Abstract
The studies reported in this thesis have been performed to gain a better understanding about motivational mediators of selective attention and memory for emotionally relevant stimuli, and about the roles that some steroid hormones play in regulation of human motivation and emotion. The stimuli used are pictures of human facial
... read more
expressions of emotion. The main interest was in establishing psychoneuronedocrine and psychological motivational predictors of biased processing of angry and fearful faces. Whereas previous research has used angry facial expressions and their attentional and mnemonic processing as models for anxiogenic selective cognition, one of the themes of this thesis is that this angry facial expression does not provide an optimal model to measure fearful responses. Motivated responses to angry facial expressions are instead inherently ambiguous. Depending on the motivational stance of the observer, expressions of anger can be met with fearful withdrawal or aggressive reciprocity. The fearful facial expression, especially when gaze direction is taken into account, is likely a better stimulus to evoke anxiogenic responses. One important goal of this thesis was to disambiguate attentional and mnemonic processing of angry facial expressions and to explore the latter claim about fearful facial expressions. This has been done by relating biases in attentional and mnemonic processing of facial expressions to individual differences in various endocrine and self report measures of motivation. In addition, this thesis describes the development and application of an innovative experimental method for measuring attentional responses to (fearful) facial expressions, utilizing manipulation of gaze direction as a critical component to emotional expression. The other main goal of this thesis was to study motivational effects of the steroid hormones testosterone and cortisol. This thesis describes several studies that have been performed to causally test relations between measures of endocrine-motivational functioning and attentional and mnemonic biases to these facial expressions. Specifically, acute effects on such motivational processes from single administrations of testosterone and cortisol have been tested and are reported here. Together, these studies provide some further insights into the fascinating interplay between emotion and cognition, between brain/body and mind. Their interest lies mainly in their relation to fundamental research questions into the nature of human motivational processes and endocrine regulation thereof, but hopefully they will also add some to our understanding of human psychopathology.
show less