Maurizio Codispoti

Emotion and Motivation II: Sex Differences in Picture Processing

Adhering to the view that emotional reactivity is organized in part by underlying motivational states--defensive and appetitive--we investigated sex differences in motivational activation. Mens and womens affective reactions were measured while participants viewed pictures with varied emotional and neutral content. As expected, highly arousing contents of threat, mutilation, and erotica prompted the largest affective reactions in both men and women. Nonetheless, women showed a broad disposition to respond with greater defensive reactivity to aversive pictures, regardless of specific content, whereas increased appetitive activation was apparent for men only when viewing erotica. Biological and sociocultural factors in shaping sex differences in emotional reactivity are considered as possible mediators of sex differences in emotional response.

Selective Visual Attention to Emotion

Visual attention can be voluntarily directed toward stimuli and is attracted by stimuli that are emotionally significant. The present study explored the case when both processes coincide and attention is directed to emotional stimuli. Participants viewed a rapid and continuous stream of high-arousing erotica and mutilation stimuli as well as low-arousing control images. Each of the three stimulus categories served in separate runs as target or nontarget category. Event-related brain potential measures revealed that the interaction of attention and emotion varied for specific processing stages. The effects of attention and emotional significance operated additively during perceptual encoding indexed by negative-going potentials over posterior regions (∼200–350 ms after stimulus onset). In contrast, thought to reflect the process of stimulus evaluation, P3 target effects (∼400–600 ms after stimulus onset) were markedly augmented when erotica and mutilation compared with control stimuli were the focus of attention. Thus, emotion potentiated attention effects specifically during later stages of processing. These findings suggest to specify the interaction of attention and emotion in distinct processing stages.

Repetition and Event-related Potentials: Distinguishing Early and Late Processes in Affective Picture Perception

A repetition paradigm was used to assess the nature of affective modulation of early and late components of the event-related potential (ERP) during picture viewing. High-density ERPs were measured while participants passively viewed affective or neutral pictures that were repeated up to 90 times each. Both ERP components were modulated by emotional arousal, with ERPs elicited when viewing pleasant and unpleasant pictures different than when viewing neutral pictures. On the other hand, repetition had different effects on these two components. The early occipitotemporal component (150300 msec) primarily showed a decrease in amplitude within a block of repetitions that did not differ as a function of picture content. The late centroparietal component (300600 msec) showed a decrease both between and within blocks of repetitions, with neutral pictures eliciting no late positive potential in the final block of the study. The data suggest that the early ERP primarily reflects obligatory perceptual processing that is facilitated by active short-term memory representations, whereas the late ERP reflects increased resource allocation due to the motivational relevance of affective cues.

Affective reactions to briefly presented pictures

Affective reactions to briefly presented pictures were investigated to determine whether fleeting stimuli engage the motivational systems mediating emotional responses. Emotional and neutral pictures were presented for 500 ms; heart rate, skin conductance, corrugator EMG, and the evoked startle reflex were measured. The time course of reflex modulation was similar to that obtained with longer (6 s) presentations, suggesting that picture processing continues in the absence of a sensory stimulus. Affective reactions found with more sustained presentation were also obtained, with more corrugator EMG activity for unpleasant pictures, and greater skin conductance reactivity for emotional pictures. Heart rate modulation, however, appears to rely on the presence of a sensory stimulus. The data also suggest that brief presentations of unpleasant pictures may result in less defensive activation than sustained presentation.

Repetitive picture processing: autonomic and cortical correlates.

Emotionally arousing pictures elicit larger late positive potentials (LPPs) than neutral pictures during passive viewing. Moreover, these cortical responses do not rely on voluntary evaluation of the hedonic content and are relatively unaffected by task demands. In this study, we examined modulation of the late positive potential as it varies with stimulus repetition. Three pictures (pleasant, neutral, unpleasant) were presented up to 60 times each. Although the amplitude of the late positive potential during picture viewing declined with stimulus repetition, affective modulation remained intact. On the other hand, autonomic responses (skin conductance and heart rate change) habituated rapidly with stimulus repetition. These findings suggest that while stimulus detection and categorization, reflected in the LPP, is mandatory, autonomic modulation reflects initial orienting responses that habituate rapidly.

Directed and motivated attention during processing of natural scenes

Visual attention can be voluntarily oriented to detect target stimuli in order to facilitate goal-directed behaviors. Other visual stimuli capture attention because of motivational significance. The aim of the present study was to investigate the relationship between directed and motivated attention using event-related potentials. Affectively engaging pictures were presented either as target stimuli or as nontargets in a categorization task. Results indicated that both task relevance and emotional significance modulated the late positive potential (LPP) over centro-parietal sensors. Effects of directed and motivated attention on the LPP were additive, with the largest centro-parietal positivity found for emotional pictures that were targets of directed attention, and the least for neutral pictures that were nontargets. Taken together, the data provide new information regarding the relationship between motivated and directed attention, and suggest that the LPP reflects the operation of attentional neural circuits that are utilized by both top-down and bottom-up processes.

Adult attachment style and alexithymia

Abstract The focus of the present study was to investigate the relationship between adult attachment behaviour and alexithymia. Adult attachment behaviour and alexithymic characteristics were assessed using questionnaire methods. In a single session, 301 University students completed an Italian version of the Attachment Style Questionnaire (ASQ) and the Italian version of the 20-Item Toronto Alexithymia Scale. Moderate positive correlations were found among TAS total score and several ASQ subscales such as the Discomfort with Closeness (0.35), the Relationships as Secondary (0.38) and the Need for Approval (0.41). On the other hand, TAS total score and the Confidence subscale of the ASQ showed a moderate negative correlation (−0.45). These results provide interesting cues. Possible hypothetical explanations of this association are discussed. Further longitudinal researches are needed to better investigate the relationship between the sociocultural environment, deficiencies in mother–child relationship and the ease of confidence in intimacy in adulthood.

Watching emotional movies: Affective reactions and gender differences

Previous studies have found that unpleasant film clips depicting mutilated bodies or injuries evoke a sustained heart rate deceleration which has been interpreted as reflecting a stimulus-specific aversive response or as increased orienting and attentional processing that varies with stimulus significance. Few studies, however, have examined cardiac changes during the viewing of high arousal pleasant films. To clarify this issue, the present study assessed evaluative, facial and autonomic reactions in both men and women during the viewing of highly arousing pleasant, as well as unpleasant, films. Results indicated a similar skin conductance increase and heart rate deceleration which were greater than those observed during the viewing of a neutral film. Compared to men, women rated both films as less pleasant and rated the unpleasant film as more arousing. The present findings suggest that sustained exposure to pleasant and unpleasant stimuli elicit similar cardiac orienting when stimuli are equated for subjective report of emotional arousal.

The categorization of natural scenes : brain attention networks revealed by dense sensor ERPs

The present study examined cortical indicators of selective attention underlying categorization based on target features in natural scenes. The primary focus was to determine the neural sources associated with the processing of target stimuli containing animals compared to non-target control stimuli. Neural source estimation techniques [current source density (CSD) and L2-minimum norm estimate (L2-MNE)] were used to determine the sources of the potential fields measured from 58 sensor sites. Assuring an excellent signal-to-noise ratio, the categorization task consisted of 2400 trials. Replicating previous findings, target and non-target ERP activity diverged sharply around 150 ms after stimulus onset and the early differential ERP activity appeared as positive deflection over fronto-central sensor sites and as negative deflection over temporo-occipital regions. Both source estimation techniques (CSD and L2-MNE) suggested primary sources of the early differential ERP activity in posterior, visual-associative brain regions and, although less pronounced, revealed the contribution of additional anterior sources. These findings suggest that selective attention to category-relevant features reflects the interactions between prefrontal and inferior temporal cortex during visual processing of natural scenes.

Repetitive exposure: Brain and reflex measures of emotion and attention

Effects of massed repetition on the modulation of the late positive potential elicited during affective picture viewing were investigated in two experiments. Despite a difference in the number of repetitions across studies (from 5 to 30), results were quite similar: The late positive potential continued to be enhanced when participants viewed emotional, compared to neutral, pictures. On the other hand, massed repetition did prompt a reduction in the late positive potential that was most pronounced for emotional pictures. Startle probe P3 amplitude generally increased with repetition, suggesting diminished attention allocation to repeated pictures. The blink reflex, however, continued to be modulated by hedonic valence, despite massive massed repetition. Taken together, the data suggest that the amplitude of the late positive potential during picture viewing reflects both motivational significance and attention allocation.