I’ll be blogging at the 2011 Society for Social Neuroscience conference on Nov 10–11, 2011, for an interdisciplinary audience. I’m excited about this; I’d like to think of the next ten years as a decade of curiosity (to work outside narrow boundaries) and transformation as much as challenge (particularly for the new generation of academics) in which the possibilities and the pitfalls of expanding social and cultural neuroscience research programs are explored.
Err, back to Earth, this morning I decided to read through the poster abstracts and was quickly overwhelmed by the need to cover everything. Below is a sampling of fifteen abstracts that piqued my interest vis-a-vis our edited volume in process and our next conference (“the emerging neuroscience of culture”). Or, better, download the full program here.
Activity of cortical midline structures during two conditions of autobiographical self Authors: Helder F. Araujo, Jonas Kaplan, Hanna Damasio, and Antonio Damasio
Abstract: At each moment, we can access information about our own body, which includes the changes that occur as a consequence of interactions with the world and of functional adjustments within the organism’s interior. Ultimately, many such moments of self-knowledge are recorded in memory and are integrated in a coherent biography (the autobiographical self, Damasio, 1998, 1999, 2010), which amplifies the scope of the self process and can be used, as needed, in conscious social interactions. The neural basis of the autobiographical self has not been fully elucidated, although one of the most consistent findings of studies about self-reference is the involvement of cortical midline structures (CMSs): medial prefrontal, anterior cingulate, and posteromedial. However, most of these studies have targeted a limited domain of autobiographical self: the investigation of personal traits. Here we explore the involvement of CMSs in the domain of factual biography, e.g. facts that compose each person’s identity. In addition, we also study the involvement of CMS in the evaluation of personal traits, a domain often approached in investigations on self-reference. This is an fMRI block design study, in which 19 subjects answered questions about their own traits, about their factual biography, about the traits of an acquaintance and about factual biography of an acquaintance (4 experimental conditions). In each run, each of the conditions (blocks of 24 seconds) is repeated 3 times and separated by a ‘one-back-task’ (also in blocks of 24 seconds). The one-back-task was used as a baseline. There were a total of three runs per study. Preliminary analysis of data suggests that CMSs are involved in processing both self and non-self biographic information. In some regions of CMSs, non-self conditions were even correlated with higher activity levels than did self-related conditions. These results prompt further discussion about the role of CMSs in self-reference.
Damasio AR: Investigating the biology of consciousness. Transactions of the Royal Society (London) 353:1879-1882, 1998.
Damasio AR: The Feeling of What Happens: Body and Emotion in the Making of Consciousness, Harcourt, New York, 1999
Damasio A: Self Comes to Mind: Constructing the Conscious Brain. Pantheon, 2010
Affiliations: Brain and Creativity Institute, University of Southern California, USA; Neuroscience Graduate Program, University of Southern California, USA; Graduate Program in Areas of Basic and Applied Biology, University of Oporto, Portugal
Keywords: self, cortical midline structures
Bounded Empathy: Neural Responses to Outgroup Targets’ (Mis)fortunes
Authors: Mina Cikara and Susan Fiske
Abstract: A cursory reading of the emotion, empathy, and perception–action literatures might leave one with the impression that people spontaneously experience empathy in response to seeing another person in distress. Recent developments in social psychological and cognitive neuroscience research suggest otherwise: People frequently fail to empathize to the same extent with outgroup members as ingroup members. Not all outgroups are equivalent, however. Depending on the target, people may feel not only less empathy but also pleasure (Schadenfreude) in response to outgroup members’ misfortunes. In contrast, there may also be specific outgroups for whom people feel even more empathy than ingroup members when they suffer a misfortune. Furthermore, no intergroup empathy study of which we are aware has assessed empathy for positive events, which demonstrably varies as a function of group membership. The current fMRI study investigates whether mere stereotypes are sufficient to modulate empathic responses to other people’s good and bad fortunes, how these modulations manifest in the brain, and whether these affective and neural responses relate to endorsing harm against different outgroup targets. Participants report that they feel least bad when misfortunes befall envied targets and worst when misfortunes befall pitied targets, as compared with ingroup targets. Participants are also least willing to endorse harming pitied targets, despite pitied targets being outgroup members. However, those participants who exhibit increased activation in functionally defined insula/middle frontal gyrus when viewing pity targets experience positive events not only report feeling worse about those events but also more willing to harm pity targets in a tradeoff scenario. Similarly, increased activation in anatomically defined bilateral anterior insula, in response to positive events, predicts increased willingness to harm envy targets, but decreased willingness to harm ingroup targets, above and beyond self-reported affect in response to the events. Stereotypes’ specific content and not just outgroup membership modulates empathic responses and related behavioral consequences including harm.
Affiliations: MIT, Princeton University
Keywords: empathy, schadendfreude, stereotypes, fMRI
Facial expressions in mice
Authors: Erwin Defensor, Michael Corley, D. Caroline Blanchard, and Robert Blanchard
Abstract: A previous study described a method to measure facial expressions in mice experiencing pain (Langford et al, 2010). The method measured graded changes in the eyes, ears, cheek, nose and vibrissae of the mouse. Similar criteria were adopted in the current study to further characterize the nature of mouse facial expressions in several conditions: a medium bristle brush approaching the face, non-aggressive social interaction, aggressive social interaction, rat exposure and cat odor exposure. Results showed situation-dependent changes in facial expressions of mice. Most notably, different facial expressions were clearly displayed by resident and intruder mice prior to and during aggressive encounters, suggesting that changes in particular facial components may serve to protect sensitive or exposed body parts. The use of facial expressions as social signals is also discussed.
Affiliation: University of Hawaii
Keywords: facial expressions, aggression, social behavior
Neurochemistry of the BTBR T+tf/J mouse model of autism Authors: Ashley L. Jensen, Erwin B. Defensor, Brandon L. Pearson, D.C. Blanchard, Robert J. Blanchard and Adrian J. Dunn
Abstract: Autism is defined by three core behavioral features: impaired reciprocal social interactions, impaired communication and repetitive and stereotyped behaviors. Despite the absence of a reliable biomarker, several neuropathologies have been associated with the disorder including increased cortical volume at particular developmental ages, agenesis of the corpus callosum and dysfunction of neurotransmitter systems. Animal models allow investigation of anatomical, neurochemical and hormonal abnormalities potentially related to this disorder. Previous studies have shown that the inbred BTBR T+tf/J mouse strain (BTBR) displays several behaviors analogous to the core symptoms of autism. The current study measured central neurotransmitter activity in the BTBR at basal concentrations and also in response to a novel environment and social proximity. Brain tissue concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and their respective metabolites were measured using high performance liquid chromatography (HPLC) with electrochemical detection. Behavioral results were consistent with previous findings in the social proximity test, showing that BTBR mice displayed decreased facial contact and increased crawl over and crawl under behaviors. Several neurochemcial strain differences were observed, especially in cortical and cerebellar concentrations of DA and 5-HT.
Affiliations: University of Hawaii at Manoa, Department of Psychology; Pacific Biosciences Research Center
Keywords: autism, animal models, neurotransmitters
From neural responses to population behavior: Neural focus group predicts population level media effects
Authors: Emily B. Falk, Elliot T. Berkman, and Matthew D. Lieberman
Abstract: Can neural responses to persuasive messages predict individual behavior change? Can the neural responses of a small group of individuals predict the behavior of larger groups of people (e.g. at the city or state level)? We will present data addressing these questions using a “brain-as-predictor” approach. Prior research demonstrates that individual and group behaviors can be predicted using neural activity recorded in response to public health messages. More specifically, neural activity in an a priori region of interest in medial prefrontal cortex (MPFC, BA10) during exposure to persuasive messages predicted behavior change above and beyond self-report measures (such as intentions and self-efficacy to change behavior). The present study builds directly on prior work in our lab in which we explored a behavior of relatively low motivational relevance (sunscreen use) and predicted individual behavior change over one week, and a follow-up study in which we predicted a behavior of high motivational relevance (smokers trying to quit) over a longer period of time (one month); in this context, neural signals more than doubled the variance explained by traditional self-report measures alone. Here, we will present results from an investigation in which neural activity in response to different mass media campaigns predicted the media campaigns’ relative success at changing behavior at the population level, significantly above chance levels. By contrast, the same participants’ self-reported projections of campaign efficacy did not predict the relative success of the campaigns at the population level. Our results highlight the use of the brain-as-predictor analysis approach, in which neural signals from a priori regions of interest are used to predict real-world outcomes of importance over weeks or months; furthermore, we extend the brain-as-predictor approach from predicting individual difference outcomes to show that neural signals not only predict individual behavior change, but may also predict population-level health behaviors. Finally, our results suggest that the brain contains hidden wisdom about the impact of persuasive messages at the individual and population level that is not otherwise accounted for in models of persuasion and behavior change.
Affiliations: University of Michigan, University of Oregon, University of California, Los Angeles
Keywords: fMRI, health, media, persuasion
Rewarding properties of aggression in the male Syrian hamster Authors: Mario Gil, Mark McDonald, Ngoc-Thao Nguyen, and H. Elliott Albers
Abstract: Conditioned place preference (CPP) is a type of classical conditioning in which an animal develops a preference for a compartment or environment that was previously paired with a rewarding stimulus. We tested the hypothesis that male Syrians hamsters can develop a CPP for aggression. Our CPP paradigm consisted of three phases: (1) initial preference tests (pretests), (2) conditioning, and (3) a final preference test (posttest). For all preference tests, the amount of time spent in each compartment of the CPP apparatus was recorded. The animals used in this study showed a clear initial preference for 1 of the 2 compartments. For the conditioning trials, an individually-housed (experimental) male was paired with a nonaggressive group-housed male (stimulus) in their non-preferred compartment for 10 min. An hour before or after stimulus-paired trials in the non-preferred compartment, experimental males were placed alone in their preferred compartment for 10 min. This procedure occurred daily for 5 consecutive days, and order of placement in the compartments was alternated daily. Preference scores and difference scores were calculated for both (pre and post) preference tests. There were no significant differences between pretest and posttest scores for control animals (n=13). Four of the experimental animals flank marked but didn’t show aggression toward the stimulus males. There was a trend toward an increase in preference scores (p=0.1) and a decrease in the difference scores (p=0.09) following conditioning in these animals. That is, before conditioning the mean preference and difference scores were 0.29 (±0.01) and 324.63 (±21.34), respectively. After conditioning, scores changed to 0.49 (±0.08) and 6.25 (±114.50), respectively. Eleven experimental animals showed low to medium levels of aggression. In these animals, conditioning significantly increased the mean preference score from 0.36 (± 0.02) to 0.50 (±0.05) (p< 0.05), while the mean difference score decreased from 208.55 (±26.17) to 5.55 (±76.82) (p< 0.05). The strongest effect was observed in 6 highly aggressive males, as conditioning significantly increased their mean preference score from 0.34 (±0.04) to 0.56 (±0.04) (p< 0.01), while their mean difference score changed from 240.42 (±54.98) to -86.50 (±68.99) (p< 0.01). Our results demonstrate that the Syrian hamster is an excellent rodent model for the study of the rewarding properties of aggression & social behavior. Our data support the hypothesis that aggression has rewarding properties and suggest that the expression of social dominance in nonaggressive animals may also be rewarding. Supported by NSF Grant IOS-0923301 to HEA.
Affiliations: Center for Behavioral Neuroscience; Neuroscience Institute, Georgia State University, Atlanta, GA USA
Keywords: aggression, social behavior, motivation, hamsters
Child maltreatment, cumulative lifetime stress and amygdala volume
Authors: Jamie Hanson, Moo Chung . Brian Avants, Karen Rudolph, Elizabeth Shirtcliff, James Gee, Richard Davidson, and Seth Pollak
Abstract: Child maltreatment and cumulative lifetime stress (e.g., unexpected deaths in the family, major health issues) are associated with a cascade of deleterious changes such as major alterations in important brain circuitry, negative outcomes in behavioral functioning, and increased risk for certain psychopathologies (for review, see Lupien et al., 2009). Child maltreatment and the associated disruption of the primary care-giving relationship, in particular, may be a unique diathesis for socio-emotional difficulties, as children who suffer abuse or deprivation/neglect experience significant problems with sensitivity to social boundaries, establishing relationships, emotion regulation under conditions of stress or change, and processing of specific emotions (Pollak, 2008). By investigating the commonalities and discontinuities existing in the sequelae of these different forms of adverse experiences, unique insights may be garnered regarding normative and atypical functioning. For example, there may be unique interactions between child maltreatment and cumulative lifetime stress, with greater negative impacts in children who have faced this early adversity than in those who have not faced this adversity. In this study, we examined the neurobiological correlates of lifetime stress exposure in a sample of children with and without a history of child maltreatment (n=128; mean age=12.6 years), using Symmetric Normalization (Avants & Gee, 2004) and a tensor-based morphometry analytic framework. We hypothesized that cumulative lifetime stress exposure would uniquely affect the amygdala, a brain region central to the processing of socio-emotional information, in children who suffered from early maltreatment but not those who did not suffer from early maltreatment. As hypothesized, a significant association emerged between higher levels of life stress and smaller amygdalae volumes in maltreated children (t=3.6, p<.005, uncorrected; see figure below) but not in non-maltreated children. Individual differences in amygdala volume were related (r=-.296, p=.015) to socio-emotional functioning (e.g., number of close friends, frequency of disciplinary issues at school) as assessed by semi-structured interviews with children and their parents. These findings suggest maltreatment and higher levels of cumulative lifetime stress may interact to uniquely affect important socio-emotional neural circuitry. Results will also be discussed in relation to neuroendocrine variables.
Affiliations: University of Wisconsin- Madison, University of Pennsylvania, University of Illinois at Urbana- Champaign, University of New Orleans
Keywords: adolescence, stress, early experience, maltreatment, socio-emotional
Do chimps “mirror” others’ actions? A functional neuroimaging study of action execution and observation
Authors: Erin Hecht, Lauren Davis and Lisa Parr
Abstract: Social learning is a behavioral adaptation that varies across primate species. Humans have a broad and complex repertoire of socially transmitted behaviors. We can duplicate not only the result of an observed action, but also the specific kinematic method in which it is achieved. In contrast, macaques have a smaller, simpler range of socially transmitted behaviors and duplicate only observed actions’ results. These species differences in behavior are paralleled by species differences in brain activity. Both humans and macaques have a fronto-parietal action observation/execution matching system. In macaques, this system responds only to object-directed actions – those that involve results. In humans, it also responds to purely kinematic, non-object-directed actions. Thus species differences in social learning may be related to which aspects of observed actions are “mirrored” in the brain. Chimpanzee social learning is intermediate to macaques and humans, but their mirror system has not yet been studied. Like humans, they are profuse social learners, but like macaques, they duplicate mainly the results of observed actions. We used positron emission tomography (PET) to investigate how the chimpanzee brain mirrors observed actions. Four chimpanzees were given a 15 mCi oral dose of flourodeoxyglucose (FDG), a radio-labeled glucose analog. Each subject was scanned in four separate conditions. In the execution condition, the chimp performed an object-directed reach-to-grasp action with a small ball. These actions occurred inside a box so that the chimp could not see its own movement. In the transitive observation condition, the chimp observed the experimenter performing the same actions. In the intransitive observation condition, the chimp observed the experimenter miming this action without the ball. In the rest condition, the chimp rested quietly. After a 45 minute testing period, subjects were anesthetized and scanned. FDG has a half-life of 110 minutes and upon decay releases a positron which is detected by the scanner. Brighter areas in the scan thus represent greater FDG uptake and therefore greater metabolic activity during the testing period. In both execution and transitive observation, chimpanzees activated frontal and parietal regions homologous to macaque and human “mirror areas.” In intransitive observation, these activations were weaker and more variable across subjects. Results are related to behavioral data on each subject’s observational learning abilities, as well as to diffusion tensor imaging data on the white matter connectivity of each subject’s activated regions.
Affiliations: Neuroscience Graduate Program, Yerkes National Primate Research Center, Center for Translational Social Neuroscience, Center for Behavioral Neuroscience, Division of Psychiatry and Behavioral Sciences
Keywords: social cognition/sensorimotor transformation: behavior and whole animal
Seeing is believing: Neural mechanisms of action perception are biased by team membership
Authors: Pascal Molenberghs, Veronika Halász, Jason Mattingley, Eric Vanman, and Ross Cunnington
Abstract: Group identification can lead to a biased view of the world in favor of “in-group” members. Studying the brain processes that underlie such in-group biases is important for a wider understanding of the potential influence of social factors on basic perceptual processes. In this study we used fMRI to investigate how people perceive the actions of in-group and out-group members, and how their biased view in favor of own-team members manifests itself in the brain. We divided participants into two teams and had them judge the relative speeds of hand actions performed by an in-group and an out-group member in a competitive situation. Participants judged hand actions performed by in-group members as being faster than those of out-group members, even when the two actions were performed at physically identical speeds. In an additional fMRI experiment we showed that, contrary to common belief, such skewed impressions arise from a subtle bias in perception and associated brain activity rather than decision making processes, and that this bias develops rapidly and involuntarily as a consequence of group affiliation. Our findings suggest that the neural mechanisms that underlie human perception are shaped by social context.
Affiliations: University of Queensland, Queensland Brain Institute; University of Queensland, School of Psychology
Keywords: fMRI, perception of action, group membership
Neural correlates of synchrony
Authors: George T. Monteleone, Elizabeth A. Majka, Haotian Zhou, J.S. Irick, Kimberly Quinn, Gun R. Semin, and John T. Cacioppo
Abstract: The human tendency to spontaneously synchronize with others has been extensively documented in various domains. In the present investigation, we experimentally investigated the neural correlates of perceived synchrony using a newly developed minimal synchrony paradigm that addresses several problems in the extant research, such as a confounding of synchrony and task performance. Specifically, individuals participated in a task similar to cell-phone texting but in which a simple beat (a single tap on the computer keyboard) replaced lexical content. The task was described to participants as “bexting,” short for beat-based texting. During the task, participants believed they were exchanging beats via computer with a human partner, unaware that the ostensible partner’s response was actually a computer-generated response manipulated to be synchronous or asynchronous. Following each condition, participants entered ratings of perceived synchrony with and affiliation for the partner. Sixteen healthy participants performed the task in a 3T Philips scanner. The experimental design was a Period (Bexting versus Rating) x 2 (Bexting Synchrony: high versus low) within-participants factorial design. In the bexting period, participants were instructed to tap beats at around 1 Hz on their own while viewing a pulsing icon representing each finger tap next to a second pulsing icon representing the ostensible partner’s response. In the rating period, participants rated how synchronous they regarded their partner, as well as a series of affiliation ratings felt towards the partner including rapport, liking, and desire to collaborate in the future. Bexting trials were 8s in duration and were blocked in sets of eight constituting each of four bexting rounds. The partner in half of the rounds produced beats that followed the participant by a mean lag of 120 or 220 ms with a temporal jitter of + 10 ms (high synchrony condition), and the partner in the other half of the blocks produced beats that followed the participant by a mean lag of 120 or 220 ms with a temporal jitter of + 110 ms added (low synchrony condition). For the fMRI analysis, 25 ROIs were identified based on prior research on social cognition including sub-regions of the medial prefrontal cortex, superior temporal sulcus, and temporo-parietal junction. Participants’ behavioral ratings were correlated with the BOLD response within participants for each ROI. R-values were converted to Fisher’s Z, and Z-scores were subjected to a one-sample, two-tailed t-tests at the group level to determine which neural regions were positively or negatively correlated with behavioral ratings at the group level. Results demonstrated a significant positive correlation between BOLD response and both perceived synchrony ratings and affiliation ratings in the ventromedial prefrontal cortex (vmPFC) during the bexting task. The vmPFC has been reported in prior research to be involved in self-relevant processing as well as theory of mind tasks involving reasoning about the thinking of others. The current study suggests that components of neural networks involved in social cognition are also incorporated in spontaneous perceptions of social synchrony even without any explicit context of observing others’ actions or thinking about oneself.
Affiliations: University of Chicago, University of Birmingham, Utrecht University
Keywords: social neuroscience, social cognition, social psychology, synchrony
Genetic variation in the oxytocin receptor is associated with alterations in perceived social isolation, social rejection and psychological stress reactivity: A population based study in older individuals
Authors: Greg J. Norman, Louise C. Hawkley, Aaron Ball, Maike Luhmann, Steve W. Cole, Gary G. Berntson, and John T. Cacioppo
Abstract: The neuropeptide oxytocin has been implicated in a wide range of social processes, such as pair bonding, social anxiety, and social judgment and decision making, that may contribute to normal adjustment and psychiatric states. Indeed, pharmacological administration of oxytocin has previously been associated with in-group trust and out-group hostility as well as diminished social threat perception and increased theory of mind. Consistent with the pharmacological manipulation studies mentioned above, recent work suggests that single nucleotide polymorphisms (SNPs) in the oxytocin receptor is associated with numerous social-affective processes. The present study sought to explore the effects of genetic variation in the oxytocin receptor (SNP; rs53576) on levels of perceived social isolation, sensitivity to social rejection and stress reactivity to psychological stress in a population based study of older individuals. Results revealed that males who were homozygous for the G allele showed the highest levels of perceived social isolation and showed significantly higher levels of sympathetic cardiac control following a psychological stressor. In contrast, females who were homozygous for the G allele were significantly more affected by social rejection, as measured by pre-post changes in negativity scores, and they showed significantly smaller parasympathetic withdrawal in response to psychological stress. These data, combined with the growing literature, suggest that variation in the oxytocin receptor system has important effects on social-affective processes related to social isolation, social rejection and stress reactivity.
Affiliations: Department of Psychology, The University of Chicago, Chicago, IL 60637; Department of Medicine, Division of Hematology-Oncology, UCLA School of Medicine, Los Angeles, CA, USA; Department of Psychology, The Ohio State University, Columbus, Ohio 43210
Keywords: oxytocin, social isolation
Mapping the mind: a constructionist view on how mental states emerge from the brain
Authors: Suzanne Oosterwijk, Kristen A. Lindquist, Eric Anderson, Rebecca Dautoff, Yoshiya Moriguchi, and Lisa Feldman Barrett
Abstract: Neuroimaging studies tend to organize around specific categories, such as memory, cognition and emotion. Psychological constructionism provides a different view on how the mind emerges from the brain and proposes that different mental events (such as emotions, feelings or thoughts) arise from the continuous interplay of the same ‘psychological ingredients’, including sensation, interoception, conceptual knowledge, executive attention, and language. In the present study we used fMRI to examine how the neural networks associated with these ingredients contribute to the experience of three different mental states; a bodily state, an emotion, or a thought. While in the scanner, participants listened to auditory scenarios describing negative events. Participants were instructed to experience these scenarios in four different ways; to focus on bodily sensations; to experience an emotion, or to think about the event in an objective way. Trials started with a cue, followed by the auditory scenario, followed by two consecutive phases. In the construction phase participants created the mental state in reaction to the scenario; in the elaboration phase participants prolonged their mental state by elaborating on its content. To investigate brain regions that are important for the generation of variable mental states, we performed conjunction analyses on the activation patterns for all three conditions during the construction and elaboration phase. Analyses demonstrate substantial overlap in the construction phase in regions associated with self-reflection (precuneus, temporal parietal junction), sensory/motor processing (precentral gyrus, postcentral gyrus, SMA, MCC), executive attention (dlPFC, frontal pole), language (pars triangularis, pars opercularis) and interoception (anterior insula). Conjunction during the elaboration phase showed similar regions, with in addition a large cluster in the left ventromedial prefrontal cortex. To examine difference between body focus, emotion and thought, we calculated contrast maps focusing on the cortical surface of the whole brain. The most prominent results concerned the listening and elaboration phase. During listening, we found stronger activation in areas associated with self-reflection and conceptual knowledge (precuneus, temporal parietal junction, posterior cingulate gyrus), interoception (insula, anterior cingulate cortex) and sensation (precentral and postcentral gyrus) when participants where cued with body focus than when they were cued with emotion or thought. In contrast, emotion and thought demonstrated stronger activation in areas associated with auditory processing (planum temporale, superior temporal gyrus, Heschl’s gyrus). During the elaboration phase, we found stronger activation in areas associated with interoception (anterior insula) and sensory motor processes (precentral and postcentral gyrus) for body focus compared to emotion. Comparing thought to body focus and emotion, we found stronger activation in the default network (medial prefrontal cortex) and in areas associated with memory and conceptual processing (anterior temporal lobe, precuneus, parahippocampal gyrus). Overall, the results show that different mental states involve similar brain areas, associated with basic processes such as conceptualization, interoception, attention and language, albeit with relative differences in strength of activation. These results enrich our understanding of how different mental states emerge from the brain.
Affiliations: Northeastern University, Harvard University, Martinos Center for Biomedical Imaging; National Institute of Mental Health, National Center of Neurology and Psychiatry
Keyword: mental states
Epigenetic modifications in the regulation of maternal experience in mice
Authors: Danielle S. Stolzenberg, Jacqueline Stevens, and Emilie F. Rissman
In numerous mammalian species experience interacting with offspring facilitates future maternal responding. In rodents, although parturitional hormones facilitate maternal responding, the facilitatory effects of maternal experience on subsequent maternal care depend on mother-infant interaction. We have recently found that experience with pups induces long-lasting effects on subsequent maternal care in spontaneously maternal C57BL/6J (B6) mice. Importantly, subtle differences in the amount of pup experience affect maternal care. For example, whereas 2 days of pup experience (2 hours/day) promoted retrieval behavior in the familiar home cage, at least 4 days of pup experience was necessary for females to retrieve pups on the novel T-maze. One mechanism through which experience-dependent behavioral modifications are regulated is epigenetic histone acetylation. Addition of acetyl groups by histone acetyltransferases (HATs) to the histone proteins around which DNA is wrapped increases the sensitivity of DNA to transcriptional regulation. Experience-dependent behavioral modifications have been linked to epigenetic modifications, however, how these mechanisms mediate experience-dependent effects on maternal care is untested. In support of the idea that experience-dependent effects on maternal responsiveness are mediated, at least in part, by epigenetic modifications, maternal experience-dependent increases in maternal care are associated with increased expression of the HAT CREB-binding protein (CBP). Further, brief periods of infant exposure that do not affect subsequent maternal care are potentiated by Sodium Butyrate (SB), a drug that enhances experience-induced histone acetylation. These data suggest that histone acetylation promotes maternal responsiveness via transcription of genes that increase maternal responsiveness. This work has been supported by NIH T32 training grant # DK007646 and R01 MH057759.
Affiliation: University of Virginia
Keywords: maternal behavior, HDAC inhibitor
Do you think it or feel it? Language and neural activity reflect individual differences in emotion processing
Authors: Xiao-Fei Yang, Darby E. Saxbe, Larissa A. Borofsky, Maeve C. Murphy, and Mary Helen Immordino-Yang
Abstract: How do people describe their emotional states, and how does their word use reflect the underlying neural processing? This study explored the relationship between subjects’ word use when responding to emotional stories and their subsequent BOLD activity elicited by the same stories. We hypothesized that subjects’ use of cognitive words (words that reflect abstract thinking, such as “understand,” “know” and “wonder”) and body words (words that describe visceral sensations and body parts) would reflect two differing emotion processing strategies: one that relies more on abstract reasoning, and another that relies more on the feeling of the physical body during emotion. We expected these strategies to correlate with BOLD activity in brain regions involved in somatosensation, such as the somatosensory cortices (SI & SII), and self-reflection, such as the dorsal medial prefrontal cortex (dMPFC) and the posteromedial cortices (PMC, including precuneus and posterior cingulate cortex, PCC). During an emotion induction interview that preceded the scanning session, 28 subjects discussed their feelings about true stories designed to elicit specific social emotions; these included stories describing self-sacrificing or heroic behavior (admiration for virtue; AV); and stories of social exclusion or isolation (compassion for social pain; CSP). During the scanning session, the subjects viewed brief reminders of the stories and were asked to become as emotional as possible (see Immordino-Yang et al., 2009). Transcripts of subjects’ verbal responses during the interviews were analyzed using the quantitative word counting software program LIWC (Linguistic Inquiry and Word Count; Pennebaker, Booth and Francis, 2001) to generate word use frequencies for cognitive and body words. BOLD activity across the AV and CSP conditions was estimated for each individual and entered into group-level whole brain correlation analyses using cognitive and body word frequencies as regressors (SPM8). Consistent with our hypotheses, subjects who used more cognitive words tended to use fewer body words (Pearson’s rho = -.375, p < .025). Cognitive word use inversely correlated with activation in dMPFC, SI and SII, while body word use directly correlated with activations in dMPFC, posterior/inferior sector of precuneus/PCC and supramarginal gyrus (p < .005, cluster threshold of 10 voxels). The word use patterns and associated BOLD results support our hypothesis that individuals adopt different strategies during emotion processing: some engage in more cognitive, abstract reasoning, while others rely more on representing their physical body states.
Affiliations: Neuroscience Graduate Program, University of Southern California; Brain and Creativity Institute, University of Southern California; Department of Psychology, University of Southern California; Rossier School of Education, University of Southern California
Keywords: social emotion, language use, embodiment
Social dominance behavior and threat orienting in young adult monkeys is modulated by fluoxetine during early adolescence
Authors: Bo Zhang, Pamela Noble, Jeremy Kruger, Stephen Suomi, Daniel Pine, Eric Nelson
Abstract: Late childhood and early adolescence is a time when dramatic changes in social behavior occur. The peri-pubertal period is also a developmental period which sees a marked increase in the incidence of mood and anxiety disorders which are often associated with social behavior. Selective serotonin reuptake inhibitors (SSRI) such as fluoxetine are a common treatment for anxiety and mood disorders in both adults and children, and clinical trials have demonstrated their efficacy. However the effects of chronic SSRI administration on development have not been fully explored. In the present study, we assessed the effects of chronic fluoxetine treatment on social behavior of adolescent and young adult monkeys both during treatment and following a washout period. Thirty-two male rhesus monkeys were randomly assigned to either peer rearing (PR) or mother rearing (MR) conditions for the first 6 months of life. MR monkeys were reared with mothers and other peers in a large social group while PR monkeys were removed from their mothers soon after birth and reared with a small group of peers. At 6 months of life both groups had identical social housing conditions. Between 2-3 years of age half of each group was treated with fluoxetine 3mg/kg/day. Social behavior was assessed both during and after treatment with a series of exposures to a novel individual and varied rearing and treatment histories. Fluoxetine treatment significantly reduced the expression of dominance behaviors during treatment and this pattern persisted in the post-treatment period. In the post-treatment period, drug treated monkeys received more dominance displays by partner than untreated animals. Attention orienting to social threat stimuli was also assessed in the post-treatment period with eyetracking methodology, and fluoxetine was found to modulate threat orienting behavior as well. These results suggest that fluoxetine exposure during early adolescence may have long term consequences on threat orienting behavior and may influence the development of social behavior in rhesus monkeys.
Affiliations: National Institute of Mental Health, National Institute of Child Health and Human Development
Keywords: ssri, social dominance, development