ABSTRACT This study aimed to investigate the intra-/inter-hemispheric interactions during visual word processing, by manipulating stimulus onset asynchrony (SOA) in a primed-lateralized lexical decision task. To assess intra-/inter-hemispheric priming effects, identical prime-target pairs were presented in the same or opposite unilateral visual fields. The study found that the right visual field advantage (RVFA) was observed when Korean words were presented sequentially within hemispheres, indicating that the inherent characteristics of the two hemispheres, rather than differences in memory or linguistic aspects of lexical processing, contributed to the hemispheric asymmetry. Additionally, intra-hemispheric priming effects were symmetrical in both hemispheres, with similar increases in priming for words and nonwords from SOA 120 ms to SOA 600 ms. Furthermore, inter-hemispheric priming effects were asymmetrical, with stronger priming when stimuli were presented in a sequence of LH→RH than in RH→LH. These findings suggest that the intrinsic differences in lexical processing between the two hemispheres may be related to the asymmetric pattern of hemispheric interactions in visual word processing.

ABSTRACT Midfrontal theta activity is crucial for attentional and cognitive control. However, its causal role in facilitating visual search, particularly from the perspective of distractor inhibition, is yet to be discovered. We applied theta band transcranial alternate current stimulation (tACS) over frontocentral regions when participants searched for targets among heterogeneous distractors with foreknowledge of distractor features. The results demonstrated improved visual search performance in the theta stimulation group compared to the active sham group. Moreover, we observed the facilitation effect of the distractor cue only in participants who exhibited larger inhibition benefits, which further confirms the role of theta stimulation in precise attentional control. Taken together, our results provide compelling causal evidence for the involvement of midfrontal theta activity in memory-guided visual search.

ABSTRACT Language comprehension must require some degree of attentional focus, but how do periods of inattention and/or split attention impact how language is processed? Here EEG was recorded while participants listened to full-length stories, and were periodically asked about whether they were fully attentive, were completely inattentive, or felt that they were in a split attention state. The ERP response to the words immediately preceding these attention questions was examined as a function of participant response, which allowed for the comparison of word processing in each of these attentional states. When participants were on-task, typical N400 effects of lexical frequency (smaller N400 for common compared to less common words), word position (smaller N400 for words appearing late in a sentence compared to words appearing with less preceding context), and surprisal (smaller N400 for relatively expected words compared to relatively unexpected words) were observed. When participants were in a fully inattentive state, the word-level effect of frequency was intact, but the context-dependent effects of word position and surprisal were significantly reduced. Interestingly, the pattern of results when participants were in a split attention state closely matched that of the fully inattentive state. Overall, the results demonstrate how attentional state influences sensitivity to language context during comprehension, and show that the consequences of inattention and split attention on word processing in context are quite similar, at least on the indices measured here.

ABSTRACT In a previous discussion paper , twenty-six working memory fMRI studies that reported activity in the hippocampus were systematically analyzed. None of these studies provided convincing evidence that the hippocampus was active during the late delay phase, the only period in which working memory can be isolated from long-term memory processes. Based on these results, it was concluded that working memory does not activate the hippocampus. Six commentaries on the discussion paper were received from Courtney (2022), Kessels and Bergmann (2022), Peters and Reithler (2022), Rose and Chao (2022), Stern and Hasselmo (2022), and Wood et al. (2022). Based on these commentaries, the present response paper considered whether there is evidence of sustained hippocampal activity during the working memory delay period based on depth-electrode recording, whether there are activity-silent working memory mechanisms in the hippocampus, and whether there is hippocampal lesion evidence indicating this region is important for working memory. There was no convincing electrophysiological or neuropsychological evidence that the hippocampus is associated with working memory maintenance, and activity-silent mechanisms were arguably speculative. Given that only a small fraction (approximately 5%) of working memory fMRI studies have reported hippocampal activity and lesion evidence indicates the hippocampus is not necessary for working memory, the burden of proof is on proponents of the view that the hippocampus is important for working memory to provide compelling evidence to support their position. To date, from my perspective, there is no convincing evidence that the hippocampus is associated with working memory.

ABSTRACT Few studies have examined the specific contribution of focal damage of the prefrontal cortex and executive dysfunction to emotion recognition deficits, with results reporting controversial findings. This study investigated the performance of 30 patients with prefrontal cortex damage and 30 matched controls on a battery of executive measures assessing processes of inhibition, flexibility, and planning and a task of emotion recognition with also a particular attention to the examination of the association between these domains. The results showed that compared with control participants, patients with prefrontal cortex damage were impaired in recognizing the three negative emotions of fear, sadness, and anger and were also impaired on all executive measures. Moreover, by examining the association between both these domains, using correlation and regression analyses, we noted that impaired performance in recognizing emotions of fear, sadness, and anger was predicted by impaired performances on the measures of inhibition and flexibility or “set-shifting” suggesting that the ability to recognize emotions could be at least to some extent cognitively mediated. Finally, using a voxel-based lesion technique, we identified a partially common prefrontal network underlying deficits on executive functions and emotions recognition centered on the ventral and medial parts of the prefrontal cortex, reflecting beyond the neural network involved in recognizing negative emotions per se that of the cognitive processes elicited by this emotion task.

ABSTRACT This commentary makes three suggestions on Willems’ neurocognitive model for understanding mixed and ambiguous emotions and morality. First, it proposes that his atheoretical approach risks unwittingly adopting theoretical and conceptual limitations implicit in reigning paradigms and overlooking the need for theoretical impetus and constraints in the development of valid constructs of targeted emotions. Second, it suggests that a dynamical systems approach to emotions provides a fruitful theory and neuro-phenomenology as a corresponding methodology. Lastly, it proposes that Willems’ objective would benefit from a more systematic integration of insights from the humanities into the nature and nuances of literary (moral) emotions.

ABSTRACT In this commentary we draw attention to a context involving mixed and ambiguous emotions: verbal irony. Irony is frequently used, evokes mixed emotional responses (e.g., criticism and amusement), and has been the focus of recent cognitive neuroscience research. Yet, irony has primarily been studied as a linguistic device, and has rarely been considered by emotion researchers. Similarly, linguistics has not considered mixed and ambiguous emotion when studying verbal irony. We argue that verbal irony offers rich opportunities to evoke and study mixed and ambiguous emotions, and might provide advantages for testing the MA-EM model.

ABSTRACT Willems (this issue) proposes a neurocognitive model with a central role allotted to ambiguity in perceived morality and emotion in driving involvement of reflective/mentalizing processes. We argue that abstractness of representation has more explanatory power in this respect. We illustrate this with examples from the verbal and non-verbal domain showing a) concrete-ambiguous emotions processed through reflexive systems and b) abstract-unambiguous emotions processed through the mentalizing system, counter to MA-EM model predictions. However, due to the natural correlation between ambiguity and abstractness, both accounts will typically make convergent predictions.

ABSTRACT The neurocognitive model of Mixed and Ambiguous Emotions and Morality (MA-EM) makes a relevant case for putting non-unidimensional emotions and morality more prominently on the research agenda. However, existing research challenges its assumptions about the distinction between mixed and ambiguous emotions and morality, and how they relate to reflective versus simulative processing routes, in three respects. First, the emotional state of being moved is generally conceptualized as a non-ambiguous rather than an ambiguous emotion. Second, mixed emotions have been found to elicit reflection rather than simulation. Third, the morality of narrative characters is typically perceived as mixed rather than ambiguous.

ABSTRACT The use of naturalistic stimuli in cognitive neuroscience experiments inspires and requires theoretical foundations that bring together different cognitive domains, such as emotion, language, and morality. By zooming in on the digital environments in which we often perceive emotional messages today, and inspired by the Mixed and Ambiguous Emotions and Morality model, we here argue that successfully processing emotional information in the twenty-first century will often have to rely not only on simulation and/or mentalizing, but also on executive control and attention regulation.