Maternal psychological risk and the neural correlates of infant face processing: A latent profile analysis.

Maternal psychological factors, including anxiety, depression, and substance use, may negatively affect parenting. Previous works with mothers have often assessed each of these factors in isolation despite their frequent co-occurrence. Psychological factors have also been associated with neural processing of facial stimuli, specifically the amplitude (i.e., size) and latency (i.e., timing) of the face-specific N170 event-related potential. In the current study, 106 mothers completed measures assessing maternal psychological factors-anxiety, depression, and substance use. A latent profile analysis was used to identify profiles of psychological factors and assess profile associations with the N170 elicited by infant faces and with parental reflective functioning (PRF) as a measure related to caregiving. Two profiles (termed high and low psychological risk) were identified, with the higher risk profile associated with delayed N170 latency responses to infant faces. An exploratory analysis evidenced an indirect effect between the higher psychological risk profile and lower PRF through delayed N170 latency responses to infant faces. Taken together, maternal psychological risk across multiple indicators may together shape neural processing of infant faces, which may have downstream consequences for caregiving.

Racial disparities in EEG research and their implications for our understanding of the maternal brain.

Racial disparities in maternal health are alarming and persistent. Use of electroencephalography (EEG) and event-related potentials (ERPs) to understand the maternal brain can improve our knowledge of maternal health by providing insight into mechanisms underlying maternal well-being, including implications for child development. However, systematic racial bias exists in EEG methodology-particularly for Black individuals-and in psychological and health research broadly. This paper discusses these biases in the context of EEG/ERP research on the maternal brain. First, we assess the racial/ethnic diversity of existing ERP studies of maternal neural responding to infant/child emotional expressions, using papers from a recent meta-analysis, finding that the majority of mothers represented in this research are of White/European ancestry and that the racially and ethnically diverse samples that are present are limited in terms of geography. Therefore, our current knowledge base in this area may be biased and not generalizable across racially diverse mothers. We outline factors underlying this problem, beginning with the racial bias in EEG equipment that systematically excludes individuals of African descent, and also considering factors specific to research with mothers. Finally, we highlight recent innovations to EEG hardware to better accommodate diverse hairstyles and textures, and other important steps to increase racial and ethnic representativeness in EEG/ERP research with mothers. We urge EEG/ERP researchers who study the maternal brain-including our own research group-to take action to increase racial diversity so that this research area can confidently inform understanding of maternal health and contribute to minimizing maternal health disparities.

Identification of a novel link between adiposity and visuospatial perception.

OBJECTIVE: Recent work has reported a negative association between BMI and performance on the Penn Line Orientation Task. To determine the reliability of this effect, a comprehensive assessment of visual function in individuals with healthy weight (HW) and those with overweight/obesity (OW/OB) was performed. METHODS: Visual acuity/contrast, Penn Line Orientation Task, and higher-order visuospatial function were measured in 80 (40 with HW, 40 with OW/OB) case-control study participants. Adiposity, fasting glucose, hemoglobin A1c, diet, physical activity, and heart rate variability were also assessed. A subgroup of 22 participants plus 5 additional participants (n = 27) underwent functional magnetic resonance imaging scanning. RESULTS: Compared with those with HW, individuals with OW/OB performed worse on tasks requiring judgments of line orientation. This effect was mediated by body fat percentage and was unrelated to other measures. Functional magnetic resonance imaging revealed a negative association between BMI and response in the primary visual cortex (V1) during line orientation judgment. Performance was unrelated to V1 response but positively correlated with response in a network of regions, including the lateral occipital cortex, when BMI was accounted for in the model. CONCLUSIONS: These results demonstrate a selective deficit in line orientation perception associated with adiposity and blunted activation in the V1 that cannot be attributed to visual acuity and does not generalize to other visuospatial tasks.

Fat and Carbohydrate Interact to Potentiate Food Reward in Healthy Weight but Not in Overweight or Obesity.

Prior work suggests that actual, but not estimated, energy density drives the reinforcing value of food and that energy from fat and carbohydrate can interact to potentiate reward. Here we sought to replicate these findings in an American sample and to determine if the effects are influenced by body mass index (BMI). Thirty participants with healthy weight (HW; BMI 21.92 ± 1.77; M ± SD) and 30 participants with overweight/obesity (OW/OB; BMI 29.42 ± 4.44) rated pictures of common American snacks in 120-kcal portions for liking, familiarity, frequency of consumption, expected satiety, healthiness, energy content, energy density, and price. Participants then completed an auction task where they bid for the opportunity to consume each food. Snacks contained either primarily carbohydrate, primarily fat, or roughly equal portions of fat and carbohydrate (combo). Replicating prior work, we found that participants with HW bid the most for combo foods in linear mixed model analyses. This effect was not observed among individuals with OW/OB. Additionally, in contrast with previous reports, our linear regression analyses revealed a negative relationship between the actual energy density of the snacks and bid amount that was mediated by food price. Our findings support altered macronutrient reinforcement in obesity and highlight potential influences of the food environment on the regulation of food reward.

Development of MacroPics: A novel food picture set to dissociate the effects of carbohydrate and fat on eating behaviors.

Emerging evidence suggests that fat and carbohydrate interact to potentiate the reward value of food (DiFeliceantonio et al., 2018). The primary goal of the current study was to develop a novel picture set to facilitate research into the effects of macronutrient composition on food choice and eating behavior. Toward this aim, we developed "MacroPics." In Experiment 1, we photographed 120-kcal portions of 60 snack foods falling into one of the three macronutrient categories: (1) mostly carbohydrate, (2) mostly fat, or (3) a combination of fat and carbohydrate. Sixty-one participants rated the images for liking, familiarity, frequency of consumption, healthiness, estimated energy content (in kcal), and expected satiation. A subset of these images consisting of 36 items was then selected in an iterative process to minimize differences in ratings between the macronutrient categories while simultaneously ensuring similar within-category variability on a number of food characteristics (e.g., energy density, portion size, retail price) and visual properties (e.g., color, complexity, visual area). In Experiment 2, an independent sample of 67 participants rated the pictures of the final 36-item MacroPics. Both experiments reveal similar participant ratings across categories for item liking, familiarity, frequency, healthiness, and estimated energy content. Protein content was higher in the fat compared to the carbohydrate and combination categories, leading to higher ratings of estimated satiety and energy density for fatty foods. Item and macronutrient category characteristics of the final MacroPics set are reported.

No evidence for an association between obesity and milkshake liking.

BACKGROUND: Prevailing models of obesity posit that hedonic signals override homeostatic mechanisms to promote overeating in today's food environment. What researchers mean by "hedonic" varies considerably, but most frequently refers to an aggregate of appetitive events including incentive salience, motivation, reinforcement, and perceived pleasantness. Here we define hedonic as orosensory pleasure experienced during eating and set out to test whether there is a relationship between adiposity and the perceived pleasure of a palatable and energy-dense milkshake. METHODS: The perceived liking, wanting, and intensity of two palatable and energy-dense milkshakes were assessed using the Labeled Hedonic Scale (1), visual analog scale (VAS), and Generalized Labeled Magnitude Scale (2) in 110 individuals ranging in body mass index (BMI) from 19.3 to 52.1 kg/m2. Waist circumference, waist-hip ratio, and percent body fat were also measured. Importantly, unlike the majority of prior studies, we attempted to standardize internal state by instructing participants to arrive to the laboratory neither hungry nor full and at least 1-h fasted. Data were analyzed with general linear and linear mixed effects models (GLMs). Hunger ratings were also examined prior to hedonic measurement and included as covariates in our analyses. RESULTS: We identified a significant association between ratings of hunger and milkshake liking and wanting. By contrast, we found no evidence for a relationship between any measure of adiposity and ratings of milkshake liking, wanting, or intensity. CONCLUSIONS: We conclude that adiposity is not associated with the pleasure experienced during consumption of our energy-dense and palatable milkshakes. Our results provide further evidence against the hypothesis that heightened hedonic signals drive weight gain.

The interactive Physical and Cognitive Exercise System (iPACES™): effects of a 3-month in-home pilot clinical trial for mild cognitive impairment and caregivers.

BACKGROUND: Alzheimer's and related dementias are on the rise, and older adults and their families are seeking accessible and effective ways to stave off or ameliorate mild cognitive impairment (MCI). AIM: This pilot clinical trial (ClinicalTrials.gov Identifier: 03069391) examined neuropsychological and neurobiological outcomes of interactive physical and mental exercise. PARTICIPANTS AND METHODS: Older adults (MCI and caregivers) were enrolled in a 3-month, in-home trial of a portable neuro-exergame (the interactive Physical and Cognitive Exercise System [iPACES™]), in which they pedaled and steered along a virtual bike path to complete a list of errands (Memory Lane™). Neuropsychological function and salivary biomarkers were measured at pre-, mid-, and posttrial. Ten older adults complied with the recommended use of iPACES (complete dose; ≥2×/wk, 67% of the 15 who also had pre- and postevaluation data). Statistical analyses compared change over time and also change among those with a complete dose vs inadequate dose. Correlations between change in neuropsychological and biomarker measures were also examined. RESULTS: Executive function and verbal memory increased after 3 months (p = 0.01; no significant change was found with an inadequate dose). Change in salivary biomarkers was moderately associated with increasing cognition (cortisol, r = 0.68; IGF-1, r = 0.37). CONCLUSION: Further research is needed, but these pilot data provide preliminary indications to suggest neuro-exergaming can impact cognitive function, perhaps via neurobiological mechanisms, and as such may provide an effective and practical way to promote healthy aging.

Flexible and Stable Value Coding Areas in Caudate Head and Tail Receive Anatomically Distinct Cortical and Subcortical Inputs.

Anatomically distinct areas within the basal ganglia encode flexible- and stable-value memories for visual objects (Hikosaka et al., 2014), but an important question remains: do they receive inputs from the same or different brain areas or neurons? To answer this question, we first located flexible and stable value-coding areas in the caudate head (CDh) and caudate tail (CDt) of two rhesus macaque monkeys, and then injected different retrograde tracers into these areas of each monkey. We found that CDh and CDt received different inputs from several cortical and subcortical areas including temporal cortex, prefrontal cortex, cingulate cortex, amygdala, claustrum and thalamus. Superior temporal cortex and inferior temporal cortex projected to both CDh and CDt, with more CDt-projecting than CDh-projecting neurons. In superior temporal cortex and dorsal inferior temporal cortex, layers 3 and 5 projected to CDh while layers 3 and 6 projected to CDt. Prefrontal and cingulate cortex projected mostly to CDh bilaterally, less to CDt unilaterally. A cluster of neurons in the basolateral amygdala projected to CDt. Rostral-dorsal claustrum projected to CDh while caudal-ventral claustrum projected to CDt. Within the thalamus, different nuclei projected to either CDh or CDt. The medial centromedian nucleus and lateral parafascicular nucleus projected to CDt while the medial parafascicular nucleus projected to CDh. The inferior pulvinar and lateral dorsal nuclei projected to CDt. The ventral anterior and medial dorsal nuclei projected to CDh. We found little evidence of neurons projecting to both CDh and CDt across the brain. These data suggest that CDh and CDt can control separate functions using anatomically separate circuits. Understanding the roles of these striatal projections will be important for understanding how value memories are created and stored.