Here we review the early research of three pioneering investigators of visual mental imagery (VMI): Fechner in Germany, Taine in France, and Galton in England.

Gustav Fechner’s 1860 work on mental imagery was his magnum opus, Elemente der Psychophysik (Elements of Psychophysics), predating both Taine and Galton’s investigations and placing him as one of the earliest systematic observers of individual differences in this domain.

While Fechner is best known for founding psychophysics and the Weber-Fechner Law (the mathematical relationship between physical stimuli and perceived sensation), the second volume of his 1860 work includes extensive, detailed phenomenological observations on visual mental imagery.

Fechner’s 1860 Research on Mental Imagery

Fechner’s contribution was about establishing the enormous variability in the vividness and control of images among different individuals.

1. Formal Observation of Individual Differences

Fechner documented systematic individual differences in imagery, focusing on his own experiences and those of a small group of colleagues (mainly intellectuals).

• Vividness and Coloration: He noted “wide individual differences were evident in both vividness and colouration” of memory and fantasy images.
• Projection: He found that some individuals reported stronger imagery with eyes open, others with eyes closed, and that most localized the images in external space, but these traits varied across his participants.
• Control and Stability: He observed that the ability to hold an image steadily was highly variable. Fechner himself noted the difficulty in holding an image for even a short time, stating, “it must, so to speak, always be recreated anew”.

2. Distinction from After-Images

A significant part of Fechner’s research was meticulously distinguishing three different types of internal visual experience:

1. After-images: Direct sensory after-effects (automatic, involuntary).
2. Memory Images: Recalled images (dependent on volition, less intense).
3. Phantasy Images: Creative or imaginary images.

Fechner noted that the characteristic differences between these types were “more or less variable and give way to transitions in different persons” (Source 1.1), directly establishing the variable nature of internal experience as a subject for study.

3. Fechner ‘Opened the Mental Imagery Door’

• Fechner’s Role was that of Innovator: Fechner explicitly discovered a wide variation in visual mental imagery including its lack in a few people (notably, himself). His observations were quantitative (measuring sensations) and qualitative (describing phenomenology), focused on the degree of vividness in the middle and upper range.
• The Existence of the Non-Imager: While Fechner’s work established that vividness varied greatly, the crucial step of isolating and reporting that some individuals have virtually no visual experience at all, is credited to Francis Galton in 1880.
• Fechner’s importance lies in providing the earliest systematic framework for studying individual differences in the phenomenology of mental imagery that ‘opened the door’ for Galton’s quantitative approach.

Taine’s 1870 Research on Mental Imagery

Hippolyte Taine (1828–1893) was a prominent French thinker, critic, and historian who made significant contributions to empirical psychology, particularly concerning mental imagery, primarily through his major work, De l’intelligence (On Intelligence), published in 1870. Taine’s key contributions to mental imagery research include:

1. Emphasis on the Primacy of Images in Consciousness

Taine’s psychological approach was rooted in his commitment to positivism and the scientific method, opposing the speculative and introspective approaches of earlier schools of thought.

• Consciousness as a System of Images: Taine described consciousness as an “ever-unstable balance of power among images.” This perspective placed internal images, or mental representations, at the core of mental function. He viewed the concept of a coherent “self” as an “invention of metaphysicians and an illusion,” instead focusing on the flux of these fundamental images.

• Empirical Psychology: Alongside figures like Théodule Ribot and Pierre Janet, Taine is considered a founder of empirical psychology, promoting the study of personality and mental processes through experimentation, the search for causes, and the study of pathological cases—a methodology he applied to the study of images.

2. The Link Between Imagery and Sensation

Taine’s work was influential in establishing an early, scientifically-oriented view of how sensations transform into mental images:

• Sensation and Memory: He detailed how the residue of past sensations forms the basis of mental images. The image is essentially a weakened, recalled sensation. This laid groundwork for the later “vision in reverse” models of mental imagery formation.

• The Power of Association: Taine emphasized the role of association in forming complex ideas and the sense of self, arguing that these are built upon the linking of primary images.

3. Study of Pathological Cases (Hallucinations)

A crucial part of Taine’s methodology and influence was his study of abnormal mental states, such as hallucinations, to understand normal functioning:

• Continuum Hypothesis: Taine’s interest in hallucinations—including his famous correspondence with novelist Gustave Flaubert, who shared details of his own artistic “hypertrophy” and quasi-hallucinatory experiences—allowed him to explore the idea that hallucinations are simply extremely vivid mental images that are misattributed to an external source.

• Reality Monitoring: This line of thinking anticipated later psychological theories that hallucinations result from a failure of “reality monitoring”—the process of distinguishing between internally generated information (imagery) and externally derived information (perception).

Taine’s work in De l’intelligence helped pivot the study of mental imagery from philosophical speculation to a subject of scientific and physiological inquiry. His emphasis on the image as a basic constituent of consciousness, his efforts to link sensation and imagery, and his focus on pathological cases like hallucinations were seminal to the development of cognitive psychology’s early investigations into internal representation.

Galton’s 1880 Research on Mental Imagery

Francis Galton (1822–1911), a renowned English polymath, statistician, and pioneer of differential psychology, made a pivotal and distinctly quantitative contribution to the study of mental imagery. His work, primarily published in the 1880s, shifted the focus of inquiry to individual differences in the vividness of people’s inner experiences.  Galton’s key contributions to mental imagery research:

1. The Development of the Questionnaire Method

Galton pioneered the systematic, quantitative use of self-report questionnaires to study psychological phenomena.

• The “Breakfast-Table Questionnaire”: In his seminal 1880 paper, “Statistics of Mental Imagery,” Galton introduced a questionnaire that asked participants to introspect on and rate their mental image of a specific, recent, and highly familiar scene—typically their breakfast table from that morning.

• Quantitative Measurement: He asked subjects to rate the vividness of the image across several dimensions, including:

  • Illumination: Is the image dim or fairly clear? Is its brightness comparable to the actual scene?

  • Definition: Are all the objects well defined at the same time?

  • Colouring: Are the colors (of the china, toast, etc.) quite distinct and natural?

This methodology was groundbreaking, as it was one of the very first attempts to measure individual differences in a complex cognitive process, moving psychology away from purely general philosophical theories.

2. Discovery of the Spectrum of Imagery Vividness

Galton’s most significant finding was the demonstration of an extraordinary range in people’s self-reported imagery abilities.

• Vast Individual Variation: His results showed that mental imagery existed on a wide spectrum, from those who reported images “quite comparable to the real object” to those who reported no visual imagery whatsoever (a phenomenon he termed “non-imagers”).

• The First Description of Aphantasia: Galton’s work provided the first documented recognition of this lack of a “mind’s eye,.  He noted that many of his colleagues in the scientific world were among these non-imagers, leading him to an (often criticized) conclusion that an over-readiness to perceive clear mental pictures might be “antagonistic to habits of highly generalized and abstract thought.”

3. Establishing Mental Imagery as a Subject of Scientific Study

While Taine emphasized the theoretical importance of the image as the fundamental element of consciousness, Galton established a practical, empirical method for its study.

• Psychometrics: His use of a structured questionnaire, along with his statistical approach to analyzing the results, contributed to the founding of psychometrics—the science of measuring mental capacities and processes.

• Focus on Subjective Experience: Galton’s work demonstrated that the highly subjective experience of mental imagery could be brought into the realm of science, even if the method (introspection/self-report) later faced criticism from behaviorists.

Comparing the three pioneers—Fechner, Taine, and Galton

Illustrates the evolution of mental imagery research by showing how it moved from introspective analysis to population-level surveying and the “discovery” of non-imagers.

The Three 19th-Century Pioneers 

Pioneer	Year(s)	Key Work / Method	Focus of Inquiry	Contribution
Gustav Fechner (Germany)	1860	Elemente der Psychophysik (Elements of Psychophysics)	Psychophysics & Phenomenology.Systematically studied the vividness, stability, and control of memory images and distinguished them from sensory after-images.	Established Individual Differences. Quantitatively and qualitatively observed that the intensity and control of images varied greatly between people. Did not identify non-imagers.
Hippolyte Taine (France)	1870	De l’intelligence (On Intelligence)	Philosophical Psychology. Emphasized the image as the fundamental element of consciousness and mind (“a polypary of images”).	Centrality of the Image. His work made the internal image a central concept in emerging empirical psychology. Did not identify non-imagers.
Francis Galton (UK)	1880	“Statistics of Mental Imagery”	Survey & Statistical Method. Distributed a questionnaire to large groups (especially scientists) asking them to describe the imagery of their breakfast table.	Was surprised to find several prominent scientists who reported an absence of visual mental imagery. His cousin, Charles Darwin, was a notable exception. Recent re-analyses suggest that Galton misinterpreted his own observations (Scientists Are Not Deficient in Mental Imagery: Galton Revised, by William F. Brewer abd Marlene Schommer-Aikins (2006).

Key Takeaways

1. Fechner (1860): Provided the earliest, most detailed systematic analysis of the variable phenomenology of image vividness, laying the conceptual groundwork for treating mental imagery differences as a measurable trait.

2. Taine (1870): Made the image a central concept in psychological theory, influencing French and European thought on consciousness.

3.Galton (1880): The first to employ a large-scale, questionnaire method that exposed the existence of a non-imager population. His paper is widely cited as the first scientific recognition of what is now called “aphantasia”. However,  William F. Brewer abd Marlene Schommer-Aikins (2006) reached the conclusion that Galton made a major error. 

This timeline shows that while Fechner ‘opened the door’ to the scientific study of individual differences in mental imagery, Taine provided a theoretical focus, and Galton provided the questionnaire method for empirical investigation.