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Biomedical subjects

Jack van Honk

Publications and source records attributed to Jack van Honk.

At least 19 recordsLinked to original sources
PubMed2006

Exogenous cortisol shifts a motivated bias from fear to anger in spatial working memory for facial expressions.

Studies assessing processing of facial expressions have established that cortisol levels, emotional traits, and affective disorders predict selective responding to these motivationally relevant stimuli in expression specific manners. For instance, increased attentional processing of fearful faces (attentional bias for fearful faces) is associated with fear and anxiety and diminishes after administration of the anxiolytic hormone testosterone. Conversely, attentional bias for angry faces has been associated with higher levels of approach motivation (e.g. anger) and testosterone, but lower levels of cortisol. This negative relation between cortisol levels and bias for angry faces was also seen in a test of biased working memory performance. However, previous research suggests that exogenous glucocorticoids acutely decrease fearful and inhibited behavior and increase aggressiveness. Hypothesizing from these findings, the present study tested this spatial working memory for faces of various emotional expressions (neutral, happy, fearful, and angry) after double-blind, placebo-controlled administration of 40 mg cortisol in 18 healthy young men. It was predicted that cortisol would acutely attenuate memory bias for fearful expressions while increasing memory bias for angry expressions, in effect creating a shift in biased motivated memory from fear to anger. Results largely confirmed the hypotheses. This is the first causal evidence that cortisol differentially regulates spatial working memory for different facial expressions. Possible biological mechanisms are discussed.

Adolescent↗
PubMed2006

The effects of social stress and cortisol responses on the preconscious selective attention to social threat.

The purpose of the present study was to investigate the effects of social stress and stress-induced cortisol on the preconscious selective attention to social threat. Twenty healthy participants were administered a masked emotional Stroop task (comparing color-naming latencies for angry, neutral and happy faces) in conditions of rest and social stress. Stress was induced by means of the Trier social stress test. Based on the stress-induced increase in cortisol levels, participants were allocated post hoc (median-split) to a high and low responders group. In contrast to low responders, high responders showed a negative or avoidant attentional bias to threat (i.e. shorter latencies for angry than neutral faces) in the rest condition. Most importantly, although low responders became avoidant, the high responders became vigilant to the angry faces after stress induction. There were no such effects for happy faces. Our findings are in line with previous studies in both animals and humans, that associate high glucocorticoid stress-responsiveness with diminished avoidance and prolonged freezing reactions during stress.

Adolescent↗
PubMed2006

An electrophysiological link between the cerebellum, cognition and emotion: frontal theta EEG activity to single-pulse cerebellar TMS.

Early intracranial electrical stimulation studies in animals demonstrated cerebellar connectivity to brain structures involved in cognitive and emotive functions. Human electrophysiological data to support cerebellum involvement in the latter functions are however lacking. In the present study, electrophysiological responses were recorded to single-pulse transcranial magnetic stimulation (TMS) over the vermis in healthy human volunteers. Increased theta activity was observed after single-pulse vermis TMS as compared to sham and occipital TMS. Both animal and human research relate theta activity with the septo-hippocampal complex, an important brain structure involved in cognition and emotion. The present electrophysiological study supports the earlier intracranial electrical stimulation findings by demonstrating cerebellar involvement in the modulation of the core frequencies related to cognitive and emotive aspects of human behavior.

Adult↗
PubMed2006

Behavioral inhibition system (BIS), behavioral activation system (BAS) and schizophrenia: relationship with psychopathology and physiology.

OBJECTIVE: The Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS) have been conceptualized as two neural motivational systems that regulate sensitivity to punishment (BIS) and reward (BAS). Imbalance in BIS and BAS levels has been reported to be related to various forms of psychopathology. Since sensitivity to stress has been supposed to be a pathway for the development of psychotic symptoms, the aim of this study is to examine BIS and BAS scores in schizophrenia and their relationship with psychopathology and physiology. METHOD: Forty-two patients with schizophrenia (26 men, 16 women), stable on atypical antipsychotics, and 37 healthy controls (17 men, 20 women) were assessed with the use of the Behavioral Inhibition and Behavioral Activation scales. Since increased average heart rate (HR) and decreased heart rate variability (HRV) have been reported in patients with schizophrenia and have been shown to correlate with inhibited behaviour, these psychophysiological measures were also obtained. The BIS/BAS data and HR/HRV data were both analyzed by a (M)ANOVA. Correlation coefficients were computed for associations between BIS/BAS data, HR/HRV data, and patient variables. RESULTS: On the BIS, patients showed higher sensitivity to threat than control subjects. Higher BIS sensitivity correlated with longer duration of illness, and lower negative symptoms on the PANSS. The BAS scores did not reveal differences between patients and controls. In patients, low BAS sensitivity correlated with low dosage of medication. On the physiological measures patients showed a significantly higher HR and lower HRV compared to controls, which was limited to clozapine treated patients. No correlations were found between HR/HRV scores and BIS/BAS scores or patient variables. CONCLUSIONS: Male as well as female patients with schizophrenia are more sensitive to threat than healthy controls. This may reflect a trait-related characteristic, and is not reflected in state-related psychophysiological measures.

Adult↗
PubMed2006

Anxious apprehension increases coupling of delta and beta oscillations.

Recent findings showing that anxiety is associated with enhanced coupling of EEG rhythms imply higher information exchange between populations of neurons associated with different oscillatory systems. In this study, influence of uncertainty on alpha-delta anticorrelation and delta-beta coupling was studied in 39 subjects (27 females) aged 19 to 30 years who also filled out the State Trait Anxiety Inventory. A measure of alpha-delta anticorrelation showed trait-like properties being uniformly higher in high trait anxiety subjects independent of experimental manipulation. Contrariwise, delta-beta coupling appeared only in anxiogenic situation both in high and low anxiety subjects.

Adult↗
PubMed2006

Identity state-dependent attentional bias for facial threat in dissociative identity disorder.

Biased attention for threatening stimuli has been associated with many forms of psychopathology. Attention to threatening faces presented below perceptual thresholds was assessed in patients diagnosed with dissociative identity disorder using a pictorial emotional Stroop task. Patients were tested in two different identity states, in one of which they claimed strong awareness of trauma. Attentional bias for social threat proved state-dependent in the patients and deviated from the patterns observed in controls.

Adult↗
PubMed2006

A single administration of testosterone reduces fear-potentiated startle in humans.

BACKGROUND: Ample evidence from animal research indicates that the gonadal steroid hormone testosterone has fear-reducing properties. Human data on this topic, however, are scarce and far less unequivocal. The present study therefore aimed to scrutinize anxiolytic effects of a single dose of testosterone, using a direct physiological index of fear in humans. METHODS: Twenty healthy female participants were tested in a double-blind, placebo-controlled crossover design involving sublingual administration of a single dose of testosterone. Four hours after intake, we assessed effects on baseline startle and fear-potentiated startle in a verbal threat-of-shock paradigm. RESULTS: In accordance with predictions, testosterone administration resulted in reduced fear-potentiated startle, without affecting baseline startle. CONCLUSIONS: This study provides direct evidence that a single dose of testosterone reduces fear in humans. The relationship of this effect to previous research on anxiolytic effects of benzodiazepines, as well as possible mechanisms of action, is discussed.

Adolescent↗
PubMed2006

Testosterone administration reduces empathetic behavior: a facial mimicry study.

Although high baseline testosterone levels correlate with low empathy, there is no causal evidence for this association in humans. The present study tested the causality of this relationship by manipulating testosterone levels in a double-blind placebo controlled crossover design. 20 healthy female participants received either a sublingual administration of a single dose of testosterone or placebo on 2 days and were tested 4 h after administration. Because research has shown that facial expression mimicry is a non-obtrusive index of empathy, facial electromyography was measured in response to dynamic facial expressions of happy and angry faces. Results showed that testosterone generally decreased facial mimicry. These findings are consistent with models that assign a critical role to mimicry in the ability to develop and communicate empathy towards conspecifics, and provide a potential causal mechanism of effects of testosterone on empathy.

Administration, Sublingual↗
PubMed2006

The cognitive-affective neuroscience of the unconscious.

There is an ongoing debate about how best to conceptualize the unconscious. Early psychodynamic views employed theories influenced by physics to explain clinical material, while subsequent cognitivist views relied on computational models of the mind to explain laboratory data. More recently, advances in cognitive-affective neuroscience have provided new insights into the workings of unconscious cognition and affect. We briefly review some of this recent work and its clinical implications.

Adult↗
PubMed2006

Anxiety meets fear in perception of dynamic expressive gaze.

This study investigated in 2 experiments whether reflexive cuing of attention that occurs after perception of a gaze cue is greater for fearful than for happy faces in normal participants, as hypothesized from a social neuroscience perspective. To increase neuroecological validity, dynamic stimulus presentation was used to display faces that simultaneously morphed from a neutral expression into a happy or fearful one and shifted eye gaze from the center to the periphery. Shifts of attention resulting from a natural fearful gaze were expected to be related to participants' anxiety traits, in agreement with the often found increased selective attention to threat in anxious participants. Both hypotheses were confirmed: Fearful faces induced stronger gaze cuing than happy faces, and the strength of this cuing effect was correlated to participants' anxiety levels. These results suggest a neural network, which integrates the processing of gaze, expression, and emotional states to adaptively prime vigilance under threatening circumstances.

Adolescent↗
PubMed2006

A case of illusory own-body perceptions after transcranial magnetic stimulation of the cerebellum.

Illusory own-body perceptions are 'body in space' misinterpretations of the brain and belong to the class of out-of-body experiences wherein the angular gyrus seems importantly implicated. In the present study additional cerebellum involvement in illusory own-body perceptions was investigated in a healthy young female right-handed volunteer. Transcranial magnetic stimulation (TMS) was applied over the cerebellum. Placebo cerebellum TMS and occipital TMS served as control conditions. Illusory own-body perceptions accompanied by electric brain activity over the somatosensory cortex were only observed after cerebellum TMS. The data provide the first evidence that the cerebellum might be involved in a neuronal network underlying illusory own-body perceptions.

Adult↗
PubMed2006

A standardized motor threshold estimation procedure for transcranial magnetic stimulation research.

OBJECTIVES: To introduce and to test a simple standardized motor threshold (MT) estimation procedure for transcranial magnetic stimulation (TMS) research. METHODS: A 5-step MT estimation procedure was introduced, and interestimator reliability was tested by comparing MTs as determined by an experienced and a trainee TMS researcher in a double-blind design. RESULTS: The parametric Pearson correlation between the MTs of the experienced and the MTs of the trainee TMS researcher was 0.95 (P < 0.001). CONCLUSIONS: The currently proposed estimation procedure may be helpful in obtaining reliable MT values in experimental and clinical settings.

Algorithms↗
PubMed2006

Increased positive emotional memory after repetitive transcranial magnetic stimulation over the orbitofrontal cortex.

OBJECTIVE: Several studies have demonstrated increased left orbitofrontal cortex (OFC) activity during negative and depressed mood. These mood states have also been associated with reduced memory for positive emotional stimuli. The aim of the present study was to investigate whether slow, inhibitory repetitive transcranial magnetic stimulation (rTMS) over the left OFC would improve memory for positive material. METHODS: We carried out a study with a double-blind, within-subjects design, in which 12 healthy volunteers received 20 minutes of slow rTMS over the left OFC, placebo treatment over the left OFC and rTMS over the left dorsolateral portion of the prefrontal cortex. Effects on memory for fearful and happy faces were investigated. RESULTS: Memory for happy faces was significantly improved after rTMS over the left OFC compared with placebo (t10 = 2.4, p = 0.037). CONCLUSIONS: These findings suggest a role of the OFC in positive emotional memory, which is in accordance with neuroimaging and neuropsychological data. It may be argued that dense projections from the OFC to the limbic emotional circuit are involved in emotional memory and, therefore, play a role in the effects of rTMS that we observed.

Adolescent↗
PubMed2005

Electrophysiological correlates of cortico-subcortical interaction: a cross-frequency spectral EEG analysis.

OBJECTIVE: Several studies have provided evidence for the notion that the coupling between slow and fast frequency in the EEG spectrum indicates cortico-subcortical cross-talk (CSC-ct). In addition, findings for increased limbic activation due to reduced cortical inhibition have recently been acquired. To get further insights into these mechanisms, the current study investigated whether CSC-ct would decrease as a function of increased slow (SW) or fast wave (FW) activity. METHODS: Resting state EEG recordings were obtained from 46 healthy, right-handed participants. CSC-ct was quantified by computing cross-frequency correlations between the power in the slow and fast frequency range. CSC-ct was compared between groups with relatively low and high SW activity and groups with relatively low and high FW activity. RESULTS: Relatively reduced SW, but not FW activity was associated with a significant coupling between slow and fast frequency EEG. Furthermore, relatively enhanced resting state SW activity was paralleled by slow and fast frequency EEG decoupling. CONCLUSIONS: These findings are in line with the notion that increased subcortical drive can go accompanied by reduced CSC-ct. SIGNIFICANCE: Cross-frequency EEG analyses might provide a unique approach to obtain novel insights into cortico-subcortical interactions in relation to affective and cognitive behavior.

Adolescent↗
PubMed2005

Testosterone reduces unconscious fear but not consciously experienced anxiety: implications for the disorders of fear and anxiety.

BACKGROUND: The fear-reducing properties of testosterone have been firmly established in animals but not in humans. However, human data on the relation between testosterone, fear, and anxiety have predominantly involved questionnaires that index cortically executed conscious appraisal of anxious mood. Animal studies, on the other hand, indicate that the effects of testosterone on motivation and emotion are of subcortical origin and of unconscious nature. Presently, it was hypothesized that a single testosterone administration to humans would reduce unconscious fear but not consciously experienced anxiety. METHODS: In a placebo-controlled, double-blind crossover design, a single dose of testosterone (.5 mg) or placebo was administered to 16 healthy female volunteers. Afterward, a masked emotional Stroop task measured unconscious emotional responses to fearful faces, while multiple self-reports of mood indexed consciously experienced anxiety. RESULTS: As hypothesized, the habitual vigilant emotional response to the masked fearful face observed in the placebo condition was significantly reduced after testosterone was administered, while the self-reported measures of anxiety remained unaffected. CONCLUSIONS: These data provide the first direct evidence for fear-reducing properties of testosterone in humans. Furthermore, by dissociating specific aspects of fear and anxiety in humans, this outcome highlights that testosterone's effects on motivation and emotion concern the subcortical affective pathways of the brain.

Adult↗