Biomedical subjects

Jan W Van Strien

Publications and source records attributed to Jan W Van Strien.

8 recordsLinked to original sources

PubMed2006

Effect of hedonic tone on event-related potential measures of cognitive processing.

Anhedonia, the inability to experience pleasure, is a core feature of several psychiatric disorders such as schizophrenia, depression, and substance dependence. Furthermore, it has been suggested that anhedonia is an important predictor of schizophrenia. Anhedonia has been associated with information-processing deficits, especially attentional deficits, which may predispose for schizophrenia. In the present study, event-related potentials (ERPs) were used to examine the influence of hedonic tone on information-processing characteristics in a sample of healthy individuals. Thirty-five healthy subjects were divided into two groups based on their scores on the Snaith-Hamilton Pleasure Scale (SHAPS). Cognitive functions were measured during an active visual oddball paradigm. It was found that both early, middle and late ERP components of subjects with low levels of hedonic tone were attenuated compared with ERPs of subjects with high levels of hedonic tone. These findings suggest that decreased hedonic tone is associated with reductions in both automatic and effortful cognitive processing of relevant stimuli. Consequences of these findings for the vulnerability to psychopathology are discussed.

Adolescent↗

PubMed2005

Attention modulates hemispheric differences in functional connectivity: evidence from MEG recordings.

The present study examined intrahemispheric functional connectivity during rest and dichotic listening in 8 male and 9 female healthy young adults measured with magnetoencephalography (MEG). Generalized synchronization within the separate hemispheres was estimated by means of the synchronization likelihood that is sensitive to linear as well as non-linear coupling of MEG signals. We found higher functional intrahemispheric connectivity of frontal and temporal areas within the right as compared to the left hemisphere in the lower and higher theta band during rest and in the lower theta band during dichotic listening. In addition, higher synchronization in the lower theta band correlated with better task performance. In the upper alpha band, hemispheric differences in intrahemispheric connectivity of the frontal regions were found to be modulated by focused attention instructions. That is, attention to the right ear exaggerates the pattern of higher synchronization likelihood for the right frontal region, while attention to the left ear has an opposite effect. We found higher intrahemispheric connectivity in males compared to females as shown by higher synchronization in the lower alpha band. Taken together, our results reflect a physiological basis for functional hemispheric laterality and support the general assumption of sex differences in brain organization. Furthermore, in addition to studies that show that controlled attention processes modulate activation of the frontal areas, our study indicates that attention modulates ipsilateral functional connectivity in the frontal areas. This supports the idea of a supervisory role for the frontal cortex in attention processes.

Acoustic Stimulation↗

PubMed2005

Changes in brain electrical activity during extended continuous word recognition.

Twenty healthy subjects (10 men, 10 women) participated in an EEG study with an extended continuous recognition memory task, in which each of 30 words was randomly shown 10 times and subjects were required to make old vs. new decisions. Both event-related brain potentials (ERPs) and induced band power (IBP) were investigated. We hypothesized that repeated presentations affect recollection rather than familiarity. For the 300- to 500-ms time window, an 'old/new' ERP effect was found for the first vs. second word presentations. The correct recognition of an 'old' word was associated with a more positive waveform than the correct identification of a new word. The old/new effect was most pronounced at and around the midline parietal electrode position. For the 500- to 800-ms time window, a linear repetition effect was found for multiple word repetitions. Correct recognition after an increasing number of repetitions was associated with increasing positivity. The multiple repetitions effect was most pronounced at the midline central (Cz) and fronto-central (FCz) electrode positions and reflects a graded recollection process: the stronger the memory trace grows, the more positive the ERP in the 500- to 800-ms time window. The ERP results support a dual-processing model, with familiarity being discernable from a more graded recollection state that depends on memory strengths. For IBP, we found 'old/new' effects for the lower-2 alpha, theta, and delta bands, with higher bandpower during 'old' words. The lower-2 alpha 'old/new' effect most probably reflects attentional processes, whereas the theta and delta effects reflect encoding and retrieval processes. Upon repeated word presentations, the magnitude of induced delta power in the 375- to 750-ms time window diminished linearly. Correlation analysis suggests that decreased delta power is moderately associated with faster decision speed and higher accuracy.

Adult↗

PubMed2005

Impulsivity affects mismatch negativity (MMN) measures of preattentive auditory processing.

The current study addresses the relation between impulsive personality and mismatch negativity (MMN) as measure of auditory processing. In a sample of 33 normals, MMN was measured and related to self-reported measures of impulsive behavior. Participants were tested using a passive auditory oddball paradigm while EEG recordings were obtained. It was found that the negative MMN amplitude at the left lateral cluster was negatively correlated with self-reported impulsivity, with high impulsive individuals showing larger MMN amplitudes than low impulsive individuals. This indicates that impulsivity is related to preattentive auditory processing, a process that is not dependent on response execution. In addition to the well-known involvement of top-down control in impulsivity, these findings implicate that the cognitive bottom-up processing of incoming stimuli is associated with individual differences in impulsivity. Since the source of the MMN is thought to be located in the auditory cortex, this suggests involvement of "lower order" temporal lobe processes in impulsive behaviors.

Adolescent↗

PubMed2004

Reduction of left visual field lexical decision accuracy as a result of concurrent nonverbal auditory stimulation.

To investigate whether concurrent nonverbal sound sequences would affect visual-hemifield lexical processing, lexical-decision performance of 24 strongly right-handed students (12 men, 12 women) was measured in three conditions: baseline, concurrent neutral sound sequence, and concurrent emotional sound sequence. With the neutral sequence, Naveteru, Roy, Ovelac, and Steinling (1992) had observed a right greater than left cerebral blood flow, and an opposite pattern with the emotional sequence. In the present study, the neutral sound sequence induced a significant accuracy reduction for lexical decisions to stimuli presented in the left visual field. It is hypothesized that RH activation in response to neutral sounds interferes with the limited lexical processing resources of that hemisphere.

Adult↗

PubMed2004

The lateralized emotional stroop task: left visual field interference in women.

In a visual hemifield emotional Stroop task, 54 women were asked to name the color of laterally flashed emotional and neutral words while ignoring their semantic content. Vocal reaction times for color naming were recorded. The participants exhibited significant emotional interference effects in the left visual field, which tended to be larger for negative words than for positive words. Participants with higher trait anxiety scores exhibited larger interference for positive words in the left relative to the right visual field. The outcome indicates that, in women, emotional Stroop interference arises in the right rather than in the left hemisphere, with a larger impact of negative than of positive words, and with trait anxiety modulating the lateralized interference for positive words.

Adolescent↗

PubMed2004

Age effects in identifying and localising dichotic stimuli: a corpus callosum deficit?

In the present study, dichotic listening performance of 31 older adults was compared with performance of 25 younger adults under free and focused attention conditions. In addition to an age-related general decrease in performance, we observed in the focused attention condition increased asymmetry in the elderly group: the decrease of recall performance was stronger for the left ear (LE) then for the right ear (RE), while the increase of localisation errors were greater for the RE than for LE. Identifying and localising digits appear to be different process mediated predominantly by the left and right hemisphere, respectively. Since age-related reduced performance is strongest for the ear ipsilateral to the hemisphere dominant to that particular function, these finding may be ascribed to decline of corpus callosum functioning resulting in decrease interhemispheric interaction rather than to a selective decline of right hemisphere functions.

Acoustic Stimulation↗

PubMed2002

Left-right and upper-lower visual field asymmetries for face matching, letter naming, and lexical decision.

The relation between left-right and upper-lower visual field (VF) asymmetries was examined for face matching, letter naming, and lexical decision. Stimuli were flashed in the VF quadrants. Face matching resulted in a lower left and upper right VF advantage. Letter-naming resulted in a distinct upper-right VF advantage. For lexical decision, no upper/lower asymmetries were found. Words were processed faster in the right than in the left VF, while nonwords were processed equally fast in both VFs. The results are discussed in terms of hypothesized structural connections of the lower versus upper visual field to dorsal versus ventral visual pathways and in terms of attentional mechanisms related to the processing of visual information in the VF quadrants.

Adult↗