The role of associative learning in healthy and sustainable food evaluations: An event-related potential study.

Individuals in industrialized societies frequently include processed foods in their diet. However, overconsumption of heavily processed foods leads to imbalanced calorie intakes as well as negative health consequences and environmental impacts. In the present study, normal-weight healthy individuals were recruited in order to test whether associative learning (Evaluative Conditioning, EC) could strengthen the association between food-types (minimally processed and heavily processed foods) and concepts (e.g., healthiness), and whether these changes would be reflected at the implicit associations, at the explicit ratings and in behavioral choices. A Semantic Congruency task (SC) during electroencephalography recordings was used to examine the neural signature of newly acquired associations between foods and concepts. The accuracy after EC towards minimally processed food (MP-food) in the SC task significantly increased, indicating strengthened associations between MP-food and the concept of healthiness through EC. At the neural level, a more negative amplitude of the N400 waveform, which reflects semantic incongruency, was shown in response to MP-foods paired with the concept of unhealthiness in proximity of the dorsal lateral prefrontal cortex (DLPFC). This implied the possible role of the left DLPFC in changing food representations by integrating stimuli's features with existing food-relevant information. Finally, the N400 effect was modulated by individuals' attentional impulsivity as well as restrained eating behavior.

Conceptual Models of Food Choice: Influential Factors Related to Foods, Individual Differences, and Society.

Understanding individual food choices is critical for transforming the current food system to ensure healthiness of people and sustainability of the planet. Throughout the years, researchers from different fields have proposed conceptual models addressing factors influencing the food choice, recognized as a key leverage to improve planetary and human health. However, a multidisciplinary approach is needed to better understand how different factors are involved and interact with each other in the decision-making process. The present paper reviews and analyzes existing models, providing an intact point-of-view by integrating key elements into a bigger framework. Key determinants of general food choice are identified and categorized, including food-internal factor (sensory and perceptual features), food-external factors (information, social environment, physical environment), personal-state factors (biological features and physiological needs, psychological components, habits and experiences), cognitive factors (knowledge and skills, attitude, liking and preference, anticipated consequences, and personal identity), as well as sociocultural factors (culture, economic variables, political elements). Moreover, possible directions of influence among the factors towards final food choice were discussed. The need of multidisciplinary impulses across research field with the support of empirical data are crucial for understanding factors influencing food choice as well as for enriching existing conceptual models. The framework proposed here would serve as a roadmap for facilitating communications and collaborations between research fields in a structural and systematic way.

Differences in age-dependent neural correlates of semantic processing between youths with autism spectrum disorder and typically developing youths.

Individuals with autism spectrum disorders (ASD) have aberrant neural activity during semantic judgments. We aimed to examine age-dependent neural correlates of semantic processing in boys with ASD as compared to typically developing boys (TD). We used functional MRI to investigate 37 boys with ASD (mean age = 13.3 years, standard deviation = 2.4) and 35 age-, sex-, Intelligence quotient (IQ)- and handedness-matched TD boys (mean age = 13.3 years, standard deviation = 2.7) from age 8 to 18 years. Participants had to indicate whether pairs of Chinese characters presented visually were related in meaning. Group (ASD, TD) × Age (Old, Young) ANOVA was used to examine the difference of age-related changes. Direct comparisons between the adolescent group and the child group were also performed. The behavioral results showed that the ASD group had lower accuracy in the related condition relative to the TD group. The neuroimaging results showed greater activation in the cuneus and less activation in the left inferior frontal gyrus in boys with ASD than TD boys. Children with ASD produced greater activation in the cuneus than TD children. Adolescents with ASD showed reduced left IFG activation as compared to TD adolescents. Our findings suggest that TD boys may engage more in higher-level processing of retrieving or selecting semantic features while boys with ASD may rely more on lower-level visual processing during semantic judgments. The findings imply different functional organizations of the semantic system between the two groups. Autism Res 2016, 9: 1263-1273. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Reduced structural integrity and functional lateralization of the dorsal language pathway correlate with hallucinations in schizophrenia: a combined diffusion spectrum imaging and functional magnetic resonance imaging study.

Recent studies suggest that structural and functional alterations of the language network are associated with auditory verbal hallucinations (AVHs) in schizophrenia. However, the ways in which the underlying structure and function of the network are altered and how these alterations are related to each other remain unclear. To elucidate this, we used diffusion spectrum imaging (DSI) to reconstruct the dorsal and ventral pathways and employed functional magnetic resonance imaging (fMRI) in a semantic task to obtain information about the functional activation in the corresponding regions in 18 patients with schizophrenia and 18 matched controls. The results demonstrated decreased structural integrity in the left ventral, right ventral and right dorsal tracts, and decreased functional lateralization of the dorsal pathway in schizophrenia. There was a positive correlation between the microstructural integrity of the right dorsal pathway and the functional lateralization of the dorsal pathway in patients with schizophrenia. Additionally, both functional lateralization of the dorsal pathway and microstructural integrity of the right dorsal pathway were negatively correlated with the scores of the delusion/hallucination symptom dimension. Our results suggest that impaired structural integrity of the right dorsal pathway is related to the reduction of functional lateralization of the dorsal pathway, and these alterations may aggravate AVHs in schizophrenia.

The deficits on a cortical-subcortical loop of meaning processing in schizophrenia.

Thought disorder is a core symptom of schizophrenia. However, the underlying mechanism is not well understood. Functional MRI (fMRI) was used to examine the neural mechanism of thought disorder in 20 patients with schizophrenia and 20 healthy controls during semantic judgments. Two indexes of disorganized thought were further used to evaluate individual differences in thought disturbance in the patients. Compared with the controls, the patients showed greater activation in left inferior frontal gyrus (BA45) and reduced activation in the left caudate nucleus for meaning-related pairs. Moreover, in patients, effective connectivity from Dynamic Causal Modeling showed that the modulatory effect from the caudate nucleus to the inferior frontal gyrus was weaker than that in controls, indicating a disrupted cortical-subcortical language loop for semantic processing in patients. Finally, increasing scores of disorganized thought were correlated with greater activation in the inferior frontal gyrus and weaker connection strength from the caudate nucleus to the inferior frontal gyrus. Patients with more severe disorganized symptoms might receive less efficient regulation from the caudate nucleus, resulting in increased demands for the inferior frontal gyrus to retrieve or select semantic knowledge in the cortical-subcortical circuit.