Giulia Buodo

Attentional Resources Measured by Reaction Times Highlight Differences Within Pleasant and Unpleasant, High Arousing Stimuli

Simple reaction times (RTs) to acoustic tones were recorded during picture viewing in order to investigate attentional resource allocation to threat stimuli compared with pleasant (sport/adventure) and neutral (household objects) contents. Stimuli were selected as equally arousing according to standardized subjective ratings. In the late stage of picture processing threat pictures showed shorter RTs compared with neutral and pleasant ones. In a second study, a choice-RT task was employed, and a wider range of both pleasant and unpleasant contents was shown. Results indicated slower RTs when blood/injury and erotic couples were presented, compared with other threat, and with other positive (sport/adventure) scenes. Specifically, erotic couples require a greater amount of attentional resources compared with sport/adventure; the same is true for blood/injury stimuli as compared with threat. Remarkable differences were thus shown in attentional deployment to specific stimulus contents within the same valence category. These differences should be taken into account when using such stimuli to investigate emotional processing.

Changes in EEG alpha power to different disgust elicitors: the specificity of mutilations

It is unclear in the literature whether the various disgust elicitors are differentially processed by the brain and/or able to elicit distinct psychophysiological response patterns. On the other hand, disgusting stimuli depicting mutilations have been proved to elicit a distinct autonomic response pattern and to demand greater attentional resources, as compared with other unpleasant visual stimuli. In this EEG study, 34 participants viewed 4 film-clips depicting surgery, cockroach invasion, human attack and neutral landscape during EEG recording, and then rated the clips for valence, arousal and the basic emotions. Independent of location, the highest cortical activation was found during the viewing of the surgery scene. Moreover, the above activation was prominent over the right posterior regions.

Cardiovascular dynamics in blood phobia: Evidence for a key role of sympathetic activity in vulnerability to syncope

This study was aimed at clarifying the mechanism predisposing people with blood phobia to syncope by investigating the complete hemodynamic response pattern and the underlying autonomic control. Blood phobics and controls were shown 3 film-clips: phobia-related, phobia-unrelated, and neutral. Hemodynamic responses were recorded using impedance cardiography and Finapres. Preejection period and respiratory sinus arrhythmia were employed as indices of cardiac sympathetic and parasympathetic activity. Self-ratings of emotion were also collected. Blood phobics displayed global heart rate and cardiac output increases to the phobic film, mediated by augmented cardiac sympathetic activity. Systolic blood pressure and total peripheral resistance markedly declined, with no evidence of diphasic reaction or parasympathetic activation. An impaired vasomotor response under sympathetic control might be the key mechanism underlying the phobic dysfunctional response.

The neural correlates of attentional bias in blood phobia as revealed by the N2pc

In the literature, a lack of attentional bias in blood phobia has been reported, using both behavioral and ERP measures. However, in the tasks employed so far, attentional resources to single stimuli, rather than attentional selection, were evaluated. The present study investigated whether in blood phobics disorder-relevant pictures can capture visuo-spatial attention when paired with neutral or non-specific unpleasant pictures (attack), and participants have to focus on a visual detection task. The N2pc component of the ERPs was measured as an index of spatial attentional selection. Results showed that in blood phobics, but not in controls, injuries elicited a larger early N2pc than attack pictures when paired with neutral material. Moreover, only in blood phobics a reliable N2pc to injury-attack pairs was found. The late N2pc reversal to injury pictures suggests that early orienting to phobic cues was followed by cognitive avoidance.

Blood pressure changes highlight gender differences in emotional reactivity to arousing pictures

The current study was aimed at investigating the effects of gender on the magnitude and patterning of blood pressure responses to specific pleasant and unpleasant, arousing visual stimuli. Systolic and diastolic blood pressure (SBP and DBP), as well as heart rate (HR) and skin conductance (SCR) responses were investigated during picture viewing in 21 female and 25 male students. The pattern of SCR and HR reactivity across emotional categories was found to be similar for men and women. Gender was found to be an effective moderator of BP responses specifically to sexual stimulus content, which prompted greater reactivity in men than in women. These findings extend prior research on gender differences in autonomic responding to emotional visual stimuli and suggest that BP changes might reflect sexual peripheral arousal more than other autonomic measures.

Auditory event-related potentials and reaction times in migraine children

Cognitive processing was investigated interictally in 18 children with migraine without aura and 18 age-matched controls by measuring event-related potentials (ERPs) and reaction times (RTs) during an acoustic oddball paradigm. Results showed that N100 amplitude evoked by frequent stimuli was significantly smaller in patients compared with controls. Habituation of target P300 amplitude was observed in patients but not in controls. Mean RTs were equivalent in the two groups, but migraine children made more errors than controls.

Influence of impulsiveness on emotional modulation of response inhibition: An ERP study

OBJECTIVE To examine how impulsiveness influences the emotional modulation of behavioral and neural correlates of response inhibition. METHODS Twenty-nine healthy individuals scoring high (HI, N=16) or low (LI, N=13) on motor impulsiveness performed an emotional Go/Nogo task, including the presentation of pleasant, neutral and unpleasant pictures. Behavioral [reaction times (RTs), accuracy to Go and Nogo trials] and neural (Nogo-N2 and Nogo-P3) correlates of response inhibition were compared between HI and LI groups. RESULTS Larger Nogo-P3 was found for emotional than neutral stimuli in HI relative to LI group. Faster RTs to Go stimuli and lower accuracy to Nogo stimuli were correlated with larger Nogo-P3 in HI, but not LI, group. No significant interactions between emotion content and impulsiveness for Nogo-N2 and behavioral measures were noted. CONCLUSIONS Impulsiveness influences the emotional modulation of response inhibition by potentiating the response tendencies evoked by the emotional stimuli. Accordingly, high impulsive individuals may need an increased and/or more effortful response inhibition in order to counteract the prepotent tendency to respond elicited by the combination of high trait impulsiveness and high emotional arousal. SIGNIFICANCE The present study suggests the importance to examine how pathological impulsiveness may interact with emotional arousal in modulating response inhibition.

Neurofeedback Training for Tourette Syndrome: An Uncontrolled Single Case Study

Gilles de la Tourette syndrome (TS) is characterized by motor and vocal tic manifestations, often accompanied by behavioral, cognitive and affective dysfunctions. Electroencephalography of patients with TS has revealed reduced Sensorimotor Rhythm (SMR) and excessive fronto-central Theta activity, that presumably underlie motor and cognitive disturbances in TS. Some evidence exists that neurofeedback (NFB) training aimed at enhancing SMR amplitude is effective for reducing tics. The present report is an uncontrolled single case study where a NFB training protocol, involving combined SMR uptraining/Theta downtraining was delivered to a 17-year-old male with TS. After sixteen SMR-Theta sessions, six additional sessions were administered with SMR uptraining alone. SMR increase was better obtained when SMR uptraining was administered alone, whereas Theta decrease was observed after both trainings. The patient showed a reduction of tics and affective symptoms, and improvement of cognitive performance after both trainings. Overall, these findings suggest that Theta decrease might account for some clinical effects seen in conjunction with SMR uptraining. Future studies should clarify the feasibility of NFB protocols for patients with TS beyond SMR uptraining alone.

Electromagnetic indication of hypervigilant responses to emotional stimuli in blood-injection-injury fear

Blood phobia differs from other phobias and anxiety disorders in that no attentional bias for blood-related stimuli has been consistently observed. The present study aimed at clarifying this characteristic by investigating electromagnetic brain activity to blood-related and -unrelated pictures in high blood-fearful and non-fearful individuals. Relative to non-fearful controls, high blood-fearful subjects displayed more intense occipito-parietal activation 190-250ms after picture onset, which was interpreted as non-specifically enhanced sensory encoding of visual stimuli. Blood-related stimuli did not elicit different activity patterns in high blood-fearful subjects and controls, supporting the hypothesis that non-specific hypervigilance does not provide a basis for subsequent, specifically enhanced processing of fear-related contents.

Assessment of cognitive functions in individuals with post-traumatic symptoms after work-related accidents.

The investigation of cognitive functions in individuals who developed post-traumatic symptoms after occupational accidents has been overlooked in the relevant literature. The present study was aimed at assessing attention, memory and executive functions in individuals with post-traumatic symptoms after a workplace accident. Moreover, possible presence of emotional interference from trauma-related cues on attentional performance was evaluated. Results showed that injured workers exhibited deficits in perceptual-psychomotor skills, executive functions, attention and concentration abilities, and memory as compared with healthy controls. With regards to emotional interference on attention, injured workers were found to perform significantly worse than controls specifically when exposed to trauma-related pictures. Overall, these findings suggest that post-traumatic symptoms following a workplace accident are associated with several cognitive and emotional dysfunctions, that should be carefully evaluated to help reduce the frequency and the adverse consequences of occupational accidents.