High working memory load impairs reappraisal but facilitates distraction : an event-related potential investigation

The present experiments investigated the impact of working memory (WM) load on emotion regulation (ER) efficacy using reappraisal (Experiment 1, n = 30) and distraction (Experiment 2, n = 30). Considering that WM is necessary for storage, elaboration, and manipulation of information and that reappraisal acts by storing, elaborating, and manipulating the stimulus meaning, we hypothesized that high (versus low) WM-load would reduce reappraisal efficacy. By contrast, given that distraction acts by blocking elaborated processing of the stimulus meaning, we expected that high WM-load would enhance distraction efficacy. To test these predictions, we employed a dual-task paradigm in which a low- or high WM-load task was combined with an ER (reappraisal or distraction) task. We measured the Late Positive Potential (LPP)–an electrocortical marker of sustained motivated attention, and a well-established index of emotional arousal–in response to negative pictures. Results confirmed that although reappraisal successfully reduced the LPP amplitude in the down- compared to up-regulation condition in low WM-load trials, high WM-load eliminated this difference, suggesting the disrupting influence of high WM-load on ER for reappraisal (Experiment 1). By contrast, although distraction failed to modulate the LPP amplitude in low WM-load trials, the difference between down- and no-regulation conditions was significant when distraction was combined with high WM-load, suggesting the facilitatory influence of high WM-load on ER for distraction (Experiment 2). Our findings show that the effect of WM-load on ER is strategy-dependent, and that the availability of WM resources is an important situational moderator of ER efficacy in healthy young adults

Subjective mood estimation co-varies with spectral power EEG characteristics

Co-variation between subjectively estimated mood/activation and EEG characteristics, based on spectral power parameters, was investigated. Subjective estimation of mood was made by using Thayer’s Activation-Deactivation Adjective Checklist, which yielded two dimensions: Energy-Tiredness (with Energy pole having positive valence connotation) and Tension-Calmness (negative connotation for Tension). A within-subject design with two sessions of EEG recording immediately followed by mood assessment was applied. These were separated by a cognitive task, introduced in order to modify the subjects’ mood. The correlations between changes in mood estimation and changes in EEG spectral power parameters were calculated. Both ADACL dimensions co-varied with EEG in a specific way according to frequency and localization. Subjective estimation of Energy correlated negatively with alpha1 and, surprisingly, positively with delta, theta1 as well as theta2 relative power. Estimation of Tension correlated positively with theta1 and beta1, and negatively with alpha2 relative power. Presented results suggest that the adjective description of mood has objectively-measurable brain correlates in the EEG

Covariation of mood and brain activity: Integration of subjective selfreport data with quantitative EEG measures

Contains fulltext : 76518.pdf (author's version ) (Open Access)RU Radboud Universiteit Nijmegen, 28 april 2010Promotores : Coenen, A.M.L., Kaiser, J.116 p

Associations Between Self-Report of Emotional State and the EEG Patterns in Affective Disorders Patients

Contains fulltext : 90660.pdf (publisher's version ) (Closed access)The study determines the associations between self-report of ongoing emotional state and EEG patterns. A group of 31 hospitalized patients were enrolled with three types of diagnosis: major depressive disorder, manic episode of bipolar affective disorder, and nonaffective patients. The Thayer ADACL checklist, which yields two subjective dimensions, was used for the assessment of affective state: Energy Tiredness (ET) and Tension Calmness (TC). Quantitative analysis of EEG was based on EEG spectral power and laterality coefficient (LC). Only the ET scale showed relationships with the laterality coefficient. The high-energy group showed right shift of activity in frontocentral and posterior areas visible in alpha and beta range, respectively. No effect of ET estimation on prefrontal asymmetry was observed. For the TC scale, an estimation of high tension was related to right prefrontal dominance and right posterior activation in beta1 band. Also, decrease of alpha2 power together with increase of beta2 power was observed over the entire scalp

Depressive rumination and the emotional control circuit : an EEG localization and effective connectivity study

Ruminations are repetitive thoughts associated with symptoms, causes, and consequences of one’s negative feelings. The objective of this study was to explore the neuronal basis of depressive rumination in a non-clinical population within the context of emotional control. Participants scoring high or low on the tendency to ruminate scale took part in the EEG experiment. Their EEG data were collected during a state of induced depressive ruminations and compared with positive and neutral conditions. We hypothesized that both groups would differ according to the level of activation and effective connectivity among the structures involved in the emotional control circuit. Clustering of independent components, together with effective connectivity (Directed Transfer Function), was performed using the EEG signal. The main findings involved decreased activation of the left dorsolateral prefrontal cortex (DLPFC) and increased activation of the left temporal lobe structures in the highly ruminating group. The latter result was most pronounced during the ruminative condition. Decreased information from the left DLPFC to the left temporal lobe structures was also found, leading to the conclusion that hypoactivation of the left DLPFC and its inability to modulate the activation of the left temporal lobe structures is crucial for the ruminative tendencies

Reappraisal is less effective than distraction in downregulation of neural responses to physical threats: An event-related potential investigation

Evolutionary threats (ETs), such as predatory animals and heights, elicit stronger fear responses and are more often the subject of specific phobias, as compared to modern threats (MTs, such as guns and motorcycles). Since processing of ET depends on lower-order, phylogenetically conserved neural fear circuits, it may be less susceptible to higher-order (vs. simpler) cognitive emotion regulation. Given the relevance for treatment of specific phobias, we tested this hypothesis in an ERP study. Sixty-one female participants passively watched high- and low-threat pictures of evolutionary (snakes, lizards) and modern (guns, water-guns) origin, and downregulated responses to the high-threat pictures (snakes and guns) using either cognitive reappraisal or a simpler cognitive distraction strategy. ET elicited stronger early (EPN) and sustained (LPP) attention processing compared to MT. Both strategies successfully downregulated subjective and LPP (but not EPN) responses compared to passive watching. Although reappraisal was more effective subjectively, distraction downregulated the LPP earlier and stronger than reappraisal, irrespective of the threat type. These findings provide novel evidence that neural responses to physical threat might be less susceptible to cognitive emotion regulation via higher-order (reappraisal) versus simpler (distraction) strategies, irrespective of the evolutionary or modern relevance of threat. Combining both strategies could be beneficial for the emotion regulation-enhancing interventions for specific phobias. Distraction could be used during initial exposure, to reduce immediate emotion responding and help endure the contact with the feared stimulus, whereas reappraisal could be used subsequently, when emotions are less intense, to change maladaptive thoughts about the stimulus for future encounters

Radial and axial water movement in adult trees recorded by stable isotope tracing

The capacity of trees to release water from storage compartments into the transpiration stream can mitigate damage to hydraulic functioning. However, the location of these 'transient' water sources and also the pathways of water movement other than vertical through tree stems still remain poorly understood. We conducted an experiment on two tree species in a common garden in eastern Australia that naturally grow in regions of high (Eucalyptus tereticornis, 'Red Gum') and low (Eucalyptus sideroxylon, 'Ironbark') annual precipitation rates. Deuterium-enriched water (1350% label strength) was directly introduced into the transpiration stream of three trees per species for four consecutive days. Subsequently, the trees were felled, woody tissue samples were collected from different heights and azimuthal positions of the stems, and stable isotope ratios were determined on the water extracted from all samples. The presence/absence of the tracer along the radial and vertical stem axes in combination with xylem hydraulic properties inferred from sapflow, leaf and stem water potentials, wood moisture contents and anatomical sapwood characteristics elucidated species-specific patterns of short-term stem water storage and movement. The distribution of water isotopes at natural abundance among woody tissues indicated systematic differences with highest values of sapwood water and lower values in inner bark and heartwood. Presence of tracer in water of the inner bark highlighted the importance of this tissue as capacitor. Although injected at the northern side of stems, tracer was also discovered at the southern side, providing empirical evidence for circumferential flow in sapwood, particularly of Ironbark. Greater vertical water transport in Red Gum compared with more radial and circumferential water transport in Ironbark were associated with species-specific sapwood anatomy. Our study highlights the value of combining information from stable isotope tracers and wood anatomy to investigate patterns of water transport and storage of tall trees in situ