Whose Signals Are Being Amplified? Towards a More Equitable Clinical Psychophysiology

Abstract

Research using psychophysiological methods holds great promise for refining clinical assessment, identifying risk factors, and informing treatment. Unfortunately, unique methodological features of existing approaches limit inclusive research participation and, consequently, generalizability. This brief overview and commentary provides a snapshot of the current state of representation in clinical psychophysiology, with a focus on the forms and consequences of ongoing exclusion of Black participants. We illustrate issues of inequity and exclusion that are unique to clinical psychophysiology, considering intersections among social constructions of Blackness and biased design of current technology used to measure electroencephalography, skin conductance, and other signals. We then highlight work by groups dedicated to quantifying and addressing these limitations. We discuss the need for reflection and input from a wider variety of stakeholders to develop and refine new technologies, given the risk of further widening disparities. Finally, we provide broad recommendations for clinical psychophysiology research.

Confronting racially exclusionary practices in the acquisition and analyses of neuroimaging data

“…Phenotypic biases against dark skin tone and curly hair are present in optical imaging, which requires adequate contact with the scalp and is influenced by melanin 44 . As a result, participants with darker skin pigmentation and coarser hair (for instance, a large subset of the Black and Hispanic/Latino populations) are often excluded from EEG and fNIRS studies 40,45 . Excitingly, Etienne and colleagues have recently designed methods for obtaining high-quality EEG readings from individuals with coarse and curly hair, to address this systemic collection bias in EEG studies 41 .…”

Hair me out: Highlighting systematic exclusion in psychophysiological methods and recommendations to increase inclusion

“…Review the extant literature for recommendations by BIPOC researchers to increase inclusion of research participants and cite such researchers (Cundiff, 2012;Roberts et al, 2020;Zurn et al, 2020;Buchanan et al, 2021;Smith et al, 2021;Bradford et al, 2022;Webb et al, 2022).…”

“…Indeed, recent papers have highlighted the shortcomings of current neuroscience methods (Choy et al, 2021 ; Parker and Ricard, 2022 ; Webb et al, 2022 ). Recently, Bradford et al ( 2022 ) discussed underrepresentation in psychophysiological research samples and offered insightful recommendations for researchers to improve inclusion. We amplify and extend these valuable efforts, with a particular focus on methods that require access to participants' hair, such as electroencephalography (EEG) and hair sample collection.…”

Demographic Reporting and Phenotypic Exclusion in fNIRS

“…Even with spring-loaded grommets and tension tops on fNIRS caps, anecdotally, the signal quality for participants with coarse and/or curly hair is poor. As a result, individuals with coarse, curly, and dark hair -often people of African, African-American, and Caribbean descent -are excluded from fNIRS studies (14)(15)(16). Therefore, fNIRS datasets tend to underrepresent Black and Brown individuals, which supports the need for our review.…”

“…Additionally, NIR light can be attenuated by melanin, which is accounted for in neither fNIRS hardware nor analysis methods. Recent work has shown that overlooking these considerations in other modalities like EEG leads to the disproportionate exclusion of individuals with these phenotypes -especially Black people -in both clinical and research literature (Bradford et al 2022, Choy 2020. In this article, we sought to determine if (1) biomedical optics developers and researchers report fNIRS performance variability between skin tones and hair textures, (2a) fNIRS neuroscience practitioners report phenotypic and demographic details in their articles, and thus, (2b) is a similar pattern of participant exclusion found in EEG also present in the fNIRS literature.…”