Overview

One of the persistent puzzles in anomalous cognition research is why certain targets yield stronger psi effects than others. While remote viewing studies had demonstrated statistically significant results, the mechanisms governing target accessibility remained unclear. May approached this problem from a physicist’s perspective, asking whether targets possess measurable physical properties that correlate with psi performance.

Rather than treating targets as interchangeable stimuli, May hypothesized that intrinsic properties of target images (particularly their information complexity) might function as sensory parameters for anomalous perception. This framework shifted the conceptual ground: instead of asking whether psi exists, it asked what properties targets must have for psi to operate effectively. The answer May developed centered on Shannon entropy, a mathematical measure from information theory that quantifies the degree of disorder, complexity, and unpredictability in a system.

This research program had practical implications for remote viewing operations and theoretical implications for understanding psi as a natural phenomenon with measurable constraints and sensory characteristics.

Shannon entropy as target property

Shannon entropy, derived from information theory, measures the average amount of information or uncertainty contained in a message or image. A highly ordered, predictable target (such as a blank wall or simple geometric shape) has low entropy; a complex, varied, or random target has high entropy. May proposed that entropy itself might be an intrinsic property of remote viewing targets that influences whether anomalous cognition can access and transmit information about them.

In 1994, May, Spottiswoode, and James published a foundational paper proposing that Shannon entropy could serve as a quantifiable target property relevant to anomalous cognition.¹ Rather than relying solely on subjective judgments about target complexity, this approach provided an objective, mathematically grounded metric. The hypothesis was that targets with particular entropy profiles might be more or less accessible to psi perception, much as the human eye is more sensitive to certain wavelengths of light.

This conceptualization represented a significant departure from earlier remote viewing research, which had typically treated targets as functionally equivalent stimuli. By identifying entropy as a measurable property, May created a framework for systematic investigation of target-psi interactions. The approach also aligned with his broader theoretical orientation: if anomalous cognition operates according to natural principles, those principles should be discoverable through rigorous measurement and analysis.

Target pool development and classification

To test hypotheses about target properties and anomalous cognition, May and colleagues developed a comprehensive target pool with systematic classification methods. In 1999, May, Faith, Blackman, Bourgeois, Kerr, and Woods published work describing a target pool and database designed specifically for anomalous cognition experiments.³ This resource provided researchers with targets that had been characterized according to multiple properties, including entropy measures.

The target pool represented a methodological advance because it allowed researchers to move beyond ad hoc target selection. Instead of choosing targets intuitively or randomly, experimenters could now select targets with known properties, enabling controlled investigation of how those properties affected psi performance. The database approach also facilitated meta-analysis and cross-study comparisons, strengthening the empirical foundation for claims about target-psi relationships.

Later, in 2014, May, Hawley, Chaganti, and Ratra extended this work using fuzzy set methodology to classify targets.⁵ Fuzzy set theory allows for more nuanced categorization than binary classification schemes; a target can be partially a member of multiple categories rather than belonging exclusively to one. This approach acknowledged that target properties exist on continua rather than in discrete bins, providing a more sophisticated framework for understanding target-anomalous cognition relationships.

Entropy gradient and AC performance

A key refinement of May’s entropy hypothesis involved not just the absolute entropy of a target, but the gradient of entropy, the rate of change in complexity across different regions of a target image. In 2000, May, James, Spottiswoode, and Faith published research examining the correlation between entropy gradient and anomalous cognition performance.²

The entropy gradient concept proposed that transitions between high-entropy and low-entropy regions within a target image might serve as detectable features for anomalous perception. Just as the human visual system is particularly sensitive to edges and boundaries where contrast changes, anomalous cognition might be especially responsive to entropy transitions. This hypothesis suggested that targets with pronounced entropy gradients (clear boundaries between complex and simple regions) would yield stronger psi effects than targets with uniform entropy throughout.

The correlation analysis provided empirical support for this refined hypothesis. May and colleagues found that the gradient of Shannon entropy correlated with the quality of anomalous cognition responses, suggesting that psi perception is not uniformly sensitive to all target properties but rather shows selectivity for particular information structures. This finding had important implications: it suggested that anomalous cognition operates with specific sensory characteristics rather than as a generalized, undifferentiated access to target information.

Anomalous cognition as sensory system

The entropy gradient research led May to propose a more comprehensive model: that anomalous cognition functions as a sensory system with its own detection thresholds, information-processing constraints, and preferred stimulus properties.² This represented a conceptual shift from viewing psi as a mysterious, unconstrained ability to viewing it as a natural phenomenon with measurable characteristics.

In conventional sensory systems, perception is not equally sensitive to all possible stimuli. The human eye has wavelength preferences, the ear has frequency sensitivity ranges, and touch has spatial resolution limits. May’s framework suggested that anomalous cognition similarly has optimal stimulus properties, in this case, targets with particular entropy characteristics and entropy gradients. Just as the eye cannot perceive infrared radiation regardless of how bright it is, anomalous cognition might have inherent limitations on what types of information it can access.

This sensory system model had several important implications. First, it suggested that psi performance variations across studies might reflect differences in target properties rather than differences in psi ability per se. Second, it implied that optimizing target selection could enhance psi detection, much as using appropriate wavelengths of light enhances visual perception. Third, it positioned anomalous cognition within a naturalistic framework where it operates according to discoverable principles rather than as a supernatural or entirely random phenomenon.

Implications and applications

May’s work on target entropy had several practical and theoretical implications for parapsychology research. On the practical level, understanding which target properties enhance anomalous cognition performance could improve experimental design. Researchers could select or construct targets specifically designed to maximize psi detection, rather than relying on arbitrary or intuitive choices. This optimization approach could increase statistical power and reduce the sample sizes needed to demonstrate psi effects.

The entropy framework also provided a bridge between parapsychology and information theory, a connection that had been largely absent from earlier psi research. By grounding anomalous cognition in concepts from physics and mathematics, May positioned parapsychology within a broader scientific context. This approach made psi phenomena more amenable to quantitative analysis and theoretical modeling.

Theoretically, the entropy work supported May’s broader vision of anomalous cognition as a natural phenomenon operating according to discoverable principles. If psi is sensitive to entropy properties, then it responds to measurable, objective features of the world rather than operating through mysterious or supernatural mechanisms. This naturalistic framing did not require skeptics to accept psi as real, but it did require them to engage with the empirical evidence on its own terms rather than dismissing psi as inherently implausible.

The target pool and classification methods developed through this research also created infrastructure for future studies. By providing researchers with systematically characterized targets, May and colleagues enabled more rigorous investigation of target-psi relationships across multiple laboratories and experimental contexts. This infrastructure approach reflected May’s commitment to building cumulative, reproducible science in parapsychology.