Change perception in complex auditory scenes

In four experiments, we examined the role of auditory transients and auditory short-term memory in perceiving changes in a complex auditory scene comprising multiple auditory objects. Participants were presented pairs of complex auditory scenes that were composed of a maximum of four animal calls delivered in free field; participants were instructed to decide whether the two scenes were the same or different (Experiments 1, 2, and 4). Changes to the second scene consisted of either the addition or the deletion of one animal call. Contrary to intuitive predictions based on results from the visual change blindness literature, substantial deafness to the change emerged without regard to whether the scenes were separated by 500 msec of masking white noise or by 500 msec of silence (Experiment 1). In fact, change deafness was not even modulated by having the two scenes presented contiguously (i.e., 0-msec interval) or separated by 500 msec of silence (Experiments 2 and 4). This result suggests that change-related auditory transients played little or no role in change detection in complex auditory scenes. Instead, the main determinant of auditory change perception (and auditory change deafness) appears to have been the capacity of auditory short-term memory (Experiments 3 and 4). Taken together, these findings indicate that the intuitive parallels between visual and auditory change perception should be reconsidered.     

Self-motion perception and vestibulo-ocular reflex during whole body yaw rotation in standing subjects: the role of head position and neck proprioception

Self-motion perception and vestibulo-ocular reflex (VOR) were studied during whole body yaw rotation in the dark at different static head positions. Rotations consisted of four cycles of symmetric sinusoidal and asymmetric oscillations. Self-motion perception was evaluated by measuring the ability of subjects to manually track a static remembered target. VOR was recorded separately and the slow phase eye position (SPEP) was computed. Three different head static yaw deviations (active and passive) relative to the trunk (0°, 45° to right and 45° to left) were examined. Active head deviations had a significant effect during asymmetric oscillation: the movement perception was enhanced when the head was kept turned toward the side of body rotation and decreased in the opposite direction. Conversely, passive head deviations had no effect on movement perception. Further, vibration (100 Hz) of the neck muscles splenius capitis and sternocleidomastoideus remarkably influenced perceived rotation during asymmetric oscillation. On the other hand, SPEP of VOR was modulated by active head deviation, but was not influenced by neck muscle vibration. Through its effects on motion perception and reflex gain, head position improved gaze stability and enhanced self-motion perception in the direction of the head deviation.     

Model checking hybrid logics (with an application to semistructured data)

We investigate the complexity of the model checking problem for hybrid logics. We provide model checking algorithms for various hybrid fragments and we prove PSPACE-completeness for hybrid fragments including binders. We complement and motivate our complexity results with an application of model checking in hybrid logic to the problems of query and constraint evaluation for semistructured data.     

Direct and indirect relationships among posttraumatic stress disorder,depression, hostility,anger, and verbal and physical aggression in returning veterans

Hostility, anger, and aggression are conceptually related but unique constructs found to occur more often among veterans with posttraumatic stress disorder (PTSD) than among civilians or veterans without PTSD. However, the pathways between PTSD, depression, hostility, anger, and aggression have not been comprehensively characterized. Therefore, drawing on a sample of returning Operation Enduring Freedom/Operation Iraqi Freedom combat veterans ( N = 175; 95% male; mean age 30 years), this study sought to examine the direct and indirect relationships among PTSD, depression, hostility, anger, and four types of aggression: verbal, and physical toward self, others, and objects. Functional modeling of direct effects was done using multiple least-squares regression and bootstrapped mediation analyses were carried out to test indirect effects. Results indicate that PTSD is not the overall direct contributor to different forms of aggression, supporting the mediating role of depression and trait anger. Depression symptoms explain part of the relationships between PTSD and verbal aggression, physical aggression toward objects, and physical aggression toward self and trait anger explains part of the relationships between PTSD and verbal aggression, physical aggression toward objects, and physical aggression toward others. Our findings support the importance of assessing for anger, depression, and different types of aggression among veterans presenting for PTSD treatment to develop individualized treatment plans that may benefit from early incorporation of interventions.     

Plumbing semantic depths in Amsterdam

The 13th Amsterdam Colloquium was held at the Institute for Logic, Language and Linguistics at the University of Amsterdam, on 17-19 December 2001.     

Hemispheric, attentional, and processing speed factors in the treatment of developmental dyslexia

Aim of the study is to analyze the contributions of hemispheric, attentional, and processing speed factors to the effects of neuropsychological treatment of developmental dyslexia. Four groups of dyslexic children (M-type dyslexia) were treated over a period of four months. A first group (n = 9) underwent Bakker's Hemisphere-Specific Stimulation, with presentation of words in the right and left visual field. A second group (n = 7) received the same stimuli randomly in either visual hemifield. A third group (n = 8) received the same words presented centrally at fixation point. A fourth group (n = 6) received central stimuli with fixed presentation time (1500 ms). The children were tested before and after treatment on reading and spelling measures. All groups improved significantly after treatment on all variables. However, the group that was treated with centrally presented stimuli improved more than the other groups in spelling measures. A possible explanation is that rapid, simultaneous presentation to both hemispheres enhances interhemispheric exchange, which could produce an advantage in tasks requiring a high degree of integration between left and right hemispheric functions, such as spelling. The absence of significant differences in reading improvement may point to the role of memory functions or strategic factors characterizing all the treatment programs, possibly overweighing the effect of the other factors.     

Slowly progressive pure dysgraphia with late apraxia of speech: a further variant of the focal cerebral degeneration

We report a longitudinal neuropsychological investigation of a patient with slowly progressive pure dysgraphia. Cognitive analysis of writing errors suggested a selective impairment of the graphemic buffer. After about seven years, the patient developed an apraxia of speech. No other linguistic or generalized cognitive impairment occurred subsequently, so that, twelve years after the beginning of the disease, the patient showed complete independence in daily life and still remained professionally active. Functional neuroimaging revealed hypoperfusion confined to left fronto-temporal lobe. This well-recognizable syndrome does not fit any of the cases described previously in the literature. This report therefore, adds another variant to heterogeneous clinical spectrum of focal neurodegenerative disorders, further suggesting the opportunity of their distinction from pathological processes leading to dementia.     

Machiavellianism and Theory of Mind in people affected by schizophrenia

CONTEXT: People affected by schizophrenia show deficits in social interaction (Cramer, Bowen, & O'Neill, 1992); such a deficit may stem from an alteration in the representation of mental states. OBJECT: In this study we have examined 42 people affected by schizophrenia, diagnosed according to DSM-IV criteria, by testing them with an instrument (the Mach IV scale, Christie & Geis, 1970) assessing "Machiavellian Intelligence" according to Niccolò Machiavelli's assertions. Schizophrenic subjects were compared to a sample of normal controls, matched for age, sex, and education. OBJECTIVE: The aim of our study was to evaluate if there were correlations between the ability to understand other people's mental states and the capacity for interpreting "Machiavellian expressions." RESULTS: Results show that people affected by schizophrenia are less able to use Machiavellian-style "tactical" abilities than controls. CONCLUSION: Such a disability seems to be correlated to poor mentalising abilities.     

Italian youth subculture: collection, self-esteem, and self-efficacy

63 young people (M age=23.9 yr., SD=2.4, 50 men, 13 women) belonging to four subculture groups (New American Punk, Cyberpunk, Trash Style, and Rasta-Hippy) were studied to examine the relationship between self-esteem, self-efficacy, and the development of a body modification collection. A survey was created to evaluate quality of life, risk behaviour, and body modification. Self-esteem and self-efficacy were assessed using the Rosenberg Self-esteem Scale and General Perceived Self-efficacy Scale. Belonging to a group which permits neglect of standard norms of communal life makes it possible to avoid facing up to low self-esteem. Adherence to a group appears, from the results of this study, to be correlated with self-efficacy; inability to cope with life situations suggests a state of malaise in these young people.