Bachevalier & Reber: Emotion

Jocelyne Bachevalier & Dierdra Reber
Cultural and Neuroscientific Perspectives on Emotion

The CMBC’s second lunch seminar of the fall semester brought together Dr. Jocelyne Bachevalier (Psychology) and Dr. Dierdra Reber (Spanish and Portuguese), Emory scholars from markedly different disciplines who share common interests in the study of emotion. Despite their differing approaches, the presentations by the two speakers – who represent the fields of affective neuroscience and cultural criticism, respectively – converged on a number of unifying themes, many of which came up in audience members’ subsequent questions. In this commentary, I’ll highlight these points of convergence and offer some additional food for thought (or food for feeling, if you will).

In her opening remarks, Bachevalier stressed the adaptive role of emotion for survival, but noted that only recently has empirical research on affective processes become widespread. Advances in operationalizing such processes, previously regarded as too subjective to be studied systematically, have led to a dramatic increase in neuroscientific research on emotion, including the use of nonhuman primate models. As described by Bachevalier, early research on emotion in nonhuman primates relied primarily on the lesion method to gain insight into the functional neuroanatomy of emotion. Focusing on the region of the brain known as the amygdala, researchers found that lesions to this area in rhesus monkeys produced drastic changes in affective behavior. Among the resulting symptoms, collectively referred to as Klüver-Bucy syndrome, are visual agnosia (the inability to recognize familiar objects) and hypoemotionality (diminished affect, with aggression replaced by docility). Bachevalier observed that a key problem with lesion experiments is that they necessarily involve damage not just to the amygdala, but also to connective fibers from the visual cortex (which may explain the recognition deficits). Avoiding this confound, Bachevalier’s research isolates functions specific to the amygdala by injecting drugs that selectively kill amygdala cells, leaving other fibers intact. Using this method, Bachevalier has shown, contrary to earlier findings, that amygdala damage results not in an overall dampening of emotional responses, but rather in an inability to modulate emotion, whether positive or negative. For example, animals with amygdala damage may show both excessive hostility and a heightened tendency to seek out positive stimuli. Thus, Bachevalier’s research has clarified the critical role of the amygdala in adequately and appropriately triggering emotional responses.

In contrast to Bachevalier’s empirical approach to investigating emotional experience, Reber focuses on the cultural meaning assigned to emotion. In her opening remarks, Reber suggested that there has been an epistemic shift in recent years toward the privileging of body over mind in characterizing how we experience and interact with the world. According to Reber, the current cultural landscape – as evidenced through various forms of media – promotes the apprehension of experience via feelings rather than via the tools of reason. For example, in illustrating Christ’s life primarily through vivid depictions of brutality, the film The Passion of the Christ relies on eliciting emotional responses in viewers rather than engaging their analytical capacities. Indeed, several viewers reportedly suffered heart attacks in the movie theater as a result of their strong emotional reactions to the film. Reber described several other examples of this use of emotion to rouse public sentiment, including George W. Bush’s politics of fear and the McDonald’s “i’m lovin’ it” advertising campaign. These and other observations led Reber to conduct an interdisciplinary examination of emotion’s rise in cultural prominence. Evidence for this trend comes from advances in understanding the neural bases of emotion, greater focus on the role of emotion in politics and decision-making, and the development of alternative ways of characterizing cultural experience that do not rely exclusively on verbal language. Reber suggested that a key factor in the shift toward a more affectively driven culture was capitalism. The notion of the invisible hand, originally coined by the economist Adam Smith to describe the self-regulating nature of the marketplace, stands in contrast to the more hierarchical, taxonomic qualities associated with reason and rationality. The fall of the Soviet Union and the triumph of capitalism, Reber asserted, opened the door to valuing affective experience, and the notion of thinking through feeling, at a broad cultural level.

Perhaps the most obvious connection between the two speakers’ presentations was the emergence of interest in affect across different fields. Bachevalier noted that early research in neuroscience privileged “cold” cognitive processes, and that it was not until much later that the role of affect in continually (and often unwittingly) modulating such processes (“hot” cognition) was appreciated. Similarly, one of Reber’s main points was that capitalism enabled a redefinition of emotion, previously regarded as chaotic or uncultivated, into positive terms. This change in characterization led to the valorization of emotion as a primary way of conveying meaning across a wide range of cultural forms. For example, as suggested by an audience member, social movements were once regarded as driven by reason, but when people no longer saw themselves as fundamentally rational beings (as in the movements of the 1960s), emotion became the catalyst. Reber cited the characterization of current popular protests across the world as movements of “indignation” as evidence that we are perceiving and analyzing social action in emotional terms.

One interesting issue raised in discussion was the idea that the study of emotion may inevitably, and perhaps paradoxically, require the tools of reason. For example, neuroscientists use systematic, quantitative methods to break down affective processes into specific components, and literary critics often describe emotion with language far removed from the vividness of affective experience. While Bachevalier pointed to the difficulty of separating emotion from cognition in scientific research, Reber suggested that the humanities may allow for greater variation in the language used to describe emotion, including the approach of purposefully avoiding conclusions and causal links as an alternative to rational discourse. Nevertheless, the methods primarily used to study emotion may serve the essential purpose of distancing researchers from their own emotions. Given that emotional signals can influence behavior even outside of awareness, it may be necessary for all disciplines to have precautions in place to avoid bias. As someone interested in the evocative power of language, I find it particularly noteworthy that language’s inability to capture our rich affective experience may be precisely what facilitates progress in the scholarly understanding of emotion.

Tamasi & McCauley: What Is Language?

Susan Tamasi & Robert McCauley
What Is Language?

Last spring, Dr. Susan Tamasi (Linguistics) and the CMBC’s own Dr. Robert McCauley co-taught the CMBC-sponsored undergraduate course Language, Mind, and Society (LING 301), a required course for the Linguistics major and the joint major in Psychology and Linguistics. On the first day of class, students were asked to complete a short writing assignment, tackling the question “What is language?” Fittingly, this question also served as the launching point for discussion when Tamasi and McCauley reunited for the CMBC’s first lunch seminar of the fall semester on Thursday, September 22. Following opening remarks from each speaker, student and faculty attendees across a range of disciplines offered their own insights on the nature of language. In this commentary, I’ll highlight some of the key issues raised in the speakers’ presentations and in the lively group discussion that ensued, while also weaving in my own thoughts and reactions.

In her opening remarks, Tamasi noted the difficulty of coming up with any single definition of language. Various definitions offered by students in LING 301 focused on language’s role as a biological construct, a reflection of thought, a transmitter of information, and a marker of social identity, with some arguing that these characteristics render language a uniquely human trait. Tamasi suggested that defining language may not simply be a matter of combining all of these characteristics; rather, there may be some additional, perhaps intangible, property yet to be identified that captures what language is at its core. The fundamental nature of language, Tamasi went on to suggest, cannot be identified merely by examining individual languages, nor by focusing exclusively on the structure of language apart from how it is used by individual speakers and communities.

McCauley’s opening remarks centered on defining language as an abstract concept, or system, akin to the study of religion, as opposed to individual religions. Drawing on his perspective from the philosophy of science, McCauley suggested that explanations of systems are most fruitful when they are mechanistic; that is, when they define the parts, their organization, and their contributions to the operation of the system. Chomsky’s conception of language as primarily a system of thought, rather than a medium of communication, lends itself to such mechanistic analysis (even if Chomsky himself has not pursued that end). According to McCauley, psychological accounts of language have the benefit of localizing the mechanisms underlying language to a physical substrate, namely the brain, with advances in the study of cognition in turn contributing to our understanding of language. McCauley also characterized language as one of several maturationally natural systems, defined in part by their significance in addressing the basic problems in life, their comparatively early appearance in development (within the first two decades of life), the automaticity with which they are engaged, and their lack of dependence on culturally distinctive support.

One issue that came up in discussion was how these criteria apply in cases of so-called feral children (e.g., “Genie”), those who grow up isolated from human contact from a very young age and who consequently are unable to develop normal language abilities, among other cognitive skills. If language does not depend on culturally distinctive support, it might seem that such children should be able to acquire language, certainly once discovered and exposed to the social world. According to McCauley, however, invoking “culture” in such cases may be overly grandiose; what feral children lack may be reduced simply to the opportunity to interact with one other conspecific. Although interactions between individuals must be critical to the typical development of language, they constitute culture in only its most minimal sense. McCauley’s point is that there is nothing special about the social interaction necessary for acquiring language, only that it must be present in some form. While parsimonious, this line of reasoning does not address the question, what is culture? At what point does a particular type of experience become distinctively cultural rather than merely providing the “bare bones” of culture? For ethical reasons, it has often been regarded as impossible to isolate the social ingredients essential for acquiring language, but perhaps greater understanding of the cognitive mechanisms supporting various social phenomena may shed light on what types of social experience are necessary versus merely ornamental.

Another discussion point concerned the extent to which language is unique to humans. Non-human animals certainly have communication systems (and some have even been successful at acquiring sizeable vocabularies), but Tamasi suggested that equating such systems with human language assumes that the principal function of language is to communicate information. Instead, Tamasi stressed, we must take seriously the structural complexity of language at multiple levels (e.g., phonological, morphological, syntactic, etc.), which allows for the coordination of thought and a level of generativity unseen in other communication systems. But do such systems possess a hidden complexity that we cannot recognize simply from observable behaviors? Perhaps, but while we cannot zoom in on the structure of such systems directly, there is one place we can look: the brain. We might posit that the “waggle dance” of the bee, which serves to recruit other bees to forage in the same area, is incredibly complex, but it is unclear how the neural system of the bee could support such complexity, particularly given that we now have some understanding of how properties of human language like recursion are neurally instantiated. As McCauley noted, knowing where to look for the mechanisms underlying language offers a methodological opportunity to understand the nature of linguistic complexity. This opportunity may be wasted if we insist on parity across species.

Interestingly, however, many linguists assume parity across individual languages. Although one language might be regarded as more complex than another in some aspect of its structure (with consequences for how easily such structure is learned), languages are assumed to be equally complex overall because they all serve the same purpose. But if languages are defined by their complexity, this argument seems circular. If some recently discovered language was found to be less complex overall, we would have to conclude that it was not in fact a language (or, alternatively, that its complexity had yet to be discovered). I wonder if it would benefit the field to abandon the notion that there are necessary and sufficient features for language, given the observation from cognitive science that it is virtually impossible to define necessary and sufficient features for anything, whether it be chairs, games, or ideas. Acknowledging a continuum of complexity in language would not render the construct “language” meaningless; it would merely suggest that there is no clear distinction between what counts as a language and what doesn’t. Of course, given that language has often been viewed as a window into the mind, abandoning the parity assumption might open another can of worms by implying an extreme form of linguistic relativity, or cognitive differences among speakers of different languages. Nevertheless, recent research indicates that there is no simple one-to-one mapping between language and the conceptual system (e.g., Malt et al., 2011; for a review, see Wolff & Holmes, 2011), suggesting that differences in linguistic complexity do not necessarily entail analogous cognitive differences.

One important aspect of what defines language seemed to be missing from the lunch discussion: the world. As cognitive scientists have noted, the world is richly structured, with inherent discontinuities in how properties are distributed. For example, concrete objects like dogs and tables form more coherent perceptual bundles than relational notions typically encoded in verbs and prepositions (e.g., throw and in). This structure constrains which components of meaning are encoded in language more generally and also serves as a standard of comparison when considering semantic variation across languages. Recent evidence suggests that universal properties of human perceptual experience may lead to a conceptual space largely shared across languages, with different languages partitioning the space differently. Our understanding of language may be enriched by considering the complex interactions among mind, world, and society that give rise to this fundamental human capacity.

References

Malt, B. C., Ameel, E., Gennari, S., Imai, M., Saji, N., & Majid, A. (2011). Do words reveal concepts? In L. Carlson, C. Hölscher, & T. Shipley (Eds.), Proceedings of the 33rd Annual Conference of the Cognitive Science Society (pp. 2884-2889). Austin, TX: Cognitive Science Society.

Wolff, P., & Holmes, K. J. (2011). Linguistic relativity. Wiley Interdisciplinary Reviews: Cognitive Science, 2, 253-265.

Spano: Conductor Prepares Orchestral Performance

Robert Spano
How a Conductor Prepares for an Orchestral Performance

Have you ever wondered what it is that an orchestra conductor does? A few weeks ago on Thursday, April 7th, a group of faculty and graduate students had the distinct privilege of discussing this topic with Maestro Robert Spano at the final CMBC lunch of the semester. Maestro Spano has been the music director for the Atlanta Symphony Orchestra for the past 10 years. He is also Emory University’s Distinguished Artist in Residence, an appointment sponsored by Emory’s Creativity & Arts Initiative.

In this highly engaging discussion, Spano provided a glimpse into the process conductors go through in preparation for an orchestral performance. It was great fun to learn about a topic I don’t typically come across as a psychology graduate student. Equally exciting though, was to take note of some overlap between music and the study of mind and brain.

Activating the Imaginative Ear

In preparing for an orchestral performance, Maestro Spano describes the first step conductors go through as activating the imaginative ear. This means that when conductors first inspect the musical score, they are able to translate in their minds the musical notations from the score into the sounds they represent. Spano noted that this capacity, also referred to as “audiating”, is not an ability unique to conductors. Some musicians can do this and, to some extent, non-musicians can engage in this process as well. Think of how we read an email from a family member and we can hear the person’s voice as we read. What distinguishes what conductors do is that they don’t only imagine one “voice”, they imagine many, and all work in concert.

What makes the task of audiating an orchestral piece complicated is not only the number of instruments but also the non-uniformity of their notational systems. For example, you may have heard a musician say, “the clarinet is in b-flat”. What this means is that the clarinet is in a different transposition than other instruments, and what is written as a C on the score for other instruments will actually be a b-flat for the clarinet.

The process of audiating is so integral to conductor training that for many the activation of sound upon sight is virtually an automatic process. In fact, Spano described it as akin to the phenomenon of Synaesthesia. Synaesthesia is the condition whereby some individuals report perceiving involuntary stimulation in one sensory dimension in response to stimulation from a different dimension. One of the more common examples of Synaesthesia is that some individuals report perceiving certain letters or numerals in particular colors (for example the letter “A” is perceived as inherently red). Spano revealed that some conductors actually report the same types of cross-sensory connections as those commonly reported by synaesthetes. For example, one conductor perceived sounds as being in particular colors. Another conductor, Spano said, associated sounds with specific scents. 

The Musical Score Is Merely a Map

Although conductors possess the capacity to automatically hear the music when they read it, this doesn’t mean that a score elicits the same sound for all conductors. This fact reflects a second aspect of a conductor’s preparation, which is to engage in an act of interpreting the score. This decision process occurs at multiple levels. For example, conductors must decide, as Spano put it, “how loud is loud, how slow is slow, and how long is long”. All musicians engage in this decision making process but conductors must make these decisions for the group.

Maestro Spano drew a loose analogy between a musical score and the directions provided by his car’s GPS earlier that morning. The GPS provided the basic route to Emory’s campus, indicating which roads to take, where to turn, etc. But alas that morning the campus’ main entrance was undergoing major construction, requiring drivers to navigate around the construction and along detours to arrive at the destination. Similarly, the score is merely a map and conductors must interpret what the sounds mean.

The byproduct of these two processes, audiating and interpreting, is a mental template of the piece to which conductors can compare the music during the actual performance. Spano describes this as the difficult, if not impossible, task of objective listening. The idea is that the conductor can notice errors or inconsistencies that violate his or her expectations based on the constructed template.

The Many Gestures of a Conductor

One thing that many of us likely associate with conductors is their distinctive gesturing during orchestral performances. As it turns out, some of these gestures are conventional and part of a universal system that all conductors, and orchestral musicians, learn in their training. These gestures can be used as a guide to musicians, when they need it, about where they are in the piece. The gestures are also used to establish the beat of the orchestra and ensure all instruments are playing at the same tempo. This is important given that orchestras can be large enough that musicians on one side of the stage may not be able to hear those on the other.

Not all of a conductor’s gestures follow the same universal code though, and this is what leads to the general percept that different conductors behave very differently on stage. Maestro Spano pointed out that for the most part, the conductor’s goal is to produce gestures that are rather low key. From what I gathered, these are the gestures that tend to be the universal, grammatical motions. These movements are made subtle so that they can then be contrasted with the more emphatic gestures conductors employ when they are trying to elicit particular things from the musicians. These gestures tend to be conductor-specific. The high degree of contrast between the subtler gestures and the more emphatic ones is due to the fact that conductors are mostly in the peripheral view of the musicians. Musicians’ central attention tends to be directed at their sheet of music or their own instruments. Thus in order to be able to capture the attention of the musicians when they need to, conductors create this large contrast between the calm baseline gestures and the forceful statement-making gestures.

A Final Note

It was a real treat to hear Maestro Spano talk about conducting and the lunch was a testament to the diversity of topics the CMBC offers in this series. Although it was certainly the case that many of us were learning about an unfamiliar subject, there was also the sense that many of the issues discussed were related to topics regularly associated with the study of the mind and the brain. For example, one obvious connection was the discussion of how the experience of translating sight into sound for conductors, and perhaps professional musicians more generally, relates to the phenomenon of synaesthesia. The nature of synaesthethic experiences, and in particular why it happens, has long been of interest to scholars in fields such as neuroscience and cognitive psychology. To the extent that the cross-sensory connections experienced by conductors are a result of years of practice and training, might this provide insight into the origins of other synaesthetic experiences?

Johnson: Bodily Aesthetics of Meaning-Making

Mark Johnson
The Bodily Aesthetics of Human Meaning-Making

Last Friday, the CMBC hosted a lunch discussion led by Dr. Mark Johnson of the University of Oregon. Following a presentation by Dr. Johnson entitled “The Bodily Aesthetics of Human Meaning-Making,” faculty and student attendees engaged in a lively open group dialogue on the nature of meaning at multiple levels of explanation – aesthetic, emotional, linguistic, and cultural.

In his pioneering work with George Lakoff, Johnson argued that meaning is of a fundamentally embodied nature, with conceptual structure derived from – and inextricably tied to – sensory-motor experience in the world. More recently, Johnson has delved more deeply into the bodily bases of meaning, drawing inspiration from the ideas of the philosopher John Dewey. In his presentation, Johnson highlighted the Deweyan maxim that meaning emerges from an organism’s ongoing interaction with its environment. On this view, Johnson argued, aesthetic dimensions of bodily experience (e.g., feelings, emotions, image schemas) are the very source of meaning. This view contrasts with the more impoverished notion of meaning in much of Western thought, namely that meaning is solely a property of language and thus strictly conceptual and propositional in nature.

Johnson went on to suggest that artistic works can offer a window into meaning beyond the abstract propositional content encoded in language. According to Johnson, encountering art is a qualitative experience (i.e., we focus on discrete features or categories, such as the redness of one’s lips or the muskiness of old wood), and it is these qualities that are the basic units, or building blocks, of meaning. Qualities are non-conceptual in that they may occur outside of consciousness and are felt directly by the body, rather than conceived at a more abstract level. Johnson used an example from music to illustrate the bodily qualities automatically elicited by art. Through dramatic changes in pitch, the first few notes of “Over the Rainbow” in turn lift us up, bring us down, and pull us back up once again, invariably giving rise to a sequence of emotions, or a feeling contour, within the body. Feeling contours, Johnson suggested, are the structures within embodied experience that constitute meaning, even though we often cannot put them into words.

At the end of his presentation, Johnson elaborated on the problems that an aesthetic view of meaning poses for cognitive science. In particular, while cognitive scientists have made great progress toward understanding meaning at the linguistic or propositional level, we may not be equipped with the resources or theoretical vocabulary to explain more aesthetic aspects of meaning. As a consequence, to the extent that aesthetic qualities are the units that undergird human conceptual structure, we may be quite far from explaining even the very basic mechanisms by which humans make sense of the world. As humans are not primarily “proposition crunchers” (in Johnson’s words), it is essential that we develop tools to examine experience in its pure, unintellectualized form.

Johnson’s presentation sparked a fascinating discussion. Below I summarize some of the topics brought up by attendees and offer my own thoughts on the issues at stake, from the perspective of a graduate student in cognitive psychology:

How to Characterize Aesthetic Experience

The challenge of developing a theoretical vocabulary to explain nonlinguistic, aesthetic qualities of meaning implies, somewhat paradoxically, that such qualities must eventually be packaged in language. On Johnson’s view, however, characterizing the ongoing flow of experience in linguistic terms will inevitably be inadequate because there are certain dimensions of experience that language cannot capture. Johnson offered the example of logicians who report that they know they have arrived at the end of a proof when they feel a sense of resolution or fulfillment. If even logical propositions have an aesthetic component, meaning may never be fully specified through symbols. It seems, then, that the challenge for cognitive scientists is to devise clever nonlinguistic measures capable of providing a fuller characterization of aesthetic experience. For example, patterns of neural activity in response to different types of art might provide some insight into the nature of the sensory-motor representations associated with particular aesthetic “qualities.” An exciting outcome of this work would be the potential to study concepts apart from language. As recent research in cognitive science has suggested differences in the range of meanings captured by linguistic and nonlinguistic representations, characterizing the representations associated with aesthetic qualities might bring us closer to understanding what “concepts” actually are. As one audience member suggested, the construction of such representations may be a matter of “aesthetic education”; that is, training the mind to recognize patterns in sensory input. I would think, though, that much of the so-called training would occur implicitly as we go about our lives and naturally develop expectancies about how the world is organized.

Abstraction and Language

During the presentation, it struck me that Johnson’s characterization of aesthetic qualities highlighted their categorical nature. If the basic units of meaning are categories (e.g., red, as opposed to a particular red thing), it would imply that we experience the world as abstractions over exemplars, rather than the exemplars themselves. If so, does that mean some fine-grained components of sensory input will inevitably escape us? Is there an advantage to experiencing the world at a relatively coarse level, rather than having access to all the fine detail that the world offers? Experiencing the world categorically also suggests how aesthetic qualities may ultimately be related to language. Words are markers of categories, so the full range of aesthetic qualities taken in by the senses may represent a sort of semantic possibility space for what can be encoded as a word. That is, the set of meanings that can be lexicalized in language may be constrained by the range of categories that the sensory-motor system is capable of accessing. Of course, any given language will only lexicalize a portion of these categories, with the rest possibly consisting of a set of meanings that are conceivable even though they are nameless. Perhaps Johnson’s approach could offer new insights on cross-linguistic differences in word meaning by specifying the cultural factors that determine which aesthetic qualities become lexicalized across languages. One audience member suggested that aesthetic experience might be defined collectively rather than at the level of the individual. An examination of cross-linguistic differences might inform what Johnson called the “character of a culture”; aspects of aesthetic experience that are codified in the lexicon are likely to be those that are highly valued by a culture.

Comparative Aesthetics?

Although Dewey drew a distinction between human and non-human animals in his writings, Johnson suggested that there is a large degree of continuity across species in aesthetic experience. It is likely, for example, that non-human animals also experience feelings and emotions as qualitative units. Johnson posited that the ability to engage in symbolic abstraction may be what separates humans from other animals. It may come as no surprise, then, that symbols have been reified in Western philosophy as constituting the fundamental units of meaning, perhaps obscuring more basic bodily aspects of experience. Johnson’s earlier work with Lakoff suggests, however, that even abstract symbolic operations are grounded in bodily experience, so where does concrete experience end and symbolic abstraction begin? If there is no clear line between the two, it becomes more difficult to specify exactly what makes human cognition unique. Indeed, if research inspired by Johnson’s ideas were to take a comparative approach, it might reveal a substantial degree of continuity across species in cognition more generally.

Roy & Wallen: The Brain, Sex, and Gender

Deboleena Roy & Kim Wallen
What Does the Brain Have To Do with Sex and Gender?

This past Tuesday, the CMBC hosted a lunch discussion titled “What does the brain have to do with sex and gender?” The discussion was led by Dr. Deboleena Roy (Women’s studies and Neuroscience) and Dr. Kim Wallen (Psychology).

The topic of sex and gender differences is of great interest to many. From my own experience as a student in the psychology department, the question of whether sex or gender differences exists in particular behaviors or traits is probably one of the most commonly asked questions both in the classroom and at research presentations. It was thus no surprise to me that Tuesday’s lunch meeting was filled to its capacity with student and faculty attendees.

Both Dr. Roy and Dr. Wallen gave brief opening remarks leading up to an open group dialogue. Unfortunately, this blog space isn’t large enough for me to report all the interesting information I learned from the lunch. So, I’ll try and highlight just some of the issues our discussion leaders raised as well as give some snippets of the directions the group discussion took.

Language and Metaphor in Science: A Feminist Scientist’s Perspective

In her opening comments, Dr. Roy provided a brief overview of some of the feminist engagements in research on gender and sex differences specifically, and in scientific research more broadly. She discussed, among other things, how feminist scholars over the years have pushed for a critical analysis on the types of language and metaphors scientists use in understanding particular biological phenomena. An example she gave was how early neuroendocrinologists would portray the workings of the Hypothalamic-Pituitary-Gonadal (HPG) axis. Early on, Dr. Roy described, many scientists explained the axis hierarchically, implying that the hypothalamus regulates the activity of the pituitary and gonad glands. A different metaphor, however, also seemed to fit the data. Namely, the axis could be thought of as a set of feedback loops between the hypothalamus, pituitary and gonad glands. In fact, some of Dr. Roy’s own research revealed that estrogen receptors exist on Gonadotropin Releasing Hormone (GnRH) neurons within the hypothalamus, suggesting that there may indeed be a feedback regulatory system from the ovaries to the hypothalamus. Dr. Roy further discussed how the metaphors scientists use not only affect the types of interpretations at which we arrive, but also the types of follow-up experiments and future directions scientists choose to make, as well as how the results are disseminated by the media.

A Recent Finding of Sex Differences in the Brain

Dr. Wallen began his opening comments with a summary of a recent finding from his lab. The goal was for the lunch attendees to work together to figure out what these findings might mean for the topic of sex and gender differences in the brain. The basic finding was that men and women subjects show differential patterns of brain activation, specifically amygdala activation, in response to viewing erotic compared to non-erotic images. Specifically, men showed greater amygdala activation to erotic images (compared to non-erotic images) than did women. Further, it doesn’t appear that this pattern can be explained simply by the fact that men found the pictures more arousing (ratings of the images revealed that men and women found the images equally arousing).

Dr. Wallen’s team didn’t look only at men and women, but also a third group of subjects, women with Complete Androgen Insensitivity Syndrome (from here on, CAIS women). According to Dr. Wallen, these women have a Y chromosome but lack typical androgen receptors. As a result, phenotypically these individuals are like women, except for the fact that they have a Y chromosome. Of interest for this study was the pattern of amygdala activation in CAIS women. As it turns out, Dr. Wallen and his students found that their amygdala activation was comparable to the women. That is, men also showed greater amygdala activation in response to the stimuli compared to CAIS women. Further, women and CAIS women did not show a differential heightened pattern of amygdala activation to the sexual images.

The ensuing discussion about what these findings mean was fascinating. One topic discussed was that in order to know what these findings mean for sex differences in the brain, we first must figure out how to best characterize CAIS women in relation to the other two groups. From a strict chromosomal standpoint, CAIS women can be thought of as genetically male. But what does it mean to be genetically male? As Dr. Wallen points out, if you consider the fact that genetic traits are only expressed in the context of an environment, and that CAIS women lack androgen receptors (which would provide the typical hormonal environment in which male traits develop), then CAIS women wouldn’t count as genetically male.

Sex vs. Gender Differences

Dr. Roy suggests that the difficulty in characterizing the CAIS women highlights the struggle we have in trying to answer a question that seems simple: what makes a male a male. She suggests that this difficulty is due to a deep bias we have in perceiving the world as strictly consisting of men and women. That is, that we have intuitions that biologically we all start out with male and female bodies. These bodies then go through a process of socialization that turns those male and female bodies into men and women.

The separation between the biological and the socio-cultural underpinnings of the differences between the sexes maps onto what are traditionally considered “sex differences” (ones due to biological factors) and “gender differences” (one due to socio-cultural factors). Dr. Roy pointed out that there is a changing trend in the object of study in feminist science scholarship. Whereas early feminist scholars focused primarily on understanding gender differences, more recent feminist scientists have begun to focus on questions related to sex differences themselves, including whether the construct of sex itself might not be as rigid as once believed.

Structural vs. Functional Differences

Dr. Roy brought up yet another issue related to the findings, which is the distinction between structural and functional sex differences. That is, although the study revealed “structural” differences across participants in the patterns of Amygdala activation, all participants reported similar arousal ratings to the erotic images. Dr. Roy suggested that when the neuro-imaging and behavioral results are considered together, they might reflect a more general fact that multiple structures may lead to the same functional outcome. Dr. Wallen agreed, suggesting that the processing of sexual imagery might go through the amygdala in men and through a different circuit in women.

A number of follow-up analyses might be informative in this respect. For example, are there correlations between ratings of arousal and heightened amygdala activation? Further, are these correlations different across the different populations? I found this issue of “multiple roads leading to the same end point” interesting as it raises the possibility that there may be important differences even within both the male and female populations.

Other possible explanations of the findings were also discussed, highlighting the difficulty of figuring out what exactly the brain has to do with sex and gender differences. For example at one point, Dr. Wallen pointed out that we don’t know if the men and women in the study are even “seeing” the same thing within the images. To further complicate the matter, Dr. Wallen also reminded us that the study only looked at a single region of the brain, a particular class of images, and using a specific experimental design. Whether the types of explanations that are currently on the table will remain viable once more data come in remains to be seen.