The contributions of the amygdala, orbital frontal cortex and hippocampal formation to primate social cognition

Deficits in social cognition are prominent symptoms of many human psychiatric disorders, but the origin of such deficits remains largely unknown. To further current knowledge regarding the neural network mediating social cognition, the present research program investigated the individual contributions of two temporal lobe structures, the amygdala and hippocampal formation, and one frontal lobe region, the orbital frontal cortex (Areas 11 and 13), to primate social cognition. Based on previous research, we hypothesized that the amygdala, hippocampal formation and orbital frontal cortex contribute significantly to the formation of new social relationships, but less to the maintenance of familiar ones. ^ Thirty-six male rhesus macaques (Macaca mulatta) served as subjects, and were divided into four experimental groups: Neurotoxic amygdala lesion (A-ibo, n = 9), neurotoxic or aspiration orbital frontal cortex lesion (O, n = 9), neurotoxic hippocampal formation lesion (H-ibo, n = 9) or sham-operated control (C, n = 9). Six social groups (tetrads) were created, each containing one member from each experimental group. The effect of lesion on established social relationships was assessed during pre- and post-surgical unrestrained social interactions, whereas the effect of lesion on the formation of new relationships was assessed during an additional phase of post-surgical testing with shuffled tetrad membership. Results indicated that these three neural structures each contribute significantly to both the formation and maintenance of social relationships. Furthermore, the amygdala appears to primarily mediate normal responses to threatening social signals, whereas the orbital frontal cortex plays a more global role in social cognition by mediating responses to both threatening and affiliative social signals. By contrast, the hippocampal formation seems to contribute to social cognition indirectly by providing access to previous experience during social judgments. ^ These conclusions were further investigated with three experiments that measured behavioral and physiological (stress hormone) reactivity to threatening stimuli, and three additional experiments that measured subjects' ability to flexibly alter behavioral responses depending on the incentive value of a food reinforcer. Data from these six experiments further confirmed and strengthened the three conclusions originating from the social behavior experiments and, when combined with the current literature, helped to formulate a simple, but testable, theoretical model of primate social cognition. ^

Effects of early and late lesion of orbital frontal cortex on visual processing of faces in rhesus macaques (Macaca mulatta)

Many mental disorders disrupt social skills, yet few studies have examined how the brain processes social information. Functional neuroimaging, neuroconnectivity and electrophysiological studies suggest that orbital frontal cortex plays important roles in social cognition, including the analysis of information from faces, which are important cues in social interactions. Studies in humans and non-human primates show that damage to orbital frontal cortex produces social behavior impairments, including abnormal aggression, but these studies have failed to determine whether damage to this area impairs face processing. In addition, it is not known whether damage early in life is more detrimental than damage in adulthood. This study examined whether orbital frontal cortex is necessary for the discrimination of face identity and facial expressions, and for appropriate behavioral responses to aggressive (threatening) facial expressions. Rhesus monkeys (Macaca mulatta) received selective lesions of orbital frontal cortex as newborns or adults. As adults, these animals were compared with sham-operated controls on their ability to discriminate between faces of individual monkeys and between different facial expressions of emotion. A passive visual paired-comparison task with standardized rhesus monkey face stimuli was designed and used to assess discrimination. In addition, looking behavior toward aggressive expressions was assessed and compared with that of normal control animals. The results showed that lesion of orbital frontal cortex (1) may impair discrimination between faces of individual monkeys, (2) does not impair facial expression discrimination, and (3) changes the amount of time spent looking at aggressive (threatening) facial expressions depending on the context. The effects of early and late lesions did not differ. Thus, orbital frontal cortex appears to be part of the neural circuitry for recognizing individuals and for modulating the response to aggression in faces, and the plasticity of the immature brain does not allow for recovery of these functions when the damage occurs early in life. This study opens new avenues for the assessment of rhesus monkey face processing and the neural basis of social cognition, and allows a better understanding of the nature of the neuropathology in patients with mental disorders that disrupt social behavior, such as autism. ^

The illness experiences of African Americans residing in an inner city community, Houston, Texas

This dissertation documents health and illness in the context of daily life circumstances and structural conditions faced by African American families living in Clover Heights (pseudonym), an inner city public housing project in the Third Ward, Houston, Texas. Drawing from Kleinman's (1980) model of culturally defined health care systems and using the holistic-content approach to narrative analysis (Lieblich, Tuval- Mashiach, & Zilber, 1998) the purpose of this research was to explore the ways in which social and health policy, economic mobility, the inner city environment, and cultural beliefs intertwined with African American families' health related ideas, behaviors, and practices. I recruited six families using a convenience sampling method (Schensul, Schensul, & LeCompte, 1999) and followed them for fourteen months (2010–2011). Family was defined as a household unit, or those living in the same residence, short or long-term. Single, African American women ranging in age from 29–80 years headed all families. All but one family included children or grandchildren 18 years of age and younger, or children or other relative 18 years of age and older. I also recruited six residents with who I became acquainted over the course of the project. I collected data using traditional ethnographic methods including participant-observation, archive review, field notes, mapping, free-listing, in-depth interviews, and life history interviews. ^ Doing ethnography afforded the families who participated in this project the freedom to construct their own experiences of health and illness. My role centered on listening to, learning from, and interpreting participants' narratives, exploring similarities and differences within and across families' experiences. As the research progressed, a pattern concerning diagnosis and pharmacotherapy for children's behavioral and emotional problems, particularly attention-deficit hyperactivity disorder (ADHD) and pediatric bipolar disorder (PBD), emerged from my formal interactions with participants and my informal interactions with residents. The findings presented in this dissertation document this pattern, focusing on how mothers and families interpreted, organized, and ascribed meaning to their experiences of ADHD and PBD. ^ In the first manuscript presented here, I documented three mothers' narrative constructions of a child's diagnosis with and pharmacotherapy for ADHD or PBD. Using Gergen's (1997) relational perspective I argued that mothers' knowledge and experiences of ADHD and PBD were not individually constructed, but were linguistically and discursively constituted through various social interactions and relationships, including family, spirituality and faith, community norms, and expert systems of knowledge. Mothers' narratives revealed the complexity of children's behavioral and emotional problems, the daily trials of living through these problems, how they coped with adversity and developed survival strategies, and how they interacted with various institutional authorities involved in evaluating, diagnosing, and encouraging pharmaceutical intervention for children's behavior. The findings highlight the ways in which mothers' social interactions and relationships introduced a scientific language and discourse for explaining children's behavior as mental illness, the discordances between expert systems of knowledge and mothers' understandings, and how discordances reflected mothers' ‘microsources of power’ for producing their own stories and experiences. ^ In the second manuscript presented here, I documented the ways in which structural factors, including gender, race/ethnicity, and socioeconomic status, coupled with a unique cultural and social standpoint (Collins, 1990/2009) influenced the strategies this group of African American mothers employed to understand and respond to ADHD or PBD. The most salient themes related to mother-child relationships coalesced around mothers' beliefs about the etiology of ADHD and PBD, ‘conceptualizing responsibility,’ and ‘protection-survival.’ The findings suggest that even though mothers' strategies varied, they were in pursuit of a common goal. Mothers' challenged the status quo, addressing children's behavioral and emotional problems in the ways that made the most sense to them, specifically protecting their children from further marginalization in society more so than believing these were the best options for their children.^

Knowledge, beliefs, risk behaviors, and social skills for HIV/STD prevention in junior college students (grades 11--12) in Bombay, India

1230 year 11 and 12 college students, modal age 16 and 17, in three colleges in Bombay, India, were studied on sexual behaviors or risk of sexual behaviors, beliefs about sex, HIV/STD knowledge, perceived norms regarding sexual behaviors, and the relationships between social skills/anxieties in HIV/STD prevention and actual and anticipated sexual behaviors. A quantitative questionnaire examining HIV/STD risk behaviors, knowledge, attitudes and beliefs, and the AIDS Social Assertiveness Scale (ASAS) were administered to these 1230 college students. Data indicated that 8% of males and 1% of females had had sexual experience, but over one third were not sure at all of being able to abstain from sexual activity with either steady or casual partners. Perceived norms were slanted toward sexual abstinence for the majority of the sample. Knowledge of protective effects of condoms was high, although half of those who had had sex did not use condoms. Logistic regression showed knowledge was higher among males, those who believed it was OK to have sex with a steady partner and that they should not wait until they were older, those who believed that condoms should be used even if the partner is known, and those who believed it was acceptable to have multiple partners. Gender differences in sexual activity and beliefs about sexual activity showed males were less likely to believe in abstaining from sexual activity. The 5 scales of the ASAS were scored and compared on ANOVA on: those who had had sexual experience (HS), those who anticipated being unable to refuse sex (AS), and those who did not anticipate problems in refusing sex (DS). Those in the AS group had greater anxieties about refusing sexual or other risk behaviors than HS and DS groups. There were greater anxieties about dealing with condoms in the AS and DS groups compared with the HS group. Confiding sexual or HIV/STD-related problems to significant others was more anxiety-provoking for the AS group compared with the HS group, and the AS group were more anxious about interactions with people with HIV. Factor analysis produced the same 5 factors as those found in previous studies. Of these, condom interactions and confiding in significant others were most anxiety provoking, and condom interactions most variable based on demographic and attitudinal factors.^ This age group is appropriate for HIV/STD reduction education given the low rate of sexual activity but despite knowledge of the importance of condom use, social skills to apply this knowledge are lacking. Social skills training in sexual negotiations, condom negotiations, and confiding HIV/STD-related concerns to significant others should reduce the risks of Indian college students having unwanted or unprotected sex. ^