Tag: Robert Chavez

Inconclusive Results of Autism Spectrum Disorder Research Could Be Due to Broad Subject Criteria

Presenter(s): Scout Galash − Biology, Human Physiology

Co Presenter(s): Fountane Chan

Faculty Mentor(s): Robert Chavez

Poster 97

Research Area: Social Science

One in sixty-eight U.S. children is diagnosed with autism. The latest version of the DSM, updated in 2013, provides diagnostic criteria for an all-inclusive autism spectrum disorder (ASD). These criteria include mild to severe social and developmental delays among a variety of other symptoms. In recent years, a surge in diagnoses due to increased awareness of autism and its symptoms has resulted in what appears to be an autism epidemic. The broadened definition of autism has ultimately placed a broad range of etiologies under the same diagnosis. Research has indicated that the causes of autism spectrum disorders could range from a point mutation in a variety of seemingly nonspecific genes to insufficient synaptic pruning.

The heterogeneity of individuals with a professional diagnosis of autism spectrum disorder and the discrepancies in what researchers have attributed to be the cause of ASD pose the question of whether autism is a spectrum of disorders or distinct, non-overlapping conditions. If the latter is true, research seeking to determine the causes of ASD must create more specific and discrete criteria for their subjects rather than studying all who fall under an umbrella diagnosis. Our research aims to investigate the potential for an array of disorders that, up to this point, have been diagnosed as an all-encompassing ASD. To do so, we will conduct a systematic review of autism research with ambiguous or inconclusive results. By analyzing the subject criteria of these studies, we hope to identify possible factors contributing to ambiguous results within autism research.

Valence modulates self/other neural recapitulation during interpersonal perception.

Presenter(s): Faith Collins—Pychology

Faculty Mentor(s): Robert Chavez, Taylor Guthrie

Session 5.5: McNair Scholars Presentations

Previous research has demonstrated that neural responses during self-referential thought are recapitulated in the brains of close friends thinking about the self . However, we also know that these processes are influenced by the affective valence of the stimuli and these processes recruit similar areas of the medial prefrontal cortex (MPFC) . Does positive or negative valence drive the coherence between these representations? We sought to test this question by recruiting small groups of close- knit individuals in a round-robin fMRI design . Subjects reflected on positive and negative traits about both themselves and their group members to estimate neural responses to self and every other person in the group . Next, we used a multi-level linear mixed effects model to compare the correlation distance between self-congruent and self-incongruent patterns striated by positive and negative affect . We found that valence, especially negative valence, modulates the strength of self/other recapitulation effects in the MPFC . These results suggest that affective information influences the neural bases of interpersonal perception and contributes to our understanding of the mechanisms by which valence influences how our sense of self is represented in the minds of others .

Convergence of dyadic similarity ratings predicts similarity in neural representations of others within social networks

Presenter(s): Youri Benadjaoud—Human Physiology/Psychology

Faculty Mentor(s): Taylor Guthrie, Rob Chavez

Session: Prerecorded Poster Presentation

A history of classic research in social psychology has demonstrated that human social groups are highly homophilous- people tend to associate with others similar to themselves . More recently, researchers showed that the brain shows similar effects of homophily, with close individuals showing greater neural response similarity to naturalistic stimuli than unfamiliar individuals (Parkinson et al ., 2018) . It is an open question, however, whether a similar degree of neural homophily exists when close individuals think of other specific members of their social group . The current study investigated this question by recruiting multiple social network groups that consisted of several close-knit individuals . Using a round robin fMRI design, individuals completed a standard self/other trait judgement task in which each participant was both the perceiver and a target . Similarity among dyadic pairs were calculated within multivoxel response patterns to each other member of their group . Using the correlation distance between multivoxel pattern response vectors combined with euclidean distance calculations between perceiver ratings of similarity with the target, we fit a multilevel linear effects model that predicted neural similarity from the convergence of dyadic similarity ratings. Our results indicate that the degree of similarity between multivoxel response patterns while individuals were rating the same target were significantly predicted by the the degree to which the perceivers agreed on how similar they were with the target . These findings suggest that people who agree on how similar a person is to themselves tend to have greater similarity in neural representations of that particular other .