“Each time you think you are unveiling the truth, all you get is a teasing glimpse of what turns out to be yet another veil,” wrote Vilayanur S. Ramachandran and Diane Rogers-Ramachandran in their February/March Illusions column [“Stability of the Visual World”]. Their words eloquently capture the stubborn persistence of researchers as they grapple with seemingly impenetrable mysteries of the mind.

Along the same lines, articles in the issue discussed the struggle to understand how mental imagery forms [“Picture This,” by Thomas Grueter], how sexuality can vary [“Do Gays Have a Choice?” by Robert Epstein], whether our fellow creatures emote [“Do Animals Have Feelings?” by Klaus Wilhelm] and more.

INNER WORLDS

I very much enjoyed the article “Picture This,” by Thomas Grueter. He is correct in asserting that the general debate about the nature of mental imagery still continues. (For the latest update, see the book I wrote with William L. Thompson and Giorgio Ganis called The Case for Mental Imagery, Oxford University Press, 2006.) He is incorrect, however, regarding the specific debate regarding brain activation.

The two major contending camps, in Caen (France) and Cambridge (U.S.), independently converged on the same account for inconsistent fi ndings: different types of mental imagery rely on different brain networks. In particular, the brain network that underlies imagery for spatial relations (as in imagining an object rotating) relies crucially on the parietal lobes, whereas the network that underlies imagery for high-resolution shapes relies crucially on the occipital lobes. Even so, key areas in each of these networks are organized so that a picturelike pattern of activation is evoked during imagery.

As far as the brain is concerned, mental images are in fact images—not merely descriptions.

Stephen M. Kosslyn John Lindsley Professor of Psychology in Memory of William James Harvard University

Grueter is correct that “the final word on mental imagery has not yet been uttered.” What seems to be missing from both schools of thought—the descriptionalists and the pictorialists—is how their image mechanisms link to the inner worlds of nonhuman species. Human neural processes are extraordinary, but they are not completely unique, having evolved with many operational features of other animals. Conversely, animals conduct their daily business based strictly on imagery, without any access to stored symbolic references as we know them.

To get at the kernel of the human imagery question, we need to explain how animals create internal images without abstractions like language or grammatical structures.

David Werdegar Naperville, Ill.

RANGE OF SEXUALITY

In Robert Epstein’s “Do Gays Have a Choice?” I was glad to see people speaking up against the excluded middle arguments inherent in the “nature versus nurture” and even the “straight versus gay” views. There are, however, a couple of notable absences in the article.

First, why no mention of Evelyn Hooker? In 1957 Hooker administered projective tests such as the Rorschach test to 30 straight and 30 gay men and then had experts evaluate their adjustment levels. The results for the two groups were essentially identical, and when the experts were asked to identify which results came from heterosexuals and which from homosexuals, their interpretations fared no better than chance. Surely this study and the ones that followed it had an impact on the American Psychiatric Association’s decision to remove homosexuality from the Diagnostic and Statistical Manual.

Second, whereas there is much print given to Robert L. Spitzer’s study presented to the APA in May 2001, why no report about a paper presented at the same convention by Ariel Shidlo and Michael Schroeder? In their study 202 homosexuals who had undergone conversion therapy were interviewed, and 88 percent stated they felt that the efforts to change their sexual orientation had failed.

David Hardison Denver

As someone who has always believed that sexuality exists in a spectrum, I found “Do Gays Have a Choice?” to be a delight. But the quiz left me with a sour aftertaste. I come out as being “predominantly homosexual.” This result came about because all the questions were regarding having feelings for, or doing something with, a person of the same sex, and the questions were not balanced with the same for the opposite sex.

My younger years were filled with experiences with both sexes. Still now, at 26, I have feelings for the same sex. Yet I am married to someone of the opposite sex, even though in the country where I come from same-sex marriage is legal. My decision was not made for procreational purposes, because I knew before the relationship that I could not have children. Nor was it done because of social pressure, because I had not had any bad experiences while in a same-sex relationship before my marriage. Opposite-sex relationships have never made me feel uncomfortable or like a lie. Nor have same-sex relationships felt like the “truth.”

I am happy and comfortable with either sex, both as friends and sexual partners. There is a name for this midpoint on the continuum: bisexual. This middle ground seems to have been totally overlooked in the questions.

Ineke Warner U.K.

EPSTEIN REPLIES: The quiz included with the article is indeed quite skewed, intended to bring out the homosexual side of people’s natures, which is why it is called “How Gay Are You?” The full test—the Epstein Sexual Orientation Inventory—from which the mini test was derived, measures both gay and straight tendencies, reports one’s Mean Sexual Orientation, and also gives one’s Sexual Orientation Range, which is a measure of choice and fl exibility. It is accessible at http://mysexualorientation.com

POWER OF PLEASURE

It speaks volumes about the inherent conservatism of science that we should still be asking the question, as author Klaus Wilhelm does, “Do Animals Have Feelings?” The weight of evidence—from the fact that emotions are adaptive to the way animals respond behaviorally and physiologically to emotive stimuli—leaves no reasonable doubt that they do. Part of the problem is that science has been too mired in seeking evolutionary explanations for animal behavior, to the neglect of an individual’s experience. Mate-seeking minks and romping ravens do not contemplate Darwinian fitness or reproductive success: they are drawn to behave adaptively because of the rewarding feelings it brings.

As I argue in my book Pleasurable Kingdom: Animals and the Nature of Feeling Good (Macmillan, 2006), we would do well to take more notice of the power of pleasure in motivating behavior.

Jonathan Balcombe Physicians Committee for Responsible Medicine Washington, D.C.

A SCIENTIFIC APPROACH

In his review of Fool’s Paradise: The Unreal World of Pop Psychology, Kenneth Silber wonders at the continuing popularity of self-help books. Perhaps one answer might be found in the shortcomings of professional psychological help.

As Scientific American Mind itself has reported, the psychology profession has a tendency to cling to unproved and even disproved practices and theories such as MBTI, Rorschach tests or repressed-memory recovery. If practitioners relied on scientific and evidence-based foundations, perhaps then we would be able, as Scott Adams (creator of cartoon character Dilbert) once satirically suggested, to replace the bookstore’s entire “Self-Help” section with a sign that reads: “Go read any book in the History, Philosophy, or Religion section and think about what it says.”

Carl Zetie Waterford, Va.

ERRATA

“Train Your Brain,” by Ulrich Kraft, mistakenly placed Neuro-Quest Ltd. in Evanston, Ill.; it is in Skokie, Ill. Also, it reported that, “Whenever the amplitude of alpha waves in the left frontal cortex rose above that in the right, the participants would hear a pleasant note played on a clarinet.” The opposite is true: Whenever the amplitude of alpha waves in the right frontal cortex rose above that in the left, the participants would hear a pleasant note played on a clarinet. In “Stability of the Visual World,” by Vilayanur S. Ramachandran and Diane Rogers-Ramachandran [Illusions], the graphic entitled “Movement Detectors” was mislabeled. The labels for “the feedforward theory (top)” and for “the feedback theory (bottom)” should have been reversed.

Along the same lines, articles in the issue discussed the struggle to understand how mental imagery forms [“Picture This,” by Thomas Grueter], how sexuality can vary [“Do Gays Have a Choice?” by Robert Epstein], whether our fellow creatures emote [“Do Animals Have Feelings?” by Klaus Wilhelm] and more.

INNER WORLDS

I very much enjoyed the article “Picture This,” by Thomas Grueter. He is correct in asserting that the general debate about the nature of mental imagery still continues. (For the latest update, see the book I wrote with William L. Thompson and Giorgio Ganis called The Case for Mental Imagery, Oxford University Press, 2006.) He is incorrect, however, regarding the specific debate regarding brain activation.

The two major contending camps, in Caen (France) and Cambridge (U.S.), independently converged on the same account for inconsistent fi ndings: different types of mental imagery rely on different brain networks. In particular, the brain network that underlies imagery for spatial relations (as in imagining an object rotating) relies crucially on the parietal lobes, whereas the network that underlies imagery for high-resolution shapes relies crucially on the occipital lobes. Even so, key areas in each of these networks are organized so that a picturelike pattern of activation is evoked during imagery.

As far as the brain is concerned, mental images are in fact images—not merely descriptions.

Stephen M. Kosslyn John Lindsley Professor of Psychology in Memory of William James Harvard University

Grueter is correct that “the final word on mental imagery has not yet been uttered.” What seems to be missing from both schools of thought—the descriptionalists and the pictorialists—is how their image mechanisms link to the inner worlds of nonhuman species. Human neural processes are extraordinary, but they are not completely unique, having evolved with many operational features of other animals. Conversely, animals conduct their daily business based strictly on imagery, without any access to stored symbolic references as we know them.

To get at the kernel of the human imagery question, we need to explain how animals create internal images without abstractions like language or grammatical structures.

David Werdegar Naperville, Ill.

RANGE OF SEXUALITY

In Robert Epstein’s “Do Gays Have a Choice?” I was glad to see people speaking up against the excluded middle arguments inherent in the “nature versus nurture” and even the “straight versus gay” views. There are, however, a couple of notable absences in the article.

First, why no mention of Evelyn Hooker? In 1957 Hooker administered projective tests such as the Rorschach test to 30 straight and 30 gay men and then had experts evaluate their adjustment levels. The results for the two groups were essentially identical, and when the experts were asked to identify which results came from heterosexuals and which from homosexuals, their interpretations fared no better than chance. Surely this study and the ones that followed it had an impact on the American Psychiatric Association’s decision to remove homosexuality from the Diagnostic and Statistical Manual.

Second, whereas there is much print given to Robert L. Spitzer’s study presented to the APA in May 2001, why no report about a paper presented at the same convention by Ariel Shidlo and Michael Schroeder? In their study 202 homosexuals who had undergone conversion therapy were interviewed, and 88 percent stated they felt that the efforts to change their sexual orientation had failed.

David Hardison Denver

As someone who has always believed that sexuality exists in a spectrum, I found “Do Gays Have a Choice?” to be a delight. But the quiz left me with a sour aftertaste. I come out as being “predominantly homosexual.” This result came about because all the questions were regarding having feelings for, or doing something with, a person of the same sex, and the questions were not balanced with the same for the opposite sex.

My younger years were filled with experiences with both sexes. Still now, at 26, I have feelings for the same sex. Yet I am married to someone of the opposite sex, even though in the country where I come from same-sex marriage is legal. My decision was not made for procreational purposes, because I knew before the relationship that I could not have children. Nor was it done because of social pressure, because I had not had any bad experiences while in a same-sex relationship before my marriage. Opposite-sex relationships have never made me feel uncomfortable or like a lie. Nor have same-sex relationships felt like the “truth.”

I am happy and comfortable with either sex, both as friends and sexual partners. There is a name for this midpoint on the continuum: bisexual. This middle ground seems to have been totally overlooked in the questions.

Ineke Warner U.K.

EPSTEIN REPLIES: The quiz included with the article is indeed quite skewed, intended to bring out the homosexual side of people’s natures, which is why it is called “How Gay Are You?” The full test—the Epstein Sexual Orientation Inventory—from which the mini test was derived, measures both gay and straight tendencies, reports one’s Mean Sexual Orientation, and also gives one’s Sexual Orientation Range, which is a measure of choice and fl exibility. It is accessible at http://mysexualorientation.com

POWER OF PLEASURE

It speaks volumes about the inherent conservatism of science that we should still be asking the question, as author Klaus Wilhelm does, “Do Animals Have Feelings?” The weight of evidence—from the fact that emotions are adaptive to the way animals respond behaviorally and physiologically to emotive stimuli—leaves no reasonable doubt that they do. Part of the problem is that science has been too mired in seeking evolutionary explanations for animal behavior, to the neglect of an individual’s experience. Mate-seeking minks and romping ravens do not contemplate Darwinian fitness or reproductive success: they are drawn to behave adaptively because of the rewarding feelings it brings.

As I argue in my book Pleasurable Kingdom: Animals and the Nature of Feeling Good (Macmillan, 2006), we would do well to take more notice of the power of pleasure in motivating behavior.

Jonathan Balcombe Physicians Committee for Responsible Medicine Washington, D.C.

A SCIENTIFIC APPROACH

In his review of Fool’s Paradise: The Unreal World of Pop Psychology, Kenneth Silber wonders at the continuing popularity of self-help books. Perhaps one answer might be found in the shortcomings of professional psychological help.

As Scientific American Mind itself has reported, the psychology profession has a tendency to cling to unproved and even disproved practices and theories such as MBTI, Rorschach tests or repressed-memory recovery. If practitioners relied on scientific and evidence-based foundations, perhaps then we would be able, as Scott Adams (creator of cartoon character Dilbert) once satirically suggested, to replace the bookstore’s entire “Self-Help” section with a sign that reads: “Go read any book in the History, Philosophy, or Religion section and think about what it says.”

Carl Zetie Waterford, Va.

ERRATA

“Train Your Brain,” by Ulrich Kraft, mistakenly placed Neuro-Quest Ltd. in Evanston, Ill.; it is in Skokie, Ill. Also, it reported that, “Whenever the amplitude of alpha waves in the left frontal cortex rose above that in the right, the participants would hear a pleasant note played on a clarinet.” The opposite is true: Whenever the amplitude of alpha waves in the right frontal cortex rose above that in the left, the participants would hear a pleasant note played on a clarinet. In “Stability of the Visual World,” by Vilayanur S. Ramachandran and Diane Rogers-Ramachandran [Illusions], the graphic entitled “Movement Detectors” was mislabeled. The labels for “the feedforward theory (top)” and for “the feedback theory (bottom)” should have been reversed.