Filters








184 Hits in 1.9 sec

Declarative Memory [chapter]

Wim J. Riedel, Arjan Blokland
2015 Handbook of Experimental Pharmacology  
Declarative memory, sometimes known as explicit memory [1], involves the conscious recollection of memories such as events, facts, figures and locations. Declarative memory is a form of long-term memory of which there are two types with the other known as procedural memory [2]. There are two subcategories: episodic [3] and semantic [4] memories. Episodic memories relate to specific things we have experienced while semantic memories involve information of a factual nature.
doi:10.1007/978-3-319-16522-6_7 pmid:25977084 fatcat:u52xkzw4ejfvrh2q7cimge2rve

Cognitive changes after acute tryptophan depletion: what can they tell us?

WIM J. RIEDEL
2004 Psychological Medicine  
In healthy subjects impaired long-term memory following ATD, including deficits in learning and memory consolidation has been reported (Park et al. 1994 ; Riedel et al. 1999 ; Rogers et al. 1999 ; Schmitt  ...  ATD effects observed in the control subjects by resembled those previously reported (Park et al. 1994 ; Coull et al. 1995 ; Riedel et al. 1999 ; Schmitt et al. 2000 ; Rubinsztein et al. 2001; Murphy  ... 
doi:10.1017/s0033291703008924 pmid:14971622 fatcat:dhob6hca5jf2rc3jlbisxgksaq

Effects of 5-HT on Memory and the Hippocampus: Model and Data

Martijn Meeter, Lucia Talamini, Jeroen A J Schmitt, Wim J Riedel
2005 Neuropsychopharmacology  
Currently, W Riedel is also affiliated to GlaxoSmithKline R&D.  ...  The contribution of W Riedel and interpretation of research data for this article were entirely carried out in the University of Maastricht.  ...  node j.  ... 
doi:10.1038/sj.npp.1300869 pmid:16132065 fatcat:exsjcgfopjga3hrwd2pe5eqgyu

The ketamine model of positive, negative and cognitive symptoms in schizophrenia: facts and frictions

Wim J. Riedel
2007 Journal of Psychopharmacology  
Corresponding author: Wim J. Riedel, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology, University of Maastricht, The Netherlands.  ... 
doi:10.1177/0269881107078769 fatcat:rf5fivuybfcixjnm5mvwvtocge

Does ketamine mimic aspects of schizophrenic speech?

MichaeL A. Covington, Wim J. Riedel, Cati Brown, Congzhou He, Eric Morris, Sara Weinstein, James SempLe, John Brown
2007 Journal of Psychopharmacology  
.; Riedel, Wim J.; Brown, Cati; He, Congzhou; Morris, Eric; Weinstein, Sara; Semple, James; and Brown, John (2007) Does ketamine mimic aspects of schizophrenic speech?  ... 
doi:10.1177/0269881107077729 pmid:17591660 fatcat:wroxz6to6bakfhxq4iaa2uk2ee

Additional dopamine reuptake inhibition attenuates vigilance impairment induced by serotonin reuptake inhibition in man

Jeroen A. J. Schmitt, Johannes G. Ramaekers, Monique J. Kruizinga, Martin P. J. van Boxtel, Eric F. P. M. Vuurman, Wim J. Riedel
2002 Journal of Psychopharmacology  
inhibition have been outlined as functions controlling wakefulness, distinctly mediated by noradrenergic, dopaminergic, cholinergic and serotonergic neurochemical modulation (Robbins and Everitt, 1995; Riedel  ... 
doi:10.1177/026988110201600303 pmid:12236626 fatcat:w4xygdltpfcuxfl7npajs3rtea

Why an M1 Antagonist Could Be a More Selective Model for Memory Impairment than Scopolamine

Arjan Blokland, Anke Sambeth, Jos Prickaerts, Wim J. Riedel
2016 Frontiers in Neurology  
Since the early studies of Deutsch (1), the non-selective muscarinic receptor antagonist scopolamine has been used as a drug that impairs memory performance in man. The notion that scopolamine could be used as a pharmacological model of age-associated memory impairment and dementia further strengthened the cholinergic hypothesis of geriatric memory dysfunction by Bartus et al. (2). Since then, a vast amount of studies applied this model to induce memory impairments in young healthy subjects to
more » ... odel age-related memory disorders. At present, scopolamine is still considered to be the best model for inducing cognitive impairments in healthy subjects (3). Scopolamine is therefore used as a pharmacological model to test novel cognition-enhancing drugs in animals [e.g.,] and in humans [e.g., Ref. (7, 8) ]. In clinical trials, scopolamine is in particular being used as a model for AD in which novel cognition-enhancing drugs are tested (see https://ClinicalTrials.gov). Further efforts have been made to compare human and animal data with scopolamine to further validate the scopolamine as a model of cognitive impairments. For example, comparable tests were developed for humans and animals to allow cross-species comparison [e.g., Ref. (9, 10)]. Another effort is comparing scopolamine effects on brain imaging parameters (11, 12) . These studies reveal great cross-species similarities in the effects of scopolamine in comparable cognitive tasks in humans and animals, and that the effects on central blood flow is also comparable. These studies have resulted in a huge database in which the effects of scopolamine on cognitive and non-cognitive functions have been documented. This also relates to doses and routes of administration. Furthermore, interactions with various other drugs (also non-cholinergic) have been documented, which supports the notion of drug interactions in memory functions. Taken together, scopolamine is considered as a golden standard for cholinergic deficits and the existing data were used as a reference for evaluating novel cognition-enhancing drugs. Although scopolamine has this established (gold standard) status, there are also some important issues related with this drug. A first point is that scopolamine is binding to both peripheral and central muscarinic receptors [see Ref. (13) ]. Thus, scopolamine binds to all five different muscarinic receptors which are located in the brain as well in the peripheral system. This may relate to the various side effects that can occur after administration of scopolamine. Typical side effects are: dry mouth or throat, dizziness, drowsiness, fatigue, nausea, light-headedness, and blurred vision [e.g., Ref. (9)]. A careful analytic review on the effects of scopolamine in animals has shown that scopolamine at low doses mainly affects attentional functions and that memory performance is only affected at higher doses [see Ref. (13) ]. Moreover, at relative low doses, typical side effects (increased omissions and latencies in responding) can be observed in rodents that may have an impact on performance in memory tasks. In humans, similar effects on sedation have been observed, but it has been suggested that these effects could be dissociated from the effects on memory impairments [see Ref. (14) ]. Interestingly, these effects seem to be dependent on the route of administration. Thus, intramuscular or intravenous administration has shown robust effects on memory performance (3), accompanied with
doi:10.3389/fneur.2016.00167 pmid:27746762 pmcid:PMC5042959 fatcat:4rbt3lu5xzdergf5ydv7gqhvvi

Atypical cognitive profile in patients with depression after myocardial infarction

Jeanette B Dijkstra, Jacqueline J.M.H Strik, Richel Lousberg, Jos Prickaerts, Wim J Riedel, Jelle Jolles, Herman M van Praag, Adriaan Honig
2002 Journal of Affective Disorders  
.  (J. Prickaerts). general perform worse than healthy controls on 0165-0327 / 02 / $ -see front matter   ...  ., 1995; Riedel et al., 1998a Riedel et al., ). et al., 1998 . Patients with depression after MI are Also a slowing of mental processes termed 'psychoprobably doubly at risk for cognitive decline.  ...  to be equal to the Riedel et al. (1998a) , using the same memory test, performances of the controls or intermediate between found that patients with non-cardiac-related depresthat of the controls and  ... 
doi:10.1016/s0165-0327(01)00348-2 pmid:12117630 fatcat:pr32e2kdizddjdjecob4hf65va

Contingent negative variation as a dopaminergic biomarker: evidence from dose-related effects of methylphenidate

Anke M. W. Linssen, Eric F. P. M. Vuurman, Anke Sambeth, Stephane Nave, Will Spooren, Gabriel Vargas, Luca Santarelli, Wim J. Riedel
2011 Psychopharmacology  
Rationale The basal ganglia play an important role in motor control, which is dependent on dopaminergic input. Preparation of a motor response has been associated with dopamine release in the basal ganglia, and response readiness may therefore serve as a pharmacodynamic marker of dopamine activity. Methods We measured response readiness using the amplitude of the contingent negative variation (CNV), a slow negative shift in the electroencephalogram. The CNV is evoked in a paradigm in which a
more » ... ning stimulus (S1) signals the occurrence of the imperative stimulus (S2) 4 s later, to which the participant has to respond. CNV was assessed in healthy volunteers after administration of placebo or 10, 20 or 40 mg of methylphenidate, a catecholamine re-uptake blocker which primarily enhances the synaptic concentration of dopamine and to a lesser extent also noradrenaline. In addition, participants filled out two visual analogue scales measuring subjective ratings of mood and alertness: Profile of Mood States and Bond and Lader. Results Methylphenidate dose dependently increased CNV amplitude and decreased reaction times. Furthermore, participants reported improved mood, feeling more alert, vigorous and content and less angry and tired after methylphenidate. Conclusions These results indicate that dopamine availability increases response readiness as measured by the CNV paradigm. The CNVappears to be a good candidate biomarker for assessing changes in dopaminergic function by treatments that either directly or indirectly target the dopaminergic system.
doi:10.1007/s00213-011-2345-x pmid:21597989 pmcid:PMC3210368 fatcat:zcxvnp2isnam7kxiizaxhfu5fe

The effects of high-dose and low-dose tryptophan depletion on mood and cognitive functions of remitted depressed patients

Linda Booij, A. J. Willem Van der Does, P. M. Judith Haffmans, Wim J. Riedel, Durk Fekkes, Marc J. B. Blom
2005 Journal of Psychopharmacology  
doi:10.1177/0269881105051538 pmid:15888512 fatcat:swspo2h6gjc2be53rf3tnd5fdi

Reply: Pronounced Cognitive Deficits Following an Intravenous L-Tryptophan Challenge in First-degree Relatives of Bipolar Patients Compared to Healthy Controls

S Sobczak, A Honig, Wim J Riedel
2003 Neuropsychopharmacology  
Sir Thank you very much for your interest in our paper 'Pronounced cognitive deficits following an intravenous L-Tryptophan challenge in first-degree relatives of bipolar patients compared to healthy controls' (Sobczak et al, 2003b) . We appreciate a critical review of the interpretation of our research findings. Next, we will give our response on the three major points of the letter.
doi:10.1038/sj.npp.1300270 fatcat:eg3sdkq2kjenzlovjobd3amuea

Electrophysiological correlates of automatic spreading of activation in patients with psychotic disorder and first-degree relatives

Stefanie Pfeifer, Niels O. Schiller, Jim van Os, Wim J. Riedel, Petra Vlamings, Claudia Simons, Lydia Krabbendam
2012 International Journal of Psychophysiology  
Background: Semantic network abnormalities in patients with psychotic disorder were examined using associative prime-target relations with two stimulus asynchronies (SOAs; −250 ms and −500 ms) to assess the time course of automatic and more controlled processes of semantic priming. To investigate whether an aberrant semantic network system is part of the familial liability for psychosis, healthy siblings of patients with psychotic disorder were additionally examined. The N400 event-related
more » ... potential (ERP) was used as a probe of semantic processing. Method: Twenty-two patients with psychotic disorder, twenty siblings of patients with psychotic disorder and twenty controls participated in a lexical decision task and ERPs were recorded to target words that were associatively, indirectly or not related to their preceding prime word. Results: Associative priming of the N400 amplitude was found across all participants and both SOAs, but no between-group differences were found for the N400 amplitude (both SOAs). The Group× Condition interaction of the indirect priming N400 latency of the three groups was just short of statistical significance (F2,59=2.7, p=.077). Patients showed an increased indirect priming effect of the N400 latency only at short SOA, with decreased latency of the indirectly related compared to the unrelated condition, while controls did not show an indirect priming N400 latency effect. No between-group differences in N400 latency of indirect priming were found at the long SOA. Only a trend towards a Group× Condition interaction of the indirect priming N400 latency between the sibling and the controls was found, but without a main effect of indirect priming in the sibling group. Conclusion: These preliminary results support the assumption of a hyperactive semantic network in patients with psychotic disorder, which develops under automatic processes and decreases with more controlled processes, but does not represent clear trait familial liability.
doi:10.1016/j.ijpsycho.2012.01.017 pmid:22296932 fatcat:fnxhac3lwnejbhs2gmb2gmmprq

Reply: Dissociable Hormonal, Cognitive and Mood Responses to Neuroendocrine Challenge: Evidence for Receptor-Specific Serotonergic Dysregulation in Depressed Mood

Wim J Riedel, Tineke Klaassen, Eric Griez, Adriaan Honig, Paul Menheere, Herman M Van Praag
2003 Neuropsychopharmacology  
(Riedel et al, 2002) So, this statement concerned the explanation of the pattern of all effects of the two substances, not just on cortisol!  ...  Sir We have read the letter by Wand and Oswald (2003) with great interest, but respectfully disagree with their position (1) that a difference in acth/cortisol ratio explains our observation (Riedel et  ...  (Riedel et al, 2002) So, this statement concerned the explanation of the pattern of all effects of the two substances, not just on cortisol!  ... 
doi:10.1038/sj.npp.1300076 fatcat:uzmlakgxizewfbnu7wevdxcxam

Acute tryptophan depletion in depressed patients treated with a selective serotonin–noradrenalin reuptake inhibitor: Augmentation of antidepressant response?

Linda Booij, A.J. Willem Van der Does, P.M. Judith Haffmans, Wim J. Riedel
2005 Journal of Affective Disorders  
It has frequently been demonstrated that experimental lowering of serotonin (5-HT) neurotransmission by acute tryptophan depletion (ATD) induces a transient depressed mood in 50-60% of patients treated with a selective serotonin reuptake inhibitor (SSRI) who are in remission from depression. In unmedicated depressed patients, ATD has no immediate effect on symptoms. The effects in currently depressed medicated patients have not been investigated. Methods: Fourteen currently depressed patients
more » ... even patients treated with a selective serotonin-noradrenalin reuptake inhibitor (SSNRI); seven other treatment, non-SSNRI) received ATD in a double-blind, crossover design. Different strengths of the ATD mixture (aimed at 50% and 90% reduction of tryptophan) were used on separate days. Psychiatric symptoms were assessed at both sessions prior to, at +6.5 h, and at +24 h after ATD. Results: The ATD mixtures induced the expected reductions of plasma tryptophan levels. Full but not partial depletion improved mood and other psychiatric symptoms at +24 h in patients who received SSNRI treatment, as indicated by clinical ratings and self-report. Subjective sleep quality also improved. Conclusions: The effects of ATD on psychiatric symptoms in currently depressed patients are remarkably different from the results in recently remitted SSRI-treated patients. ATD in currently depressed patients treated with serotonergic antidepressants possibly provides important information about the mechanism of action of SSRIs. D
doi:10.1016/j.jad.2005.01.012 pmid:15935252 fatcat:gzijeo2vcrfj5hr7zyr2hy2dvy

Nicotine deprivation elevates neural representation of smoking-related cues in object-sensitive visual cortex: a proof of concept study

Anne Havermans, Onno C. P. van Schayck, Eric F. P. M. Vuurman, Wim J. Riedel, Job van den Hurk
2017 Psychopharmacology  
Objective In the current study, we use functional magnetic resonance imaging (fMRI) and multi-voxel pattern analysis (MVPA) to investigate whether tobacco addiction biases basic visual processing in favour of smoking-related images. We hypothesize that the neural representation of smoking-related stimuli in the lateral occipital complex (LOC) is elevated after a period of nicotine deprivation compared to a satiated state, but that this is not the case for object categories unrelated to smoking.
more » ... Methods Current smokers (≥10 cigarettes a day) underwent two fMRI scanning sessions: one after 10 h of nicotine abstinence and the other one after smoking ad libitum. Regional blood oxygenated level-dependent (BOLD) response was measured while participants were presented with 24 blocks of 8 colour-matched pictures of cigarettes, pencils or chairs. The functional data of 10 participants were analysed through a pattern classification approach. Results In bilateral LOC clusters, the classifier was able to discriminate between patterns of activity elicited by visually similar smoking-related (cigarettes) and neutral objects (pencils) above empirically estimated chance levels only during deprivation (mean = 61.0%, chance (permutations) = 50.0%, p = .01) but not during satiation (mean = 53.5%, chance (permutations) = 49.9%, ns.). For all other stimulus contrasts, there was no difference in discriminability between the deprived and satiated conditions. Conclusion The discriminability between smoking and nonsmoking visual objects was elevated in object-selective brain region LOC after a period of nicotine abstinence. This indicates that attention bias likely affects basic visual object processing.
doi:10.1007/s00213-017-4628-3 pmid:28429068 pmcid:PMC5537335 fatcat:rea2lbef3ravtarvqzvwfptxoq
« Previous Showing results 1 — 15 out of 184 results