Biomedical subjects

Frederik M van der Veen

Publications and source records attributed to Frederik M van der Veen.

8 recordsLinked to original sources

PubMed2006

Effects of acute tryptophan depletion on mood and facial emotion perception related brain activation and performance in healthy women with and without a family history of depression.

The present study examined the effects of acute tryptophan (Trp) depletion (ATD), a well-recognized method to lower central serotonin (5-HT) metabolism, on brain activation during a facial emotion perception task. Brain activation was measured using fMRI, and healthy female volunteers with a positive family history of unipolar depression (FH+) were compared to healthy female volunteers without such a history (FH-). Participants viewed two morphed faces and were instructed to choose between the faces based either on the intensity of the emotional expression (direct task) or the gender of the face (incidental task). In the FH+ group, depletion led to the expected lowering of mood, which partly determined the effect of depletion on performance and brain activation. A stronger mood lowering effect was associated with less accurate performance on faces expressing a negative emotion in the incidental task and a stronger right amygdala response to fearful faces in comparison to happy faces. These results were explained in terms of a mood-induced bias leading to a stronger impact of the expressed negative emotion which subsequently leads to more interference in the incidental task and a stronger amygdala response. It was concluded that the effects of ATD on mood, performance, and brain activation in a facial emotion perception task depend on family history of depression. Performance and brain activation partly depend on the effect of ATD on mood.

Adult↗

PubMed2006

Effects of aging on recognition of intentionally and incidentally stored words: an fMRI study.

Functional magnetic resonance imaging (fMRI) was used to gain more insight in the mechanism underlying a decline in recognition memory function with age. Twelve young (23-27 years) and 12 older (63-67 years) healthy men performed two types of word encoding tasks, in which words were either incidentally or intentionally encoded for storage in memory. After a 30min delay, participants performed a recognition task. Older participants were less accurate and slower than young on the recognition task. In the both groups, successful retrieval was accompanied by activation in the left inferior frontal gyrus, left precentral gyrus and right cerebellum. Older participants showed additional activity in the bilateral medial prefrontal gyrus and right parahippocampal gyrus. Correlational analyses showed that only the additional parahippocampal activation correlated positively with task performance in the older but not young participants, suggesting that activation in this area served the purpose of functional compensation. The additional activation in the medial prefrontal cortex, on the other hand, was explained in terms of increased conflict, that is, reduced distinction between target and distracter words leading to increased simultaneous activity of both response tendencies. In a comparison between incidentally and intentionally remembered words the young group showed additional activation in the right middle occipital gyrus. This last result was explained in terms of strategic differences between the young and older group.

Adult↗

PubMed2006

The effect of acute tryptophan depletion on the BOLD response during performance monitoring and response inhibition in healthy male volunteers.

RATIONALE: Serotonin (5-HT) was implicated in both clinical and experimental studies in flexible, goal-directed behavior. However, the way in which 5-HT manipulations affect brain activation patterns underlying different subprocesses of cognitive flexibility remains largely unknown. OBJECTIVES: The aim of this study was to investigate the effect of a transient lowering of 5-HT on brain activation during performance monitoring and response inhibition. MATERIALS AND METHODS: We used acute tryptophan depletion (ATD), a well-known method to reduce central 5-HT, to investigate the effect of a transient lowering of 5-HT on the blood-oxygen-level dependent (BOLD) response in an event-related functional MRI study. Thirteen healthy male volunteers performed a modified Go/NoGo task in a counterbalanced, placebo-controlled, within-subject design. RESULTS: ATD significantly lowered plasma tryptophan but did not affect mood and cognitive performance. ATD decreased the BOLD response in the dorsomedial prefrontal cortex (BA 8) during performance monitoring. ATD did not affect the BOLD response during response inhibition. CONCLUSIONS: This study provides more evidence for the suggested role of 5-HT in performance monitoring. Because ATD studies have revealed inconsistent effects of ATD on performance and on brain activation, it was suggested that gender and personality traits are important variables to take into account for future research.

Adult↗

PubMed2006

Verbal and spatial working memory in older individuals: A positron emission tomography study.

Recent reviews of a substantial number of studies have partially resolved questions concerning the brain regions used by working memory for manipulation and representation. We report a large single experiment in middle-aged to older adults (n = 89), classified by hypertensive status. Our design addresses the question of regions related to manipulation and representation, most particularly comparing spatial and verbal working memory. A control, memory search, and 2-back running memory task were performed with identical stimuli and responses during whole-brain 15O water positron emission tomography (PET) scans. Letter or spatial position instructions created verbal or spatial working memory versions of the tasks. We assessed agreement with the literature using regions of interest that were defined by clusters of activation empirically derived from the literature by Wager and Smith (Wager, T.D. and Smith, E.E., Neuroimaging studies of working memory: a meta-analysis, Cognitive, Affective and Behavioral Neuroscience, 3 (2003) 255-274). Our results largely confirmed conclusions from the review on the organization of working memory into dorsal prefrontal manipulation and ventrolateral prefrontal maintenance areas and representation in dorsal and ventral paths. Specific verbal versus spatial comparisons were also concordant with prior work establishing posterior lateralized representation for different contents by working memory. The similarity of results between this older sample and results derived by others from younger participants is notable.

Aged↗

PubMed2006

Acute tryptophan depletion reduces activation in the right hippocampus during encoding in an episodic memory task.

Acute tryptophan depletion (ATD), a well-recognized method to lower central serotonin levels, was used to examine the effects of lower central serotonin levels on memory function in healthy males. Functional Magnetic Resonance Imaging (fMRI) was used to examine changes in brain activation during the encoding and the retrieval phase of a visual verbal episodic memory task. ATD led to more positively rated words in the encoding phase and to poorer recognition of these positively rated words in the retrieval phase. Furthermore, encoding was accompanied by enhanced brain activation in occipital, middle and superior frontal, anterior and posterior cingulate and striatal areas. Retrieval attempt was accompanied by enhanced activation in the cuneus, inferior occipital gyrus and inferior and middle frontal areas. Retrieval success was accompanied by activation in an extensive network including frontal, parietal, temporal, cingulate, striatal and cerebellar areas. In the encoding phase ATD attenuated activation in the right hippocampus and ATD did not affect brain activity in the retrieval phase. These results show that serotonin is important in long term memory processes, and that serotonin acts on the encoding phase and not on the retrieval phase.

Adult↗

PubMed2005

Serotonergic modulation of prefrontal cortex during negative feedback in probabilistic reversal learning.

This study used functional magnetic resonance imaging to examine the effects of acute tryptophan (TRP) depletion (ATD), a well-recognized method for inducing transient cerebral serotonin depletion, on brain activity during probabilistic reversal learning. Twelve healthy male volunteers received a TRP-depleting drink or a balanced amino-acid drink (placebo) in a double-blind crossover design. At 5 h after drink ingestion, subjects were scanned while performing a probabilistic reversal learning task and while viewing a flashing checkerboard. The probabilistic reversal learning task enabled the separate examination of the effects of ATD on behavioral reversal following negative feedback and negative feedback per se that was not followed by behavioral adaptation. Consistent with previous findings, behavioral reversal was accompanied by significant signal change in the right ventrolateral prefrontal cortex (PFC) and the dorsomedial prefrontal cortex. ATD enhanced reversal-related signal change in the dorsomedial PFC, but did not modulate the ventrolateral PFC response. The ATD-induced signal change in the dorsomedial PFC during behavioral reversal learning extended to trials where subjects received negative feedback but did not change their behavior. These data suggest that ATD affects reversal learning and the processing of aversive signals by modulation of the dorsomedial PFC.

Adolescent↗

PubMed2004

Phasic heart rate responses to performance feedback in a time production task: effects of information versus valence.

This study examined the cardiac concomitants of feedback processing in a time production task derived from [Mittner et al., J. Cogn. Neurosci. 9 (1997) 788]. Participants performed the time production task (i.e. 1-s intervals) under two conditions. In the experimental condition, feedback informed them that the produced interval was within or outside the acceptable range (too long or too short). In the other, yoked-control, condition feedback was unrelated to the actual estimate. The performance findings indicated that in the experimental condition, participants tended to adjust the new interval in the direction indicated by the feedback. In the control condition, however, the adjustments were largely unrelated to the information provided by the feedback. Heart rate slowed to feedback stimuli indicating that the estimate was outside the acceptable range. Surprisingly, cardiac slowing did not discriminate between experimental and control conditions. This finding seems to suggest that heart rate is sensitive to the valence rather than the information provided by the feedback. This finding is discussed vis-à-vis current neuroimaging and psychophysiological studies of performance monitoring.

Adolescent↗

PubMed2003

Cardiac concomitants of feedback processing.

This study examined the heart rate changes associated with positive and negative performance feedback in a probabilistic learning task derived from Holroyd and Coles (Psychological Review, 109 (2002) 679). In this task, subjects were presented with six stimuli and asked to respond by pressing a left versus right key. Responses were followed by positive or negative feedback. Subjects had to infer the S-R mapping rule on the basis of feedback provided to them. Two stimuli were consistently mapped onto the left versus right key (100% mapping). Two other stimuli were randomly mapped onto the keys (50% mapping) and responses to the two remaining stimuli received always positive or negative feedback (always condition). Negative feedback was associated with heart rate slowing in the 100% condition. Heart rate slowed following both positive and negative feedback in the 50% condition, but only when the previous encounter with the stimulus was followed by alternate feedback. Heart rate did not differentiate between positive and negative feedback in the always condition. The results were interpreted in support of the hypothesis assuming that heart rate slowing is elicited when performance-based expectations are violated.

Adult↗