Biomedical subjects

Maurizio Codispoti

Publications and source records attributed to Maurizio Codispoti.

11 recordsLinked to original sources

PubMed2006

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.

Adult↗

PubMed2006

Stimulus novelty and emotion perception: the near absence of habituation in the visual cortex.

In rapid serial visual presentation of pictures, an early event-related brain potential component shows enlarged negativity over occipital regions for emotional pictures compared with neutral pictures. The present study examined whether the processing of emotional target pictures varies as a function of stimulus repetition. Accordingly, pictures of erotica, neutral contents, and mutilations were repeatedly presented (90 times) while the electroencephalogram was recorded with a 129 dense sensor array. As in previous studies, emotional pictures were associated with a larger posterior negativity than neutral pictures. Furthermore, differential emotion processing did not vary as a function of stimulus repetition and was similarly expressed across blocks of picture presentation. These findings suggest the near absence of habituation in differential emotion processing during perceptual processing.

Adult↗

PubMed2006

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.

Adult↗

PubMed2006

Event-related potentials and visual avoidance in blood phobics: is there any attentional bias?

The possible presence of processing biases for threat-relevant information in blood-injection-injury phobia has been largely neglected in the literature. This issue was addressed by recording the late components (P300 and slow waves) of event-related potentials (ERPs) in the context of affective picture perception, as indicators of processing resources allocation. Blood phobics and healthy controls were shown threat-relevant, emotional threat-irrelevant, and neutral pictures. Free viewing time (VT) was measured as an index of voluntary visual avoidance, along with self-reports of pleasantness and arousal. No group differences as a function of picture content emerged for ERPs. Blood phobics spent less time viewing mutilations than did controls, but they did not show a clear-cut visual avoidance. As expected, individuals with phobias rated blood-related pictures as more unpleasant and arousing relative to controls. ERP results are in line with the limited behavioral data in the literature in demonstrating that blood phobics do not show an attentional bias toward threat-relevant stimuli.

Adult↗

PubMed2006

Implicit and explicit categorization of natural scenes.

Event-related potential (ERP) studies have consistently found that emotionally arousing (pleasant and unpleasant) pictures elicit a larger late positive potential (LPP) than neutral pictures in a window from 400 to 800 ms after picture onset. In addition, an early ERP component has been reported to vary with emotional arousal in a window from about 150 to 300 ms with affective, compared to neutral stimuli, prompting significantly less positivity over occipito-temporal sites. Similar early and late ERP components have been found in explicit categorization tasks, suggesting that selective attention to target features results in similar cortical changes. Several studies have shown that the affective modulation of the LPP persisted even when the same pictures are repeated several times, when they are presented as distractors, or when participants are engaged in a competing task. These results indicate that categorization of affective stimuli is an obligatory process. On the other hand, perceptual factors (e.g., stimulus size) seem to affect the early ERP component but not the affective modulation of the LPP. Although early and late ERP components vary with stimulus relevance, given that they are differentially affected by stimulus and task manipulations, they appear to index different facets of picture processing.

Attention↗

PubMed2006

When does size not matter? Effects of stimulus size on affective modulation.

Motivationally relevant stimuli have been shown to receive prioritized processing compared to neutral stimuli at distinct processing stages. This effect has been related to the evolutionary importance of rapidly detecting dangers and potential rewards and has been shown to be modulated by the distance between an organism and a faced stimulus. Similarly, recent studies showed degrees of emotional modulation of autonomic responses and subjective arousal ratings depending on stimulus size. In the present study, affective modulation of pictures presented in different sizes was investigated by measuring event-related potentials during a two-choice categorization task. Results showed significant emotional modulation across all sizes at both earlier and later stages of processing. Moreover, affective modulation of earlier processes was reduced in smaller compared to larger sizes, whereas no changes in affective modulation were observed at later stages.

Adult↗

PubMed2006

A multi-process account of startle modulation during affective perception.

Modulation of the startle reflex by sensory, attentional, and emotional processes was explored by presenting acoustic startle probes at various delays following picture onset. Within 500 ms of onset, blinks were first greatly facilitated and then inhibited, indicating prepulse facilitation and prepulse inhibition that did not vary with affect. Attention allocation to the picture continued across the viewing interval and was most pronounced for emotional pictures, as determined by attenuation of the P3 component to the startle probe. Startle potentiation for unpleasant pictures occurred later in the viewing interval and was strongest for highly arousing pictures. Taken together, the startle reflex during picture viewing is modulated by sequential and sometimes concurrent processes of prepulse facilitation, prepulse inhibition, attentional inhibition, and affective modulation, with reflex magnitude reflecting the net effect of multiple processes.

Adult↗

PubMed2005

Selectively attending to natural scenes after alcohol consumption: an ERP analysis.

Alcohol effects on cognitive, emotional and behavioral processes have been linked to an impairment of attention. Because attention operates at the level of specific cognitive subsystems, recent studies demonstrated alcohol effects in specific post-perceptual processes such as response selection and working memory. Measuring event-related potentials, the present study focused on perceptual processes by utilizing a categorization task where participants had to decide whether briefly presented images contained an animal or not. Findings demonstrate an early differential ERP activity for target compared to non-target images, which was reduced after alcohol intoxication. Thus, alcohol intoxication had deleterious effects at the perceptual level of processing considered to reflect the interaction of top-down (category-related) and bottom-up (stimulus-driven) processes. In addition, post-perceptual processes were also impaired by alcohol intoxication.

Adult↗

PubMed2005

Facial emotion recognition in trait anxiety.

The study investigated the relationship between recognition of emotional facial expressions and trait anxiety. A nonclinical sample of 19 participants with high-trait anxiety was selected, using the trait version of the State-Trait Anxiety Inventory, and compared with a sample of 20 participants with low-trait anxiety on a facial expression recognition task. Visual stimuli were 42 faces, representing seven emotional expressions: anger, sadness, happiness, fear, surprise, disgust and neutral. Participants had to identify the emotion portrayed by each face. Results showed that participants with high-trait anxiety recognized fear faces significantly better while the two groups did not differ in recognition of other facial expressions.

Adolescent↗

PubMed2003

Psychological distress of conservative and nonconservative uterine surgery: a prospective study.

OBJECTIVE: The aim of the present study is to evaluate the psychological reaction to conization before and after the operation compared to hysterectomy. To study the incidence of psychological stress related to conization, 60 women undergoing conization were compared to 40 women who had undergone hysterectomy. METHOD: Psychological disease was rated in the pre- and postoperative periods using the Symptom Questionnaire (SQ). Each patient was evaluated 2 weeks before the operation, and 3, 6 and 12 months after it. RESULTS: Both the conization and hysterectomy groups showed a significant reduction in anxiety and depression at the 3-, 6- and 12-month follow-ups compared to the preoperative period. Two weeks before surgery, 8 conization patients (19.5%) showed an anxious status, while 10 (24.3%) presented high levels of anxiety and depression. Within hysterectomy patients, the occurrence was respectively of 4 (12.9%) and 10 women (32.2%). Twelve months after surgery, of the women with preoperative depression, only four (9.7%) conization and four (12.9%) hysterectomy patients presented a negative mood status. A similar trend was present for somatic symptoms but only in the conization group, because the hysterectomy patients did not show a reduction in these symptoms from the preoperative to the postoperative period. This result could be related to the surgical menopause due to the bilateral oophoriectomy executed in more than half of the hysterectomy group. CONCLUSION: In general, the results of the present study show that the conservative and nonconservative uterine surgery determines a good psychological prognosis in the short- and long-term postoperative periods.

Adult↗

PubMed2003

Emotional perception and neuroendocrine changes.

The present study was designed to investigate the neuroendocrine modifications during affective states. In particular, we investigate if the pleasantness of the stimuli has a different effect on neuroendocrine responses. To address this issue, we compared the effects of pleasant, neutral, and unpleasant pictures on catecholamine, adrenocorticotrophic hormone (ACTH), cortisol, and prolactin plasma levels. Ten male participants were submitted to three experimental sessions, each on one of the three experimental days, a week apart in a counterbalanced order. Although in the subjective arousal rating, pleasant (erotic pictures) and unpleasant stimuli (pictures of mutilated bodies) receive the same high score, a different neuroendocrine pattern was obtained: unpleasant stimuli elicited a decrease in prolactin concentration and increases in noradrenaline, cortisol, and ACTH levels, whereas pleasant slide set viewing induced an increase in prolactin levels. The results suggest that the neuroendocrine system responds selectively to affective motivationally relevant pictures.

Adrenocorticotropic Hormone↗