Perceptual and physiological dysfunction in depression

Dopaminergic neurotransmission in the ventral and dorsal striatum interact with central processing of rewarding and reward-indicating stimuli, and may affect frontocortical-striatal-thalamic circuits regulating goal-directed behaviour. Thirteen healthy male volunteers were investigated with multimodal imaging, using the radioligand 6-[(18)F]fluoro-l-DOPA (FDOPA) for positron emission tomography (PET) measurements of dopamine synthesis capacity, and also functional magnetic resonance imaging (fMRI) in a cognitive activation paradigm. We calculated the correlation between FDOPA net blood-brain influx (; ml/g/min) in the ventral and associative dorsal striatum and BOLD signal changes elicited by standardized affectively positive, negative and neutral visual stimuli. The magnitude of in the ventral striatum was positively correlated with BOLD signal increases in the left anterior cingulate cortex and right insular operculum elicited by positive vs. neutral stimuli, but not negative vs. neutral stimuli. In the dorsal striatum, the magnitude of was positively correlated with processing of positive and negative stimuli in the left dorsolateral prefrontal cortex. These findings suggest that dopamine synthesis capacity in the ventral striatum correlates with the attentional processing of rewarding positive stimuli in the anterior cingulate cortex of healthy subjects. Dopaminergic neurotransmission in the associative dorsal striatum has been associated previously with habit learning. The observed correlation between dopamine synthesis capacity in the dorsal striatum and BOLD signal changes in the dorsolateral prefrontal cortex suggests dopaminergic modulation of processing of emotional stimuli in brain areas associated with motor planning and executive behaviour control.

Research has indicated that negative and positive thoughts may affect sport performance. The purpose of this analogue study was to assess whether negative and positive stimuli influenced tennis performance similar to positive and negative thought. The reaction time (RT) of 40 competitive tennis players was measured during a timed response to a tennis ball rotating in a topspin, sidespin, or backspin direction on the computer screen. Immediately prior to the ball presentation, a phrase (accessory stimulus) was presented visually or aurally. The accessory stimulus provided either positive (e.g., 'nice shot') or negative information (e.g., 'bad shot') followed by the subject's name. Analysis showed a main effect only for the type of spin. The slowest RT occurred when responding to a tennis ball rotating in a backspin direction. A significant interaction was found for the sensory modality (audition vs vision) and polarity (positive vs negative) of the accessory stimulus. RT to negative stimuli was slowest when the accessory stimulus was presented aurally. The quickest RT to positive stimuli occurred when the accessory stimulus was presented aurally. These results indicated that negative and positive stimuli, when presented aurally, affected performance as positive and negative thoughts measured in other studies. Not measured was whether negative and positive stimuli actually produce the negative and positive thoughts, respectively, that have been reported to affect performance.

Research evaluating mental state identification in individuals with borderline pathology has yielded inconsistent results; contradictory findings were hypothesized to be driven by moderating effects of childhood trauma. Participants were 105 ethnically diverse men and women who exhibited a range of borderline pathology measured by Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria for borderline personality disorder. Mental state identification accuracy was measured using the Reading the Mind in the Eyes Test (RMET). Greater childhood abuse, but not childhood neglect, was associated with enhanced mental state identification accuracy on negative stimuli, when controlling for dissociation (ps < .05); these findings could not be explained by reaction time (RT) or response bias. Childhood abuse and childhood neglect were not related to mental state identification accuracy on neutral or positive stimuli, and they did not moderate the relationship between borderline pathology and mental state identification accuracy on negative, neutral, or positive stimuli. Borderline pathology was not independently related to mental state identification accuracy on negative, neutral, or positive stimuli. Greater childhood neglect, but not childhood abuse, was related to slower RTs on negative, neutral, and positive stimuli (ps < .05). Results underline the importance of separately assessing childhood abuse and childhood neglect and of controlling for dissociation, and they suggest borderline pathology may not universally hinder complex mental state identification.

The attentional system tends to prioritize negative stimuli in the early stages of processing, favoring threat detection. However, it is unclear whether this bias is maintained or reversed toward positive stimuli at later stages. In this study, we used a free-viewing paradigm with eye tracking to examine early and late attentional biases toward negative, positive, and neutral stimuli (humans in emotionally unloaded activities) versus control stimuli (inanimate objects) in 122 participants without affective disorders (64 men, 58 women). We fitted generalized linear mixed models with random intercepts for stimuli and random intercepts and slopes for participants, and used non-parametric bootstrap resampling to obtain robust estimates and confidence intervals. Additionally, the number of first fixations was analyzed with a COM-Poisson. Results showed that participants fixated faster (χ2(3) = 97.55, p < .001) and for longer durations (χ2(3) = 337.45, p < .001) on negative stimuli compared to the other categories, confirming a negativity bias in early attention In late attention, we found longer total fixation durations (χ2(3) = 200.24, p < .001) and a greater number of fixations (χ2(3) = 207.02, p< .001) for negative stimuli, contradicting the hypothesis of a positivity shift during emotional regulation. This sustained negativity bias may reflect an adaptive regulatory process in which individuals allocate attentional resources to threat-related information to enhance learning and emotional preparedness. Future studies should examine these effects across diverse sociocultural settings and in clinical populations.

P3-048: Comparison of the Fuld Object Memory Evaluation Test in Brazilian Alzheimer’s disease and depressed patients

ABSTRACTExtensive evidence has been obtained that supports an association between an attentional bias (AB) toward negative stimuli and vulnerability to stress-related psychopathology, little is known regarding the characteristics of individual AB in different posttraumatic growth (PTG) levels. The current study used a modified dot-probe task to investigate if individual differences in AB towards either positive or negative emotional stimuli, are related to self-reported PTG. A sample of 202 patients completed the experiment. Patients with low levels of PTG did not exhibit AB toward negative or positive stimuli, patients with medium levels of PTG had difficulty disengaging attention from negative stimuli, patients with high levels of PTG had difficulty disengaging attention from positive stimuli. And the AB towards positive stimuli was only predictive for PTG. An implication of this finding is that there are different characteristics of implicit cognitive processing in patients with different levels of PTG, suggesting the necessity of psychological intervention on the accidentally injured patients.

Thyroid stimulating hormone response after thyrotropin releasing hormone in depressed, schizophrenic and normal women

The present study investigated how pubertal development and sex interact to influence humans’ emotion susceptibility during adolescence. Event-related potentials were recorded for highly emotional, mildly emotional and neutral stimuli in positive and negative blocks, when 73 adolescents (36 pre-/early pubertal students, 19 boys, 10–12 years old; 37 mid-/late pubertal students, 18 boys, 11–13 years old) performed an implicit emotion task. Behavioral analysis showed higher positive mood ratings for pre-/early compared to mid-/late pubertal subjects, irrespective of sex and block. ERP analysis demonstrated increasing Late Positive Potential (LPP) amplitudes from neutral, Mildly Positive (MP) to Highly Positive (HP) stimuli in pre-/early pubertal, but not in mid-/late pubertal adolescents. However, girls exhibited higher P3a amplitudes during mid-/late relative to pre-/early puberty for negative stimuli irrespective of intensity; while this puberty effect was absent in boys. In addition, girls compared to boys exhibited a more pronounced LPP enhancement effect for Highly Negative (HN) stimuli and a lower threshold of responding to negative stimuli in P3b amplitudes, regardless of puberty. These results suggest that, though there is a puberty-independent sensitivity to negative stimuli in girls relative to boys, puberty selectively intensifies girls’ attention bias for negative stimuli and reduces experiential sensitivity to positive stimuli in both sexes. The implication of these results for the sex-related psychopathology during adolescence were discussed.

Laboratory paradigms are useful for investigating mechanisms of human alcohol cue reactivity in a highly controlled environment. A number of studies have examined the effects of beverage exposure or negative affective stimuli on cue reactivity independently, but only a few have reported on interaction effects between beverage cue and affective stimuli, and none have evaluated the effects of positive stimuli on beverage cue reactivity. To assess independent and interactive effects of both positive and negative affective stimuli and beverage cue on psychophysiological and subjective measures of reactivity in alcohol dependence. A total of 47 non-treatment-seeking paid volunteers with current alcohol dependence participated in a within-subjects trial where each was exposed to a standardized set of pleasant, neutral, or unpleasant visual stimuli followed by alcohol or water cues. Psychophysiological cue-reactivity measures were obtained during beverage presentation, and subjective reactivity measures were taken directly following beverage presentation. Mixed-effect models revealed a significant main effect of beverage and positive (but not negative) affective stimuli on subjective strength of craving and significant main effects of both positive and negative affective stimuli on ratings of emotionality. Despite the power to detect relatively small interaction effects, no significant interactions were observed between affect and beverage conditions on any reactivity measure. A key finding of this study is that positive affective stimuli commonly associated with drinking situations can induce craving in the absence of alcohol cues. Main effects of beverage cue replicated results from previous studies. Beverage and affective cues showed no interaction effects.

Short-term escitalopram treatment normalizes aberrant self-referential processing in major depressive disorder

This study investigated whether the human sensitivity to valence intensity changes in positive stimuli varies with extraversion. Event-related potentials were recorded for highly positive, moderately positive, and neutral stimuli while participants (extraverts and nonextraverts) performed a standard/deviant categorization task, irrespective of the emotionality of deviants. The results of extraverts showed larger P2 and P3 amplitudes during highly positive condition than during moderately positive condition which, in turn, elicited larger P2 than neutral condition. Conversely, nonextraverts showed no differences at both P2 and P3 components. Thus, extraverts, unlike less extraverted individuals, are sensitive to valence changes in positive stimuli, which may be underlain by certain biogenetic mechanism.

A large number of studies have demonstrated that depression patients have cognitive dysfunction. With recently developed brain functional imaging, studies have focused on changes in brain function to investigate cognitive changes. However, there is still controversy regarding abnormalities in brain functions or correlation between cognitive impairment and brain function changes. Thus, it is important to design an emotion-related task for research into brain function changes. We selected positive, neutral, and negative pictures from the International Affective Picture System. Patients with major depressive disorder were asked to judge emotion pictures. In addition, functional MRI was performed to synchronously record behavior data and imaging data. Results showed that the total correct rate for recognizing pictures was lower in patients compared with normal controls. Moreover, the consistency for recognizing pictures for depressed patients was worse than normal controls, and they frequently recognized positive pictures as negative pictures. The consistency for recognizing pictures was negatively correlated with the Hamilton Depression Rating Scale. Functional MRI suggested that the activation of some areas in the frontal lobe, temporal lobe, parietal lobe, limbic lobe, and cerebellum was enhanced, but that the activation of some areas in the frontal lobe, parietal lobe and occipital lobe was weakened while the patients were watching positive and neutral pictures compared with normal controls. The activation of some areas in the frontal lobe, temporal lobe, parietal lobe, and limbic lobe was enhanced, but the activation of some areas in the occipital lobe were weakened while the patients were watching the negative pictures compared with normal controls. These findings indicate that patients with major depressive disorder have negative cognitive disorder and extensive brain dysfunction. Thus, reduced activation of the occipital lobe may be an initiating factor for cognitive disorder in depressed patients.

Neural correlates of intrusion of emotion words in a modified Stroop task

Clinical reasoning assessment is an essential component of determining a health professional’s competence. Clinical reasoning cannot be assessed directly. It must be gleaned from a health professional’s choices and decisions. Clinical knowledge and knowledge organization, rather than a general problem solving process, serve as the substrate for clinical reasoning ability. Unfortunately, the lack of a gold standard for the clinical reasoning process and the observation of context specificity make it difficult to assess clinical reasoning. Information processing theory, which focuses on the way the brain processes and organizes knowledge, has provided valuable insights into the cognitive psychology of diagnostic and therapeutic reasoning but failed to explain the variance in health professional’s diagnostic performance. Situativity theory has emerged suggesting that this variance relates to context-specific factors that impact a health professional’s clinical reasoning performance. Both information processing and situativity theory inform the way in which we assess clinical reasoning. Current assessment methods focus on standardized testing of knowledge to maximize psychometric parameters and work-based assessments which evaluate clinical reasoning under authentic, uncertain conditions that can decrease the reliability of these measurements. Issues of inter-rater reliability and context specificity require that multiple raters assess multiple encounters in multiple contexts to optimize validity and reliability. No single assessment method can assess all aspects of clinical reasoning; therefore, in order to improve the quality of assessments of clinical reasoning ability, different combinations of methods that measure different components of the clinical reasoning process are needed.

Stimuli that are regularly associated with alcohol intake (AI) may acquire incentive salience, while other reinforcers can be devalued. We assessed whether brain activation elicited by (1) alcohol associated, (2) affectively positive, and (3) negative versus neutral stimuli is associated with the subsequent risk of relapse. Twelve detoxified alcoholic subjects (6 women and 6 men) and 12 age-matched and gender-matched healthy control subjects were assessed with functional magnetic resonance imaging (fMRI) and a fast single-event paradigm using standardized affective and alcohol-associated pictures. Patients were followed for 6 months and AI was recorded. In alcoholic subjects, compared with healthy control subjects, (1) alcohol-related versus neutral visual stimuli elicited increased activation in the prefrontal (PFC; BA 6 and 10) and cingulate cortex (BA 23 and 24), precuneus and adjacent parietal cortex; (2) positive versus neutral stimuli elicited increased activation in the anterior cingulate cortex (ACC; BA 24), PFC (BA 10), ventral striatum and thalamus; and (3) negative versus neutral stimuli elicited increased activation in the PFC (BA 10). Seven alcoholic subjects relapsed. Within the follow-up period of 6 months, the number of subsequent drinking days (DD) and the amount of AI were inversely correlated with brain activation elicited by positive versus neutral stimuli in the thalamus (DD: r=-0.63, p=0.03; AI: r=-0.63, p=0.03) and in the ventral striatum (DD: r=-0.60, p=0.04; AI: r=-0.48, p=0.11). In this study, brain activation elicited by briefly presented alcohol-associated stimuli was not associated with the prospective risk of relapse. Unexpectedly, alcoholic subjects displayed increased limbic brain activation during the presentation of affectively positive but not negative stimuli, which may reflect a protective factor in detoxified alcoholic subjects.