© The Author(s) 2020

L. Schlicht et al. (eds.)Mind Reading as a Cultural PracticePalgrave Studies in Science and Popular Culturehttps://doi.org/10.1007/978-3-030-39419-6_4

4. Visualizing Thoughts: Photography, Neurology and Neuroimaging

Anthony Enns¹  

(1)

Dalhousie University, Halifax, NS, Canada

 

 

Anthony Enns

Email: Anthony.Enns@Dal.Ca

As scientific knowledge became institutionalized and specialized in the nineteenth century, there were several disciplines devoted to the study of the mind, including psychology, psychiatry, phrenology, physiology, psychophysics, psychotechnics and even psychical research. These disciplines focused on different aspects of the mind using different scientific instruments and methodologies, yet they were all concerned with the common problem of how to produce objective evidence of fundamentally subjective phenomena. While some scientists were convinced that an objective understanding of the mind could only be achieved by studying the physiological structures of the brain, others maintained a strict division between the body and the mind by conceiving of consciousness as an invisible force superadded to the body, which could not be fully explained in terms of physiological processes. While the materialist model of consciousness gradually replaced the vitalist model,¹ nineteenth-century neurologists often attempted to reconcile these competing approaches by conceiving of consciousness as a material yet invisible force that was distributed throughout the brain and could even extend beyond it.

As this chapter will show, the integration of these competing approaches often relied on the photographic apparatus, which provided a new scientific practice as well as a new conceptual metaphor for understanding the mind, as thoughts were increasingly understood as material yet invisible forces that emanated from the brain and that could be impressed directly onto photographic plates. On the one hand, this practice clearly resembled the kinds of materialist theories developed by physiologists, as it similarly represented an attempt to register and record visible traces of previously invisible psychic phenomena and it was similarly based on the idea that psychic phenomena were manifestations of physical forces. On the other hand, it also challenged the concept of cerebral localization (the notion that cognitive processes were linked to particular areas of the brain) by conceiving of the mind as an energy field and of mind reading as the transfer of energy—an idea that more closely resembled the kinds of vitalist theories promoted by mesmerists and mediums. The practice of “thought photography” thus allowed nineteenth-century neurologists to integrate the materialist and vitalist models of consciousness by blurring the boundaries between visibility and invisibility, materiality and immateriality, and objectivity and subjectivity.

As historians often note, the photographic apparatus was seen as an ideal tool for scientific research at this time because it embodied what Lorraine Daston and Peter Galison refer to as “mechanical objectivity.”² First, photography was understood as both a pictorial medium, which recorded and preserved visual impressions, as well as a graphic medium, which registered and measured physical phenomena, as photographs were considered indexical signs that had a material connection to the objects they represented. Photography also reinforced the idea that visual perception was inherently subjective and unreliable, as photographic plates could register the existence of material forces that remained invisible to the eye, and the automatic functioning of the photographic camera allowed it to capture images without human intervention, which seemed to eliminate any possibility of error or manipulation. In other words, nineteenth-century neurologists conceived of the photographic apparatus as an ideal mind reader not only because it was believed to be capable of registering and recording previously invisible thoughts but also because it seemed to allow these thoughts to register and record themselves, which was seen as an assurance against fraud or deception. The following chapter will argue that this history remains relevant today because it raises important questions concerning the reliability of neuroimaging technologies and their claims to provide objective evidence of psychic phenomena. It also remains relevant because the practice of thought photography was explicitly designed to challenge the reductive tendencies of neurophysiology, which is a problem that continues to plague contemporary neuroscience. Despite their acceptance of the material basis of cognitive processes and their embrace of new optical media, for example, nineteenth-century neurologists often challenged the idea of cerebral localization, and their arguments bear a striking resemblance to contemporary critiques of neuroscience as a form of “neophrenology” that is unable to capture the essence of consciousness because it places undue emphasis on the physiological structures of the brain. The practice of thought photography thus exposes the limitations of neuroimaging technologies while at the same time offering an alternative model of consciousness that more closely resembles contemporary discussions of “distributed,” “extended” or “embodied” cognition.

The emergence of a new photographic model of consciousness can be traced back to the invention of the daguerreotype, which was immediately employed as a metaphor to explain the transmission of thoughts. For example, British physician Robert Collyer claimed that it was possible to transmit mental images between minds, and he explicitly described this phenomenon as a photographic process: “I was obligated to embody the image[s]…in my own mind, before they could be recognized by the recipients; whose brain during the congestive state was so sentient that the impression was conveyed to the mind similar to the photographic process of Daguerre.”³ Collyer thus argued that the practice of “thought-reading” or “psychography” was based on the same scientific principles as photography, and he demonstrated this parallel during public lectures by asking a member of the audience to sit facing a somnambulist (someone in a mesmeric trance) and gaze into a bowl of molasses (or any dark fluid), which would reflect the sitter’s mental images into the somnambulist’s mind (see Fig. 4.1).⁴ During these performances the bowl thus functioned as both a reflecting lens, which focused the sender’s thoughts, and a developing tray, which enabled their visualization. This practice also led to the invention of “phreno-mesmerism”—a new scientific theory that sought to integrate the materialist and vitalist models of consciousness by arguing that the physiological organs of the brain could be activated by an invisible “nervous force” that emanated beyond the brain itself .⁵

Fig. 4.1

Bowl of molasses experiment

(Source Robert Collyer, Psychography, or, the Embodiment of Thought; with an Analysis of Phreno-Magnetism, “Neurology,” and Mental Hallucination [Philadelphia: Zieber and Co., 1843], 31)

German chemist Karl von Reichenbach subsequently claimed that magnets emit an invisible fluid called “od” or “odic force” and that the brain is “also gifted and imbued with the delicate potentiality of Od.”⁶ However, Reichenbach’s theories were dismissed by the scientific establishment due to “the absence of any general odoscope or odometer which anyone might use, and so prove its existence.”⁷ In the early 1860s, Reichenbach attempted to develop such an “odoscope” by theorizing that a photographic apparatus would allow the invisible force to register and record itself. Instead of using a lens, however, he placed his hand (the most external part of the nervous system) directly onto a photographic plate covered with a piece of pasteboard in which geometrical shapes were cut. The shapes were clearly visible in the resulting images, which Reichenbach interpreted as scientific proof of the existence of od (see Fig. 4.2).⁸ Like Collyer, therefore, Reichenbach conceived of thought as an invisible yet material force, and he argued that the photographic plate could register and record this force because of its heightened sensitivity. He also sought to reconcile this discovery with the claims of nineteenth-century phrenologists by arguing that the odic force activated the physiological organs of the brain, which implied that vitalism was entirely consistent and even foundational to the materialist model of consciousness.⁹

Fig. 4.2

Photograph of the od

(Source Karl von Reichenbach, Odische Begebenheiten zu Berlin in den Jahren 1861 and 1862 [Berlin: E. H. Schroeder, 1862], n.p.)

In the late 1860s, British journalist James Knowles attempted to update this theory by arguing that “no brain action can take place without creating a wave or undulation (whether electric or otherwise) in the ether.”¹⁰ He also argued that these “Brain-Waves [proceed] from every brain when in action,” as every brain is “a centre of undulations transmitted from it in all directions through space.”¹¹ While the concept of “brain waves” later became associated with wireless technology,¹² it was initially linked to photography because these cerebral undulations were understood as comparable to light waves: “Why might not such undulations, when meeting with and falling upon duly sensitive substances, as if upon the sensitized paper of the photographer, produce impressions, dim portraits of thoughts, as undulations of light produce portraits of objects?”¹³ Like Collyer and Reichenbach , therefore, Knowles conceived of thoughts as invisible yet material waves that could be registered and recorded by the brain in the same way that photographs register and record light. His theory received additional support from British physicists Balfour Stewart and Peter Guthrie Tait, who similarly argued that “every thought that we think is accompanied by a displacement and motion of the particles of the brain, and…these motions are propagated throughout the universe.”¹⁴ Stewart and Tait also claimed that these motions could be impressed onto light waves and that “continual photographs of all occurrences are thus produced and retained.”¹⁵ In other words, the ether was understood not only as a communication medium that facilitated the transmission and reception of “brain waves” but also as a storage medium that registered and recorded them in the form of photographic images.

The first electrophysiological conception of the brain was introduced in 1870, when German anatomist Gustav Fritsch and German neurologist Eduard Hitzig demonstrated that muscular contractions could be induced when particular areas of the brain were stimulated with electricity.¹⁶ These experiments suggested that the brain operated like an electrical apparatus, which was confirmed and further developed by British neurologist David Ferrier, who identified the functional specializations of various areas of the cerebral cortex.¹⁷ In 1875, British physician Richard Caton developed a device that could translate the electrical currents in the exposed brains of monkeys and rabbits into visible wave forms, and these results were seen as confirmation of Ferrier’s theory of cerebral localization, as “the electric currents of the grey matter appear to have a relation to its function.”¹⁸ In the 1880s, Polish physiologist Adolf Beck also developed a device to measure the electrical currents in the exposed brains of rabbits and dogs, and he became famous for locating the visual cortex.¹⁹ The data generated by the first electroencephalograms was thus used to reinforce the materialist model of consciousness, although scientists at the time were unable to produce permanent recordings of these electrical signals.²⁰

The discovery of the electrical nature of neural activity inspired several new devices to register nervous impulses, such as French neurologist Hippolyte Baraduc’s “biometer.” Baraduc began conducting electrophysical experiments at the Salpêtrière Hospital in Paris in the 1880s, and in one of these experiments he noticed that his right hand attracted the needle of a magnetometer and that his left hand repelled it (see Fig. 4.3). In 1891, he revealed his discovery in a report submitted to the Académie des Sciences, in which he claimed that these “biometric” readings represented scientific proof of the existence of an invisible yet material force that was inhaled and exhaled by the nervous system.²¹ He also theorized that this device could be used as a diagnostic tool, as the readings would indicate the presence of various nervous illnesses. In the case of neurasthenia, for example, the right hand would move the needle 30 degrees and the left hand would move it 20 degrees, while in the case of neurosis the right hand would move the needle 30 degrees and the left hand would move it 0 degrees.²² French neurologist Paul Joire later developed a similar device to register and measure this nervous force, and he concurred that “this force is found to be modified in various maladies of the nervous system” and that “the observation of these modifications will be of very great utility for the diagnosis, prognosis, and treatment of these illnesses.”²³

Fig. 4.3

Biometric device

(Source Hippolyte Baraduc, Les vibrations de la vitalité humaine: Méthode biométrique appliquée aux sensitifs et aux névrosés [Paris: Baillière, 1904], 6)

Following the invention of electrography ,²⁴ Baraduc realized that the photographic apparatus could function as a more highly effective biometer, as photographic plates were also capable of registering and recording invisible forces emanating from the nervous system. These photographs were first published in his 1896 book The Human Soul, which described the process as follows:

The plate receives, very slowly, no longer by the solar ray, but by an electro-vital current (wind, breeze) or simply by a direct emission, no longer, the exterior light of the object, but what is called its internal light…. To produce this image, the condensing apparatus, the lense is not necessary…[as the process is] not governed by laws of refraction and inflected foci; it is a law peculiar to this vital force, to our soul of life, of directly graphing itself.²⁵

In other words, Baraduc argued that this “electro-vital current” could impress itself directly onto a photographic plate, so it was sufficient to place the plate to one’s forehead without any intervening lens (see Fig. 4.4). Baraduc even constructed a “portable radiographer” that consisted of a small case containing a plate that could be fixed to the forehead with a headband (see Fig. 4.5).²⁶ Like his biometer, this device was also intended as a diagnostic tool, and Baraduc’s photographs can thus be understood as part of the larger effort among neurologists at the Salpêtrière to produce a catalogue of visual representations of pathological conditions.²⁷

Fig. 4.4

Luminous peas extracted from my forehead

(Source Hippolyte Baraduc, The Human Soul: Its Movements, Its Lights, and the Iconography of the Fluidic Invisible [Paris: Librairie Internationale de la Pensée Nouvelle, 1913], 204)

Fig. 4.5

The portable radiographer

(Source Fernand Girod, Pour photographier les rayons humains: Exposé historique et pratique de toutes les méthodes concourant à la mise en valeur du rayonnement fluidique humain [Paris: Bibliothèque générale d’édition, 1912], 149)

Other researchers soon began to replicate these experiments. For example, Russian physician Jacob von Narkiewicz-Jodko developed a similar apparatus that consisted of a Rumkorff coil, a Crookes tube and a photographic plate. Patients were instructed to hold a wire connected to the coil in one hand while placing the other hand on a photographic plate, and “an electric flow was given off which recorded itself on the photographic film” (see Fig. 4.6).²⁸ The resulting images were identical to the electrographs taken by German photographer Hermann Schnauss and French artist Etienne Léopold Trouvelot, yet Narkiewicz-Jodko interpreted the discharges around the fingertips as evidence of a “nervous force.”²⁹ Like Baraduc, he also interpreted these photographs as visible manifestations of internal psychic states, as he believed that the photographic apparatus could visualize the forces of sympathy and antipathy. If the hands of two people were electrographed, for example, antipathy would be indicated when a diffused light appeared between the tips of the fingers and sympathy would be indicated when the emanations from the fingertips intermingled.

Fig. 4.6

Effluvia from an electrified hand resting on a photographic plate

(Source Hippolyte Baraduc, The Human Soul: Its Movements, Its Lights, and the Iconography of the Fluidic Invisible [Paris: Librairie Internationale de la Pensée Nouvelle, 1913], 222)

In the course of his experiments with hypnosis, French neurologist Jules-Bernard Luys noted that his patients often claimed to perceive coloured fluids emanating from bodies.³⁰ In an effort to determine whether these emanations had a physical origin, he asked his patients to place their fingertips on photographic plates, and he interpreted the resulting images as scientific proof of the existence of a material yet invisible fluid emanating from the nerves (see Fig. 4.7). When he presented these findings to the Société de Biologie in Paris in 1897, he added that the photographic registration of these fluids reflected the patient’s psychological symptoms, as a photograph produced by a hysterical woman did not register any emanations, while the emanations were particularly active in the case of a lethargic patient.³¹ While scientists disagreed as to the underlying cause of this phenomenon,³² Luys’ photographs were evidently quite persuasive, and some editors actively encouraged neurologists to explore their potential significance.³³

Fig. 4.7

Digital effluvia

(Source Jules-Bernard Luys and Émile David, “Note sur l’enregistrement photographique des effluves qui se dégagent des extrémités des doigts et du fond de l’oeil de l’être vivant, a l’état physiologique et a l’état pathologique,” Comptes rendus hebdomadaires des séances et mémoires de la Société de biologie 4, no. 10 [1897]: 516)

Baraduc also interpreted German physicist Wilhelm Röntgen’s discovery of “X-rays”³⁴ as further evidence of the existence of an “electro-vital current,” as X-ray photographs allegedly demonstrated “the faculty which this invisible light had of lighting up the cavity of the body by illumining or by exciting, so to speak, the intimate and interior light of the fluidic body.”³⁵ While X-ray photographs looked very different from Baraduc’s images, as they depicted internal bone structures rather than psychic states, they were thus nevertheless understood as recordings of an interior light that was generated by an invisible force superadded to the body. The discovery of X-rays also inspired a retired French soldier named Louis Darget to produce a series of photographs that revealed a new invisible force called “vital rays” (or “V-rays”).³⁶ Like Baraduc’s images, these photographs were similarly based on the premise that thoughts constituted a material yet invisible force that could impress itself directly onto photographic plates, yet Darget updated this idea by describing the process in terms of phosphorescence: “When a human soul emits a thought…it causes the phosphorus within the brain to radiate and the rays are projected outside.”³⁷ Darget’s theory was clearly inspired by Röntgen’s discovery that the presence of X-rays caused phosphorus material to glow, and it incorporated this discovery into the photographic model of consciousness by speculating that thoughts must cause similar particles in the brain to glow, which would allow them to be registered and recorded on photographic plates. Darget’s images also resembled X-ray photographs in that they marked a shift from abstract to pictorial representation. For example, his first photograph supposedly represented the bottle at which he was staring before he placed his forehead directly onto the plate (see Fig. 4.8): “It seems that the bottle-shape I was deliberately maintaining in my brain was projected onto the plate, that, luminous, it left the brain, passing through the cranium in the manner of X-rays.”³⁸ Instead of simply registering and recording phosphorescent activity in the brain, therefore, this photograph was understood as a visual manifestation of the thought that initiated the phosphorescent reaction—a practice that soon became known as “thought photography.”³⁹ Like Baraduc’s images, these photographs were also intended to be used for diagnostic purposes, as Darget claimed that nervous illnesses resulted from either a deficit or a surfeit of “V-rays.” In the words of one journalist, “the effluvia will never flow in the same way from a morbid organism as from a healthy one; the functional disturbance of the mechanism has repercussions on the outflow of forces. If this discovery, as yet at an embryonic stage, is confirmed, it will mean a radical revolution in diagnostic science.”⁴⁰

Fig. 4.8

The first bottle

(Source Louis Darget, Exposé des différentes méthodes pour l’obtention de photographies fluido-magnétiques et spirites: Rayons V [Vitaux] [Paris: L’Initiation, 1909], n.p.)

The use of photography to record the emanations of radioactive substances was seen as further confirmation of thought photography, although the term “radiation” had long been used to describe the transmission of thoughts. For example, the concept of “cerebral radiation” first appeared in English psychiatrist Henry Maudsley’s 1876 book The Physiology of Mind,⁴¹ and it was later popularized by American inventor Edwin J. Houston, who similarly described thought as a material yet invisible force emanating from the brain: “Cerebral energy, or energy thus expended in producing thought, is dissipated by imparting wave motions to the surrounding ether, and such waves are sent out in all directions from the brain.”⁴² Houston also theorized that “if thought radiations or waves partake of the nature of light, then it would seem among the remote possibilities of science to obtain…a photographic impression of such thought-waves on a suitably sensitized plate.”⁴³ This theory seemed to be corroborated by French physicist Henri Becquerel’s discovery that uranium salts emitted an invisible radiation that produced images on sealed photographic plates,⁴⁴ which offered a convincing explanation for the underlying mechanism of thought photography.⁴⁵ Becquerel’s discovery also inspired German physician Ludwig Tormin to replicate Reichenbach’s experiments from the 1860s. In his 1896 book Magical Rays, for example, Tormin described an experiment using a photographic plate holder with a cross cut in its draw slide. After placing his hand on the holder, the plate was developed and the cross was clearly visible (see Fig. 4.9).⁴⁶ Like Houston, therefore, Tormin concluded that the nervous system emitted an invisible radiation that could be impressed directly onto photographic plates .

Fig. 4.9

Untitled

(Source Ludwig Tormin, Magische Strahlen: Die Gewinnung photographischer Lichtbilder lediglich durch odisch-magnetische Ausstrahlung des menschlichen Körpers [Düsseldorf: Schmitz and Olbertz, 1896], 1)

Proponents of thought photography like James Coates frequently argued that “a consideration of what are now called ‘Becquerel rays’ brings us into a realm of invisible energy,”⁴⁷ which “partakes of all the bodily, mental, and psychical conditions of the person or persons from whom [it is] emanating.”⁴⁸ Over time, however, Coates gradually shifted his emphasis from “Becquerel rays” to “N-rays,” which “proceed from the human organism and…fluctuate according to one’s state of health and mental activities.”⁴⁹ N-rays were reportedly discovered in 1903 at the University of Nancy (“N-ray” was short for “Nancy ray”) by French physicist René Blondlot, who claimed that these rays were comparable to “the radiant properties of uranium, discovered by M. H. Becquerel,”⁵⁰ and that it was “possible to utilize photography to reveal their presence and study their action.”⁵¹ French physicians Arsène d’Arsonval and Augustin Charpentier subsequently claimed that N-rays represented a form of neural energy that emanated from the brain,⁵² and French physicist Edmond Rothé developed a method of photographing variations in phosphorescence due to the influence of N-rays, which could be used to diagnose various nervous illnesses.⁵³ Russian psychiatrist Naum Kotik even argued that “the thoughts of one person can be transferred to another through N-rays”⁵⁴ and that these “brain rays” could impress themselves directly onto photographic paper.⁵⁵ Like X-rays and Becquerel rays, therefore, N-rays promised to provide a concrete scientific explanation for thought photography,⁵⁶ which served to reconcile the vitalist and materialist models of consciousness.

The existence of N-rays was eventually disproven by American physicist Robert W. Wood,⁵⁷ and neurologists subsequently abandoned the practice of thought photography. In the early twentieth century, British physician Walter Kilner introduced a somewhat similar practice using a screen that consisted of two glass plates stained with a dicyanin solution that could visualize the “auras” of patients. Like many of the scientific instruments developed by nineteenth-century neurologists, this screen was also promoted as a diagnostic tool, as nervous illnesses allegedly altered the size, colour and shape of these auras: “If the theory be correct that the sources of the Aura are forces generated within the body, and that their action upon the ether is the cause of their visibility, it is reasonable to expect that these forces will not be exactly the same in health and disease.”⁵⁸ While this screen was reportedly used to diagnose patients at St. Thomas’ Hospital in London, Kilner’s research was dismissed by the scientific establishment,⁵⁹ and the visualization of auras remained a fringe practice .

These devices were eventually replaced by German psychiatrist Hans Berger’s electroencephalograph (EEG), which was widely accepted as a more accurate and practical method of visualizing thoughts. The acceptance of this new scientific instrument was largely due to the fact that it could provide more precise measurements of the electrical currents in the brain. Its results were also seen as more objective because they were consistent with the known laws of physics and their explanation did not depend on the discovery and verification of previously unknown natural forces. It is important to note, however, that this invention was a direct result of Berger’s interest in psychical research. In his diary, for example, he reported a case of “spontaneous telepathy” that occurred when he was nineteen years old,⁶⁰ and historians note that “this telepathic experience initiated Berger’s decision to explore the relation between physical and psychical events.”⁶¹ He initially attempted to measure neural activity by recording changes in the flow of blood to the brain, yet these changes “failed to capture meaningful information about the most important process in Berger’s model of brain function, namely the transformation of energy in the cerebral cortex.”⁶² Berger then turned to the work of German physiologist Max Verworn, who theorized that psychic states were linked to the transfer of energy in cortical tissue. This theory led Berger to conclude that “precise measurements of the cortical energy converted into heat and electricity” would enable him to “calculate the energy converted into conscious perception, emotion, thought, and perhaps even mental telepathy .”⁶³ Like thought photography, therefore, the EEG was similarly designed to visualize the material yet invisible forces emanating from the brain, which could potentially provide scientific proof of the legitimacy of psychic phenomena.

The first account of Berger’s invention was published in 1929,⁶⁴ and journalists quickly embraced the idea that the lines it produced represented “the language of the operating brain.”⁶⁵ As one journalist claimed: “Today, the brain still writes secret signs. Tomorrow, we will probably be able to read neurological and psychiatric diseases in it. And the day after tomorrow, we will start to write our first honest letters in brainscript.”⁶⁶ However, scientists were initially sceptical of Berger’s discovery due to his involvement in psychical research and his rejection of cerebral localization. As David Millett explains, “Berger’s thermodynamic approach to brain function transcended…contemporary debates on the structural architecture of cerebral function,” as “he articulated a compromise between these positions that emerged out of his EEG work.”⁶⁷ This compromise was dismissed by German physiologists like Jan Friedrich Tönnies, who attacked Berger for having “never carried out his recordings with the question of localization in mind.”⁶⁸ Berger was thus considered an amateur because he rejected the theory of cerebral localization, but in 1932 a group of scientists working at Oskar Vogt’s brain research institute in Berlin developed an improved version of the EEG called the “neurograph,” which inspired English electrophysiologist Edgar Douglas Adrian to replicate Berger’s experiments and verify his results.⁶⁹ Berger was subsequently invited to present his invention at the International Congress of Neurological Sciences in London in 1935, and scientists from Harvard Medical School demonstrated his device at the annual meeting of the Federation of American Societies for Experimental Biology later that year.

Despite the fact that his invention was gradually accepted by the scientific establishment, Berger continued to reject a purely materialist model of consciousness, and the popular press often drew comparisons between EEG readings and thought photographs. In his coverage of the first American demonstration of Berger’s “thought recorder,” for example, one journalist described thoughts as “waves” that “change with the various mental and physical states of the individual,” and he claimed that EEG readings represented “pictures” of these waves, as the device converted the “electrical currents generated by mental processes…into telltale, visible patterns.”⁷⁰ The EEG thus replaced the photographic apparatus as the primary tool for studying the mind because it provided a model of consciousness that was more firmly grounded in the physiological structures of the brain, yet it also seemed to challenge this model by demonstrating that neural activity was distributed throughout the brain and that thoughts were material yet invisible forces that emanated beyond it.

Although the EEG gradually replaced the photographic apparatus as the primary tool for studying the mind, there was renewed interest in “auras” in the post-war period, when Russian electrical engineer Semyon Kirlian and his wife Valentina developed a new method of photographing this invisible force, which became known as “Kirlian photography.”⁷¹ Psychical researchers also resurrected many of the claims made by nineteenth-century neurologists, as they frequently argued that these photographs represented scientific proof of the existence of Reichenbach’s “odic force” and that they could be used to “diagnose all kinds of illnesses long before they manifested as physical disorders.”⁷² Despite the fact that this practice was endorsed by American psychologist Thelma Moss, a professor at the Neuropsychiatric Institute of the University of California, Los Angeles, and that it was reportedly employed by American physician David Sheinkin to diagnose mental illnesses at Rockland State Hospital in New York,⁷³ it was never treated as a topic of serious scientific inquiry. It was also fundamentally different from thought photography, as the invisible forces that it registered and recorded were understood not as manifestations of internal psychic states but rather as evidence of a generalized life force inhabiting all living things (including vegetation).

The recent development of new neuroimaging technologies, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), has inspired a tremendous resurgence of interest in the visualization of thoughts. In the 1990s, for example, three new scientific journals were dedicated to the study of neuroimages (Journal of Neuroimaging, NeuroImage and Human Brain Mapping), and American neuropsychiatrist Nancy Coover Andreasen predicted that these images would enable a new psychopathology that directly linked the functional organization of the brain to the workings of the mind.⁷⁴ British psychologist Adrian Raine also claimed that PET scans revealed a significant reduction in the development of the prefrontal cortex among convicted murderers, and he later coined the term “neurocriminology” to describe a new scientific discipline that involved “the application of the principles and techniques of neuroscience to understand the origins of antisocial behavior.”⁷⁵ In the 2000s, British neuroscientists John-Dylan Haynes and Geraint Rees published their preliminary research on the use of fMRI to record cognitive processes, which they described as a form of “brain-reading.”⁷⁶ Neuroscientists also argued that neuroimaging technologies could be used to diagnose and treat a wide range of illnesses, including addictions, anxiety disorders, eating disorders, obsessive-compulsive disorders, post-traumatic stress and schizophrenia, and some even suggested that they could enable telepathic communication. As American neuroscientists Marcel Just and Tom Mitchell explain: “Telepathy is communication across a distance. Well, we can already go a few millimeters. It’s just a matter of time before we can go thousands of miles.” ⁷⁷

Contemporary neuroimages are thus informed by many of the same goals as nineteenth-century thought photographs, yet they are fundamentally different in terms of their material form and their underlying assumptions. Unlike thought photographs, for example, fMRI images are visualizations of computer-generated data concerning the flow of blood in the brain, which is believed to correspond to neural activity. Instead of representing the direct inscription of invisible thoughts, therefore, these images are conceived as statistical predictions of what a patient might be thinking based on previously recorded hemodynamic activity. Furthermore, neuroscientists frequently point out that hemodynamic activity is only indirectly related to neural activity, as some neurons might require less blood than others and smaller groups of neurons could perform more significant functions than larger groups.⁷⁸ As Greek neuroscientist Nikos K. Logothetis argues, “fMRI is not and will never be a mind reader.”⁷⁹ Despite the fact that contemporary neuroimaging technologies are designed to reinforce a materialist model of the mind, the images they produce are thus mediated by human operators, who arbitrarily choose which physiological features should be considered valid indicators of cognitive functions.

Neuroimaging technologies have also been criticized as a form of “neophrenology” because they are similarly based on the principle of cerebral localization.⁸⁰ Some researchers, like American neuroscientist Carl Schoonover, embrace the idea that phrenology “guides us to this day—only the coordinate system has shifted to indicate positions within the brain rather than on the skull.”⁸¹ Others, like Chinese psychologist Yan Bao and German neuroscientist Ernst Pöppel, argue that “an uncritical use of new imaging technology may open the door to a new kind of old fashioned phrenology, i.e., looking at specific areas only and neglecting the interconnectivity of a neuronal network.”⁸² In other words, some contemporary neuroscientists seek to locate neural activity in specific regions of the brain, which replicates the materialist approach used by nineteenth-century phrenologists, while others insist that this approach is fundamentally misguided, as it is more important to study the connections between these various regions. German historian Frank W. Stahnisch similarly notes that “a critique of functional neuroimaging as a form of neophrenology can be seen as valid in so far as it remains a critique of the reductionism implied in many interpretations of modern neuroimaging studies,”⁸³ and American neuroscientist Russell A. Poldrack emphasizes that “there is no simple one-to-one mapping between psychological states and activity in specific brain areas.”⁸⁴ Contemporary neuroimaging technologies are thus based on a model of the mind that is directly opposed to the idea of “distributed,” “extended” or “embodied” cognition,⁸⁵ and some neuroscientists have challenged this model in ways that resemble the arguments made by nineteenth-century neurologists.

The history of thought photography also shows that neuroimaging technologies do not simply function as objective scientific instruments; rather, they convert or translate natural phenomena into visual representations that are highly artificial and subject to interpretation. In other words, the practice of thought photography not only challenged the materialist model of consciousness, which was becoming increasingly dominant in the field of neurology, but also exposed the limitations of the scientific paradigm of mechanical objectivity on which this model was based. Despite the claims made by nineteenth-century neurologists, who described these images as scientific proof of the existence of material yet invisible forces emanating from the brain, this practice actually revealed a change in the understanding of objectivity itself and the ways in which it could be achieved, as American historian Jennifer Tucker explains:

Contrary to what we might expect about scientific photography, disagreement over photographers’ practical expertise, interpretive skills, and powers of judgment suffused scientific and popular discussions about photography…. Objectivity, it seems, was in the eye of the beholder.⁸⁶

Photography curator Corey Keller similarly argues that “the faith once placed in the human eye has today been replaced by a near-total dependence on technologically inflected vision, resulting in a disconnect between seeing and knowing so pervasive that it goes almost entirely unacknowledged.” Keller thus questions “our willingness to trust the visual data produced by such imaging technologies,” as scientific images are never purely objective or value-neutral.⁸⁷

Like thought photographs, contemporary neuroimages are considered to be visualizations of previously invisible thoughts, yet the devices used to create these images clearly shape the way they are understood. Indeed, the mind only exists as an object of knowledge through the technologies and techniques used to study it—in terms of both the material practices they enable and the conceptual metaphors they inspire—and it can thus be seen as part of an experimental apparatus that effectively produces the phenomena it seeks to register and record. German historian Nicolas Pethes also notes that this problem first became apparent through the practice of thought photography , which sought to “produce material traces from immaterial sources and thus create an ‘epistemic thing’ through the agency of a material device.”⁸⁸ While these images seem “unscientific from today’s point of view,” they reveal “the closely woven network between scientists, publicists, media technologies and discursive orders that […] is still active today.”⁸⁹ Thought photographs remain relevant, in other words, because contemporary neuroimages are similarly presented as objective realities when they are actually cultural constructions, and the institutional and technological networks that sought to legitimize these photographs in the nineteenth century are largely the same as the networks that seek to legitimize neuroimages today.

What Pethes’ argument overlooks is that the practice of thought photography was ultimately rejected by the scientific establishment due to the fact that it challenged the materialist model of consciousness—a model that continues to dominate the field of neurology as well as the contemporary practice of neuroimaging. While thought photography was partly informed by an understanding of consciousness as a material force that inhabited the physical body, it also incorporated aspects of vitalist philosophy by imagining that this invisible force was distributed throughout the brain and could even extend beyond it, which supposedly explained the underlying mechanism of mind reading. Despite the fact that thought photography is no longer recognized as a legitimate scientific practice, it thus offers a valuable critique of contemporary neuroimaging technologies by illustrating the limitations of mechanical objectivity as well as the reductive tendencies of neurophysiology, which still remain a subject of heated debate.

Notes

1. 1.

   Studies conducted by German neuroanatomists Franz Gall and Carl Wernicke and French neuroanatomists Pierre Flourens and Paul Broca, among others, concluded that cognitive processes were linked to particular areas of the brain, which challenged the idea of consciousness as an extra-corporeal spirit. Spanish neuroanatomist Santiago Ramon y Cajal and English neuroanatomist Sir Charles Sherrington provided even more detailed information concerning the circuitry of the brain, which further reinforced the idea that cognitive processes were inherently physiological. For more on the convergence of mind and brain, see David M. Armstrong, A Materialist Theory of the Mind (London: Routledge, 1968); John C. Eccles and Alexander G. Karczmar, eds., Brain and Human Behavior (New York: Springer, 1972); John C. Eccles, The Understanding of Mind (New York: McGraw-Hill, 1973); Marc Jeannerod, The Brain Machine: The Development of Neurophysiological Thought (Cambridge, MA: Harvard University Press, 1985); Patricia S. Churchland, Neurophilosophy: Toward a Unified Science of the Mind/Brain (Cambridge, MA: MIT Press, 1986).

    
2. 2.

   See Lorraine Daston and Peter Galison, Objectivity (New York: Zone Books, 2007); Kelley Wilder, Photography and Science (London: Reaktion Books, 2009).

    
3. 3.

   Robert Collyer, Psychography, or, the Embodiment of Thought; with an Analysis of Phreno-Magnetism, “Neurology,” and Mental Hallucination (Philadelphia: Zieber and Co., 1843), 30.

    
4. 4.

   Ibid., 31.

    
5. 5.

   Ibid., 5–23.

    
6. 6.

   Karl von Reichenbach, Physico-Physiological Researches on the Dynamics of Magnetism, Electricity, Heat, Light, Crystallization, and Chemism, in their Relations to Vital Force. Translated by John Ashburner (London: Hippolyte Baillière, 1850), 265–266.

    
7. 7.

   Karl von Reichenbach, Letters on Od and Magnetism. Translated by. F. D. O’Byrne (London: Hutchinson and Co., 1926), 92.

    
8. 8.

   Karl von Reichenbach, Odische Begebenheiten zu Berlin in den Jahren 1861 und 1862 (Berlin: E. H. Schroeder, 1862), n.p. For a discussion of the scientific debates surrounding these images, see Rolf H. Krauss, Beyond Light and Shadow: The Role of Photography in Certain Paranormal Phenomena. Translated by Timothy Bell and John Gledhill (Tucson, AZ: Nazraeli Press, 1995), 21–26.

    
9. 9.

   Reichenbach, Physico-Physiological Researches, 266.

    
10. 10.

    James T. Knowles, “Brain-Waves: A Theory,” The Spectator 42 (1869): 135–137, here 136. The concept of the “ether” can be traced back to the writings of British physicist Thomas Young, whose wave theory of light was based on the premise that a “luminiferous” (light-bearing) substance “pervades the Universe.” Thomas Young, “On the Theory of Light and Colors,” Philosophical Transactions of the Royal Society of London 92 (1802): 12–48, here 14.

     
11. 11.

    Knowles, “Brain-Waves,” 136.

     
12. 12.

    For more on brain waves and wireless technology, see Anthony Enns, “Psychic Radio: Sound Technologies, Ether Bodies and Spiritual Vibrations,” Senses and Society 3, no. 2 (2008): 137–152.

     
13. 13.

    Knowles, “Brain-Waves,” 136.

     
14. 14.

    Balfour Stewart and Peter Guthrie Tait, The Unseen Universe or Physical Speculations on a Future State (London: Macmillan and Co., 1875), 156.

     
15. 15.

    Ibid.

     
16. 16.

    Gustav Fritsch and Eduard Hitzig, “Über die elektrische Erregbarkeit des Grosshirns,” Archiv für Anatomie, Physiologie und wissenschaftliche Medicin 37 (1870): 300–332.

     
17. 17.

    David Ferrier, Functions of the Brain (New York: Putnam, 1876).

     
18. 18.

    Richard Caton, “The Electric Currents of the Brain,” British Medical Journal 2 (1875): 278.

     
19. 19.

    Adolf Beck, “Die Bestimmung der Localisation der Gehirn- und Rückenmarksfunctionen vermittelst der elektrischen Erscheinungen,” Centralblatt für Physiologie 4 (1890): 473–476.

     
20. 20.

    The first photograph of “brain waves” was reportedly produced by Russian physiologist Vladimir Pravdich-Neminsky in 1913. See Jacob Empson, Human Brainwaves: The Psychological Significance of the Electroencephalogram (New York: Stockton Press, 1986), 4.

     
21. 21.

    “Correspondance,” Comptes rendus de l’Académie des sciences 113 (1891): 291–300, here 300.

     
22. 22.

    “Biométrie,” Revue encyclopédique 26 (1892): 77.

     
23. 23.

    Paul Joire, Psychical and Supernatural Phenomena: Their Observation and Experimentation. Translated by Dudley Wright (London: William Rider and Son, 1916), 416. British astrophysicist Frederick John Marrian Stratton reportedly tested Joire’s device and concluded that the results were due to the influence of body heat. See F. J. M. Stratton and P. Phillips, “Some Experiments with the Sthenometer,” Journal of the Society for Psychical Research 12 (1906): 335–339.

     
24. 24.

    The term “electrography” was coined by Czech physicist Bartholomew Navrátil, who invented the process in the 1880s. For a description of his experiments, see Karl Wilhelm Wolf-Czapek, Angewandte Photographie in Wissenschaft und Technik (Berlin: Union Deutsche Verlagsgesellschaft Zweigniederlassung, 1911).

     
25. 25.

    Hippolyte Baraduc, The Human Soul: Its Movements, Its Lights, and the Iconography of the Fluidic Invisible (Paris: Librairie Internationale de la Pensée Nouvelle, 1913), 33.

     
26. 26.

    Fernand Girod, Pour photographier les rayons humains: Exposé historique et pratique de toutes les méthodes concourant à la mise en valeur du rayonnement fluidique humain (Paris: Bibliothèque générale d’édition, 1912), 149. See also Clément Chéroux, “Photographs of Fluids: An Alphabet of Invisible Rays,” The Perfect Medium: Photography and the Occult, eds. Clément Chéroux and Andreas Fischer (New Haven: Yale University Press, 2005), 114–124, here 118.

     
27. 27.

    As Albert Londe, head of the Salpêtrière’s photography department, explained: “It is a question…of preserving the durable trace of all pathological manifestations.” Albert Londe, La photographie médicale: Application aux sciences médicales et physiologiques (Paris: Gauthier-Villars, 1893), 64. See also Georges Didi-Huberman, Invention of Hysteria: Charcot and the Photographic Iconography of the Salpêtrière. Translated by Alisa Hartz (Cambridge, MA: MIT Press, 2003), 29–66.

     
28. 28.

    Albert de Rochas, L’Extériorisation de la sensibilité (Paris: Chamuel 1895), 45–46.

     
29. 29.

    Marius Decrespe, L’Extériorisation de la force nerveuse et les Travaux de M. de Narkiewicz-Iodko (Paris: Chamuel, 1896), 39.

     
30. 30.

    Jules-Bernard Luys, “De la visibilité par les sujets en état hypnotique des effluves dégagés par les êtres vivants,” Annales de Psychiatrie et d’Hypnologie dans Leurs Rapports avec la Psychologie et la Médicine Légale 2 (1892): 321–323.

     
31. 31.

    Jules-Bernard Luys and Émile David, “Note sur l’enregistrement photographique des effluves qui se dégagent des extrémités des doigts et du fond de l’oeil de l’être vivant, a l’état physiologique et a l’état pathologique,” Comptes rendus hebdomadaires des séances et mémoires de la Société de biologie 4, no. 10 (1897): 515–519.

     
32. 32.

    For more on this debate, see Krauss, Beyond Light and Shadow, 28–30; Peter Geimer, Inadvertent Images: A History of Photographic Apparitions. Translated by Gerrit Jackson (Chicago: University of Chicago Press, 2018), 84–88.

     
33. 33.

    Ludwig Jankau, “Neues über das Reichenbach’sche ‘Od,’” Internationale photographische Monatsschrift für Medezin 4 (1897): 98.

     
34. 34.

    Wilhelm Röntgen, “Über eine neue Art von Strahlen,” Aus den Sitzungsberichten der Würzburger Physik.-medic. Gesellschaft Würzburg (1895): 137–147.

     
35. 35.

    Baraduc, The Human Soul, 77.

     
36. 36.

    See Louis Darget, “Exposé des différentes méthodes pour l’obtention de photographies fluido-magnétiques et spirites: Rayons V (Vitaux),” L’Initiation 84, no. 10 (1909): 1–21.

     
37. 37.

    Qtd. in Charles Proth, La photographie transcendantale: les êtres et les radiations de l’espace (Paris: Librairie Nationale, 1908), 31.

     
38. 38.

    Louis Darget, “Photographie des radiations psychiques,” Le Spiritualisme moderne 3, no. 2 (1899): 18–20, here 18.

     
39. 39.

    British photographer W. Ingles Rogers introduced the term “thought photography” to refer to the direct impression of thoughts: “When we recall an image or scene from memory it is evident that we excite certain electrical conditions that transmit force of the kind we recognize as light, and which is doubtless the highest modification of that element. This transmission, or projection (call it what you will) is evidently […] capable of exciting certain sensible surfaces (such as photographic plates) into chemical action.” W. Ingles Rogers, “Can Thought Be Photographed? The Problem Solved,” Amateur Photographer 23, no. 595 (February 28, 1896): 186. While Rogers was evidently unaware of the experiments conducted by French neurologists, his work was immediately translated into French, and Baraduc and Darget’s images were subsequently referred to as “thought photographs.” See Ingles Rogus [sic], “Photographie de la pensée,” Photo-Gazette (February 25, 1896): 72–74; Guy Tomel, “La photographie de la pensée,” Le Monde illustré 2047 (June 20, 1896): 430–431.

     
40. 40.

    Marius Decrespe, “L’Invisible et la photographie,” Photo-Revue (October 1, 1896): 47.

     
41. 41.

    Henry Maudsley, The Physiology of Mind (London: Macmillan and Co., 1876), 317.

     
42. 42.

    Edwin J. Houston, “Cerebral Radiation,” Journal of the Franklin Institute 133, no. 6 (1892): 488–497, here 489–490.

     
43. 43.

    Ibid., 494.

     
44. 44.

    See Henri Becquerel, “Sur les radiations invisibles émises par les corps phosphorescents,” Comptes rendus de l’Académie des sciences 122 (1896): 501–503.

     
45. 45.

    Thought photographs were also frequently described as “radiographs.” See, for example, Albert de Rochas, Les Frontières de la science (Paris: Librarie des sciences psychologiques, 1902), 1: 98 and Girod, Pour photographier les rayons humains, 63.

     
46. 46.

    Ludwig Tormin, Magische Strahlen: Die Gewinnung photographischer Lichtbilder lediglich durch odisch-magnetische Ausstrahlung des menschlichen Körpers (Düsseldorf: Schmitz and Olbertz, 1896), 18.

     
47. 47.

    James Coates, Seeing the Invisible: Practical Studies in Psychometry, Thought Transference, Telepathy, and Allied Phenomena (London: L. N. Fowler, 1906), 28.

     
48. 48.

    Ibid., 30.

     
49. 49.

    James Coates, Photographing the Invisible: Practical Studies in Spirit Photography, Spirit Portraiture, and Other Rare but Allied Phenomena (London: L. N. Fowler, 1911), 3.

     
50. 50.

    René Blondlot, “N” Rays: A Collection of Papers Communicated to the Academy of Sciences. Translated by J. Garcin (London: Longmans, Green and Co., 1905), 52.

     
51. 51.

    Ibid., 61.

     
52. 52.

    See Arsène d’Arsonval, “Les radiations N,” Bulletin de l’Institut général psychologique 3 (1903): 25–30; Augustin Charpentier, “Nouvel exemple d’adaptation physique entre un excitant naturel (vibration sonore) et l’organe percepteur central,” Comptes rendus hebdomadaires des séances de l’Académie des sciences 138 (1904): 1540–1541.

     
53. 53.

    Edmond Rothé, “Essai d’une méthode photographique pour étudier l’action des rayons N sur la phosphorescence,” Comptes rendus hebdomadaires des séances de l’Académie des sciences 138 (1904): 1589–1591.

     
54. 54.

    Qtd. in Mikhail Agursky, “An Occult Source of Socialist Realism: Gorky and Theories of Thought Transference,” The Occult in Russian and Soviet Culture, ed. Bernice Glatzer Rosenthal (Ithaca: Cornell University Press, 1997), 247–272, here 250.

     
55. 55.

    Naum Kotik, Die Emanation der psychophysischen Energie: Eine experimentelle Untersuchung über die unmittelbare Gedankenübertragung im Zusammenhang mit der Frage über die Radioaktivität des Gehirns (Wiesbaden: J. F. Bergmann, 1908), 80–101.

     
56. 56.

    See also Mary Jo Nye, “N-Rays: An Episode in the History and Psychology of Science,” Historical Studies in the Physical Sciences 11, no. 1 (1980): 125-156.

     
57. 57.

    Robert W. Wood, “The N-Rays,” Nature 70, no. 1822 (1904): 530–531.

     
58. 58.

    Walter Kilner, The Human Atmosphere or the Aura Made Visible by the Aid of Chemical Screens (London: Rebman, 1911), 147. See also Hereward Carrington, The Story of Psychic Science (London: Rider and Co., 1930): 123–131.

     
59. 59.

    Several scientists attempted to replicate Kilner’s experiments, but the results were “entirely negative.” “The Human Atmosphere,” British Medical Journal 1, no. 2662 (January 6, 1912): 21–22.

     
60. 60.

    Hans Berger, Psyche (Jena: Gustav Fischer, 1940), 6.

     
61. 61.

    Jonna Brenninkmeijer, Neurotechnologies of the Self: Mind, Brain and Subjectivity (London: Palgrave Macmillan, 2016), 48.

     
62. 62.

    David Millett, “Hans Berger: From Psychic Energy to the EEG,” Perspectives on Biology and Medicine 44, no. 4 (2001): 522–542, here 528.

     
63. 63.

    Ibid., 529.

     
64. 64.

    Hans Berger, “Über das Elektrenkephalogramm des Menschen,” Archiv für Psychiatrie und Nervenkrankheiten 87 (1929): 527–570.

     
65. 65.

    Cornelius Borck, “Electricity as a Medium of Psychic Life: Electrotechnical Adventures into Psychodiagnosis in Weimar Germany,” Science in Context 14, no. 4 (2001): 565–590, here 584.

     
66. 66.

    Walter Finkler, “Die elektrische Schrift des Gehirns, Die Zickzackkurve der Menschenseele—Bahnbrechende Versuche eines deutschen Psychiaters,” Neues Wiener Journal (July 4, 1930): 7.

     
67. 67.

    Millett, “Hans Berger,” 540.

     
68. 68.

    Jan Friedrich Tönnies, “Die Ableitung bioelektrisher Effekte vom uneröffneten Schaedel,” Journal für Psychologie und Neurologie 45 (1933): 155.

     
69. 69.

    See Stanley Finger, Minds Behind the Brain: A History of the Pioneers and Their Discoveries (Oxford: Oxford University Press, 2005), 239–258; Cornelius Borck, “Recording the Brain at Work: The Visible, the Readable, and the Invisible in Electroencephalography,” Journal of the History of the Neurosciences 17, no. 3 (2008): 367–379.

     
70. 70.

    William Laurence, “Electricity in the Brain Records a Picture of Action of Thought,” New York Times (April 14, 1935): 1, 32.

     
71. 71.

    Semyon Davidovich Kirlian and Valentina Khrisanovna Kirlian, “Photography and Visual Observations by Means of High-Frequency Currents,” Journal of Scientific and Applied Photography 6 (1961): 397–403.

     
72. 72.

    Sheila Ostrander and Lynn Schroeder, Psychic Discoveries Behind the Iron Curtain (Englewood Cliffs, NJ: Prentice-Hall, 1970), 196–209.

     
73. 73.

    Thelma Moss, The Probability of the Impossible: Scientific Discovery and Explorations in the Psychic World (London: Routledge and Kegan Paul, 1976), 58.

     
74. 74.

    Nancy Coover Andreasen, “Linking Mind and Brain in the Study of Mental Illnesses: A Project for a Scientific Psychopathology,” Science 275, no. 5306 (1997): 1586–1593.

     
75. 75.

    Adrian Raine, The Anatomy of Violence: The Biological Roots of Crime (New York: Patheon, 2013), 8.

     
76. 76.

    John-Dylan Haynes and Geraint Rees, “Decoding Mental States from Brain Activity in Humans,” Nature Reviews Neuroscience 7 (2006): 523–534.

     
77. 77.

    Lo and Behold: Reveries of the Connected World, dir. Werner Herzog (Magnolia Pictures, 2016), film.

     
78. 78.

    See David J. Heeger and David Ress, “What Does fMRI Tell Us About Neuronal Activity?” Nature Reviews Neuroscience 3, no. 2 (2002): 142–151; Nikos K. Logothetis and Brian A. Wandell, “Interpreting the BOLD Signal,” Annual Review of Physiology 66 (2004): 735–769.

     
79. 79.

    Nikos K. Logothetis, “What We Can Do and What We Cannot Do with fMRI,” Nature 453, no. 7197 (2008): 869–878, here 869.

     
80. 80.

    See, for example, William R. Uttal, The New Phrenology: The Limits of Localizing Cognitive Processes in the Brain (Cambridge, MA: MIT, 2001); Steven F. Faux, “Cognitive Neuroscience from a Behavioral Perspective: A Critique of Chasing Ghosts with Geiger Counters,” Behavior Analyst 25 (2002): 161–173; Michael Hagner, Der Geist bei der Arbeit: Historische Untersuchungen zur Hirnforschung (Göttingen: Wallstein, 2006).

     
81. 81.

    Carl Schoonover, Portraits of the Mind: Visualizing the Brain from Antiquity to the 21st Century (New York: Abrams, 2010), 38.

     
82. 82.

    Yan Bao and Ernst Pöppel, “Anthropological Universals and Cultural Specifics: Conceptual and Methodological Challenges in Cultural Neuroscience,” Neuroscience & Biobehavioral Reviews 36, no. 9 (2012): 2143–2146, here 2144.

     
83. 83.

    Frank W. Stahnisch, “The Language of Visual Representations in the Neurosciences: Relating Past and Future,” Translational Neuroscience 5, no. 1 (2014): 78–90, here 86.

     
84. 84.

    Russell A. Poldrack, The New Mind Readers: What Neuroimaging Can and Cannot Reveal about Our Thoughts (Princeton: Princeton University Press, 2018), 22.

     
85. 85.

    For more on these concepts, see Andy Clark and David Chalmers, “The Extended Mind,” Analysis 58, no. 1 (1998): 7–19; George Lakoff and Mark Johnson, Philosophy in the Flesh: The Embodied Mind and its Challenge to Western Thought (New York: Basic Books, 1999).

     
86. 86.

    Jennifer Tucker, “The Social Photographic Eye,” Brought to Light: Photography and the Invisible 1840–1900, ed. Corey Keller (New Haven: Yale University Press, 2008), 37–49, here 48.

     
87. 87.

    Corey Keller, “Sight Unseen: Picturing the Invisible,” Brought to Light: Photography and the Invisible 1840–1900, ed. Corey Keller (New Haven: Yale University Press, 2008), 18–35, here 35.

     
88. 88.

    Nicolas Pethes, “Psychicones: Visual Traces of the Soul in Late Nineteenth-Century Fluidic Photography,” Medical History 60, no. 3 (2016): 325–341, here 326.

     
89. 89.

    Ibid., 327.