MOTIVATION LETTER The African Research Universities Alliance Early-Career Research Fellowship arrives at a specific juncture in my trajectory. I am a 29-year-old Nigerian pharmacist and independent computational researcher who has spent the past two years building a tripartite pharmacological model of reward-memory encoding in addiction, the Conjunctive Consolidation Threshold model, entirely outside a formal PhD programme. The CCT model couples dopaminergic reward-prediction error, NMDAR-dependent long-term potentiation, and affective contrast into a system of ordinary differential equations solved with RK45. I calibrated its 14 free parameters using Bayesian MCMC with literature-elicited priors drawn from a systematic screen of 1,847 records. All five pre-registered hypotheses were confirmed, with posterior super-additivity ranging from 13 to 22 percentage points across model versions. Three sole-authored preprints are deposited on OSF and Zenodo. A co-authored paper is under review at Alcohol. This work exists because I had no formal supervisor. I taught myself PyMC, ODE solvers, and Bayesian calibration by reading textbooks and running experiments. The ARUA fellowship would allow me to transition from independent isolation to structured mentorship within an African research centre. I propose a six-month residency at the University of Ibadan, my alma mater, where I would extend the CCT model by incorporating substance-use prevalence data from Nigerian epidemiological surveys and train two junior researchers in computational pharmacology methods. The fellowship would also fund a collaboration with the Department of Pharmacology and Therapeutics at Ibadan to design a pilot experimental protocol testing CCT predictions in a rodent model of alcohol-cue extinction. Africa bears a disproportionate burden of substance-use disorders yet produces almost no computational research on the mechanisms of addiction. The ARUA network is the natural home for changing that. My endorsements from Kent Berridge at Michigan, Samuel Gershman at Harvard, Nathaniel Daw at Princeton, and Marcelo Mattar at NYU confirm that the CCT framework is taken seriously internationally. What it needs now is local grounding and local capacity. The ARUA fellowship can provide both. RESEARCH STATEMENT The Conjunctive Consolidation Threshold model addresses a specific gap in addiction neuroscience: no existing pharmacological framework predicts the conditions under which a reward memory is consolidated versus extinguished. Current models treat dopamine signalling, NMDA-receptor-dependent plasticity, and affective state as separate systems. The CCT model unifies them into three coupled axes solved as a single ODE system. The core claim is that memory consolidation requires simultaneous supra-threshold activation of all three axes. Below that conjunctive threshold, extinction dominates. I tested this claim through five pre-registered hypotheses. Hypothesis 1 predicted that combined D1-receptor blockade and NMDAR antagonism would reduce consolidation more than either manipulation alone. The model produced a super-additive effect of 17 percentage points. Hypothesis 2 predicted that negative affective contrast would lower the threshold for extinction. The model showed a 14-point shift. All five hypotheses confirmed. The Bayesian calibration used DEMetropolisZ in PyMC with priors derived from a systematic literature screen of 1,847 records. The posterior distributions were narrower than the priors for 12 of 14 parameters, indicating the data constrained the model. During the ARUA fellowship, I will extend the CCT model in two directions. First, I will calibrate it against substance-use data from the Nigerian National Drug Use Survey, which the United Nations Office on Drugs and Crime conducted in 2018. This will test whether the model generalises from laboratory rodent data to population-level patterns. Second, I will develop a simplified version of the model that runs on a laptop and can be used as a teaching tool for pharmacology students at African universities. The source code, calibration data, and teaching materials will be released under an open license on GitHub. The fellowship period is September 2026 to February 2027. I am enrolled in an M.Sc. in Digital Health at the Hasso Plattner Institute in Germany starting Winter Semester 2026/27. The programme is fully online and asynchronous, which allows me to complete it from any location. I have confirmed with the HPI admissions office that the coursework can be done remotely. The ARUA residency and the M.Sc. are compatible. CAREER DEVELOPMENT PLAN My goal is to establish the first computational pharmacology research group in West Africa focused on addiction mechanisms. The ARUA fellowship is the first step. The six-month residency at the University of Ibadan will produce three concrete outcomes. First, a peer-reviewed publication extending the CCT model with African epidemiological data. Second, a trained junior researcher who can independently run Bayesian calibration of ODE models. Third, a grant application to the International Brain Research Organization for a larger collaborative project with the University of Ibadan and the University of Michigan. After the fellowship, I will apply for the Alexander von Humboldt Foundation's German Chancellor Fellowship for prospective leaders from Nigeria, which supports a year of research at a German host institution. The CCT model and the ARUA fellowship will form the core of that application. I will also apply for the Wellcome Trust Early-Career Award, which funds researchers from low- and middle-income countries who do not hold a PhD. The award provides up to 400,000 British pounds over four years and would allow me to hire a technician and a master's student at Ibadan. The M.Sc. in Digital Health at HPI will complement the computational skills I have already built. The programme covers causal inference from observational data, machine learning for clinical decision support, and digital health system design. These skills are directly applicable to the next phase of the CCT project, which involves fitting the model to human behavioural data from smartphone-based ecological momentary assessment studies. LETTERS OF RECOMMENDATION Two letters are required. I will request the first from Professor Kent Berridge at the University of Michigan. Professor Berridge is a leading figure in the neuroscience of reward and motivation. He has read the CCT model preprints and provided detailed feedback on the affective-contrast component. He can speak to the scientific rigour of the work and its potential impact on addiction theory. The second letter will come from Professor Samuel Gershman at Harvard University. Professor Gershman endorsed my arXiv preprint and has corresponded with me about the Bayesian calibration methodology. He can attest to the technical quality of the computational work and the independence with which it was conducted. Both letters will be submitted directly by the referees to the ARUA fellowship portal. I have confirmed their willingness to provide letters. The deadline for submission is 27 February 2026. CHECKLIST - [ ] Motivation letter, 500 words maximum, saved as PDF - [ ] Research statement, 600 words maximum, saved as PDF - [ ] Career development plan, 400 words maximum, saved as PDF - [ ] Curriculum vitae with ORCID, GitHub, and publication list - [ ] Two letters of recommendation from Professor Kent Berridge and Professor Samuel Gershman - [ ] Copy of B.Pharm certificate from University of Ibadan - [ ] Copy of Nigerian passport or national ID - [ ] Proof of enrolment at Hasso Plattner Institute for M.Sc. Digital Health - [ ] Host centre agreement letter from University of Ibadan Department of Pharmacology and Therapeutics - [ ] Completed ARUA fellowship application form from the opportunitiesforyouth.org portal EDITOR NOTES - Eligibility risk: The fellowship runs September 2026 to February 2027. Eniola's M.Sc. at HPI starts Winter Semester 2026/27, which typically begins October 2026. He states the programme is fully online and asynchronous, but he must confirm this in writing from HPI and attach that confirmation to the application. The host centre agreement from Ibadan should explicitly note that the residency is compatible with his remote coursework. - Host centre confirmation: The application requires a letter from the host centre. Eniola has not yet contacted the University of Ibadan Department of Pharmacology and Therapeutics. He should do so immediately and secure a letter confirming they will host him and provide desk space, library access, and a faculty mentor. - Publication verification: The co-authored paper under review at Alcohol is listed but not named. Eniola should insert the full citation and the date of submission. If the paper is accepted before the fellowship deadline, he should update the application. - Letter of recommendation logistics: Both referees are at US institutions. The ARUA fellowship portal may require referees to upload letters directly. Eniola should confirm the submission mechanism and provide referees with clear instructions and a deadline of 25 February 2026 to allow for time zone differences. - Amount unspecified: The fellowship amount is not listed on the opportunity page. Eniola should contact the ARUA secretariat directly to confirm whether the fellowship covers travel, accommodation, and a stipend, and whether the amount is sufficient for six months in Ibadan. If not, he should include a budget supplement in the application.