Quizás el mejor modo de cumplir con la exhortación del frontispicio del Templo de Delfos, “Conócete a ti mismo” sea conocer cómo nuestros afectos afloran desde nuestros organismos y cerebros, y cómo operan, en combinación con el ambiente, ora subrepticia ora abiertamente, para guiarnos por la vida.
Consagrado a la labor de entender las emociones en los animales y en el hombre, más allá de la faz de su expresión, profundizando en el cerebro mamífero que las alberga y produce y retomando el trabajo de Darwin donde este lo dejó, el neurocientífico estonio-americano de la Washington State University,Jaak Panksepp, ha dedicado toda una vida investigadora y publicado cientos de artículos girando siempre en torno al núcleo fundamental de las emociones básicas que la Madre Naturaleza hizo surgir de los cerebros hace millones de años. Él mismo ha bautizado su campo como neurociencia de la afectividad.
Entrevista en ESPAÑOL acá
1. What are emotions? What are feelings? What is their evolutionary sense?
Emotions are complex functions of the brain, with the best early scientific description provided by Darwin in his 1872 Expression of Emotions in Man and Animals. We now know there are coherent brain operating systems, homologous across mammalian species, that generate many of these coherent behavioral manifestations; this is because we can simply activate them by electrically stimulating specific brain networks. Raw emotional feelings apparently emerge from these evolutionarily provided brain systems, since activation of some (SEEKING, LUST, CARE and PLAY) can serve as "rewards", while activation of others (RAGE, FEAR and PANIC) can serve as "punishments" (these systems are capitalized to highlight that distinct networks in the BrainMind, with distinct affective properties, are referents so as to avoid part-whole confusions). There are, of course, other sensory and bodily-homeostatic feelings (superbly studied by Kent Berridge and Derek Denton, respectively), all very difficult to talk about clearly in animal models. However, our group is most interested in the within-brain emotional feelings (emotions being defined by brain circuit characteristics, and categories of "instinctual" behaviors) since they are most important for understanding psychiatric disorders.
Parenthetically, the use of human languages to discuss the nature of animal minds is problematic, and one way to skirt the Pandora's Box is to generate a new, more scientifically limited type of linguistic-conventions as highlighted also by our use of capitalizations. Vernacular language usages are intrinsically confusing, especially when applied to animals; hence we need new terms to discuss the nature of their minds.
Emotional systems are very "sensible" since they provide a neural substrate for various types of organismic coherence. They also make animals "active agents" in the world as opposed to just behavioristic "information processors". To have raw feelings built into these systems, as evolutionary memories, allows animals to anticipate survival issues automatically, and also provide a substrate for further learning. In a sense, the main function of the MindBrain (we need a unified concept such as this), is to anticipate future survival needs. The evolutionary "sense" of having raw (primary-process) affective feelings is that they "unconditionally" identify specific primal survival issues, and those brain states can also be used as tokens of information for higher learning-mental processes.
It is scientific "nonsense" for neuroscientists and evolutionary psychologists to ignore such primary-process BrainMind issues (the so-called unconditioned responses of the brain), and to devote much more effort to secondary and tertiary processes with which they are linked though learning. The behaviorist, cognitivist, and evolutionary psychologist agendas can never be fully achieved without a clearer understanding of the unconditioned stimulus and unconditioned response networks of the brain (i.e., the many "instinctual" and "innate" but experientially refined neuropsychological tools for living)
2. Since the 19th century evolutionary arguments have been used to describe the evolution of the mammalian nervous system. A common picture is the "triune brain" model proposed by Paul MacLean that consists of three separate brains: the reptilian brain, the old-mammalian brain and the neo-mammalian (primate) brain, each with its own way of functioning. Does this view still hold among neuroscientists or is an oversimplification that does not take into consideration the complex interrelationships between different parts of the brain, viewing it as an integrated entity?
I think we can all agree that the brain evolved, and hence, so did certain aspects of our minds. No simple tripartite view of brain evolution will be a fully accurate and adequate depiction; MacLean's view was a didactic simplification that brought people's attention to global stages in BrainMind evolution, but it approximated matters well. It is a view that helped focus many people's attention to the fact that ancient minds do still exist within our modern human minds, and that we will not understand our higher mental processes unless we have a serious confrontation with earlier neural solutions that still influence the complex mental apparatus of highly-encephalized mammals.
With as complex an organ as the mammalian BrainMind, we do need some conceptual guidance, often evolutionary simplifications, to begin making sense of the integrated whole. I prefer to have slightly different tripartite view of the complexities which do not get us into neuroanatomical "problems": i) primary-processes, which are evolutionarily provide rough-and-read tools for living, many of which typically reflect intrinsic "intentions-in-actions"--processes traditionally discussed as "innate" or "instinctual" processes that have engendered so much heated debate (the neural substrates generally corresponds to MacLean's reptilian and old-mammalian brains), ii) secondary-processes, which reflect the basic abilities of the brain to learn via sensitization-habituation, classical and operant conditioning etc. (these are represented at all levels of brain organization), and ii) tertiary-processes, which include all those "reflective" higher MindBrain processes that we include under concepts such as thought, deliberation, planning and higher forms of intentionality (i.e., intentions-to-act) and we can't have much of that without the evolutionarily-grooved general-learning functions of our neocortical expansions.
As one ascends this hierarchy of mental complexity, there is some kind of parallel neural complexity. MacLean's trichotomy was in the right direction for his time--a time when evolutionary issues were not popular in either psychology or neuroscience. Modern evolutionary thought will need to retain the best of that vision and to move forward to confronting, ever more realistically, the real hierarchical two-way complexities of BrainMind evolution. As we do this, I expect that we will find the more discrete and definitive evolved-mind functions exist mostly in the lower, more ancient, caudal and medial regions of the brain.
The more developmentally and epigenetically emergent mind functions rely much more on recent rostral and lateral brain expansions found in abundance in the neocortex. We can have more confidence of evolved functional specializations in lower-ancient brain regions than the higher, more recent expansions such as neocortex. "Modularization" of function (a very dicey concept), especially when monitored in adults with techniques like fMRI and PET, is not evidence for evolutionary-genetic modularization. Despite the dreams and best wishes of evolutionary psychologists, piles of evidence suggest that most neocortex is akin to tabula rasa at birth. The future joining of evolutionary psychology with modern brain imaging must remember that what eventually becomes "modularized" in higher regions of the brain was not so at birth. This also goes for "mirror neurons". Also, some of our spectacular new tools, like fMRI, are not well suited for studying ancient MindBrain functions where the release of powerful nerochemistries (e.g., neuropeptides) is more important than massively changing frequencies of action potentials that characterize higher brain functions.
3. Our brain's intrinsic affective responses are more subtle and complex than we thought. Can we say that they are "intelligent"?
Yes, the subtlety of the primary-process affective mind has barely been studied in human neuroscience or psychology. Largely this is because there is no ready access to such fundamental processes in human research. To make progress we need animal models, and our intellectual traditions, steeped in logical positivism, have chosen to deny or diminish the mental lives of other animals. However, we can be confident that even at the primary-process level, affects come in many varieties, including ones that emerge directly from peripheral sensory inputs, other from internal bodily interoceptive and homeostatic abilities and some that are largely within-brain functions such as the emotional affects.
My work has focused on the latter, and we can be confident that there are many intrinsic "rewards" and "punishments" (i.e., affects) within the brain. The primary-process emotional ones include affects arising from SEEKING urges, FEAR, RAGE, sexual LUST, maternal CARE, social-loss PANIC, and joyful-PLAY systems. We know much about the affective nature of these ancestral tools for living because the networks can be aroused using localized brains stimulation in all mammals, and these activations can serve as "rewards" and "punishments" in traditional learning tasks. The challenge now is to more clearly distinguish these affects objectively using various discrimination and state-dependent learning tasks in animals, as well as psychologically-sophisticated brain stimulation studies in humans.
As soon as we proceed to secondary and tertiary levels of MindBrain emergence, the complexities increase tremendously, often in idiographic (individualistic and culture-dependent) ways. Many can only be studied in humans.
Are these systems "intelligent"? It depends on how one uses that complex concept. Surely they would not exist if they had not been very useful for survival and reproduction. They are "street-wise" in the sense that the affects provide immediate indications of what to do--if it feels good, do more of it, and if it feels bad, do less of it. However, such simple-minded responses can become foolish in various complex situations, especially social ones. Evolution did not always build in an understanding of how foolish or wise they may be at a higher mental level. That mostly was left to learning. However, some paths of development are evolutionarily "prepared". One should readily learn that ones desires are being compromised, and if some interloper tries to entice away your social-sexual security, it would be useful to readily learn various jealous response which may be a complex elaboration on SEEKING, FEAR, RAGE and PANIC feelings.
I think the human dilemma is how we make our "street-wise" instinctual responses more intelligent and more capable of serving our higher desires and expectations. If we allow the lower-brain to rule, we get ourselves in all kinds of troubles. Academically, one is that the amygdala is "the center" of our emotional lives. Nonsense. Adult human emotional lives are as strongly linked to our higher cognitive capacities as our lower emotional networks. But the former do not have a "life of their own". Everything upstairs remains tethered to the many emotional networks in lower BrainMind regions. These subcortical systems can have a "life of their own". Young rats with the whole neocortex removed surgically, are very emotionally coherent creatures, that students cannot distinguish from normal, neurologically intact littermates. They simply would not survive for long in the outside world. The intrinsic emotional-motivational-perceptual coherence of lower brain regions is an important lesson for evolutionary psychology.
4. Is there any innate fear?
Yes, of course. As far as we know there is an evolutionarily-provided FEAR network, running from central amygdala, through medial hypothalamus to the dorsal regions of the Periaqueductal Gray that can orchestrate a coherent fear response that includes visceral, somatic, and affective components. How do we know? Localized brain stimulation along this network activates a coherent fear response in all mammalian species ever tested, and animals dislike this stimulation as indicated by the ability of the stimulation to serve as "punishment" in various learning tasks (i.e., escape and conditioned place preferences). It is a pity that most fear-conditioners do not acknowledge this system in the brain, probably because they are more interested in individual learning and memory rather than the nature of the universal "instinctual" unconditioned emotional response systems that evolution built into mammalian brains.
The primary-process FEAR system, as all the other emotional primes, is born largely "objectless"--i.e., most of our specific fears are learned. However, this system does appear to have certain intrinsic inputs, no doubt slightly different in different species. Pain, loss of physical support and rapidly looming objects are effective instigators of fearfulness in most vertebrate species. However, prey species, have other more specific sensory-perceptual inputs into the FEAR system, the best studied being the smell of predators in rodents. This input, from their accessory olfactory systems (via vomeronasal nerves), directly accesses the headwater of the FEAR system in the amygdala. Rats become spontaneously afraid when exposed to the smell of cats. This reflexive fear can turn into a "fatal attraction": Some parasites (e.g., Toxoplasma gondii) that need to complete their life-cycle in a single type of "definitive host"--namely cats--have devised a way to facilitate "intermediate hosts" such as rats to land in their stomachs. Namely, when rats are infected with T. gondii, they lose their innate fear of cat odors. When infected, fearful smells from cats are blocked from entering the unconditional FEAR circuitry (as shown by recent work from Robert Sapolsky's laboratory). Indeed, rats begin to find feline smells to be attractive. Ha!
5. Why do we laugh?
Human laughter is a most puzzling instinctual-unconditioned response that is most common early in development during physical play. It has to have a long-evolutionary history, since dedicated circuitry for laughter is situated in deep subcortical regions of the brain. Indeed, primary-process laughter can be provoked by tickling in both human children and juvenile rats (where it takes the form of a 50 kHz "chirp"). We think the primary-process function is to facilitate affectively positive coordination of many appetitive behaviors, from general-social to specific-sexual sharing, among animals that are friendly with each other. Hence laugher can increase reproductive fitness by facilitating social bonds.
We can activate the laughter-type chirping response in rodent brains response by electrically stimulating the SEEKING System. Indeed, wherever we get stimulation-induced chirping, the stimulation is rewarding! When this primary-process brain function interacts with secondary and tertiary brain processes we are sure to find many fascinating additional complexities, including, no-doubt, the emergence of humor. We can be confident that playful fun-joy generating urges are built into the brain, but doubt if a sense of humor was built in by evolution. However, humor seems to be the higher-order positive state generated by verbal-play, which probably emerges mostly through learning. I expect that the affective impact of humor arises from the same matrix as the joy of play. I would be surprised if the higher reaches of the human brain contain intrinsic genetically-provided "humor modules" since those ludic potentials could as readily emerge through learning. Humor can be used in so many ways--to facilitate social bonding and to marginalize others. However, a genetically promoted play-loving temperament would, I suspect, readily promote a fine sense of fun and humor.
6. What does not function correctly in a mental illness?
I wish we knew! My best hunch is that constitutional mental problems reflect deficits within the primary-process emotional-affective networks in the brain. If so, it would be very important for biological psychiatry to invest more effort in decoding the details, especially the neurochemical details of primary-process emotional endophenotypes in animal brains. Envisioning imbalances in basic emotional systems, and their higher regulatory controls (e.g., cortical inhibition of emotional arousals), may be a better way to discuss psychiatric problems than the current "syndromal" approaches handed down to us from pre-neuroscientific times.
Once neuroscience begins to have a serious and concerted confrontation with the ancient emotional networks of the brain, many new biochemical pathways will be identified that may be yield new possibilities for medicinal development. For instance, using genetic technique (along with my colleagues Jeff Burgdorf and Joe Moskal), we have identified Insulin Like Growth Factor-1 to be a positive affective system that is aroused by social play. Might that yield brand new antidepressants? There will be many emotion-modulating neuropeptide systems that will be imbalanced in psychiatric disorders, allowing us to better envision and treat the MindBrain complexities underlying psychiatric disorders.
7. Why you are so reluctant about the evolutionary psychology program?
I am both "reluctant" and enthusiastic. My reluctance is based on the fact that most evolutionary psychologists seem little interested in the real functions of genetic controls and instinctual (unconditioned) brain functions. It probably reflects lack of expertise in those matters. So far, the traditional form of Evolutionary Psychology (EP) has arisen from a social-psychology tradition that has been primarily focusing their thoughts and hypotheses on the higher, tertiary aspects of mind, and pursuing plausibility stories with little interest in linking their ideas to either neuroscientific or genetic analyzes. In doing so, their ideas are very susceptible to fundamental errors that they do not seem all too ready to correct. We have seen how compelling half-truths, such as those advanced by behaviorists, have captivated generations of students to the present day. I fear that EP will do that once again, but now adding intriguing mental complexities that may emerge from our developmental/epigenetic confrontations with the world rather than direct evolutionary-genetic effects arising from the transcriptions-translations of our DNA-RNA. I think the statistical trends that they describe can be readily explained if they had clear visions of what actually evolved in the lower reaches of mammalian brains than the higher reaches of human minds. Consider a very complex "for instance": Language learning may be initiated more through a prosodic-emotional communicative urges (affective vocalizations that may have been the foundations of primal music) rather than any kind of inherent propositional language instinct. The fact that speech comprehension cortex (Wernicke's Area) is situated where it is easily explained by it being nestled between visual, auditory and somatosensory cortices allowing optimal multi-modal processing of incoming information.
Overall, it is scientifically wiser first to see whether we can generate a lasting neurobiological understanding of primary-process brain functions that more clearly evolved, often shared homologously by all mammals, rather than reach so vigorously for higher-order MindBrain complexities. To make progress at higher levels, we may have to find ways to link foundational issues to higher mental ones, and I think emerging disciplines such as neuropsychoanalysis are doing this in more scientifically balanced ways than any traditional social-science based Evolutionary Psychology.
It would be wise for evolutionary psychologists to recognize some fundamental principles of BrainMind organization. For instance, higher regions of the neocortex, with arrays of self-similar cortical "columns" that resemble computer chips is, at birth, functionally more similar to general purpose, random-access information processing units, than the substrates for evolutionarily-dedicated, functionally-specialized psychological "modules". To the best of neuroscientific knowledge, there is no intrinsic, genetically-dictated visual neocortex in the brain. As Mriganka Sur's group at MIT has dramatically demonstrated, visual competence in mice is epigenetically programmed during early development. The same can be surmised for every cortical function, even though I expect frontal-executive functions have more definitive evolutionary engravings. If upheld for other sensory-perceptual processes of the neocortex, such data throws an enormous monkey-wrench into the traditional Evolutionary Psychology agenda. Yes, the brain is genetically-prepared to learn in many distinct ways, but the end result does not justify an evolutionary story unless one has considered how ancient brain systems control the development and programming of more recent evolved brain networks such as those in the neocortex.
Evolutionary Psychology needs to be more disciplined in its speculations, or we will have a more robust "monster" to contend with than the one passed down to us by never-mind behaviorism. Considering the evolutionary value of self-aggrandizement, it is unlikely that the perpetrators of such flaws will seek to correct their own mistakes. In any event, at the present time, most evolutionary stories arising from psychology-only analyzes, are promissory notes that can be explained more parsimoniously by the manner our ancestral affects may control and regulate our higher cognitive processes. What is truly unique in humans is the complexity of our linguistic abilities (all our other achievement follow from that), but even that is permitted by, not dictated by, the random-access-memory types of evolutionary expansions in our higher neocortical regions.
8. What are you now working on? What is your highest challenge? What is the mystery you would dream to unveil?
We remain very interested in all the basic emotional systems and how they relate to psychiatric disorders. We are most interested in how the social-loss sensitive PANIC system mediates separation-distress (a form of "psychic pain") and how that contributes to depression. We are equally interested in the intricacies of PLAY systems, since they are so important for understanding positive social affect, various childhood problems (e.g., ADHD), counteracting depression, and understanding power politics (as symbolized by our love of professional sports). We are also probing how early play, which clearly arises from subcortical circuits, epigentically programs higher brain functions.
The highest conceptual challenge is to weed the field of useless and wrong-headed concepts that misdirect our thinking--for instance the postulation of "evolved psychological modules" in higher regions of the brain, long before there is satisfactory genetic evidence for such specializations. A similar conceptual shoddiness also hurts my own field, behavioral neuroscience, which is still fixated on the existence of a mythologically unitary "the brain reward system" isomorphic with ascending dopamine systems. There are many, many reward-related processes in the brain. There are various distinct sensory rewards, homeostatic rewards and emotional rewards, with good evidence that the mesolimbic/mesocortical DA system and endogenous opioids participating, to some extent in each. However, the primal role of "the brain reward system" is to promote coherent but generalized action-tendencies involved in obtaining all kinds of distinct rewards detected through our sensory portals. Thus, currently there is a mass of evidence that this system participates affectively much more in the "anticipatory-enthusiasms" or all reward-seeking behaviors, rather than in the "reward-consummation" delights. Aside from some like-minded investigators, most prominently Kent Berridge, this appetitive-motivational viewpoint continues to be neglected. Instead, those who love behaviorist-cognitivist concepts, such as "reward-prediction error" information-processing concepts, rather than ethological ones such as SEEKING/wanting, potentially misinterpret their superb dopamine neuron firing studies in chair-bound monkeys that inform us richly about what the dopamine system is listening to, but nothing about what the system is doing downstream (i.e., a classic case of correlates being confused with causes?).
Thus, our three decades old EXPECTANCY-SEEKING concept is still radical to most investigators, but we should not forget that this system is most active as animals are foraging for resources, not when rewards are consumed. If we continue making conceptual errors such as "The" Brain Reward System, we will continue to sustain the hegemony of behavioristic-errors in our thinking about the primal organization of the MindBrain. We currently still invest more in the myth that good scientific concepts for describing the primary-process BrainMind can be gleaned from learning-experiments conducted on animals restricted to prison-house observational chambers (e.g., Skinner boxes), which are terribly convenient for our research needs, rather than from the study of the natural (unconditional in form if not direction) behavior sequences animals exhibit in the world. By doing so, the ethologically-relevant, emotion-mediating BrainMind concepts get less experimental attention than they deserve.
The biggest scientific challenge is to generate a neuroscientifically credible understanding of raw emotional feelings. We now know where to look. Raw feelings are intimately intermeshed with primary-process emotional operating systems that engender coherent emotional responses. But how the magic of affective feelings actually emerges from these systemic activities, remains largely an undeveloped project requiring better ideas and technologies. One challenge is to discover credible ways to study network dynamics within the brains of living animals, comparable to those we have for studying single neuron activities. So far, the study of the neural nature of instinctual emotional behaviors, the many ancestral tools for living that can be aroused by localized brain stimulation in whole animals, appears to be the best method we have for studying primary-process experiences in the mammalian brain. However, we are currently discussing projects to see if we can develop an in vitro brain-slice model to monitor spontaneous anticipatory learning within SEEKING circuits.
My dream? To penetrate further into the experienced aspects of brain activities in animals and humans. To achieve this, I expect that we will have to have a neuro-conceptual and empirical confrontation with the mammalian "soul"--those ancient (i.e., subcortical) "core-SELF" types of neural networks that allow organisms to be coherent, spontaneously active, feeling organisms on the stage of life. I suspect that the understanding of the nomothetic (universal) SELF processes of the mammalian brain will set the stage for understanding the many higher idiographic (individualistic) selves that emerge developmentally-epigenetically in the higher regions of our brains/minds. If true, the most neuroscientifically compelling variants of evolutionary psychology will arise coherently from bottom-up comparative analyzes of the mammalian BrainMinds rather than the prevailing human-oriented, psychology-only variants that seem de rigeur at the present time.
We humans are spectacular variants on ancient mammalian themes, but most of our uniqueness may arise from how the "nature of nurture" (epigenesis) molds the expansive functionality of higher regions of our brains. But that will be hard science, perhaps also a hard sell, like evolution itself. Regrettably, if our functional hypotheses are not constrained by what we already know about the evolution and organization of the brain, we are prone to make many conceptual errors. If so, others will eventually have to "mop-up" after us... usually more slowly than is beneficial for the advancement of substantive knowledge. But that is a perennial risk of deep scientific inquiries, helping explain why most in basic neuroscience seek to remain completely at detailed, surface levels of analysis, learning more and more about less and less.
La Nueva ilustración evolucionista
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