Cornelia Herbert

Buzzwords Early Cortical Responses to Emotional Words During Reading

Electroencephalographic event-related brain potentials were recorded as subjects read, without further instruction, consecutively presented sequences of words. We varied the speed at which the sequences were presented (3 Hz and 1 Hz) and the words emotional significance. Early event-related cortical responses during reading differentiated pleasant and unpleasant words from neutral words. Emotional words were associated with enhanced brain responses arising in predominantly left occipito-temporal areas 200 to 300 ms after presentation. Emotional words were also spontaneously better remembered than neutral words. The early cortical amplification was stable across 10 repetitions, providing evidence for robust enhancement of early visual processing of stimuli with learned emotional significance and underscoring the salience of emotional connotations during reading. During early processing stages, emotion-related enhancement of cortical activity along the dominant processing pathway is due to arousal, rather than valence of the stimuli. This enhancement may be driven by cortico-amygdaloid connections.

On the relationship between interoceptive awareness and alexithymia - is interoceptive awareness related to emotional awareness?

Interoceptive awareness (IA) is associated with emotional experience, the processing of emotional stimuli, and activation of brain structures that monitor the internal visceral and emotional state of the organism. Alexithymia is characterized by difficulties in identifying and describing ones emotions and externally oriented thinking (EOT) and reflects impairments in emotional awareness and the regulation of emotions. This study examined the relationship between alexithymia and IA in a healthy population of N=155 persons. A well-validated heartbeat perception task to measure interoceptive awareness, the Toronto Alexithymia Scale (TAS-20) and a depression questionnaire (BDI-2) were administered to 88 women and 67 men. IA was inversely associated with all features of alexithymia in the whole sample. When considering sex differences, IA turned out to be a relevant negative predictor for the EOT subscale only in men. This large sample investigation in a nonclinical population indicates that IA represents a relevant negative predictor for alexithymia.

Interoception across Modalities: On the Relationship between Cardiac Awareness and the Sensitivity for Gastric Functions

The individual sensitivity for ones internal bodily signals (“interoceptive awareness”) has been shown to be of relevance for a broad range of cognitive and affective functions. Interoceptive awareness has been primarily assessed via measuring the sensitivity for ones cardiac signals (“cardiac awareness”) which can be non-invasively measured by heartbeat perception tasks. It is an open question whether cardiac awareness is related to the sensitivity for other bodily, visceral functions. This study investigated the relationship between cardiac awareness and the sensitivity for gastric functions in healthy female persons by using non-invasive methods. Heartbeat perception as a measure for cardiac awareness was assessed by a heartbeat tracking task and gastric sensitivity was assessed by a water load test. Gastric myoelectrical activity was measured by electrogastrography (EGG) and subjective feelings of fullness, valence, arousal and nausea were assessed. The results show that cardiac awareness was inversely correlated with ingested water volume and with normogastric activity after water load. However, persons with good and poor cardiac awareness did not differ in their subjective ratings of fullness, nausea and affective feelings after drinking. This suggests that good heartbeat perceivers ingested less water because they subjectively felt more intense signals of fullness during this lower amount of water intake compared to poor heartbeat perceivers who ingested more water until feeling the same signs of fullness. These findings demonstrate that cardiac awareness is related to greater sensitivity for gastric functions, suggesting that there is a general sensitivity for interoceptive processes across the gastric and cardiac modality.

Intuitive eating is associated with interoceptive sensitivity. Effects on body mass index.

Intuitive eating is relevant for adaptive eating, body weight and well-being and impairments are associated with dieting and eating disorders. It is assumed to depend on the ability to recognize ones signs of hunger and fullness and to eat accordingly. This suggests a link to the individual ability to perceive and processes bodily signals (interoceptive sensitivity, IS) which has been shown to be associated with emotion processing and behavior regulation. This study was designed to clarify the relationships between IS as measured by a heartbeat perception task, intuitive eating and body mass index (BMI) in N=111 healthy young women. Intuitive eating was assessed by the Intuitive Eating Scale (IES) with three facets, reliance on internal hunger and satiety cues (RIH), eating for physical rather than emotional reasons (EPR), and unconditional permission to eat when hungry (UPE). IS was not only positively related to total IES score and RIH and EPR, and negatively predicted BMI, but also proved to fully mediate the negative relationship between RIH, as well as EPR and BMI. Additionally, the subjective appraisal of ones interoceptive signals independently predicted EPR and BMI. IS represents a promising mechanism in research on eating behavior and body weight.

Brain Painting

BACKGROUNDnFor many years the reestablishment of communication for people with severe motor paralysis has been in the focus of brain-computer interface (BCI) research. Recently applications for entertainment have also been developed. Brain Painting allows the user creative expression through painting pictures.nnnOBJECTIVEnThe second, revised prototype of the BCI Brain Painting application was evaluated in its target function - free painting - and compared to the P300 spelling application by four end users with severe disabilities.nnnMETHODSnAccording to the International Organization for Standardization (ISO), usability was evaluated in terms of effectiveness (accuracy), efficiency (information transfer rate (ITR)), utility metric, subjective workload (National Aeronautics and Space Administration Task Load Index (NASA TLX)) and user satisfaction (Quebec User Evaluation of Satisfaction with assistive Technology (QUEST) 2.0 and Assistive Technology Device Predisposition Assessment (ATD PA), Device Form).nnnRESULTSnThe results revealed high performance levels (M≥80% accuracy) in the free painting and the copy painting conditions, ITRs (4.47-6.65bits/min) comparable to other P300 applications and only low to moderate workload levels (5-49 of 100), thereby proving that the complex task of free painting did neither impair performance nor impose insurmountable workload. Users were satisfied with the BCI Brain Painting application. Main obstacles for use in daily life were the system operability and the EEG cap, particularly the need of extensive support for adjustment.nnnCONCLUSIONnThe P300 Brain Painting application can be operated with high effectiveness and efficiency. End users with severe motor paralysis would like to use the application in daily life. User-friendliness, specifically ease of use, is a mandatory necessity when bringing BCI to end users. Early and active involvement of users and iterative user-centered evaluation enable developers to work toward this goal.

Self-reference modulates the processing of emotional stimuli in the absence of explicit self-referential appraisal instructions

Self-referential evaluation of emotional stimuli has been shown to modify the way emotional stimuli are processed. This study aimed at a new approach by investigating whether self-reference alters emotion processing in the absence of explicit self-referential appraisal instructions. Event-related potentials were measured while subjects spontaneously viewed a series of emotional and neutral nouns. Nouns were preceded either by personal pronouns (my) indicating self-reference or a definite article (the) without self-reference. The early posterior negativity, a brain potential reflecting rapid attention capture by emotional stimuli was enhanced for unpleasant and pleasant nouns relative to neutral nouns irrespective of whether nouns were preceded by personal pronouns or articles. Later brain potentials such as the late positive potential were enhanced for unpleasant nouns only when preceded by personal pronouns. Unpleasant nouns were better remembered than pleasant or neutral nouns when paired with a personal pronoun. Correlation analysis showed that this bias in favor of self-related unpleasant concepts can be explained by participants depression scores. Our results demonstrate that self-reference acts as a first processing filter for emotional material to receive higher order processing after an initial rapid attention capture by emotional content has been completed. Mood-congruent processing may contribute to this effect.

Out of the frying pan into the fire--the P300-based BCI faces real-world challenges.

Brain-computer interfaces (BCIs) have been investigated for more than 20 years. Many BCIs use noninvasive electroencephalography as a measurement technique and the P300 event-related potential as an input signal (P300 BCI). Since the first experiment with a P300 BCI system in 1988 by Farwell and Donchin, not only data processing has improved but also stimuli presentation has been varied and a plethora of applications was developed and refined. Nowadays, these applications are facing the challenge of being transferred from the research laboratory into real-life situations to serve motor-impaired people in their homes as assistive technology.

His or mine? The time course of self–other discrimination in emotion processing

This electroencephalography (EEG) study investigated at which temporal processing stages self–other discrimination in emotion processing occurs. EEG was recorded in 23 healthy participants during silent reading of unpleasant, pleasant, and neutral pronoun–noun and article–noun expressions that were related to the participants themselves, related to an unknown third person, or had no self–other reference at all. Self- and other-related pronoun–noun pairs elicited larger cortical negativity relative to the processing of article–noun pairs at left posterior electrodes as early as 200 ms after stimulus onset. In the same time windows (from 200 ms to 300 ms and 300 ms to 400 ms) the emotionality of the words enhanced event-related brain potential (ERP) amplitudes at parieto-occipital electrodes. From 350 ms onwards, processing of self-related unpleasant words elicited larger frontal negativity compared to unpleasant words that were related to the other or that had no reference at all. In addition, processing of pleasant words vs. neutral or unpleasant words elicited larger positive amplitudes over parietal electrodes from 450 ms after stimulus onset, in particular when words were self-related. Our findings demonstrate that for verbal emotional stimuli, self–other discrimination first occurs at higher-order, cortical processing stages. This is consistent with the view that categorization of information according to certain stimulus aspects (self–other reference, emotionality) occurs before its meaning is integrated.

Effects of short-term food deprivation on interoceptive awareness, feelings and autonomic cardiac activity.

The perception of internal bodily signals (interoception) plays a relevant role for emotion processing and feelings. This study investigated changes of interoceptive awareness and cardiac autonomic activity induced by short-term food deprivation and its relationship to hunger and affective experience. 20 healthy women were exposed to 24h of food deprivation in a controlled setting. Interoceptive awareness was assessed by using a heartbeat tracking task. Felt hunger, cardiac autonomic activity, mood and subjective appraisal of interoceptive sensations were assessed before and after fasting. Results show that short-term fasting intensifies interoceptive awareness, not restricted to food cues, via changes of autonomic cardiac and/or cardiodynamic activity. The increase of interoceptive awareness was positively related to felt hunger. Additionally, the results demonstrate the role of cardiac vagal activity as a potential index of emotion related self-regulation, for hunger, mood and the affective appraisal of interoceptive signals during acute fasting.

Emotional self-reference: brain structures involved in the processing of words describing one's own emotions.

The present functional magnetic resonance imaging study investigated the role of emotion-related (e.g., amygdala) and self-related brain structures (MPFC in particular) in the processing of emotional words varying in stimulus reference. Healthy subjects (N=22) were presented with emotional (pleasant or unpleasant) or neutral words in three different conditions: (1) self (e.g., my fear), (2) other (e.g., his fear) and (3) no reference (e.g., the fear). Processing of unpleasant words was associated with increased amygdala and also insula activation across all conditions. Pleasant stimuli were specifically associated with increased activation of amygdala and insula when related to the self (vs. other and no reference). Activity in the MPFC (vMPFC in particular) and anterior cingulate cortex (ACC) was preferentially increased during processing of self-related emotional words (vs. other and no reference). These results demonstrate that amygdala activation in response to emotional stimuli is modulated by stimulus reference and that brain structures implicated in emotional and self-related processing might be important for the subjective experience of ones own emotions.