Barry D. Berger

Characterization of Empathy Deficits following Prefrontal Brain Damage: The Role of the Right Ventromedial Prefrontal Cortex

Impaired empathic response has been described in patients following brain injury, suggesting that empathy may be a fundamental aspect of the social behavior disturbed by brain damage. However, the neuroanatomical basis of impaired empathy has not been studied in detail. The empathic response of patients with localized lesions in the prefrontal cortex (n = 25) was compared to responses of patients with posterior (n = 17) and healthy control subjects (n = 19). To examine the cognitive processes that underlie the empathic ability, the relationships between empathy scores and the performance on tasks that assess processes of cognitive flexibility, affect recognition, and theory of mind (TOM) were also examined. Patients with prefrontal lesions, particularly when their damage included the ventromedial prefrontal cortex, were significantly impaired in empathy as compared to patients with posterior lesions and healthy controls. However, among patients with posterior lesions, those with damage to the right hemisphere were impaired, whereas those with left posterior lesions displayed empathy levels similar to healthy controls. Seven of nine patients with the most profound empathy deficit had a right ventromedial lesion. A differential pattern regarding the relationships between empathy and cognitive performance was also found: Whereas among patients with dorsolateral prefrontal damage empathy was related to cognitive flexibility but not to TOM and affect recognition, empathy scores in patients with ventromedial lesions were related to TOM but not to cognitive flexibility. Our findings suggest that prefrontal structures play an important part in a network mediating the empathic response and specifically that the right ventromedial cortex has a unique role in integrating cognition and affect to produce the empathic response.

Impairment in Cognitive and Affective Empathy in Patients with Brain Lesions: Anatomical and Cognitive Correlates

ABSTRACT The present study was designed to examine the degree of impairment in cognitive and affective empathy among patients with focal brain lesions, and the contribution of specific cognitive abilities (such as cognitive flexibility and processing of emotional information), to empathy. The cognitive and affective empathic response of patients with localized prefrontal lesions (n=36) was compared to responses of patients with parietal lesions (n=15) and healthy control subjects (n=19). Results indicate that patients with prefrontal lesions (especially those with lesions involving the orbitoprefrontal and medial regions) were significantly impaired in both cognitive and affective empathy as compared to parietal patients and healthy controls. When the damage was restricted to the prefrontal cortex, either left- or right-hemisphere lesions resulted in impaired empathy. However, when the lesion involved the right hemisphere, patients with parietal lesions were also impaired. The pattern of relationships between cognitive performance and empathy suggested dissociation between the cognitive correlates of affective and cognitive empathy.

Animal-Assisted Therapy Ameliorates Anhedonia in Schizophrenia Patients

Background: Anhedonia, a component of the negative symptom dimension and a core phenomenon in schizophrenia, is associated with poor social functioning and is resistant to treatment. We tested the hypothesis that animal-assisted therapy (AAT) may improve anhedonia. Objective: To compare the effect of psychosocial treatment sessions in which a dog was an active participant (AAT) with comparable sessions without a dog, using a controlled protocol. Method: The hedonic tone of 10 chronic schizophrenia patients who participated in 10 weekly interactive sessions of AAT was compared to a control group treated without animal assistance. The hedonic tone was measured with the Snaith-Hamilton Pleasure Scale. Subjective quality of life variables and clinical symptoms were also assessed. Results: The AAT group showed a significant improvement in the hedonic tone compared to controls. They also showed an improvement in the use of leisure time and a trend towards improvement in motivation. Conclusion: AAT may contribute to the psychosocial rehabilitation and quality of life of chronic schizophrenia patients.

When two become one: The role of oxytocin in interpersonal coordination and cooperation

Cooperation involves intentional coordinated acts performed to achieve potentially positive outcomes. Here we present a novel explanatory model of cooperation, which focuses on the role of the oxytocinergic system in promoting interpersonal coordination and synchrony. Cooperation was assessed using a novel computerized drawing task that may be performed individually or cooperatively by two participants who coordinate their actions. Using a within-subject crossover design, 42 participants performed the task alone and with a partner following the administration of placebo and oxytocin 1 week apart. The data indicate that following placebo administration, participants performed better alone than in pairs. Yet, the administration of oxytocin improved paired performance up to the level of individual performance. This effect depended on the personality traits of cooperativeness or competitiveness. It is concluded that oxytocin may play a key role in enhancing social synchrony and coordination of behaviors required for cooperation.

The Antiaggressive Action of Combined Haloperidol-Propranolol Treatment in Schizophrenia

Psychopharmacological interventions for managing aggression in schizophrenia have thus far yielded inconsistent results. This study evaluates the antiaggressive efficacy of combined haloperidol-propranolol treatment. Thirty-four newly admitted schizophrenic patients were studied in a controlled double-blind trial. Following a 3-day drug-free period and 7 days of haloperidol treatment, patients were randomly assigned to receive either haloperidol-propranolol or haloperidol-placebo for eight consecutive weeks. Doses of medications were adjusted as necessary; biperiden was administered if required. Rating scales were applied to assess aggression, anger, psychosis, depression, anxiety and extrapyramidal symptoms. The mean daily dose of haloperidol was 21 mg (SD = 6.4) in the research group and 29 mg (SD = 6.9) in the controls. Mean and maximal daily doses of propranolol were 159 mg (SD = 61) and 192 mg (SD = 83), and of placebo, 145 mg (SD = 50) and 180 mg (SD = 70), respectively. Compared with the controls, ...

Resource loss and posttraumatic responses in Bedouin members of the Israeli Defense Forces

This study examined the impact of exposure to traumatizing events in an ethnic minority group of Bedouin members of the Israel Defense Forces (N = 317). Guided by the conservation of resources (COR) theory (Hobfoll, 1988), the authors hypothesized that loss of resources would mediate the relationship between trauma and posttraumatic responses. We found that loss of personal resources (e.g., self-esteem, self-mastery) was the best predictor of psychological distress among traumatized Bedouin servicemen. Our findings suggest the significance of personal resources within collectivist communities in coping with trauma and maintaining resilience. This study contributes to the understanding of the ethnocultural aspects of trauma and the potential interventions that may be tailored for minority groups.

Cooperative social coordination and aggression: Sex and strain differences in the effects of housing on gonadectomized rats with hormone replacement

Laboratory rats were used to investigate sex and strain differences in the effects of aggression on a cooperative behavior in which pairs learned to coordinate shuttling in a rectangular chamber. The level of aggression was manipulated by comparing males and females of the aggressive S3 strain and a less aggressive Sprague-Dawley-derived strain and housing same-sex partners either together or individually (8 groups, n = 7 pairs per group). Hormone levels were stabilized by gonadectomy and daily injections of the appropriate sex hormone. The only serious coordination deficits were in individually housed males, associated with violent fighting and an extreme dominance/subordinance relationship that was not observed in females. All other groups readily learned and performed the coordination with evidence that low and moderate levels of aggression could facilitate coordination by evoking species-typical behaviors that increased proximity, synchrony, and differentiation within pairs. The discussion focused on models of affiliative behavior in the study of aggression and the compatibility between moderate levels of aggression and cooperation.

Pharmacological Aspects of Social Cooperation

At first impression, it may seem paradoxical that a paper on cooperation would be included in a symposium devoted to aggression. Aggression and cooperation are usually depicted as contrasting and unrelated phenomena. Aggression is typically applied to an inherently selfish interaction, whereby one individual gains at the expense of another who loses by virtue of injury, expulsion, or reduced access to a desired resource. In cooperation, the social interaction is usually characterized as positive, involving a joint or collaborative action directed towards obtaining a desired goal for one or both (Hake and Vukelich 1972; Nisbet 1968). This dichotomous approach is supported by a tendency in laboratory research to study aggression or cooperation in isolation from one another. Aggression has been by far the more popular subject. The few studies on cooperation have been aimed at demonstrating whether animals are capable of behaviour meeting the criteria of cooperation. Thus, rats learned to coordinate an exchange of places for feeding without obtaining shock (Daniel 1942), chimpanzees learned a series of food discrimination tasks (Crawford 1941), rhesus monkeys learned to avoid shock by attending to social cues of fear (Miller et al. 1962), and pigeons learned to peck on corresponding keys in near simultaneity (Skinner 1953).

An Animal Model for the Measurement and Manipulation of Problem Solving Ability

Changes in learning, memory, attention, and other cognitive processes often accompany the mood disorders. Indeed, as in schizophrenia, disturbances of thought represent one of the central features of the disease, manifesting itself in a variety of symptoms. However, research on the etiology and treatment of these disorders has focused primarily on the mood characteristics and has more or less neglected the cognitive deficits.