Lateralisation of diffuse positive and negative affect: Ascribing valence to ambiguous stimuli

The available evidence regarding the lateralisation of affect is rather divergent. Interestingly, the common procedure in previous research on affective lateralisation has been to measure hemispheric dominance following exposure to concrete affective stimuli. Therefore, prior research seems to tap primarily into the lateralisation of specific approach–avoidance motivations rather than diffuse affective states. The present research adopted an alternative methodological approach that excluded approach–avoidance motivations and merely studied the lateralised nature of diffuse affect. Participants evaluated ambiguous stimuli presented in either the right or left visual field. Results showed that stimuli presented in the left visual field were significantly more often ascribed a positive meaning compared to information in the right visual field. The present findings are compatible with related lateralised processes and underscore the necessity of distinguishing between specific motivations and diffuse affect.     

Regulating cognitive control through approach-avoidance motor actions

In two studies, the regulatory function of approach-avoidance cues in activating cognitive control processes was investigated. It was hypothesized that avoidance motor actions, relative to approach motor actions, increase the recruitment of cognitive resources, resulting in better performance on tasks that draw on these capacities. In Study 1, error rates on a verbal response mode version of the Stroop task were analyzed. On inconsistent Stroop trials, participants in the avoidance condition made significantly fewer errors than those in the approach condition. In Study 2, performance differences on a task switching paradigm were investigated. Crucially, approach and avoidance motor actions were manipulated within-subjects by alternating between approach and avoidance motor actions on 4 blocks of trials. Temporal switching costs were significantly lower while performing an avoidance, compared to an approach motor action. These results support our hypothesis that avoidance cues, relative to approach cues, lead to improved performance on cognitive control tasks.     

The influence of social category cues on the happy categorisation advantage depends on expression valence

Facial race and sex cues can influence the magnitude of the happy categorisation advantage. It has been proposed that implicit race or sex based evaluations drive this influence. Within this account a uniform influence of social category cues on the happy categorisation advantage should be observed for all negative expressions. Support has been shown with angry and sad expressions but evidence to the contrary has been found for fearful expressions. To determine the generality of the evaluative congruence account, participants categorised happiness with either sadness, fear, or surprise displayed on White male as well as White female, Black male, or Black female faces across three experiments. Faster categorisation of happy than negative expressions was observed for female faces when presented among White male faces, and for White male faces when presented among Black male faces. These results support the evaluative congruence account when both positive and negative expressions are presented.     

Temporal dynamics of awareness for facial identity revealed with ERP

In this study, we investigated the scalp recorded event-related potential (ERP) responses related to visual awareness. A backward masking procedure was performed while high-density EEG recordings were carried out. Subjects were asked to detect a familiar face, presented at durations that varied parametrically between 16 and 266 ms. ERPs were computed and awareness was assessed using a sensitivity measure from signal detection theory (d'). Modifications in the electrical scalp topographies were found to reflect visual awareness of the stimulus. In particular, an early map topography was found to emerge progressively around 230 ms, showing a pattern of increase similar to the measure of visual awareness. This was followed by an increase in duration of a second, P300-like map. Source localisation for the early awareness-related topography revealed the activation of a distributed network of brain areas including frontal and temporo-occipital regions. Our results suggest that conscious experience emerges in parallel with the activation of a specific neural network that occurs in a time window beginning from about 200 ms.