A brief history of cortical functional localization and its relevance to neurosurgery

The promise of precision functional mapping for neuroimaging in psychiatry

Precision functional mapping (PFM) is a neuroimaging approach to reliably estimate metrics of brain function from individual people via the collection of large amounts of fMRI data (hours per person). This method has revealed much about the inter-individual variation of functional brain networks. While standard group-level studies, in which we average brain measures across groups of people, are important in understanding the generalizable neural underpinnings of neuropsychiatric disorders, many disorders are heterogeneous in nature. This heterogeneity often complicates clinical care, leading to patient uncertainty when considering prognosis or treatment options. We posit that PFM methods may help streamline clinical care in the future, fast-tracking the choice of personalized treatment that is most compatible with the individual. In this review, we provide a history of PFM studies, foundational results highlighting the benefits of PFM methods in the pursuit of an advanced understanding of individual differences in functional network organization, and possible avenues where PFM can contribute to clinical translation of neuroimaging research results in the way of personalized treatment in psychiatry.

The changing landscape of electrical stimulation language mapping with subdural electrodes and stereoelectroencephalography for pediatric epilepsy: A literature review and commentary

Electrical stimulation mapping (ESM) is used to locate the brain areas supporting language directly within the human cortex to minimize the risk of functional decline following epilepsy surgery. ESM is completed by utilizing subdural grid or depth electrodes (stereo-electroencephalography [sEEG]) in combination with behavioral evaluation of language. Despite technological advances, there is no standardized method of assessing language during pediatric ESM. To identify current clinical practices for pediatric ESM of language, we surveyed neuropsychologists in the Pediatric Epilepsy Research Consortium. Results indicated that sEEG is used for functional mapping at >80% of participating epilepsy surgery centers (n = 13/16) in the United States. However, >65% of sites did not report a standardized protocol to map language. Survey results indicated a clear need for practice recommendations regarding ESM of language. We then utilized PubMed/Medline and PsychInfo to identify 42 articles that reported on ESM of language, of which 18 met inclusion criteria, which included use of ESM/signal recording to localize language regions in children (<21 years) and a detailed account of the procedure and language measures used, and region-specific language localization outcomes. Articles were grouped based on the language domain assessed, language measures used, and the brain regions involved. Our review revealed the need for evidence-based clinical guidelines for pediatric language paradigms during ESM and a standardized language mapping protocol as well as standardized reporting of brain regions in research. Relevant limitations and future directions are discussed with a focus on considerations for pediatric language mapping.

Methodological advice for the young at heart investigator: Triangulation to build better foundations

In medicine and science, one is typically taught the main theories in a discipline or field along with standard models before receiving more instructions on how to apply certain methods. The aim of this work is not to address one method, but rather methodology, the study and evaluation of methods, by taking a philosophy of science detour. In this, a critique of biomedicine will be used as a starting point to address some positions regarding reductionism, specifying notions such as systems and mechanisms, as well as regarding the mind-body problem discussing psychosomatic medicine and psychoneuroimmunology. Some recommendations to make science more pluralistic, robust and translationally-relevant will then be made as a way to foster constructive debates on reductionism and the mind-body problem and, in turn, favor more interdisciplinary research.

Analysis and/or Interpretation in Neurophysiology? A Transatlantic Discussion Between F. J. J. Buytendijk and K. S. Lashley, 1929-1932

In the interwar period, biologists employed a diverse set of holistic approaches that were connected to different research methodologies. Against this background, this article explores attempts in the 1920s and 1930s to negotiate quantitative and qualitative methods in the field of neurophysiology. It focuses on the work of two scientists on different sides of the Atlantic: the Dutch animal psychologist and physiologist Frederik J.J. Buytendijk and the American neuropsychologist Karl S. Lashley, specifically analyzing their critical correspondence, 1929-1932, on the problems surrounding the term intelligence. It discusses the inexplicable anomalies in neurophysiology as well as the reliability of quantitative and qualitative methods. While in his laboratory work Lashley adhered to a strictly analytic approach, Buytendijk tried to combine quantitative methods with phenomenological and hermeneutical approaches. The starting point of their discussion is Lashley's monograph on Brain Mechanisms and Intelligence (1929) and the rat experiments discussed therein. Buytendijk questioned the viability of the maze-learning method and the use of statistics to test intelligence in animals; he reproduced Lashley's experiments and then confronted Lashley with his critical findings. In addition to elucidating this exchange, this paper will, more generally, shed light on the nature of the disagreements and shared assumptions prevalent among interwar neurophysiologists. In turn, it contributes to historiographical debates on localization and functionalism and the discrepancy between analytic (quantitative) and interpretative (qualitative) approaches.