Structural-functional correlations between hippocampal volume and cortico-limbic emotional responses in depressed children

Although hippocampal atrophy and altered functional brain responses to emotional stimuli have been found in major depressive disorder (MDD), the relationship between the two is not yet well understood. The present study focused on children with and without a history of preschool onset MDD (PO-MDD) and directly examined the relations between hippocampal volume and functional brain activation to affect-eliciting stimuli. Children completed annual diagnostic assessments starting at preschool. When children were school-aged, high-resolution structural MRI and task-related functional MRI data were acquired from N = 64 nonmedicated children. During fMRI, subjects were shown emotional faces. Results from the total sample indicated that smaller bilateral hippocampal volumes were associated with greater cortico-limbic (e.g., amygdala, hippocampus, dorsolateral prefrontal cortex) activation to sad or negative faces versus neutral faces. Left hippocampal volume was negatively associated with the cortico-limbic activation in both the PO-MDD and healthy children. Right hippocampal volume was negatively correlated with amygdala responses in the PO-MDD group, but not in the healthy comparison group. These findings suggest that there may be important interrelationships between reduced hippocampal volume and hyperactivation of brain responses in children, both those with and those without a history of PO-MDD.     

Action enhances auditory but not visual temporal sensitivity

People naturally dance to music, and research has shown that rhythmic auditory stimuli facilitate production of precisely timed body movements. If motor mechanisms are closely linked to auditory temporal processing, just as auditory temporal processing facilitates movement production, producing action might reciprocally enhance auditory temporal sensitivity. We tested this novel hypothesis with a standard temporal-bisection paradigm, in which the slope of the temporal-bisection function provides a measure of temporal sensitivity. The bisection slope for auditory time perception was steeper when participants initiated each auditory stimulus sequence via a keypress than when they passively heard each sequence, demonstrating that initiating action enhances auditory temporal sensitivity. This enhancement is specific to the auditory modality, because voluntarily initiating each sequence did not enhance visual temporal sensitivity. A control experiment ruled out the possibility that tactile sensation associated with a keypress increased auditory temporal sensitivity. Taken together, these results demonstrate a unique reciprocal relationship between auditory time perception and motor mechanisms. As auditory perception facilitates precisely timed movements, generating action enhances auditory temporal sensitivity.     

The association of religiosity,spirituality, and ethnic background with ego-pathology in acute schizophrenia

Studies have highlighted the impact of ego-consciousness, religiosity and spirituality on psychotic symptoms, although so far no study has investigated if and how these factors may be interrelated. In this exploratory cross-sectional study, involving 42 patients with a diagnosis of acute paranoid schizophrenia (DSM-IV), we assessed religiosity (Religious Orientation Test) spirituality (Spiritual Transcendence Scale) and ego-pathology (Ego Pathology Inventory) and analysed any relationship with these and psychopathological symptoms (Positive and Negative Symptom Scale). The subjects were divided into four ethnic groups (Caucasian, Afro-Caribbean, African, and Asian) and a structured, qualitative interview on religious needs and self-concepts was also conducted. Using a multivariate analysis, we found statistically significant negative associations between the scores on ego and common pathology and religiosity and spirituality as covariates. This was seen across all ethnic groups. The findings are discussed in respect of the potential clinical importance of ethnic, religious and spiritual factors for assessment and management of patients with schizophrenia.     

Object-based auditory facilitation of visual search for pictures and words with frequent and rare targets

Auditory and visual processes demonstrably enhance each other based on spatial and temporal coincidence. Our recent results on visual search have shown that auditory signals also enhance visual salience of specific objects based on multimodal experience. For example, we tend to see an object (e.g., a cat) and simultaneously hear its characteristic sound (e.g., “meow”), to name an object when we see it, and to vocalize a word when we read it, but we do not tend to see a word (e.g., cat) and simultaneously hear the characteristic sound (e.g., “meow”) of the named object. If auditory–visual enhancements occur based on this pattern of experiential associations, playing a characteristic sound (e.g., “meow”) should facilitate visual search for the corresponding object (e.g., an image of a cat), hearing a name should facilitate visual search for both the corresponding object and corresponding word, but playing a characteristic sound should not facilitate visual search for the name of the corresponding object. Our present and prior results together confirmed these experiential association predictions. We also recently showed that the underlying object-based auditory–visual interactions occur rapidly (within 220 ms) and guide initial saccades towards target objects. If object-based auditory–visual enhancements are automatic and persistent, an interesting application would be to use characteristic sounds to facilitate visual search when targets are rare, such as during baggage screening. Our participants searched for a gun among other objects when a gun was presented on only 10% of the trials. The search time was speeded when a gun sound was played on every trial (primarily on gun-absent trials); importantly, playing gun sounds facilitated both gun-present and gun-absent responses, suggesting that object-based auditory–visual enhancements persistently increase the detectability of guns rather than simply biasing gun-present responses. Thus, object-based auditory–visual interactions that derive from experiential associations rapidly and persistently increase visual salience of corresponding objects.     

Kripke bundles for intermediate predicate logics and Kripke frames for intuitionistic modal logics

Shehtman and Skvortsov introduced Kripke bundles as semantics of non-classical first-order predicate logics. We show the structural equivalence between Kripke bundles for intermediate predicate logics and Kripke-type frames for intuitionistic modal prepositional logics. This equivalence enables us to develop the semantical study of relations between intermediate predicate logics and intuitionistic modal propositional logics. New examples of modal counterparts of intermediate predicate logics are given.The author would like to express his gratitude to Professor Hiroakira Ono for his comments, and to Professor Tadashi Kuroda for his encouragement.The author wishes to express his gratitude to Professors V. B. Shehtman, D. P. Skvortsov and M. Takano for their comments.     

Stimulus control of spatial behavior on the eight-arm maze in rats

Rats were trained on an eight-arm, elevated radial maze in a large cylindrical chamber where extramaze stimuli could be manipulated. The first experiment indicated that rats could use extramaze stimuli to locate the arms if such stimuli were available, whereas they performed less effectively and tended to employ response chaining if these stimuli were not available. The second experiment demonstrated that maze performance was disrupted by transposition of the stimuli but was relatively unaffected by rotation of the same stimuli. The third experiment suggested that the disruptive effect of stimulus transposition might be due to a “resetting” process elicited by the alteration in the configuration of the stimuli after stimulus transposition. These results suggest that when extramaze stimuli are available, rats tend to use such stimuli in a configurational manner to locate the arms rather than as a list of items processed independently of their spatial relationships to each other.     

Geometrical haptic illusions revisited: Haptic illusions compared with visual illusions

Révész (1934) reported that haptic illusions were observed in almost all of the geometrical optical illusion figures. The present study reexamined seven geometrical illusions in both haptic and visual modes. In the Müller-Lyer, Ponzo, and vertical-horizontal figures, haptic illusions equivalent to the visual illusions were observed. In the Oppel-Kundt figure, a haptic illusion similar to the visual one was obtained. In the haptic Delboeuf stimuli, the size illusion of the outer circle occurred, whereas that of the inner circle did not. No haptic illusion was obtained in the Poggendorff figure. In the Zöllner figure, a haptic illusion directionally opposite to the visual one was obtained. These results show that haptic illusions do not occur in all of the geometrical illusion figures. They also suggest that haptic illusions are not necessarily mediated by visualization and that haptic processing of the figures often occurs in a manner different from vision.     

Canadian,Greek, and Japanese freely produced emotion labels for facial expressions

Observers in Canada (n=50), Greece (n=38), and Japan (n=50) were shown seven of Matsumoto and Ekman's (1988) photographs reported to show universally recognizable facial expressions of basic emotions. Observers were asked to name the emotion expressed with any single emotion label they wanted. Across cultures, recognition (percentage of observers agreeing with prediction) was high (>80%) for thehappy expression (indicating that observers understood the task), low for thecontempt expression (0 to 2%), and intermediate for the others (14 to 80% forsurprise, sadness, anger, disgust, andfear). Recognition for some facial expressions varied with the culture of the observer: For example, recognition of thefear expression was moderate to high in the two Western samples (62 to 87%) but low in the Japanese (14%); indeed, the Japanese modal response wassurprise rather thanfear.This study was funded by a grant from the Social Sciences and Humanities Research Council of Canada.We thank Konstandina Nelos for her help in gathering the data in Greece.