Francisco Román

Emotional Response in Patients With Frontal Brain Damage: Effects of Affective Valence and Information Content

The authors investigated the role of the frontal lobes in the emotional response in 19 patients with brain damage and 23 control subjects. They studied the modulation of the startle blink reflex by affective pictures, and other autonomic responses. Patients showed a dissociation between the startle reflex and the affective valence ratings of the pictures, as a result of a low inhibition of the startle reflex by pleasant pictures. Pictures elicited lower skin conductance responses (SCRs) in patients than in controls, whereas the groups did not differ in the SCRs prompted by less significant acoustic stimuli. The findings point to the frontal lobe as a structure involved in the emotional response and in the physiological emotional arousal related to the complexity of the stimuli.

Sex differences and the asymmetry of specific and non-specific electrodermal responses

Phasic electrodermal conductance responses were bilaterally recorded from 30 subjects (15 males and 15 females). After a 5-min adaptation period subjects were presented with two series of ten 80-dB tones each, with a 4-min rest period between the two series. Data from sinistrals, ambidextrous, and from subjects with familial sinistrality were excluded from statistical analysis. Males displayed more asymmetry between hands both in their non-specific and specific responses, with larger skin conductance responses on the left hand. Females showed a less marked asymmetry, with larger skin conductance responses on the right hand. Similar results were found in skin conductance levels. It was concluded that sex differences are an important variable in the study of electrodermal asymmetry.

The Effect of Content and Physical Properties of Affective Pictures on Emotional Responses

The aim of this research was to study the influence of both the emotional content and the physical characteristics of affective stimuli on the psychophysiological, behavioral and cognitive indexes of the emotional response. We selected 54 pictures from the IAPS, depicting unpleasant, neutral, and pleasant contents, and used two picture sizes as experimental conditions (120 x 90 cm and 52 x 42 cm). Sixty-one subjects were randomly assigned to each experimental condition. We recorded the startle blink reflex, skin conductance response, heart rate, free viewing time, and picture valence and arousal ratings. In line with previous research (e.g., Bradley, Codispoti, Cuthbert, and Lang, 2001), our data showed an effect of the affective content on all the measurements recorded. Importantly, effects of the size of the affective pictures on emotional responses were not found, indicating that the emotional content is more important than the formal properties of the stimuli in evoking the emotional response.

Electrodermal activity, hormonal levels and subjective experience during the menstrual cycle☆

Changes in electrodermal activity and subjective experience were studied during the menstrual cycle. Sixty-two women, grouped into menstrual, follicular, ovulatory, luteal and premenstrual phases, were presented with 15, 4-s, 80-dB, 1000-Hz tones. Psychological states and psychosomatic symptoms were tested with Spielbergers State-Trait Anxiety Inventory and a self-report questionnaire. Two estimation procedures of the hormonal phases were used: one based on the onset of menses and cycle length, and another on the basal body temperature. Subjects were grouped into low or high levels of luteinizing hormone, follicle-stimulating hormone and progesterone. There were significant increases in nonspecific response frequency, skin conductance response magnitude, skin conductance level, and a decrease in habituation rate at the ovulatory phase in comparison with luteal and premenstrual phases. No changes between the cycle phases were found in subjective experience. High follicle-stimulating hormone levels were associated with slower habituation rates and low trait-anxiety. The relationship between arousal changes and subjective experience in menstrual cycle is discussed.

Psychophysiological, behavioral, and cognitive indices of the emotional response: a factor-analytic study

Previous research on the components of the emotional response employing factor analytic studies has yielded a two-factor structure (Lang, Greenwald, Bradley, & Hamm, 1993; Cuthbert, Schupp, Bradley, Birbaumer, & Lang, 2000). However, the startle blink reflex, a widely employed measure of the emotional response, has not been considered to date. We decided to include two parameters of the startle reflex (magnitude and latency) in order to explore further how this response fits into the two-factor model of emotion. We recorded the acoustic startle blink response, skin conductance response, heart rate, free viewing time, and picture valence and arousal ratings of 45 subjects while viewing 54 pictures from the International Affective Picture System (IAPS; 18 unpleasant, 18 neutral, and 18 pleasant). Factorizations of all measures gave a two-factor solution (valence and arousal) that accounted for 70% of the variance. Although some measurements, including heart rate change, did not behave as predicted, our results reinforce the two-dimension model of the emotion, and show that startle fits into the model.

Electrodermal activity in menstrual cycle phases: A comparison of within- and between-subjects designs.

Electrodermal activity (EDA) changes in menstrual cycle were studied in two experiments. In both experiments subjects were presented with 16 80-dB tones; 15 tones were 4 s, 1000 Hz, and the last one - change trial - was a 6-s, 3000-Hz tone. In Expt. 1, a within-subjects design was employed, and 15 women were studied throughout a complete menstrual cycle. No significant changes in EDA associated with menstrual cycle phases were found, but significant decreases in electrodermal responsiveness during experimental sessions in EDA parameters were observed. In Expt. 2, with a between-subjects design, 56 women were divided in menstrual (n = 10), follicular (n = 12), ovulatory (n = 14), luteal (n = 13) and premenstrual (n = 7) groups, according to the cycle phase in which the subject was at the time of recording. At the ovulatory phase there were significant increases in skin conductance response (SCR) magnitude, skin conductance level, SCR habituation rate, and SCR amplitude to stimulus change, in relation to menstrual, luteal, and premenstrual phases. The discrepancies in the EDA data coming from the two experiments may be explained by practice effects appearing in Expt. 1.

Sex differences, activation level, and bilateral electrodermal activity

The effects of the activation level and subject’s sex on bilateral skin conductance measures were studied. Thirty right-handed subjects (15 males and 15 females) were exposed to three types of stimulus conditions: rest-period, verbal task and spatial task. Results showed that no relationship was observed between EDA asymmetry and the increase in the activation level induced by the verbal and the spatial tasks. Males showed both higher SCRs and greater frequency of responses on the left than on the right hand. The direction of electrodermal asymmetry remained constant regardless of the stimulus conditions. It was concluded that sex differences are important in the study of EDA asymmetry and that this asymmetry appeared to depend on peripheral variations.

Sex and menstrual cycle differences in the habituation and spontaneous recovery of the electrodermal orienting reaction

Abstract Sex and menstrual cycle differences have been widely observed in electrodermal activity. The aim of this study was to investigate these differences in the electrodermal orienting reaction employing a habituation-spontaneous recovery procedure. According to previous research it was predicted that men and preovulatory women should show higher electrodermal responses, higher skin conductance levels, and slower habituation rates. Thirty-two subjects (16 males and 16 females) were presented with two series of tones, 10 in the first series and eight in the second, with a 4-min rest period between the two series. Half of the subjects received the same 5-sec tone (80 dB, 1000 Hz) in each presentation while the other half received 80-dB, 5-sec tones which varied randomly in frequency (100, 500, 1000 Hz). Women were divided into two groups; preovulatory ( n = 7) and postovulatory ( n = 8) according to their answers to a retrospective questionnaire. The mean response amplitude was higher in the group of males, who habituated later than females. Postovulatory women showed lower orienting reactions in the first series, and habituated faster than did preovulatory women in the two series. There were neither significant differences between males and females, nor between preovulatory and postovulatory women in tonic conductance levels. These results support the existence of greater electrodermal reactivity in males and in preovulatory women.

Neuropsychological deficits in a child with a left penetrating brain injury.

This case study reports neuropsychological and structural magnetic resonance (MRI) studies of a 10-year-old girl with a left hemisphere lesion, caused by an underwater fishing harpoon penetrating her head when she was 6 years old. The patient showed a marked deficit in the acquisition of reading, writing and arithmetic, as well as an attentional deficit. Magnetic resonance images revealed left cortical lesions in the orbital region and the gyrus angularis, as well as in the caudate and putamen nuclei and longitudinal inferior fascicle. Neuropsychological assessment showed frontal and parietal lobe dysfunctions consistent with the lesional data. The structural data explain the neuropsychological impairment and suggest that, although the left lesion was early and relatively small, plasticity was incomplete.

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.