the amount of time subjects had to process the primes, Neely showed that for trials in which the two types of priming were in conflict, the automatic semantic priming dominated for short SOAs, whereas the controlled expectancy priming dominated for long SOAs.

In general agreement with the Neely's findings but using affectively connotated stimuli, Richards & French (1992) and Calvo & Castillo (1997) also found that controlled processing generally operates independently of automatic processing for long time periods. However, they also revealed evidence that when stimuli were highly relevant (i.e. threat-related stimuli for high anxiety participants), automatic processing persisted and impinged on cognitive processing over a longer period of time. Thus the hypothesis of Posner & Snyder that conscious processing dominates or overrides automatic response elicitation whenever sufficient time is available for stimulus processing might not hold entirely for emotion stimuli. The extent to which conscious or high level processing can override automatic processing could depend on the personal relevance of emotional stimuli, in particular those with negative

implications. When the relevance as evaluated by automatic processes is sufficiently strong, perhaps the ensuing response is entirely determined by automatic processes, irrespective of the time available for further processing.

The resistance of automatic processing of fear-relevant stimuli to overriding by higher level representations such as explicitly knowing that actual threat is unlikely, has been demonstrated by Lanzetta and Orr (1986). In this study, pictures of a fearful face for one group of subjects or a happy face for another were presented contingently with a tone previously conditioned to an electric shock. For half of the subjects of each face group, the shock electrodes were removed just before the presentation of the stimuli, whilst for the remaining subjects the electrodes remained attached, without shocks

1 Stimulus onset asynchrony is the delay between prime and target.

being delivered. The results show that the anticipatory and phasic skin conductance activity was higher for the fear faces than for the happy faces, irrespective of the presence or absence of the shock electrodes. Thus, even in the presence of explicit knowledge that shocks cannot be obtained (as was verified with a self-report on beliefs), the fearful face still showed its potency in eliciting emotional arousal automatically.

In contrast to the resistance of automatically threatening stimuli to conceptual processing, the susceptibility of automatic, affective judgements to higher level

processes such as introspection has been demonstrated by Wilson and Schooler (1991) and Wilson, Lisle, Schooler, Hodges, Klaaren, and LaFleur (1993). These studies showed that introspection about the reasons for one’s preference resulted in lower liking ratings for stimuli than in people who were not prompted to reason about their evaluation. Even though the conditions under which introspection can change initial preference evaluations need to be further specified, it seems that initial affect can be overruled by reasoning processes (given that the reasons are in conflict with the initial affect) resulting in a muted or even affectively opposite response.

In summary, whereas dominance of high-level cognitive processing might be

expected when given enough time to “kick in” in semantic processing, time might not play an equally crucial role in emotion processing. In the processing of emotionally relevant information, automatic evaluations can persist despite the conflicting efforts of conceptual or conscious processing. One of the mechanisms underlying this persistence of automatic emotional processing could be “relevance” or “urgency”

(Robinson, 1998), although most of the studies reviewed above pertained more specifically to threat-related stimuli, or “potential threat-value”. With other types of affect, such as preference, the persistence of automatic processing is not so clear.

Studies trying to directly address the issue of dominance of one level over another might try to use affectively ambiguous stimuli, which would lead to a conflict in the evaluations of different processing levels, such as opposing evaluations of valence (good versus bad) or coping potential (easy versus difficult) and so on. Such research has not yet been performed.