No abstract

Finding reliable imaging biomarkers of mental illness has been a major challenge, on a par with the quest for biomarkers of the male versus the female brain, as the two types of imaging inform one another. We explored the hypothesis that the degree of coherence (internal isomorphism) between brain volumes of the left versus the right hemisphere for patients with psychopathological conditions follows the brain coherence pattern of the healthy male or healthy female. We developed the distance index (DI) as a biomarker of brain coherence and compared it with three ad hoc coherence measures. We found that only DI could reliably distinguish males from females and patients from controls. Also, cortical regions with highest DI scores were swapped between males and females across groups following male/female models of psychopathology. Furthermore, although indices were similar in predicting cognitive performance, DI provided a more proportionate prediction pattern across diagnosis groups, and more robust interactions with males/females. These findings highlight the importance of brain coherence, particularly measured by DI, for phenotyping sex and mental illness.

We used a 10-question self-report questionnaire, Mini Voice Questionnaire (MVQ), for mapping the phenomenology of auditory verbal hallucinations (AVH). The MVQ contains questions related to daily AVH frequency and duration, the events preceding AVH episode onset and offset, the very first AVH episode, emotional content, coping strategies, if the voice comes from the inside or outside of head, if it is the own voice heard, and whether the voice is present when filling out the questionnaire. Forty-one patients with a diagnosis of schizophrenia spectrum disorder participated in the study. The construction of the MVQ was originally driven by an interest in whether AVH-episode onsets and offsets, that is, the coming and going of the voice, are initiated by specific environmental events or mental states, or whether they occur spontaneously, which could have both theoretical and clinical implications. MVQ scores were correlated with PANSS and BAVQ questionnaire scores. The results showed that specific events do not precede onset or offset of AVH episodes except for the very first episode which was often associated with trauma or other negative events. This finding could have implications for neurobiological models of AVH, showing that AVH episodes are spontaneously initiated, pointing to a neuronal origin of AVH episode onsets and offsets. The P3 (hallucinatory behavior) item of the PANSS questionnaire correlated significantly with frequency and duration of AVH episodes: More frequent and longer AVH episodes were associated with higher P3 scores, implying more severe symptoms. The results are discussed in terms of recent AVH models.

Egocentric distance estimation has been shown to depend on wearing safety gear, which promotes compensatory behavior, and on target type, which regulates fight-or-flight responses. We hypothesized that the two factors interact, possibly in asymmetric fashion, and set out to uncover the limits of this interaction in a perceptual task where individuals wearing helmets or baseball caps estimated egocentric distance to non-threatening and threatening animals depicted on cards (i.e., safe and unsafe targets). We found that, compared to participants wearing caps, participants wearing helmets overshoot distance estimations and were able to distinguish not only between targets situated at two depth levels as participants wearing caps could, but also between safe targets situated at wide and narrow visual angles. Our findings help define the interaction between safety devices and target type, thereby contributing to the debate between advocates of prevention models and those who maintain that these are offset by compensatory strategies.

In previous studies investigating logical-connectives simulations, participants focused their attention on verifying truth-condition satisfaction for connective expressions describing visual stimuli (e.g., Dumitru, 2014; Dumitru and Joergensen, 2016). Here, we sought to replicate and extend the findings that conjunction and disjunction simulations are structured as one and two Gestalts, respectively, by using language – picture matching tasks where participants focused their attention exclusively on stimuli visuospatial properties. Three studies evaluated perceptual compatibility effects between visual displays varying stimuli direction, size, and orientation, and basic sentences featuring the logical connectives AND, OR, BUT, IF, ALTHOUGH, BECAUSE, and THEREFORE (e.g., “There is blue AND there is red”). Response times highlight correlations between the Gestalt arity of connective simulations and visual attention patterns, such that words referring to constituents in the same Gestalt were matched faster to visual stimuli displayed sequentially rather than alternatively, having the same size rather than different sizes, and being oriented along axes other than horizontal. The results also highlight attentional patterns orthogonal to Gestalt arity: visual stimuli corresponding to simulation constituents were processed faster when they appeared onscreen from left to right than from right to left, when they were emphasized or de-emphasized together (i.e., faster processing of all-small or all-large stimuli pairs), and when they formed a downward-oriented diagonal, which signals a simulation boundary. More generally, our findings suggest that logical connectives rapidly evoke simulations that trigger top-down attention patterns over the grouping and properties of visual stimuli corresponding to the constituents they link together.