This review of symmetry perception has six parts. Psychophysical studies have investigated symmetry perception for over 100 years (part 1). Neuroscientific studies on symmetry perception have accumulated in the last 20 years. Functional MRI and EEG experiments have conclusively shown that regular visual arrangements, such as reflectional symmetry, Glass patterns, and the 17 wallpaper groups all activate the extrastriate visual cortex. This activation generates an event-related potential (ERP) called sustained posterior negativity (SPN). SPN amplitude scales with the degree of regularity in the display, and the SPN is generated whether participants attend to symmetry or not (part 2). It is likely that some forms of symmetry are detected automatically, unconsciously, and pre-attentively (part 3). It might be that the brain is hardwired to detect reflectional symmetry (part 4), and this could contribute to its aesthetic appeal (part 5). Visual symmetry and fractal geometry are prominent in hallucinations induced by the psychedelic drug N,N-dimethyltryptamine (DMT), and visual flicker (part 6). Integrating what we know about symmetry processing with features of induced hallucinations is a new frontier in neuroscience. We propose that the extrastriate cortex can generate aesthetically fascinating symmetrical representations spontaneously, in the absence of external symmetrical stimuli.

e13608 Background: Poor control of disease- and treatment-related symptoms can impact negatively on quality of life and clinical outcomes in pts with cancer. DPM can improve cancer care by facilitating earlier symptom management, and reducing symptom burden and the need for emergency visits/consultations. However, adherence is a challenge for digital health solutions. We assessed adoption/adherence, duration of use, user experience, and perceived clinical impact of treatment-/disease-specific DPM modules in pts with LA/M non-small/small cell lung or HER2-positive breast cancer. Methods: Eligible pts were treated with locally approved and reimbursed drugs alongside use of the DPM modules. Pts could use Roche (drug-/drug class-specific) or Kaiku (drug class-specific only) DPM modules, all hosted on the Kaiku Health DPM platform. Respective thresholds for positive adoption and week 1–6 adherence (primary objectives) were 60% and 70%. Secondary objectives were user experience and clinical impact. Data were collected via questionnaires or extracted directly from the DPM platform. Results: At data cutoff (December 1, 2021), 93 pts were enrolled in eight clinics in Estonia, Finland, Greece, Norway, and Spain. The majority of pts had lung cancer, 52/79 (65.8%) had stage IV cancer, 72/79 (91.1%) had an Eastern Cooperative Oncology Group performance status of 0/1, and 30/52 (57.7%) were aged ≥60. Of the 52 pts and 20 healthcare professionals (HCPs) who completed a user experience questionnaire at Week 6, 37% and 30%, respectively, had previous experience with DPM. Pt adoption was 83.8% and adherence in weeks 1–6 was 73.4%. Average weekly time on the platform was ≤18 minutes for pts (median: 1–5 minutes per symptom questionnaire). HCPs spent a weekly average of 1–6 minutes per pt reviewing symptom reports on the platform. Most pts (87%) and HCPs (82%) were satisfied/very satisfied with the service and found it easy/very easy to use. Symptoms were described as fully/mostly covered by the tailored symptom questionnaire by 81% of pts and 71% of HCPs. Upon completion of a symptom questionnaire, pts received tailored feedback, on which half took action, most often with self-management instructions for mild/moderate symptoms. After 6 weeks of use, most pts and HCPs agreed that the Roche and Kaiku Health DPM service helps pts to be better informed about their disease/care (71% and 95%, respectively), facilitates better pt–care team discussions (79% and 81%), and improves cancer care (60% and 71%). Conclusions: The tailored DPM modules had high pt adoption/adherence in the first 6 weeks of use. Most pts and HCPs had positive user experiences with the DPM platform. Care impact experience was positive for both pts and HCPs in terms of improved pt education, pt–HCP communication, and overall cancer care.

Background: Recent evidence suggests that the dorsal medial frontal cortex (dMFC) may make an important contribution to perceptual decision-making, and not only to motor control. Objective/hypothesis: By fitting psychometric functions to behavioural data after TMS we tested whether the dMFC is critical specifically for the precision and/or bias of perceptual judgements. Additionally we aimed to disentangle potential roles of the dMFC in dealing with perceptual versus response switching. Methods: A subjective visual vertical task (SVV) was used in which participants weight visual (and other, e.g., vestibular) information to establish whether a line is oriented vertically. To ensure a high perceptual demand (putatively necessary to demonstrate a dMFC involvement) SVV lines were presented inside pop-out targets within a visual search array. Distinct features of perceptual performance were analysed before as compared to following theta-burst TMS stimulation of the dMFC, a control site, or no stimulation, in three groups, each of 20 healthy participants. Results: dMFC stimulation improved the precision of verticality judgments. Moreover, dMFC stimulation improved accuracy, selectively when response switches occurred with perceptual repeats. Conclusion: These findings point to a causal role of the dMFC in establishing the precision of perceptual decision making, demonstrably dissociable from an additional role in motor control in attentionally demanding contexts.

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