Juan P. Sánchez-Navarro

Altered associative learning and emotional decision making in fibromyalgia

OBJECTIVE The present study examines the possibility that a chronic pain condition, such as fibromyalgia, was associated with deficits in decision making and associative learning. METHODS Fifteen patients with fibromyalgia (aged 42-59 years) and 15 healthy controls (aged 39-61 years) participated in the experiment. Subjects completed anxiety (STAI) and depression (BDI) questionnaires, as well as standardized neuropsychological tests (Stroop and WAIS subscales). In addition, an emotional decision-making task (Iowa Gambling Task) and a conditional associative learning task (CALT) were administered to all participants. RESULTS Results indicated that fibromyalgia had a poorer performance than healthy controls in both tasks, showing more perseveration errors in the learning task, and more disadvantageous decisions, as well as a more random behavior in the gambling task. Moreover, we observed that poor performance on the associative learning task was mediated by depression, whereas performance on the gambling task was not influenced by depression. No group differences were found on the standardized neuropsychological tests. CONCLUSION These findings indicate that pain and depressive symptoms in fibromyalgia might lead to significant deficits in emotionally charged cognitive tasks. Furthermore, it suggests that chronic pain might impose a high cost on executive control, undermining mainly affective processes involved in learning, memory, attention, and decision-making.

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.

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.

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.

Salivary alpha-amylase changes promoted by sustained exposure to affective pictures

We studied the changes in salivary alpha-amylase (sAA) and other psychophysiological indices (heart rate, skin conductance, and corrugator supercilii activity) elicited by sustained exposure to affective pictures. Thirty-nine subjects viewed five blocks of pictures depicting mutilations, human attack, neutral scenes, sport/adventure, and erotica. Each block comprised 12 pictures of the same content. Saliva samples were collected before and after each block of pictures. The results showed that mutilation pictures promoted the greatest increase in sAA activity and output, as well as greater corrugator supercilii activity than pleasant pictures. Skin conductance response did not differ among high arousal picture contents. Changes in sAA varied with the affective valence but not with the arousal ratings of the pictures. Our results point to sAA as an index directly related to the unpleasantness elicited by sustained exposure to affective stimuli.

Alterations of attention and emotional processing following childhood-onset damage to the prefrontal cortex.

The prefrontal cortex (PFC), especially the medial sector, plays a crucial role in emotional processing. Damage to this region results in impaired processing of emotional information, perhaps attributable to an inability to initiate and maintain attention toward emotional materials, a process that is normally automatic. Childhood onset damage to the PFC impairs emotional processing more than adult-onset PFC damage. The aim of this work was to study the involvement of the PFC in attention to emotional stimuli, and to explore how age at lesion onset affects this involvement. To address these issues, we studied both the emotional and attentional modulation of the startle reflex. Our sample was composed of 4 patients with childhood-onset PFC damage, 6 patients with adult-onset PFC damage, and 10 healthy comparison participants. Subjects viewed 54 affective pictures; acoustic startle probes were presented at 300 ms after picture onset in 18 pictures (as an index of attentional modulation) and at 3,800 ms after picture onset in 18 pictures (as an index of emotional modulation). Childhood-onset PFC patients did not show attentional or emotional modulation of the response, in contrast to adult-onset PFC damage and comparison participants. Early onset damage to the PFC results, therefore, in more severe dysfunction in the processing of affective stimuli than adult-onset PFC damage, perhaps reflecting limited plasticity in the neural systems that support these processes.

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.

Preattentive processing of feared stimuli in blood-injection-injury fearful subjects.

This research aimed to study the defence responses of blood-injection-injury (BII) fearful subjects elicited by the preattentive processing of their feared objects and by an abrupt acoustic stimulus. We selected 21 BII fearful subjects and 25 non-fearful controls from an initial sample of 128 women, according to their scores on the Fear Survey Scale (damage subscale) and the Mutilation Questionnaire. Subjects were exposed to a burst of white noise to promote a defence response, and to 48 pictures, depicting mutilations, as well as other affective contents, displayed through a backward masking procedure. Heart rate (HR), skin conductance response (SCR) and corrugator supercilii activity were continuously recorded throughout the task. Both groups showed similar SCRs, EMG activity and cardiac defence responses to the acoustic stimulus, though fearful subjects showed greater initial HR deceleration than controls. While BII fearful subjects displayed the usual defence response when exposed to a non-feared threatening stimulus, the preattentive processing of the pictures did not reveal autonomic differences between fearful subjects and controls. Mutilation pictures, however, evoked the greatest EMG activity, but only in the fearful group. These data further extend previous research on conscious perception of blood-related stimuli in BII fearful subjects, by showing a failure to recruit autonomic defence responses when blood-related pictures appear outside of conscious awareness.

Effects of social and affective content on exogenous attention as revealed by event-related potentials

ABSTRACT The social content of affective stimuli has been proposed as having an influence on cognitive processing and behaviour. This research was aimed, therefore, at studying whether automatic exogenous attention demanded by affective pictures was related to their social value. We hypothesised that affective social pictures would capture attention to a greater extent than non-social affective stimuli. For this purpose, we recorded event-related potentials in a sample of 24 participants engaged in a digit categorisation task. Distracters were affective pictures varying in social content, in addition to affective valence and arousal, which appeared in the background during the task. Our data revealed that pictures depicting high social content captured greater automatic attention than other pictures, as reflected by the greater amplitude and shorter latency of anterior P2, and anterior and posterior N2 components of the ERPs. In addition, social content also provoked greater allocation of processing resources as manifested by P3 amplitude, likely related to the high arousal they elicited. These results extend data from previous research by showing the relevance of the social value of the affective stimuli on automatic attentional processing.