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Biomedical subjects

J van Honk

Publications and source records attributed to J van Honk.

12 recordsLinked to original sources
PubMed2002

Spatial and temporal characteristics of visual motion perception involving V5 visual cortex.

The anatomical substrates of the perception of motion have not yet been established in a detailed way on an individual level. The aim of this study was to develop a systematic procedure for mapping the visual cortex using Transcranial Magnetic Stimulation (TMS). The results showed that such an individual and detailed map of the spatial and temporal characteristics of motion perception can be constructed using TMS.

Adult↗
PubMed2001

Parietal electroencephalogram beta asymmetry and selective attention to angry facial expressions in healthy human subjects.

Research on cerebral affective processing in humans has concentrated on the lateralization of the prefrontal cortex. However, the parietal cortex also seems to play a role in motivation and emotion. In the present study the lateralized role of the parietal cortex in motivated attention was investigated, using an electrophysiological correlate of brain activity (electroencephalogram (EEG)) and a modified Dot probe task, which indexes selective, i.e. avoidant or vigilant attention for angry faces in a spatial display. Twenty-two participants underwent an EEG baseline recording from the F3, F4, P3 and P4 electrode positions, which was followed by the modified Dot probe task. Spectral power in 1 Hz frequency bins were derived for each electrode site and transformed to power density values in the 8-12 Hz (alpha) and 13-30 Hz (beta) frequency range. Log-transformed prefrontal and parietal asymmetries and bias scores for selective attention to angry and happy faces were calculated. Results showed a highly significant relationship between the asymmetry in parietal EEG beta activity and the attentional response to the angry face. Relative more right-sided parietal EEG activity in the beta frequency domain was predictive of a more avoidant response to angry facial expression. This finding suggests that asymmetrical parietal beta activity might be linked to the behavioural dimensions of approach and withdrawal.

Adult↗
PubMed2001

Effects of slow rTMS at the right dorsolateral prefrontal cortex on EEG asymmetry and mood.

In a sham-controlled design (n = 12), slow repetitive transcranial magnetic stimulation (rTMS) was applied to the right dorsolateral prefrontal cortex for 20 min, and the subsequent effects on mood and the EEG spectrum were investigated, Analysis revealed a significant left hemisphere increase in EEG theta activity at 25-35 and 55-65 min after stimulation. In addition, participants reported significant decrease in anxiety immediately after stimulation, as well as 35 and 65 min after rTMS. These findings indicate that reductions in anxiety after slow rTMS at the right dorsolateral prefrontal cortex are associated with a contralateral increase in theta activity.

Adult↗
PubMed2001

A single administration of testosterone induces cardiac accelerative responses to angry faces in healthy young women.

Recently, it was demonstrated how individuals with high levels of testosterone selectively attend toward angry faces. It was argued that this suggests that high levels of testosterone are associated with an aggressive, dominating personality style. In this study, the authors used a double-blind, placebo-controlled design to examine whether exogenous testosterone would induce cardiac acceleration in response to angry faces. Participants (healthy young women) were exposed to neutral, happy, or angry faces. Administration of a single dosage of testosterone (0.5 mg) induced an accelerative cardiac response to angry faces. It is argued that this effect is due to the encouragement of dominance behavior and the inclination toward aggression. Possible mechanisms behind testosterone-driven changes in behavior are discussed with relevance to steroid-responsive networks in the limbic system that drive and control motivational and physiological aspects of social behavior.

Adult↗
PubMed2000

Laterality effects in selective attention to threat after repetitive transcranial magnetic stimulation at the prefrontal cortex in female subjects.

Recently, several experiments have indicated that the left and right prefrontal cortex (PFC) are differently involved in emotional processing. The aim of this study was to investigate the role of the left and right PFC in selective attention to angry faces by using a pictorial emotional Stroop task. Slow repetitive transcranial magnetic stimulation (rTMS) was applied to the left and right PFC of 10 female subjects for 15 min on separate days. Results showed a significant effect of stimulation position: right PFC rTMS resulted in selective attention towards angry faces, whereas left PFC rTMS resulted in selective attention away from angry faces. This finding is in accordance with theoretical accounts of the neural implementation of approach and withdrawal systems.

Adult↗
PubMed2000

Effects of testosterone administration on selective aspects of object-location memory in healthy young women.

Previous work has indicated that object-location memory is sensitive to sex differences as well as variations in the menstrual cycle. The goal of the present study was to further examine the hormonal basis of human spatial memory by assessing the effects of a single dose of exogenous testosterone in healthy young women on three recall conditions: positional reconstruction; object-to-position-assignment; and the combined condition in which subjects both have to reconstruct the precise locations and to link the different objects to the correct places. In the latter condition, delayed recall (3 min delay) improved with testosterone. Although the effects were only small and need further substantiation, they support the idea that testosterone may have an activational effect on selective aspects of cognitive functioning.

Adolescent↗
PubMed2000

Conscious and preconscious selective attention to social threat: different neuroendocrine response patterns.

This study was designed to investigate the relationship between selective attention to social threat and neuroendocrine activity. Selective attention to social threat was measured using a supraliminal (unmasked) and a subliminal (masked) version of a pictorial emotional Stroop task, comparing color-naming latencies of neutral and angry faces. Neuroendocrine activity was assessed as (pre-task to post-task) increases in salivary cortisol and testosterone. Forty subjects were randomly assigned to the unmasked or masked version of the task. Analyses for the unmasked task revealed that post-task cortisol levels were significantly increased in subjects showing selective attention to angry faces. Results for the masked task indicated that post-task cortisol and testosterone levels were significantly increased in subjects showing preconscious selective attention to angry faces. The difference in neuroendocrine activity between tasks is suggested to depend on cortical (i.e. prefrontal) control in the unmasked task. Thus, psychological affective regulatory processes were involved in the unmasked task, whereas the neuroendocrine response patterns in the masked task indicates a biologically prepared mechanism.

Adult↗
PubMed1999

Correlations among salivary testosterone, mood, and selective attention to threat in humans.

An experiment was designed to investigate the relation among salivary testosterone, mood, and selective attention to threat. The participant group consisted of 32 nonclinical subjects (16 men and 16 women). Individuals completed the Profile Of Mood States (POMS) and performed a pictorial emotional Stroop task measuring selective attention to angry faces. Anticipating a time lag between testosterone (as measured in saliva) and cognitive emotional behavior, multiple time-coursed saliva samples were taken preceding the assessment of questionnaire and task for every subject. In both sexes, salivary testosterone was significantly related to mood (i.e., anger and tension) and selective attention to angry faces when saliva samples were taken 6 h before questionnaire and task assessment. Research on the relation between testosterone and human behavior might benefit by taking into account time lags between the behavioral manifestations and the continuously changing levels of testosterone.

Adolescent↗
PubMed1999

Sex differences and menstrual cycle effects in human spatial memory.

A typical test of spatial memory requires subjects to relocate a number of objects in their original, previously studied positions. It has been argued that this test includes multiple separate processing components (Postma, A., De Haan, E.H.F., 1996. Quarterly Journal of Experimental Psychology 48A (1), 178-199; Postma, A., Izendoorn, R., De Haan, E.H.F., 1998. Brain and Cognition 36, 334-345). One has to encode the precise positions occupied, assign the various objects to the correct (relative) locations, and achieve an integration of both types of spatial information. The present study examined the presence of sex differences and the role of hormonal factors for these selective components of spatial memory. A computerised, immediate (working) memory version of the test was used, comparing 23 males and 34 females on three experimental conditions: positions only, object-to-position-assignment, and the combined condition, requiring integration of the other two components. In line with previous research (Postma et al., 1998) males showed a selective advantage for fine-grained, metric positional reconstruction (i.e. positions-only). Interestingly, a within-subjects comparison in the females only revealed a menstrual cycle effect for exactly the same dimension of spatial memory. In the nonmenstrual phase, females were better than during menstruation. This clearly implies a role for sex hormones in spatial memory, even though a subsequent analysis of testosterone samples in saliva did not reveal a significant correlation with measures of spatial memory in both males and females.

Adolescent↗
PubMed1998

Baseline salivary cortisol levels and preconscious selective attention for threat. A pilot study.

This study was conducted to examine the relationship between baseline salivary cortisol (CORT) levels and selective attention for displays of angry faces. Selective attention was investigated using a pictorial emotional Stroop task, comparing colournaming-speed of angry and neutral faces. The task was assessed in supraliminal (unmasked) and subliminal (masked) conditions to 28 non-clinical subjects (14 male and 14 female). Repeated measures analysis of variance revealed a significant interaction between median split CORT levels (low vs. high) and masked face valence (angry vs. neutral). The latter effect was mainly due to significant facilitation in the high CORT subject-group; these subjects seemed to allocate their attention away from the masked angry face. A relation between baseline CORT levels and fast withdrawal behavior is suggested.

Adult↗
PubMedDate not supplied

Cortisol, depression and reduced cortico-cortical cross-talk in Cushing's syndrome.

In the present report assumed relationships between hypercortisolism, depression and cortico-cortical cross-talk in Cushing's syndrome were investigated. Electroencephalographic (EEG) recordings and depression ratings from three patients diagnosed with mild, moderate and severe hypercortisolism were obtained. Reductions in cortico-cortical cross-talk as quantified by EEG coherence together with increases in depression were observed in the moderate and severe as compared to the mild hypercorticolism state. These findings provide preliminary evidence for the hypothesis that loss of cortico-cortical cross-talk might be linked to hypercortisolism and the severity of depressive symptoms.

Cerebral Cortex↗