In the contemporary forensic landscape, attorneys increasingly encounter scientific evidence that purports to link cognitive test scores and neuroimaging findings to specific brain structures and behavioral outcomes. Understanding the scientific strengths and limitations of this evidence is essential for effective advocacy whether presenting or challenging expert testimony. This Forensic Update reviews recent literature on how closely cognitive test scores can be localized to brain regions, discusses the integration of imaging and psychometric data, and offers guidance on their appropriate and inappropriate uses in forensic settings.

Neuropsychological Tests and Anatomical Localization

Neuropsychological tests are standardized assessments designed to quantify performance across distinct cognitive domains such as memory, executive function, and language. These batteries produce scores widely used in clinical settings to infer functional impairment and guide diagnosis. However, the ability of such scores to pinpoint dysfunction in specific brain regions remains scientifically circumscribed.

Classically, cognitive tests have been interpreted within a framework of brain-behavior relationships supported by lesion studies and clinical observations. For instance, memory tasks have frequently been associated with medial temporal lobe functioning, and language tests with left-hemisphere structures. Meyers and colleagues found that traditional CT and MRI findings showed concordance with expected neuropsychological test localizations in about 84% of cases studied, indicating a reasonable, but not perfect link between test performance and structural abnormalities (Meyers et al., 2009). Yet, their review underscored that localization is not the primary goal of modern neuropsychological testing, which is often more sensitive to global or domain-specific deficits than to precise anatomical loci.

Moreover, comprehensive review of cognitive assessment tools shows that while performance on tasks such as the Trail Making Test or memory batteries can suggest frontal or temporal lobe involvement, these associations are probabilistic, not deterministic (Kopp, Rößer, & Tabeling, 2015). In many cases, overlapping networks support cognitive domains, limiting precise localization based solely on test scores.

Neuroimaging Correlates of Cognitive Performance

Advances in structural and functional imaging have renewed interest in linking brain anatomy and activity patterns with cognitive performance. Functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI), and resting-state connectivity analyses now allow researchers to observe brain–behavior associations in vivo.

Recent large-scale studies, such as those using the NIH Toolbox Cognition Battery with imaging data from thousands of participants, have demonstrated associations between composite cognitive scores and measures of white matter integrity, cortical thickness, and functional connectivity. For example, fluid cognition scores have been linked to greater white matter microstructural integrity on DTI and distinct patterns of network connectivity, though the relationships vary by cognitive domain and imaging modality (Snitz, et. al., 2020). These relationships underscore that cognitive ability correlates with distributed brain systems rather than isolated focal regions.

Similarly, in neurodegenerative conditions such as progressive supranuclear palsy, voxel-wise analyses of glucose metabolism (FDG-PET) revealed that performance on specific neuropsychological tests correlated with metabolic activity in distinct frontal and parietal regions (Doll-Lee et al., 2025). Such findings are informative for understanding disease mechanisms and guiding diagnosis, but they also highlight that imaging correlates are context-dependent and influenced by clinical variables.

It is also important to recognize that meta-analytic work on psychiatric traits like psychopathy shows weak spatial convergence across studies, with heterogeneous peak activations mapping onto broad brain networks rather than specific loci (Dugré et al., 2025). These results caution against oversimplified localization claims and reinforce the concept of distributed functional networks rather than singular “crime centers” in the brain.

Parieto-Frontal Integration Theory and General Intelligence

The Parieto-Frontal Integration Theory (P-FIT) of intelligence represents one of the more developed models linking psychometric constructs to neuroimaging data. Jung and Haier’s work synthesizes evidence showing that scores on general intelligence tests correlate with structural and functional measures in frontal and parietal cortices, as well as connected networks (Jung & Haier, 2007). While these findings are compelling in research contexts, they are correlational and do not allow for reliable individual-level localization in forensic settings.

Furthermore, broad psychometric constructs like “g” (general intelligence) have modest correlations with overall brain volume and structural measures (e.g., frontal and temporal cortices) on the order of about 0.25–0.4 (Cox, et. al., 2019). Such effect sizes reflect population-level associations, not deterministic mappings that could definitively place specific test performance within a forensic individual’s brain anatomy.

Forensic Considerations: Admissibility and Interpretation

In forensic cases, neuroimaging evidence is often introduced alongside neuropsychological testing to support claims about cognitive impairment or culpability. Attorneys must be vigilant about the scientific validity and interpretative limits of such evidence.

One longstanding example is the attempt to use fMRI for lie detection. While laboratory studies have explored neural signatures associated with deception, the literature consistently emphasizes the need for rigorous clinical trials to establish error rates and external validity before such techniques can meet legal reliability standards (Langleben & Farwell, 2012). Without established error rates and clear validation, introducing fMRI lie detection remains scientifically and legally tenuous.

Similarly, imaging data may show structural abnormalities (e.g., lesions, atrophy, etc.), but interpreting these findings as causally linked to specific behavioral outcomes absent a comprehensive clinical context is fraught with risk. Courts applying Daubert and Frye standards require that scientific evidence be grounded in well-accepted methodologies with known reliability and validity. The probabilistic nature of brain–behavior associations requires expert testimony that carefully frames imaging results as correlates, not definitive indicators of cognitive function.

Integrating Imaging and Test Scores: Best Practices

The literature supports a multimodal approach in which neuropsychological test scores and imaging findings are interpreted conjointly within the broader clinical and behavioral context. Imaging is most valuable when it corroborates a well-documented pattern of cognitive deficit that aligns with established neuropathological knowledge. Conversely, test scores can gain explanatory depth when supported by imaging evidence showing relevant structural or functional abnormalities.

However, attorneys should avoid overreliance on either modality in isolation. Neuroimaging should not be used to validate test scores in a vacuum, nor should test scores be presented as precise markers of localized brain injury without rigorous scientific backing.

Conclusion

In forensic settings, the linkage between cognitive test scores and specific brain regions is scientifically grounded in probabilistic associations, not deterministic localization. Modern neuroimaging enriches our understanding of brain–behavior relationships, but it does not, by itself, offer definitive answers about individual cognitive function or legal culpability. Attorneys must work with qualified experts who appreciate the limitations of the science, articulate the appropriate level of inference, and contextualize findings within a comprehensive clinical narrative. By recognizing both the potential and the boundaries of imaging and psychometric evidence, legal professionals can better navigate complex cases where neuroscience intersects with the law. ◆

References

• Calvillo, M. (2020). Neuroimaging and psychometric assessment of mild cognitive impairment. Frontiers in Psychology.
• Doll-Lee, J., et al. (2025). Associations between neuropsychological profile and regional brain FDG uptake in progressive supranuclear palsy. Journal of Parkinson’s Disease.
• Dugré, J. R., et al. (2025). Divergent neuroimaging findings converge onto a common functional network in psychopathy. Neuroscience Review.
• Jung, R. E., & Haier, R. J. (2007). The parieto-frontal integration theory (P-FIT) of intelligence: Converging neuroimaging evidence. Behavioral and Brain Sciences, 30(2), 135–187.
• Kopp, B., Rößer, N., & Tabeling, S. (2015). Errors on the Trail Making Test are associated with right hemispheric frontal lobe damage in stroke patients. Behavioural Neurology, 2015, 309235.
• Langleben, D. D., & Farwell, L. A. (2012). Using brain imaging for lie detection: Science and law. NeuroImage, 59(1), 119–130.
• Meyers, J. E., et al. (2009). CT and MRI correlations with neuropsychological tests. The Clinical Neuropsychologist, 23(3), 475–490.
• Snitz, B. E., Tudorascu, D. L., Yu, Z., Campbell, E., Lopresti, B., Laymon, C., Minhas, D., Nadkarni, N., Aizenstein, H., Klunk, W., Weintraub, S., Gershon, R., & Cohen, A. (2020). Associations between NIH Toolbox Cognition Battery and in vivo brain amyloid and tau pathology in non-demented older adults. Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, 12(1), e12018.