Papers by Hendrik Peuskens
Animal studies suggest an important role for the metabotropic glutamate receptor subtype 5 (mGlu5... more Animal studies suggest an important role for the metabotropic glutamate receptor subtype 5 (mGlu5) in the pathophysiology of alcohol dependence, but direct human evidence is lacking. The goal of this study was to investigate cerebral mGlu5 availability in alcohol-dependent subjects versus controls using 18 F-3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile (18 F-FPEB) PET. Methods: Dynamic 90-min 18 F-FPEB scans combined with arterial blood sampling were acquired for 16 recently abstinent alcohol-dependent subjects and 32 age-matched controls. Regional mGlu5 availability was quantified by the 18 F-FPEB total distribution volume using both a voxel-by-voxel and a volume-of-interest analysis with partial-volume effect correction. Alcohol consumption within the last 3 mo was assessed by questionnaires and by hair ethyl glucuronide analysis. Craving was assessed using the Desire for Alcohol Questionnaire. Results: mGlu5 availability was lower in mainly limbic regions of alcohol-dependent subjects than in controls (P , 0.05, familywise error-corrected), ranging from 14% in the posterior cingulate cortex to 36% in the caudate nucleus. Lower mGlu5 availability was associated with higher hair ethyl glucuronide levels for most regions and was related to a lower level of craving specifically in the middle frontal gyrus, cingulate cortex, and inferolateral temporal lobe. Conclusion: These findings provide human in vivo evidence that limbic mGlu5 has a role in the pathophysiology of alcohol dependence, possibly involved in a compensatory mechanism helping to reduce craving during abstinence.
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience
Observer motion in a stationary visual environment results in an optic flow pattern on the retina... more Observer motion in a stationary visual environment results in an optic flow pattern on the retina, which in simple situations can be used to determine the direction of self motion or heading. The present study, using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), investigated the human cerebral activation pattern, elicited when subjects viewing a ground plane optic flow pattern actively judged heading. Several successive experiments controlled for visual input, visuospatial attention, and motor response effects. Results indicate that the network specifically involved in heading consists of only two motion sensitive areas: human MT/V5+, including an inferior satellite, and dorsal intraparietal sulcus area (DIPSM/L), predominantly in the right hemisphere, plus a dorsal premotor region bilaterally. These results suggest possible homologies with the dorsal part of the medial superior temporal area and area 7a in the monkey.
Journal of personality assessment, Jan 2, 2015
Studies on the face validity of DSM-5 Section II categorical personality disorder (PD) symptoms i... more Studies on the face validity of DSM-5 Section II categorical personality disorder (PD) symptoms indicate a bias against older adults. To extend these results, this article explores whether categorically and dimensionally scored PD symptoms of DSM-5 Section II, as measured in the Assessment of DSM-IV Personality Disorders (ADP-IV; Schotte & de Doncker, 1994), corroborate potential age bias across younger (aged 18-34), middle-aged (35-59 years), and older adults (aged 60-75). Differential item functioning (DIF) analyses, following a classical test theory approach, showed that 2 of the 79 symptoms were measured differently across 3 age groups when categorically assessed, and 4 when dimensionally measured. Nevertheless, subsequent differential test functioning analyses supported a low aggregated impact of DIF on the dimensional scales, justifying mean-level comparisons across age groups. Generalizability of the results is discussed in light of methodological issues concerning the resear...
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2001
Observer motion in a stationary visual environment results in an optic flow pattern on the retina... more Observer motion in a stationary visual environment results in an optic flow pattern on the retina, which in simple situations can be used to determine the direction of self motion or heading. The present study, using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), investigated the human cerebral activation pattern, elicited when subjects viewing a ground plane optic flow pattern actively judged heading. Several successive experiments controlled for visual input, visuospatial attention, and motor response effects. Results indicate that the network specifically involved in heading consists of only two motion sensitive areas: human MT/V5+, including an inferior satellite, and dorsal intraparietal sulcus area (DIPSM/L), predominantly in the right hemisphere, plus a dorsal premotor region bilaterally. These results suggest possible homologies with the dorsal part of the medial superior temporal area and area 7a in the monkey.
Journal of Neuroscience, 2014
Compared with baseline, ALC ACU resulted in a global increase of CB 1 R availability (ϩ15.8%). In... more Compared with baseline, ALC ACU resulted in a global increase of CB 1 R availability (ϩ15.8%). In contrast, a global decreased CB 1 R availability was found in ALC CHR patients (Ϫ16.1%) compared with controls, which remained unaltered after abstinence (Ϫ17.0%). Voxel-based analysis showed that ALC CHR patients had reduced CB 1 R availability, especially in the cerebellum and parieto-occipital cortex. After abstinence, reduced CB 1 R availability extended also to other areas such as the ventral striatum and mesotemporal lobe.
Journal of Neuroscience, 2004
We compared neural substrates of two-dimensional shape processing in human and nonhuman primates ... more We compared neural substrates of two-dimensional shape processing in human and nonhuman primates using functional magnetic resonance (MR) imaging in awake subjects. The comparison of MR activity evoked by viewing intact and scrambled images of objects revealed shape-sensitive regions in occipital, temporal, and parietal cortex of both humans and macaques. Intraparietal cortex in monkeys was relatively more two-dimensional shape sensitive than that of humans. In both species, there was an interaction between scrambling and type of stimuli (grayscale images and drawings), but the effect of stimulus type was much stronger in monkeys than in humans. Shape-and motion-sensitive regions overlapped to some degree. However, this overlap was much more marked in humans than in monkeys. The shape-sensitive regions can be used to constrain the warping of monkey to human cortex and suggest a large expansion of lateral parietal and superior temporal cortex in humans compared with monkeys.
Science, 2002
We compared three-dimensional structure-from-motion (3D-SFM) processing in awake monkeys and huma... more We compared three-dimensional structure-from-motion (3D-SFM) processing in awake monkeys and humans using functional magnetic resonance imaging. Occipital and midlevel extrastriate visual areas showed similar activation by 3D-SFM stimuli in both species. In contrast, intraparietal areas showed significant 3D-SFM activation in humans but not in monkeys. This suggests that human intraparietal cortex contains visuospatial processing areas that are not present in monkeys.
Neuropsychologia, 2003
The present report reviews a series of functional magnetic resonance imaging (fMRI) activation st... more The present report reviews a series of functional magnetic resonance imaging (fMRI) activation studies conducted in parallel in awake monkeys and humans using the same motion stimuli in both species. These studies reveal that motion stimuli engage largely similar cortical regions in the two species. These common regions include MT/V5 and its satellites, of which FST contributes more to the human motion complex than is generally assumed in human imaging. These results also establish a direct link between selectivity of MT/V5 neurons for speed gradients and functional activation of human MT/V5 by three-dimensional (3D) structure from motion stimuli. On the other hand, striking functional differences also emerged: in humans V3A and several regions in the intraparietal sulcus (IPS) are much more motion sensitive than their simian counterparts.
Processing 3-dimensional structure from motion in humans and macaques
Journal of Vision, 2010
Journal of Cognitive Neuroscience, 2004
& We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and mot... more & We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and motion processing for realistic textured objects rotating in depth. Subjects made judgments about several different attributes of these objects, including 3-D shape, the 3-D motion, and the scale of surface texture. For all of these tasks, we equated visual input, motor output, and task difficulty, and we controlled for differ-ences in spatial attention. Judgments about 3-D shape from motion involve both parietal and occipito-temporal regions. The processing of 3-D shape is associated with the analysis of 3-D motion in parietal regions and the analysis of surface texture in occipito-temporal regions, which is consistent with the different behavioral roles that are typically attributed to the dorsal and ventral processing streams. &
International Psychogeriatrics, 2014
Background: Young's Schema Focused Therapy (SFT) is gaining popularity in the treatment of older ... more Background: Young's Schema Focused Therapy (SFT) is gaining popularity in the treatment of older adults. In the context of this therapy, the Young Schema Questionnaire (YSQ) was developed to assess the early maladaptive schemas (EMS). EMS are considered to be relatively stable over time, but research shows that questionnaires often lack face validity in older adults, which makes it difficult to investigate EMS in older adults and their stability across the lifespan.
European Psychiatry, 2006
Objective. -A recent consensus conference has proposed guidelines for the monitoring for diabetes... more Objective. -A recent consensus conference has proposed guidelines for the monitoring for diabetes in patients with schizophrenia and also identifies the need of long-term prospective studies.
European Journal of Neuroscience, 2003
Using PET, we studied the processing of different types of motion in an opposed-direction discrim... more Using PET, we studied the processing of different types of motion in an opposed-direction discrimination task. We used first-order motion and two types of higher-order motion (presented as moving gratings with stripes defined by flickering texture and kinetic boundaries, respectively). In these experiments, we found that all types of motion activate a common set of cortical regions when comparing a direction discrimination task to a detection of the dimming of the fixation point. This set includes left hV3A, bilateral hMT/ V5þ and regions in the middle occipital gyrus, bilateral activations in the posterior and anterior parts of the intraparietal sulcus, bilateral precentral gyrus, medial frontal cortex and regions in the cerebellum. No significant differences were observed between different types of motion, even at low statistical thresholds. From this we conclude that, under our experimental conditions, the same cerebral regions are involved in the processing of first-order and higher-order motion in an opposed-direction discrimination task.
Validation and Reliability of the Young Schema Questionnaire in a Flemish Inpatient Eating Disorder and Alcohol and Substance Use Disorder Sample
Cognitive Therapy and Research, 2013
ABSTRACT This study focuses on the psychometric properties of Young Schema Questionnaire-Long For... more ABSTRACT This study focuses on the psychometric properties of Young Schema Questionnaire-Long Form (YSQL2, Young in Cognitive therapy for personality disorders: a schema-focused approach. Professional Resource Exchange, Sarasota, 1990) in a large Flemish sample of inpatients with an eating or substance use disorder. Eating disorders (ED) and alcohol/substance use disorders commonly co-occur and have been linked by several theoretical models, making it important to study the psychometric properties of the YSQL2 in these populations. In the present study, a confirmatory factor analysis was used to investigate the latent structure of the YSQL2 in a sample of ED patients (n = 218) and alcohol and substance use disorder (AD) patients (n = 351). Internal consistency, divergent, and convergent validity between early maladaptive schemas (EMS) and personality disorder symptoms were investigated. Results confirm the 16 factor structure of the YSQL2 as well as good internal consistency for all scales. Significant gender differences were observed for some scales within the AD sample, along with different patterns of correlations between age and select scales within the ED and AD groups. Convergent validity was supported by similar elevations on the schema scales and personality disorder symptoms in both subgroups separately. The YSQL2 appears to be a valid instrument to assess EMS among Flemish inpatients with an ED or an alcohol disorder.
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Papers by Hendrik Peuskens