Research & Evidence Base
For more than two decades, the Purple Framework has been used as a core research tool across psychology, cognitive neuroscience, psychophysiology, pharmacology and occupational performance. Its ability to induce controlled multi-tasking stress while capturing detailed behavioural and reaction-time data has made it valuable in studies examining stress responses, immunity, performance, coping styles and the effects of interventions.
Key Research Areas
Acute Stress & Cognitive Load
The Framework reliably increases cognitive workload using simultaneous tasks and adjustable intensities, allowing researchers to measure attention, accuracy and performance under sustained stress.
Stress, Immunity & Physiology
Studies have examined changes in secretory Immunoglobulin A (S-IgA) following multi-tasking stress, revealing how immune responses differ based on workload intensity and individual coping styles.
Intervention Studies
Used in trials assessing the effects of herbal extracts such as lemon balm (Melissa officinalis), the Framework has demonstrated reductions in subjective stress without impairing performance accuracy.
Individual Differences & Coping
Research has shown clear distinctions between individuals who cope well under increasing workload and those who find the tasks overwhelming, offering a way to study stress resilience.
Occupational & Applied Research
Custom modules have enabled researchers to simulate clinical and professional environments, allowing performance to be measured under realistic and controlled conditions.
Featured Research Highlights
Workload Intensity & Immune Function
Medium-intensity multi-tasking was shown to temporarily increase S-IgA, while high-intensity workloads produced decreases — demonstrating how workload affects immune activation and recovery.
Coping Styles & Repeated Exposure
Repeated testing sessions revealed that individuals who perceived tasks as overly demanding showed reductions in immune markers and higher rates of minor illness.
Herbal Extracts & Stress Reduction
Kennedy et al. (2004) used the Framework to show that lemon balm significantly reduced stress responses without affecting accuracy or reaction times.
Medical Training & Realistic Workload Simulation
The Medical Research Council and University of Bristol used bespoke medical modules to simulate clinical decision-making and measure performance under pressure.
Why Researchers Choose the Purple Framework
- Proven in peer-reviewed research for more than 25 years
- Reliable multi-tasking stress induction
- Fine control over workload, task intensity and competition
- Real-time accuracy and reaction-time data
- Modular and customisable task environments
- Suitable for rapid experiments and long-form protocols
- Intuitive interface for participants
- Clean data export for statistical analysis
- Ecologically valid — mirrors real cognitive demands
Selected Publications Using the Purple Multitasking Framework
Below is a list of peer-reviewed papers, theses, patents and clinical studies that have used the Purple Research Framework, the Purple Multitasking Framework (MTF), or the earlier Defined Intensity Stressor Simulation (DISS).
Foundational & Psychobiology Research
These papers established the Framework (originally “DISS – Defined Intensity Stressor Simulator”) as a reliable multi-tasking stressor:
Wetherell MA & Sidgreaves MC (2003)
The Defined Intensity Stressor Simulation (DISS): Effects of increasing intensity on S-IgA reactivity and perceptions of workload, stress and arousal.
British Psychological Society (Conference paper).
Wetherell MA & Sidgreaves MC (2005)
Secretory Immunoglobulin-A reactivity following increases in workload intensity using the Defined Intensity Stressor Simulation (DISS).
Stress and Health, 21(2), 99–106.
Wetherell MA et al. (2014)
The Multitasking Framework: Effects of increasing workload on acute psychobiological stress reactivity.
Human Psychopharmacology.
Wetherell MA et al. (2012)
The effects of multitasking on psychobiological stress reactivity and cognitive performance.
Human Psychopharmacology.
Kennedy DO et al. (2004)
Melissa officinalis (lemon balm) attenuates laboratory-induced stress without impairing performance.
Uses a 20-min DISS protocol.
Johnson AJ (2011)
Chewing gum moderates multi-task induced shifts in stress, mood and alertness.
Appetite / Physiology & Behavior.
Stress, Immunity & Physiological Response
Studies using the Framework to explore psychoneuroimmunology:
Wetherell MA & Sidgreaves MC (2005)
Core S-IgA stress response paper, widely cited.
Johnson AJ (2010, BPS Poster)
Multitask-induced stress and immune response.
Uses DISS to explore S-IgA behaviour during workload stress.
Reviews / psychobiology summaries
Multiple reviews reference DISS as a validated multi-tasking stressor capable of inducing immune changes.
Neuroimaging, Attention & Cognitive Control
Used alongside fNIRS, EEG, eye tracking and physiological monitoring:
Roberts CA et al. (2015)
Differences in prefrontal blood oxygenation during an acute multitasking stressor in ecstasy polydrug users.
Participants completed a DISS / Purple Framework session during fNIRS monitoring.
Frontiers in Psychology (2021) — Wetherell et al.
Describes the Purple Multitasking Framework (MTF; Purple Research Solutions, UK) as a performance-driven stressor.
Van Schrojenstein Lantman (2017)
PhD thesis on multitasking, personality and stress using the Purple MTF.
Nutraceutical, Herbal & Pharmacological Intervention Studies
The Framework is heavily used in dietary supplement research because it provides a repeatable cognitive stress test:
Wong RHX et al. (2012)
Effects of wild green oat extract (Neuravena®) on cognitive performance.
Uses a computerised multi-tasking battery (Purple Research Solutions, UK).
Wong RHX et al. (2016)
Acute resveratrol consumption improves neurovascular coupling.
Includes the Purple Framework as a cognitive demand measure.
Dzator JSA et al. (2023)
Resveratrol supplementation in hormonal migraineurs.
Uses a four-task Purple Framework workload test.
Howe PRC et al. (2018)
Omega-3 PUFA supplementation and cognitive performance.
Uses the Computerised Multitasking Test Battery (Purple Framework).
Blackcurrant / Polyphenol / Flavonoid trials (Gillies NA et al., 2024)
Use the Purple MTF as a high-demand cognitive workload test.
Occupational & Applied Research
Medical Research Council & University of Bristol
Custom clinical-decision modules were developed to study medical multitasking under load.
MRC trials on early-career doctors
Used custom developed bespoke medical versions of the Multitasking Framework.
Applied human-performance research
Multiple unpublished MSc/PhD projects using Purple Framework as a controlled multitasking stressor.
Theses, Academic Reports & Posters
Johnson AJ (2010)
British Psychological Society poster: Multi-tasking induced stress and psychobiological response.
Van Schrojenstein Lantman (2017)
PhD thesis on personality, stress and multitasking using the Purple MTF.
Numerous undergraduate & MSc dissertations
Often use the Framework as a controlled multi-tasking stressor (not all indexed publicly).
Patents Citing the Purple Framework (MTF/DISS)
These patents explicitly cite the Framework as a validated stressor for cognitive testing:
WO2014085851A1 / JP2016501235A / KR20150103679A
Uses of Bacopa monnieri extract.
Describes the Purple Multitasking Framework (MTF) as:
- A validated laboratory stressor
- Capable of inducing measurable psychophysiological stress responses
- Superior to public-speaking stressors for repeatability
These patents are rich with citations to The Purple Framework platform.
Registered Clinical Trials
ACTRN12614000891628
Resveratrol and cerebrovascular function; includes the Purple Framework cognitive test battery as an outcome measure.
Associated ANZCTR & EUCTR Trials
Use the Framework under descriptions like:
“computerised multi-tasking task battery”,
“multi-tasking workload test”, or
“Purple Framework cognitive stress test”.
Media & Broadcast Use
BBC Horizon (2022)
How to Sleep Well with Michael Mosley
Used the Purple Framework to measure cognitive performance under a reduced sleep regime.