PubMed Health⌕ Search

Biomedical subjects

Odin van der Stelt

Publications and source records attributed to Odin van der Stelt.

5 recordsLinked to original sources
PubMed2006

Attentional modulation of early-stage visual processing in schizophrenia.

This study shows that paying attention to the color of a visual stimulus is manifested by an early endogenous scalp-positive event-related brain potential (ERP) component, referred to as "selection positivity", that emerges within the first 100 ms after stimulus onset in healthy observers. In contrast, recently ill and chronically ill schizophrenia patients as well as patients at high risk for schizophrenia all failed to show this early ERP component while attending to color. These results suggest that a relatively early stage of visual-selective processing in posterior extrastriate cortex is disrupted in schizophrenia.

Adolescent↗
PubMed2006

Relations among intelligence, executive function, and P300 event related potentials in schizophrenia.

Prior research has demonstrated that the P300 response may be related to neuropsychological functioning in nonclinical samples. However, the nature of this relation is unclear, and its characteristics in schizophrenia are unexplored. We assessed estimated IQ, neuropsychological tests that assess components of executive functioning, and the P300 component of the event-related brain potential elicited by auditory and visual oddball paradigms in individuals with and without schizophrenia. We observed modest relations between P300 indices and neuropsychological tests purported to assess aspects of executive functioning in both diagnostic groups. Furthermore, multiple regression analyses revealed that whereas control participants with higher estimated IQs demonstrated larger P3 amplitudes to attended auditory targets, the opposite relation appeared evident in schizophrenic participants when variance due to Trailmaking A or a continuous performance task was held constant. Additionally, control participants with higher estimated IQs demonstrated shorter P3 latencies to attended visual targets whereas schizophrenic participants did not when variance due to the Tower of London was held constant. These results suggest diagnostic group differences in the association between P300 and IQ and indicate that investigations designed to explore P300-IQ relations should include measures of executive functioning in their models.

Acoustic Stimulation↗
PubMed2005

Auditory P300 in high-risk, recent-onset and chronic schizophrenia.

BACKGROUND: The present study examined the integrity of the P300 component of the event-related potential (ERP) in patients at high imminent risk for schizophrenia in relation to healthy comparison subjects and patients in the recent-onset and chronic stages of schizophrenia. METHODS: The P300 was recorded by using an auditory oddball task in 10 patients clinically considered at risk of being prodromally symptomatic for schizophrenia, 10 patients with recent-onset schizophrenia, 14 patients with chronic schizophrenia, 14 young healthy comparison subjects, who were age-matched to the high-risk and recent-onset schizophrenia groups, and 14 older healthy comparison subjects, who were age-matched to the chronic schizophrenia group. RESULTS: High-risk subjects displayed smaller than normal P300 amplitudes at the parietal, centroparietal and central scalp locations. The observed P300 amplitude abnormalities in high-risk subjects were severe, being comparable in magnitude to the abnormalities seen in recent-onset and chronic schizophrenia subjects. However, whereas high-risk subjects showed P300 amplitude abnormalities that were bilaterally symmetrical, subjects with recent-onset schizophrenia and, particularly, subjects with chronic schizophrenia exhibited abnormalities that were markedly larger over the left temporal scalp sites. CONCLUSIONS: Patients at high imminent risk for developing a first florid psychotic episode seem to manifest auditory P300 amplitude abnormalities that are similar, but not identical, to those observed in patients in the recent-onset and chronic stages of schizophrenia. These results support the idea that auditory P300 abnormalities in schizophrenia reflect a primary cognitive and pathophysiological feature of the illness.

Adult↗
PubMed2004

Impaired P3 generation reflects high-level and progressive neurocognitive dysfunction in schizophrenia.

BACKGROUND: In this study, we assessed the integrity of several components of the event-related potential (ERP) associated with different levels of visual and auditory processing in patients with schizophrenia. The objective was to clarify whether high-level attention-dependent cognitive deficits, as indexed by the P3 component, in patients with schizophrenia are related to or originate from potential preceding deficits at lower levels of information processing, as indexed by earlier-occurring ERP components. Also, given that the auditory P3 amplitude has recently been observed to be inversely correlated with illness duration and, hence, may potentially track the operation of a putative neurodegenerative process across the illness course, we recruited patients with schizophrenia varying greatly in illness duration to attempt to replicate this observation. METHODS: Multichannel ERPs were recorded in 22 patients with schizophrenia at different stages of illness and 22 age-matched healthy control subjects while they performed a visual and auditory oddball task. RESULTS: Patients displayed smaller P3 amplitudes to visual novel and auditory target stimuli than did control subjects, whereas small or no significant between-group differences were observed in sensory-evoked and cognitive-related ERP components preceding P3. Additionally, patients showed a distinct left-smaller-than-right auditory P3 temporal scalp voltage asymmetry. Furthermore, we replicated previous study results of an inverse correlation between the auditory P3 amplitude and illness duration. CONCLUSIONS: These results indicate that high-level attention-dependent cognitive deficits central to schizophrenia do not originate from potential preceding impairments at lower levels of sensory, perceptual, or cognitive processing. The data support the view that schizophrenia is characterized by fundamental deficits in integrative cortical functions that specifically impair the ability to analyze and represent stimulus context to guide behavior. Moreover, abnormalities of the auditory P3 amplitude in schizophrenia seem to reflect a basic underlying pathophysiological process that is present at illness onset and progresses across the illness course.

Adolescent↗