Human social motivation is characterized by the pursuit of social reward and the avoidance of social punishment. The ventral striatum/nucleus accumbens (VS/Nacc), in particular, has been implicated in the reward component of social motivation, i.e., the ‘wanting’ of social incentives like approval. However, it is unclear to what extent the VS/Nacc is involved in avoiding social punishment like disapproval, an intrinsically pleasant outcome. Thus, we conducted an event-related functional magnetic resonance imaging (fMRI) study using a social incentive delay task with dynamic video stimuli instead of static pictures as social incentives in order to examine participants' motivation for social reward gain and social punishment avoidance. As predicted, the anticipation of avoidable social punishment (i.e., disapproval) recruited the VS/Nacc in a manner that was similar to VS/Nacc activation observed during the anticipation of social reward gain (i.e., approval). Stronger VS/Nacc activity was accompanied by faster reaction times of the participants to obtain those desired outcomes. This data support the assumption that dynamic social incentives elicit robust VS/Nacc activity, which likely reflects motivation to obtain social reward and to avoid social punishment. Clinical implications regarding the involvement of the VS/Nacc in social motivation dysfunction in autism and social phobia are discussed.

Decades of research have documented the specialization of fusiform gyrus (FG) for facial information processes. Recent theories indicate that FG activity is shaped by input from amygdala, but effective connectivity from amygdala to FG remains undocumented. In this fMRI study, 39 participants completed a face recognition task. 11 participants underwent the same experiment approximately four months later. Robust face-selective activation of FG, amygdala, and lateral occipital cortex were observed. Dynamic causal modeling and Bayesian Model Selection (BMS) were used to test the intrinsic connections between these structures, and their modulation by face perception. BMS results strongly favored a dynamic causal model with bidirectional, face-modulated amygdala-FG connections. However, the right hemisphere connections diminished at time 2, with the face modulation parameter no longer surviving Bonferroni correction. These findings suggest that amygdala strongly influences FG function during face perception, and that this influence is shaped by experience and stimulus salience.

Background Indicators of poor oral health, including smoking, have been associated with increased risk of head and neck squamous cell carcinoma, especially oropharyngeal carcinoma (OPSCC), yet few studies have examined whether this association is modified by HPV-status. Methods We used interview and tumor HPV-status data from a large population-based case-control study, the Carolina Head and Neck Cancer Study (CHANCE), to estimate the association between oral health indicators and smoking among 102 HPV-positive and 145 HPV-negative OPSCC cases and 1396 controls. HPV-status was determined by immunohistochemistry of p16INK4a expression. Unconditional multinomial logistic regression was used to estimate odds ratios (OR) for all oral health indictors adjusting for important covariates. Results Routine dental exams were associated with decreased risk of both HPV-negative [OR: 0.52; 95% confidence interval (CI): 0.35-0.76] and HPV-positive OPSCC (OR: 0.55; 95% CI: 0.36-.86). Tooth mobility (a proxy for periodontal disease) increased the risk of HPV-negative (OR: 1.70; 95% CI: 1.18-2.43) slightly more than HPV-positive OPSCC (OR: 1.45; 95% CI: 0.95-2.20). Ten or more pack-years of cigarette smoking was strongly associated with increased risk of HPV-negative OPSCC (OR: 4.26; 95% CI: 2.85-6.37) and less so with HPV-positive OPSCC (OR: 1.62; 95% CI: 1.10-2.38). Conclusions While HPV-positive and HPV-negative HNSCC differ significantly with respect to etiology and tumorigenesis, our findings suggest a similar pattern of association between poor oral health, frequency of dental examinations, and both HPV-positive and HPV-negative OPSCC. Future research is required to elucidate interactions between poor oral health, tobacco use, and HPV in the development of OPSCC.

Advances in the use of noninvasive neuroimaging to study the neural correlates of pathological and non-pathological anxiety have shone new light on the underlying neural bases for both the development and manifestation of anxiety. This review summarizes the most commonly observed neural substrates of the phenotype of anxiety. We focus on the neuroimaging paradigms that have shown promise in exposing this relevant brain circuitry. In this way, we offer a broad overview of how anxiety is studied in the neuroimaging laboratory and the key findings that offer promise for future research and a clearer understanding of anxiety.

The aim of this review is to show the fruitfulness of using images of facial expressions as experimental stimuli in order to study how neural systems support biologically relevant learning as it relates to social interactions. Here we consider facial expressions as naturally conditioned stimuli which, when presented in experimental paradigms, evoke activation in amygdala–prefrontal neural circuits that serve to decipher the predictive meaning of the expressions. Facial expressions offer a relatively innocuous strategy with which to investigate these normal variations in affective information processing, as well as the promise of elucidating what role the aberrance of such processing might play in emotional disorders.