A theme throughout this book has been that the neocortex is not essential for the experience of emotions. The neocortex has an amazing capacity to re-represent and refine input from the more genetically defined parts of the nervous system, such as the subcortical emotional and motivational networks that guide diverse affective survival responses and to allow the rest of the brain to integrate those “survival values” with our various sensory-perceptual organs that provide information primarily about our external (rather than internal) worlds. Because cortical capacities are acquired—developmentally programmed, if you will—by our basic affective (sensory, homeostatic, and emotional) direct survival systems, there are bound to be more individual differences in cortical brain regions than the more ancient intrinsic subcortical functions. This helps explain the dramatic cortical flexibility demonstrated in Sur’s animal brain research showing how temporal cortex can assume a visual function rather than its more typical auditory function (Sur & Rubenstein, 2005), as well as the dramatic cortical plasticity being demonstrated in subjects who recover from relatively minor cortical brain damage (Nudo, 2013).
Moreover, there is also convincing evidence for the recruitment of visual cortex for somatosensory processing—exercising well-developed tactile skills for reading braille or identifying objects by finger tracing—in individuals who have been blind from an early age (Cohen et al., 1997). Indeed, Sadato et al. (1998) further compared PET imaging of blind and sighted subjects and found imaging results during braille and nonbraille tasks, suggesting that tactile input usually processed in the somatosensory cortex (closer to the top of the skull) of sighted individuals was rerouted in subjects blinded early in life to occipital cortical regions that typically specialize for visual processing. Further, Weeks et al. (2000) used PET to investigate which cortical areas were activated in blind versus sighted subjects when performing auditory localization tasks. Indeed, congruent with the aforementioned work, these investigators observed auditory to visual plasticity: while sighted and blind participants both showed activated posterior parietal cortex, blind participants also showed activated right occipital cortex, a region typically identified with vision. Thus, the superior touch and hearing skills of blind individuals may be due to occipital regions (normally involved in the visual processing of sighted individuals) being “programmed” to participate in the processing of tactile and auditory information, thus providing additional cortical resources enabling expanded tactile and auditory abilities.
Perhaps one day new brain analysis tools will provide a means to show how much of the variability in cortical brain function researchers are currently observing is due to the variability in how neocortical regions are differentially “programmed” in individuals beginning life with distinct genetically promoted endophenotypes and then growing up and maturing under the influence of different environmental circumstances. One might anticipate a clearer appreciation of developmental plasticity in the cortical processing and regulation of emotions.
FIRST-ORDER EMERGENCE OF EMOTIONS: THE DAMASIO GROUP
It is fitting to close this chapter using another contribution from the Damasio group (Damasio, Damasio, & Tranel, 2013), which like the Panksepp group has challenged “the traditional view that mental states are subserved mainly or exclusively by the cerebral cortex” (p. 833). Many have proposed cortical structures as the basis for emotional experience, but A. D. “Bud” Craig (2009, 2011) has asserted that the insula, an interior region of cortex inside the cortical temporal lobe, holds the keys to the kingdom, so to speak, and is the primary neural platform for feelings of emotion.
In response to this argument, Damasio et al. (2013) reviewed subcortical evidence for the first-order emergence of emotions, but more important for this chapter, they put the insula hypothesis to the test by publishing brain images and corresponding emotional data from a person that had sustained extensive brain damage, which included bilateral insula destruction. In their 2013 paper, Damasio’s group described patient B, who as a result of herpes simplex encephalitis had lost not only his insula but also his amygdala, hippocampus, and other brain cortices, including much of his orbitofrontal cortex, the temporal pole, the parahippocampal cortex, and the anterior cingulate cortex. Importantly, there was no insular cortex remaining in either hemisphere of his brain, which was clearly evident in the brain images presented by Damasio et al. (2013). They further stated that, perhaps surprising to some, “unwarned strangers interacting with him for the first time had no inkling that he had major neurological damage, the fact only becoming apparent once his dense amnesia was exposed. To put it plainly, patient-B was a whole human being suffering from a very poor episodic memory” (p. 834). Patient B’s spouse completed a structured questionnaire comparing his behavior before and after his disease, with twenty-five of the questions dealing explicitly with emotions. On eighteen of the twenty-five items, his spouse rated him the same before and after he lost significant portions of his cerebral cortex. On three items she rated him up a point and on four down a point. In addition, patient B frequently and routinely expressed his pleasure or displeasure with life events, including lab procedures such as taking tape off his arm that pulled on his hairs. In short, the questionnaire data, the observations of strangers, and the observations of the research team, including psychological evaluations, all indicated patient B retained a full range of appropriate emotions after his brain disease.
The data from patient B describing his full emotional life makes it difficult to support the idea that the insula is necessary for subjective affective experiences. Indeed, this case provides compelling evidence that structures such as the amygdala, the hippocampus, the parahippocampal gyrus, the temporal pole, the orbitofrontal cortex, and the anterior cingulate cortex are not essential for the expression and experience of emotion. Thus, we agree with Damasio’s group and argue that the structures essential for the generation of emotions are largely subcortical brain regions, especially the PAG and hypothalamus. Clearly, cortical regions play a big role in the full sophistication of human emotional life, but that role is largely a secondary-level one that is acquired—“programmed”—through learning resulting from life experiences, with perhaps early life experiences being especially influential. It isn’t that cortical areas do not play an important emotional role—especially with humans. Many regions of cortex elaborate emotional learning. However, that function is similar to the one provided for all our sensory and motor modalities: Learning provides nuanced refinements that not only enrich and complexify our affective experiences but also offer the potential for diverse learned regulations and elaborations of our emotions—both augmenting and inhibiting (Frank et al., 2014). Without our subcortical affective systems we lose cognitive consciousness. Without our neocortices, at least if lost near birth, affective consciousness survives, without the developmentally added cognitive complexities such as the capacity for spoken language that patient B was fortunately spared.
As neuroscientists become more sophisticated in the use of brain imaging and as new techniques emerge, such as diffusion tensor imaging, which has enabled Coenen et al. (2012) to better understand subcortical deep brain stimulation options for the treatment of psychiatric disorders (Coenen et al., 2012; Panksepp et al., 2014; Panksepp, 2016), we will better understand the origins of subcortical affective imbalances and the role cortical regions contribute to both affective equilibrium and disequilibrium (Panksepp, 2015, 2016).
An important theme running throughout this book is the necessity of first understanding our subcortical primary-process emotional action-affect systems before we can hope to illuminate the subtleties of the human mind and the heights and depths it can traverse through learning and culture. At the core of our mental lives there are profound positive and negative affects, which find their origins in ancient regions of our brain that we share homologously with all the other mammals. The massive “mushrooming” of our neocortex expands our subcortical capacities and allows us complex thoughts and unique creati
ve endeavors of our own making. With the addition of abundant neocortex instantiated and energized by our lower mind, our upper mind can reach creatively, indeed uniquely, into the depths of each human life, as it attempts to optimize its present moment as well as imagined mindscape trajectories into the future.
CHAPTER 17
Personality and the Self
A tolerance for multiple alternative representations may provide the critical ingredient that sets the special flavour of human consciousness. It is reasonable to assume that animals have a relatively simple sort of consciousness, the content of which is closely determined by the here-and-now of immediate needs and sensations. A more complex form of consciousness would be expected to emerge if some critical mass of neurons, freed from the household chores of sensation and action, could afford to form alternative and annotated representations of ambient events. One consequence of this process could be the emergence of an observing self who becomes differentiated from the sensory flux and who can therefore intentionally comment (introspect) on experience.
—M. Marsel Mesulam, “From Sensation to Cognition”
WHAT WOULD PERSONALITY be without a sense of self? The “miracle” of the mind is that humans experience themselves, and this is essential to a sense of self. The “self” is a fundamental sense of who and what we are as distinct from all other beings and all other things. This suggests that a sense of self would include our sense of our own personality, but it surely is a broader concept than personality, accounting for a wider array of behaviors and experiences than personality. Beyond personality, the experience of our own personal affects, and the basic mechanisms of learning and memory, the human self would include
intelligence
cognitive, physical, and social skills and abilities
an awareness of our own and others’ personal characteristics, such as attractiveness, size, and strength
a life story line of autobiographical memories that constitute our unique personal history
our relationships to other beings and to unfolding life events in general
a continuous experience of our mental and bodily states
an explicit sense of owning our body
a feeling of agency, meaning a sense that when our body moves, we are making it move
a moment-by-moment assessment of the position of our body and body parts in time and space
being able to distinguish our body from the external world
There are probably more, depending on how we want to slice that ineffable feeling of being a mind that exists in a world that exists, and now, after modern science, the existential perspective of being an ineffable “dot” in a cosmic universe that may be one among many.
This long list, which moves from more elaborate to more basic abilities (to an existential entity in the cosmos), suggests that the self is a very complex psychological construct with a long evolutionary and cultural history. However, it is difficult to imagine a meaningful human life without even the most elementary of these existential-mental capacities, which is perhaps why Alzheimer’s disease, with the expectation of losing various cognitive mental faculties, is such a feared diagnosis.
This chapter reviews various ideas about the self-concept from a general neuroscience research orientation, much of which focuses on the cortex, which is easier to study in humans because of our neocortical capacity for language. Indeed, as we described in Chapter 16, with current neuroimaging techniques cortical changes are much easier to study than the prelinguistic subcortical functions of the brain, partly because neuronal firing rates are much higher in cortical brain regions than in subcortical areas where our basic emotional circuits are concentrated. With damage to any single major region of our neocortex, we remain sentient beings. In contrast, following relatively small damage to subcortical brain regions, the mental “light” of consciousness disappears, especially when damage is concentrated in the most ancient mid-brainstem region of the periaqueductal gray (PAG) and very closely associated brainstem regions that as a group have been called the reticular activating system.
In any case, a great deal of work remains to be done relating the self to the ancient subcortical brain regions and circuits that are essential for constituting the core of our primary emotion networks. While an autobiographical sense of self may reach its fullest elaboration in the recently evolved human neocortex, here we try to illuminate the SELF (a Simple Ego-type Life Form) from a brain evolutionary perspective (see Panksepp, 1998a; Panksepp & Biven, 2012). In this chapter we try to demonstrate the limitations of a purely neocortically based self-concept and conclude with a cross-species affective neuroscience interpretation of the core self, shared across mammals, at the very least.
Focusing first on our most basic SELF and self-related capacities, imagine yourself in a physical fight against a human attacker. What psychological self constructs would be critical for survival? First of all, you would need to experience an emotion (with all its physiological, motivational, and motor action tendencies) in response to the attack. Second, you would need to automatically distinguish your body from your attacker’s body. Third, during the fight, it would be adaptive to have an automatic moment-to-moment sense of where your body and its various parts are located. Fourth, with a bit more mind power, it would also help to have a sense of agency—that you could make your body do things to achieve goals, such as using your fist to hit the attacker hard enough to undo their attack, to functionally drive him or her away.
While these four capacities seem rather elementary, they constitute quite a remarkable evolutionary accomplishment. A self that was characterized by only the four basic abilities required by our fighter would be a very elementary SELF, but these minimal features of raw existence represent real evolved solutions to problems faced by all animals with nervous systems capable of adapting to and surviving basic life challenges. Of primary importance in this chapter is that very basic cross-species mental powers remain essential for humans to maintain a coherent sense of self. We have already used several different conceptions of the self, and now we will try to flesh out the several levels of BrainMind organization that need to be considered to understand this multidimensional BrainMind process.
THE PROTO-SELF AND CORE SELF
For creatures with a brain, even a primitive or proto-self (see Damasio, 1999; Panksepp, 1998b, 2005) probably includes the capacity to respond to bodily metabolic needs in addition to the ability to spontaneously generate body movements, and the ability to implicitly distinguish self from nonself. Further on, evolution may have integrated primary sensory, homeostatic, and emotional affects and primitive coherent-instinctual, sensory-motor processes with a proto-self to create what the second author of this book has called the core SELF (Panksepp, 1998a). However, even then we are still just talking about a type of pure affective experience without the capacity to reflect on that experience with awareness, namely, as a third-party observer of sorts that neocortical self-reflective experiences allow—an explicit characteristic perhaps unique to humans, or perhaps shared implicitly with as yet undetermined numbers of other species, although without language and hence probably in a more limited capacity.
Simple amphibian vertebrates, such as the much-studied northern leopard frog, Rana pipiens, would be a good example of a species with a core SELF. Because frogs possess limited cortex, they would largely have subcortical body maps. Affects and sensory inputs would be processed in areas homologous to the mammalian subcortical brain, such as the PAG and the superior and inferior colliculi. Yet, even though a frog’s visual acuity, for example, would not be considered 20–20 from a human viewpoint, and frogs can be easily visually fooled (Lettvin, Maturana, McCulloch, & Pitts, 1968), they still manage to fill their tummies with flies, which is no small achievement. But, their limited self-representational brain capacity relative to humans likely leaves them with a rather minimal self (for an evolutionary synthesis, see Feinberg & Mallatt, 2016).
It is generally thought that the c
ore SELF is generated as the Brain-Mind represents somatic and visceral states in neural maps, which are able to integrate inputs from various sources to generate a sense of bodily coherence. Such neuropsychic map-like representations probably occur at many levels throughout the brain. In the lower midbrain, they are found in the PAG as well as inferior and superior colliculi; they are also found in the upper midbrain and diencephalon (that is, in the hypothalamus and midline thalamic regions), before they are re-represented with additional cognitive complexities in the forebrain. In mammals, the cerebral cortex acquires (probably through developmental learning mechanisms that are still poorly mapped) well-developed body sensory maps, motor maps, and extensive higher-order visual and auditory processing areas, which we increasingly come to rely on as we mature, and which at least in humans permit thoughts about our place in the world.
THE EMERGENCE OF SELF-AWARENESS
Humans have a subcortical brain anatomy homologous to the frog’s but with many additions, including more sophisticated “switchboards” and cortical regions for processing sensory inputs that we grow ever more dependent on from infancy to adulthood. With our ample neocortex, humans have inherited spectacular representational and re-representational upgrades, which not only provide us with self-awareness but also allows us to observe ourselves and even see ourselves from the viewpoint of others. We are able to know that mom told us not to eat any of the freshly baked cookies we love until after dinner but at the same time to be aware that mom is out on the front porch talking to the neighbor and that we have an opportunity to easily sneak one of those sugary gems up to our room and enjoy it without her ever knowing.
It is not clear how many other species are capable of this level of awareness. However, Nicola Clayton’s group at Cambridge University has reported that if one scrub jay (Aphelocoma californica), a rather intelligent bird, notices another scrub jay watching it hide food, the first scrub jay will retrieve the food later and hide it in a new place after the onlooker has left (Dally, Emery, & Clayton, 2006), seeming to demonstrate the ability to appreciate the contents of other minds, which some earlier investigators prematurely granted only to humans. This group of researchers has also demonstrated that this is learned behavior, because some hand-reared birds do not exhibit this recaching behavior, and only birds mature enough to display Piagetian “object permanence” are able to learn the behavior.
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