Effects of transcranial alternating current stimulation over right-DLPFC on vigilance tasks depend on the arousal level

Current theoretical accounts on the oscillatory nature of sustained attention predict that entrainment via transcranial alternating current stimulation (tACS) at alpha and theta frequencies on specific areas of the prefrontal cortex could prevent the drops in vigilance across time-on-task. Nonetheless, most previous studies have neglected both the fact that vigilance comprises two dissociable components (i.e., arousal and executive vigilance) and the potential role of differences in arousal levels. We examined the effects of theta- and alpha-tACS over the right dorsolateral prefrontal cortex in both components of vigilance and in participants who differed in arousal level according to their chronotype and time of testing. Intermediate-types performed the vigilance tasks when their arousal level was optimal, whereas evening-types performed the vigilance tasks when their arousal levels were non-optimal. Both theta- and alpha-tACS improved arousal vigilance in the psychomotor vigilance task (PVT), whereas alpha-tACS, but not theta-tACS, improved executive vigilance in the sustained attention to response task (SART), and counteracted the typical vigilance decrement usually observed in this task. Importantly, these stimulation effects were only found when arousal was low (i.e., with evening-types performing the tasks at their non-optimal time of day). The results support the multicomponent view of vigilance, the relevance of heeding individual differences in arousal, and the role of alpha oscillations as a long-range cortical scale synchronization mechanism that compensates the decrements in performance as a function of time-on-task by exerting and maintaining cognitive control attributed to activation of the right dorsolateral prefrontal cortex.

Time pressure in translation

Translators may experience significant psychological and physiological responses to time pressure. This study examines such responses with the aim of identifying valid indicators of time pressure in written translation. Forty-five postgraduates participated in the study, translating three comparable English texts into Chinese under three time conditions (Short, Standard, and Free). A positive relation between time stringency and the arousal level detected by a set of self-reporting and biomarker measures was hypothesised. The hypothesis was corroborated by results derived from participants’ self-reporting on stress and anxiety, and the biomarkers of heart rate, blood pressure, and pupil dilation, but not by skin temperature, galvanic skin response (GSR), and heart rate variability (HRV). Thus, the measures that confirm the hypothesis are considered successful indicators of time pressure in translation. In addition, an inverted ‘U-shaped’ pattern was observed in the relation between time stringency and the arousal level indexed by GSR and HRV. These findings may facilitate research and training in translation and other cognitively demanding language-processing activities.

Multimodal Affect Models: An Investigation of Relative Salience of Audio and Visual Cues for Emotion Prediction

People perceive emotions via multiple cues, predominantly speech and visual cues, and a number of emotion recognition systems utilize both audio and visual cues. Moreover, the perception of static aspects of emotion (speaker's arousal level is high/low) and the dynamic aspects of emotion (speaker is becoming more aroused) might be perceived via different expressive cues and these two aspects are integrated to provide a unified sense of emotion state. However, existing multimodal systems only focus on single aspect of emotion perception and the contributions of different modalities toward modeling static and dynamic emotion aspects are not well explored. In this paper, we investigate the relative salience of audio and video modalities to emotion state prediction and emotion change prediction using a Multimodal Markovian affect model. Experiments conducted in the RECOLA database showed that audio modality is better at modeling the emotion state of arousal and video for emotion state of valence, whereas audio shows superior advantages over video in modeling emotion changes for both arousal and valence.

The Effect of Valence and Arousal on Spatial Attention

<p>Conceptual metaphor theory suggests that to mentally represent abstract concepts we use metaphorical associations to map them onto more concrete constructs (Lakoff & Johnson, 1980; 1999). Using a choice reaction time (CRT) task, Meier and Robinson (2004) found that positively valenced words primed attention to higher areas in vertical space, while negatively valenced words primed attention to lower areas in vertical space, consistent with the good is up/bad is down conceptual metaphor. Meier and Robinson (2004; 2005) suggest this provides evidence that emotional words create an automatic and obligatory metaphor-congruent shift in spatial attention, driven by a Valence x Position interaction. However, other research shows that the arousal level, not just the valence of emotional words can affect reaction time (Robinson, Storbeck, Meier & Kirkeby, 2004). This means concluding that valence alone is driving the shift in attention is premature. Furthermore, Brookshire, Irvy and Casasanto (2010) dispute Meier and Robinson’s claim that the relationship between affect and metaphor is automatic, instead suggesting that affect-metaphor associations are optional and only accessed under certain contextual conditions. The purpose of this thesis was therefore two-fold. First, it aimed to explore whether valence, arousal, or an interaction between the two was responsible for driving the metaphor-consistent shift in spatial attention observed by Meier and Robinson (2004). Second, it aimed to progress the discussion about when affective stimuli, in the form of emotional words, automatically activate the good is up/bad is down conceptual metaphor. Three CRT experiments were conducted in which (a) emotional stimulus words were differentiated by arousal level as well as valence and (b) the evaluation of stimulus words’ affective tone (pleasant/unpleasant) was manipulated. A Valence x Position interaction in relation to the good is up but not bad is down conceptual metaphor was found when the valence of priming words was evaluated, suggesting valence, rather than arousal or a combination of both, is driving the affect-metaphor relationship. No evidence for the automatic activation of affect-metaphor associations was found when the word’s affective tone was not evaluated. These findings suggest that while driven by valence, affect-metaphor associations are not fully automatic and occur only under certain contextual conditions. The implications for our understanding of how emotion impacts spatial attention are discussed, suggesting metaphors enrich, rather than monopolise our mental representation of abstract, affective concepts.</p>

The Effect of Valence and Arousal on Spatial Attention

<p>Conceptual metaphor theory suggests that to mentally represent abstract concepts we use metaphorical associations to map them onto more concrete constructs (Lakoff & Johnson, 1980; 1999). Using a choice reaction time (CRT) task, Meier and Robinson (2004) found that positively valenced words primed attention to higher areas in vertical space, while negatively valenced words primed attention to lower areas in vertical space, consistent with the good is up/bad is down conceptual metaphor. Meier and Robinson (2004; 2005) suggest this provides evidence that emotional words create an automatic and obligatory metaphor-congruent shift in spatial attention, driven by a Valence x Position interaction. However, other research shows that the arousal level, not just the valence of emotional words can affect reaction time (Robinson, Storbeck, Meier & Kirkeby, 2004). This means concluding that valence alone is driving the shift in attention is premature. Furthermore, Brookshire, Irvy and Casasanto (2010) dispute Meier and Robinson’s claim that the relationship between affect and metaphor is automatic, instead suggesting that affect-metaphor associations are optional and only accessed under certain contextual conditions. The purpose of this thesis was therefore two-fold. First, it aimed to explore whether valence, arousal, or an interaction between the two was responsible for driving the metaphor-consistent shift in spatial attention observed by Meier and Robinson (2004). Second, it aimed to progress the discussion about when affective stimuli, in the form of emotional words, automatically activate the good is up/bad is down conceptual metaphor. Three CRT experiments were conducted in which (a) emotional stimulus words were differentiated by arousal level as well as valence and (b) the evaluation of stimulus words’ affective tone (pleasant/unpleasant) was manipulated. A Valence x Position interaction in relation to the good is up but not bad is down conceptual metaphor was found when the valence of priming words was evaluated, suggesting valence, rather than arousal or a combination of both, is driving the affect-metaphor relationship. No evidence for the automatic activation of affect-metaphor associations was found when the word’s affective tone was not evaluated. These findings suggest that while driven by valence, affect-metaphor associations are not fully automatic and occur only under certain contextual conditions. The implications for our understanding of how emotion impacts spatial attention are discussed, suggesting metaphors enrich, rather than monopolise our mental representation of abstract, affective concepts.</p>