Reduced prepulse inhibition as an early vulnerability marker of the psychosis prodrome in adolescence.

Background: The onset of psychosis is thought to be preceded by neurodevelopmental changes in the brain. However, the timing and nature of these changes have not been established. The aim of the present study was to determine whether three "classic" neurophysiological markers of schizophrenia are also characteristic of young adolescents (12-18 years) at ultra-high risk for psychosis (UHR).

Proline and COMT status affect visual connectivity in children with 22q11.2 deletion syndrome.

Background: Individuals with the 22q11.2 deletion syndrome (22q11DS) are at increased risk for schizophrenia and Autism Spectrum Disorders (ASDs). Given the prevalence of visual processing deficits in these three disorders, a causal relationship between genes in the deleted region of chromosome 22 and visual processing is likely.

Multisensory integration and attention in autism spectrum disorder: evidence from event-related potentials.

Successful integration of various simultaneously perceived perceptual signals is crucial for social behavior. Recent findings indicate that this multisensory integration (MSI) can be modulated by attention. Theories of Autism Spectrum Disorders (ASDs) suggest that MSI is affected in this population while it remains unclear to what extent this is related to impairments in attentional capacity.

Reduced prepulse inhibition in adolescents at risk for psychosis: a 2-year follow-up study.

Background: Reduced prepulse inhibition (PPI) of the auditory startle reflex is a hallmark feature of attention-processing deficits in patients with schizophrenia and other psychotic disorders. Recent evidence suggests that these deficits may also be present before the onset of psychosis in individuals at ultra-high risk (UHR) and become progressively worse as psychosis develops. We conducted a longitudinal follow-up study to observe the development of PPI over time in UHR adolescents and healthy controls.

More prolonged brain activity related to gaze cueing in schizophrenia.

Objective: The ability to use the gaze direction of another person to guide attention is important for social functioning, but behavioral reports on this topic among individuals with schizophrenia are inconclusive. Event Related Potentials (ERPs) can very accurately pinpoint the shifting of attention, and can therefore shed more light on cueing abilities in schizophrenia.

Methods: ERPs were measured during two spatial attention tasks in 14 high-functioning, young adult schizophrenic individuals and 19 age- and IQ-matched controls.

Cross-sensory gating in schizophrenia and autism spectrum disorder: EEG evidence for impaired brain connectivity?

Autism spectrum disorders (ASD) and schizophrenia are both neurodevelopmental disorders that have extensively been associated with impairments in functional brain connectivity. Using a cross-sensory P50 suppression paradigm, this study investigated low-level audiovisual interactions on cortical EEG activation, which provides crucial information about functional integrity of connections between brain areas involved in cross-sensory processing in both disorders. Thirteen high functioning adult males with ASD, 13 high functioning adult males with schizophrenia, and 16 healthy adult males participated in the study.

Audiovisual speech integration in pervasive developmental disorder: evidence from event-related potentials.

Background: Integration of information from multiple sensory sources is an important prerequisite for successful social behavior, especially during face-to-face conversation. It has been suggested that communicative impairments among individuals with pervasive developmental disorders (PDD) might be caused by an inability to integrate synchronously presented visual and auditory cues.

Method: We investigated audiovisual integration of speech stimuli among a group of high-functioning adult PDD individuals and age- and IQ-matched controls using electroencephalography, measuring both early pre-phonological, as well as late phonologically driven integration.

Facial electromyographic responses to emotional information from faces and voices in individuals with pervasive developmental disorder.

Background: Despite extensive research, it is still debated whether impairments in social skills of individuals with pervasive developmental disorder (PDD) are related to specific deficits in the early processing of emotional information. We aimed to test both automatic processing of facial affect as well as the integration of auditory and visual emotion cues in individuals with PDD.

Methods: In a group of high-functioning adult individuals with PDD and an age- and IQ-matched control group, we measured facial electromyography (EMG) following presentation of visual emotion stimuli (facial expressions) as well as the presentation of audiovisual emotion pairs (faces plus voices).

Similar facial electromyographic responses to faces, voices, and body expressions.

Observing facial expressions automatically prompts imitation, as can be seen with facial electromyography. To investigate whether this reaction is driven by automatic mimicry or by recognition of the emotion displayed we recorded electromyograph responses to presentations of facial expressions, face-voice combinations and bodily expressions, which resulted from happy and fearful stimuli. We observed emotion-specific facial muscle activity (zygomaticus for happiness, corrugator for fear) for all three stimulus categories.