We used behavioral and pupillary measures during an analogical reasoning task to investigate the processing of conceptual and emotional relations as well as their interaction. In particular, we examined how mental resource consumption is modulated by individual differences in neuroticism in healthy participants during conditions with emotional interference.
Two word pairs were presented simultaneously, each with a conceptual and an emotional relation. In one experimental block, participants had to decide whether conceptual relations between the two word pairs were corresponding (conceptual task). In the other block, participants had to decide whether emotional relations were corresponding (emotional task).
When participants had to focus on the correspondence of emotional relations, they were faster, more accurate, and showed greater pupillary responses than during the conceptual task. Moreover, participants with comparably higher neuroticism scores showed increased pupillary responses during conditions with emotional interference (i.e., during the conceptual task when they had to ignore incongruent information on the correspondence provided by the task-irrelevant emotional relations).
These results demonstrate that affective aspects of stimuli (here: emotional relations) are preferentially selected for information processing. Moreover, increased mental resource consumption due to emotional interference in participants with comparably higher neuroticism scores might reflect a possible mechanism making these individuals more vulnerable to mood or anxiety disorders.
Everyday decision making includes both cognitive as well as affective aspects. Affective aspects of a situation are very important for immediate survival of the organism because they might signify a potential threat or a possible reward. Therefore, affective aspects, such as the valence of a stimulus, are selectively attended and processed automatically and more quickly than cognitive aspects, such as conceptual features (for reviews see Compton et al., 2003, Ochsner and Feldman Barrett, 2001, Pessoa and Ungerleider, 2003 and Phelps, 2006). Although it might be a selective advantage for the organism to direct information processing toward those aspects of a situation that are emotional and important, effective mental functioning also requires that cognitive deliberation processes are protected from emotional interference induced by task-irrelevant but emotionally salient stimuli.
To gain a more comprehensive understanding of the underlying mechanisms concerning effective mental functioning, in the present study we investigated affective and cognitive processing as well as their interaction in healthy participants which individually differ in their susceptibility to emotional interference.
Traditionally, emotional interference has been investigated using the emotional Stroop task. In this task participants have to identify the ink color of words while they have to ignore the word meaning in neutral words contrasted with emotionally negative and positive words (Mathews and Macleod, 1985 and McKenna, 1986). Responses are typically slower for color naming of emotional words relative to color naming of neutral words, at least, in participants with clinically manifest mood or anxiety disorders (e.g., Mathews and Macleod, 1985 and Williams et al., 1996). Slowing of response times for color naming of emotional words relative to neutral words in the emotional Stroop task serves as a measure of emotional interference. However, the meaning of the emotional words, which interferes with identifying the ink color, is neither semantically related to the task-relevant information (namely, the ink color), nor do the emotional stimuli lead to responses that directly compete with the selection of the correct response (Algom et al., 2004 and Etkin et al., 2006). Therefore, in this task there is no direct interaction between affective and cognitive processing and only the extent to which the emotional content of the word stimuli withdraws attention from the main task (namely, identifying the ink color) is measured.
To directly compare cognitive and affective processing and to investigate how affective processing interferes with cognitive processing, we developed an analogical reasoning task (cf. van der Meer, 1989). In this task two word pairs were presented simultaneously (e.g., TUMOR — BRAIN and RAT — CELLAR, cf. Methods and Table 1). Between the words of each pair there was a conceptual relation. The word pair TUMOR — BRAIN, for instance, is characterized by a location relation (“The tumor is in the brain.”). Other types of conceptual relations were actor relations (e.g., BIRD — CHIRP) and object relations (e.g., FEED — BIRD; Collins and Quillian, 1969, Herrmann and Chaffin, 1986 and Klix, 1992). Word pairs could additionally be characterized by an emotional relation which signified a positive (e.g., BIRD — SING), neutral (e.g., BIRD — FLY) or negative (e.g., BIRD — ROT) valence.
