Cortex; a journal devoted to the study of the nervous system and behavior
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Face pareidolia is the illusory perception of non-existent faces. The present study, for the first time, contrasted behavioral and neural responses of face pareidolia with those of letter pareidolia to explore face-specific behavioral and neural responses during illusory face processing. Participants were shown pure-noise images but were led to believe that 50% of them contained either faces or letters; they reported seeing faces or letters illusorily 34% and 38% of the time, respectively. ⋯ This finding suggests that the rFFA plays a specific role not only in processing of real faces but also in illusory face perception, perhaps serving to facilitate the interaction between bottom-up information from the primary visual cortex and top-down signals from the prefrontal cortex (PFC). Whole brain analyses revealed a network specialized in face pareidolia, including both the frontal and occipitotemporal regions. Our findings suggest that human face processing has a strong top-down component whereby sensory input with even the slightest suggestion of a face can result in the interpretation of a face.
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Speech signals are often compromised by disruptions originating from external (e.g., masking noise) or internal (e.g., inaccurate articulation) sources. Speech comprehension thus entails detecting and replacing missing information based on predictive and restorative neural mechanisms. The present study targets predictive mechanisms by investigating the influence of a speech segment's predictability on early, modality-specific electrophysiological responses to this segment's omission. ⋯ Suggestive of a general auditory predictive mechanism at work, this main observation was robust against varying source of predictive information or attentional allocation, differing between the two experiments. Source localization further suggested the omission response enhancement by predictability to emerge from left superior temporal gyrus and left angular gyrus in both experiments, with additional experiment-specific contributions. These results are consistent with the existence of predictive coding mechanisms in the central auditory system, and suggestive of the general predictive properties of the auditory system to support spoken word recognition.
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Amyotrophic Lateral Sclerosis (ALS) is associated in about half of the cases with behavioral and cognitive disorders, including impairments in socio-emotional processing, considered as key-features for the diagnosis of the behavioral variant of frontotemporal dementia (bv-FTD). The neurostructural bases of emotional deficits in ALS, however, still remain largely unexplored. Here we aim to assess emotion recognition in non-demented sporadic ALS patients compared with healthy controls, and to explore for the first time its microstructural white-matter correlates. ⋯ Moreover, the Diffusion Tensor Imaging analyses revealed a correlation between this impairment and the alteration of white-matter integrity along the right inferior longitudinal fasciculus and inferior fronto-occipital fasciculus. Our findings indicate the presence of an early emotion recognition deficit in non-demented sporadic ALS patients, associated with microstructural changes in ventral associative bundles connecting occipital, temporo-limbic and orbitofrontal regions in the right hemisphere. These changes may represent a frontotemporal-limbic microstructural marker of socio-emotional impairment in ALS.