A Theory of Mind III: Emotions

Introduction
In laying out the essential ingredients for a theory of mind, I previously elaborated on the crucial roles of language and memory with illustrative examples. A befitting saying proclaims that a stool needs three legs to stand. Emotions represent another important ingredient of our mind. They seem to narrow our choices by focusing or diverting our attention, thus limiting our choices and profoundly affecting our behavior. They strengthen our memory of particularly intense moments. Plenty important decisions in our lives are being made because of the emotions we attach to a loved one. Therefore, emotions constitute a worthy third leg for the theory I strive to construct. Multifarious types of emotions have been recognized. We may distinguish the simple emotions of “affect programs”, like fear and aversion, from the complex, more “cognitively penetrable” ones (see de Sousa, 2003 for review).

Complex Emotions
Complex emotions have been recognized since the middle of the 19^th century, when the tragic fate of the railroad construction worker Phineas P. Gage in New England brought the fundamental role of emotions in defining our personality and their roots in the brain to public attention.

Phineas Gage and his tamping iron
(from the collection of Jack and Beverly Wilgus)

Phineas miraculously survived a grave accident at age 25 which destroyed primarily his left frontal lobe. On Sep. 13, 1848, he was tamping blasting powder down into a borehole with a solid iron rod that weighed 13.25 lbs and was 1.25 inches in diameter and 3 feet and 7 inches long. A spark triggered an explosion and the rod shot straight up like a missile, tapered end first, entirely penetrating Phineas' skull. The iron was found later 80 feet away from the site of the accident. Astoundingly, Gage reportedly did not lose consciousness. He was brought home where Dr. John Martyn Harlow found him sitting up and talking. Harlow was an observant physician who diligently recorded Gage's condition and the progress of his recovery. Phineas, by then a cause célèbre, was a changed man. Before the accident, he used to conduct himself in an even-keeled, considerate manner fit to work as a foreman for the railroad. After the accident, his behavior had become more irritable and irate, and he struggled with a lack of focus. Yet, he managed to hold down a job as a stage coach driver in Chile for several years and lived for another twelve. At the age of 37, he developed severe seizures and passed away within a few months.

Informed of Phineas' death, Harlow sought out the family and was able to procure the tamping iron. He gained permission for a brief exhumation of Phineas' remains during which he retrieved the skull. Harlow published his observations on Gage in a scientific journal (Harlow, 1848) as one of the first documented neurological case histories that related anatomical with behavioral findings. Skull and iron are in the possession of the Warren Anatomical Museum at Harvard Medical School today, and several attempts have been made to reconstruct the damage to Phineas' brain. Certainly, his left frontal lobe, but likely also a part of the right frontal lobe, were severely compromised by the rod's impact.

Phineas' terrible accident kindled intense scientific interest in the role that the frontal lobes play in our emotions and specific frontal lobe areas have been associated with distinct aspects of emotional behavior. For example, the anterior cingulate cortex near the juncture of the cortical hemispheres and the frontal orbital cortex, that is the very nose-ward aspect of the cerebral cortex, seem engaged in focus, decision making and judgment, notably of pain and danger, and are considered part of our attention and risk assessment mechanisms. In addition, anterior cingulate cortex influences autonomic functions like blood pressure and heart rate.

The anterior cingulate cortex sends output to insular cortex wedged between the frontal and the temporal lobe under the operculum, and frontal orbital cortex receives input from this region. Insular cortex receives sensory as well as visceral input, integrating information from inside and outside our body. Von Economo first discovered spindle cells there. Spindle cells are a particular morphological type of nerve cell peculiar to a select number of cortical areas of high-level functional specialization among which we also find anterior cingulate cortex. I have written about these cells in my post with the title "Constantin von Economo's Spindle Cells & The Mind" dated Aug. 21, 2009. Moreover, a special functional type of nerve cells, known as mirror neurons, have been found in anterior cingulate cortex (Rizzolatti and Sinigaglia, 2008). They have been implicated in empathy. I have written about them in my post with the title "fMRI III: Religiosity & Brain Activation" published Mar. 31, 2009. Anterior cingulate, frontal orbital and insular cortex are considered extended parts of the limbic system.

Simple Emotions
Simple emotions are processed by members of the limbic system that are phylogenetically older brain structures than the cortical regions discussed above. We widely share them with less developed vertebrates (Ebner, 1969), inspiring Paul McLean's hypothesis of the triune brain (McLean, 1990). Structures laying down long-term episodic memory have been included here. They comprise the hippocampus, composed of dentate gyrus, fornix, fimbria, and subiculum, as well as the parahippocampal gyrus, divided into perirhinal and the entorhinal cortex.  Particularly, the amygdalae, almond-shaped structures composed of histologically and functionally distinct, interconnected subregions at the bottom of the medial temporal lobe of cerebral cortex, are instrumental in startle and fear. They are strongly influenced by the neurotransmitter dopamine (Reynolds, 1983) and known to play an instrumental role in the influence of emotional arousal on the strength of the memory for our experiences (LeDoux, 1998).

The amygdalae provide output to the reticular formation, instrumental to alert and arousal, the striatum, involved in motor control, as well as structures in the brainstem, mesencephalon and diencephalon that control visceral, gustatory, nociceptive, motor and humoral functions. Moreover, they project to hippocampus, entorhinal cortex, prefrontal cortex, sensory cortical areas of all modalities and multimodal sensory association cortex. While the outputs can be either inhibitory or excitatory, inputs to the amygdalae are predominantly excitatory, utilizing the neurotransmitter glutamate. Fear conditioning in rats has been shown to increase their synaptic strength through a plastic mechanism known as long-term potentiation (Paré and others, 2003).

The inputs to the amygdala originate in most cortical and subcortical areas the structures project to, plus the olfactory bulbs (McDonald, 1998). Moreover, in opossums (Kudo and others, 1986), rats (Ottersen and Ben-Ari, 1979; Doron and Ledoux, 2000) and cats (Ottersen and Ben-Ari Y, 1979), the amygdalae also receive multimodal sensory direct input from the diencephalon, notably the visual (lateral posterior nucleus equivalent to the pulvinar in us) and auditory thalamus (medial geniculate body). The medial geniculate body is a relay station of the ascending auditory pathway. The direct connection with the amygdalae facilitates rapid responses to unexpected menacing stimuli. Alas, the input from the auditory thalamus does not appear to exist in us (Munoz-Lopez and others, 2010), and the one from the pulvinar seems to exert less impact on the amygdalae than in rodents (Pessoa and Adolphs, 2010). This paucity may manifest itself in a less abrupt startle reflex, because cortical processing is involved. Regardless, we immediately seem to duck when we hear a loud bang. When others take cover or flight, we do not hesitate either, as the video of this horrific incident shows. We only need to watch the beginning of the clip. Amygdala in action is visible at 10 seconds:

A story on National Public Radio's Talk of the Nation Science Friday with the title "No Fear" broadcast Dec. 18, 2010, informs us about patient S.M. whose amygdalae have been damaged on both sides (Feinstein and others, 2010). She literally knows no fear. The insights she provides may invaluably help advance treatments for people with anxiety and post-traumatic stress disorder.

Conclusion
Perhaps the founder of human ethology Irenäus Eibl-Eibesfeldt most strikingly revealed the prevalent and universal role of emotions in our lives. He developed camera lenses with a mirror that permitted him to record the facial expressions of unsuspecting bystanders unnoticed. By filming people around the world through these right-angle lenses, he and his colleagues were able to identify archetypal face expressions commonly used to communicate emotions across diverse cultures (Eibl-Eibesfeldt, 1989). The raising of the eye brows to signal readiness for social interaction constitutes one impressive example. Pictures of this behavior are shown on the home page of the Film Archive of Human Ethology. It is a wonderfully emotional scene.

References

• De Sousa R (2003) Emotion. The Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.).
• Doron NN, Ledoux JE (2000) Organization of projections to the lateral amygdala from auditory and visual areas of the thalamus in the rat. J Comp Neurol 417:385–386.
• Ebner FF (1969) A comparison of primitive forebrain organization in methaterian and eutherian mammals. Ann NY Acad Sci 167:241–257.
• Eibl-Eibesfeldt I (1989) Human Ethology. DeGruyter, New York.
• Feinstein JS, Adolphs R, Damasio A, Tranel D (2010) The Human Amygdala and the Induction and Experience of Fear. Curr Biol: 10.1016/j.cub.2010.11.042.
• Harlow JM (1848) Passage of an iron rod through the head. Boston Medical and Surgical Journal 39:389–393.
• Kudo M, Glendenning KK, Frost SB, Masterton RB (1986) Origin of mammalian thalamocortical projections. I. Telencephalic projections of the medial geniculate body in the opossum (Didelphis virginiana). J Comp Neurol 245:176-197.
• LeDoux JE (1998)The Emotional Brain: The Mysterious Underpinnings of Emotional Life. Simon and Schuster, New York.
• McDonald, AJ (1998) Cortical pathways to the mamalian amygdala. Prog Neurobiol 55:257–332.
• McLean PD (1990) The Triune Brain in Evolution: Role in Paleocerebral Functions. Springer, New York.
• Munoz-Lopez MM, Mohedano-Moriano A, Insausti R (2010) Anatomical pathways for auditory memory in primates. Front Neuroanat 4:129.
• Ottersen OP, Ben-Ari Y (1979) Afferent connections to the amygdaloid complex of the rat and cat. I. Projections from the thalamus. J Comp Neurol 187:401–424.
• Paré D, Quirk, GJ, LeDoux JE (2003) New vistas on amygdala networks in conditioned fear. J Neurophysiol 92:1-9.
• Pessoa L, Adolphs R (2010) Emotion processing and the amygdala: from a 'low road' to 'many roads' of evaluating biological significance. Nature Rev Neurosci 11:773-783.
• Reynolds GP (1983) Increased concentrations and lateral asymmetry of amygdala dopamine in schizophrenia. Nature 305:527–529.
• Rizzolatti G, Sinigaglia C (2008) Mirrors in the Brain: How Our Minds Share Actions, Emotions, and Experience. Oxford University Press, New York.
  

Related Posts

• About Us & Other Minds
• Constantin von Economo's Spindle Cells & The Mind
• fMRI III: Religiosity & Brain Activation
• Prologue to A Theory of Mind
• Theory of Mind I: Feral Children & Language Development
• A Theory of Mind II: H.M.'s Memory

A Theory of Mind II: H.M.'s Memory

In the first installment of this series posted on Dec. 31, 2008, I argued the importance of language for a Theory of Mind. In this installment, I discuss a role for memory.

On Dec. 2, 2008, Henry Gustav Molaison, passed away at the age of 82. H.M., as he became known to scientists around the world, developed seizure activity after an accident at the age of 9 and began to suffer from severe bouts of epilepsy from the age of 16. Since his seizures recurred progressively more frequently and gained in intensity, turning unbearable at the age of 27, the middle temporal lobe of the cerebral cortex was surgically removed from both hemispheres, including parts of the hippocampus and the amygdala.

After surgery, Henry would experience only two other severe seizures in his life, but was a changed man forever. He developed profound amnesia, becoming the subject of intense scientific study for the rest of his life and, since he dedicated his body to science, beyond.

He was well-mannered, could speak eloquently and execute daily routines of hygiene, dress and nourishment. He could mow a lawn and do small household chores. He retained memories of some major historic events before his surgery. He could remember where is family was from. He remembered his name, but he did not know how old he was. He could recall immediate events instantaneously and could judge against internalized references. That is, seeing himself in a mirror he would exclaim: "I am not a boy!" However, he was not able to remember persons or events from the day before and could not make any plans for tomorrow, as if he lived in permanent presence every day anew.

The eminent British psychologist Brenda Milner and her colleagues could demonstrate in elegant series of tests that H.M. was able to learn subconsciously procedural skills involving so-called implicit memory, but could not retrieve declarative explicit memory of episodes in the past. The hippocampus was implicated in the latter type, playing a crucial role in the processing of our conscious thoughts. H.M. retained a sense of self, but could not remember who he was. He had lost a distinct piece of his identity, an essential ingredient of his mind. His neurosurgeon William Beecher Scoville, who strongly opposed this type of surgery after this devastating outcome, and Brenda Milner published their first observations on H.M. in the Journal of Neurology, Neurosurgery and Psychiatry in the late 1950s (Scoville and Milner, 1958).

In 1985, the Swedish neuroscientist David Ingvar published a remarkable essay in the now defunct scientific journal Human Neurobiology on the role of memory and the areas in prefrontal cortex known to be involved in the processing of memory at the time(Ingvar, 1985). About 1970 he, Niels Lassen and others had successfully assembled a scanning device at Bispebjerg Hospital in Copenhagen, Denmark, with which local cerebral blood flow in human cerebral cortex could be mapped non-invasively using radioactive xenon-133 gas as tracer (Lassen, 1985), while the participants were exposed to sensory stimuli or were executing tasks. The Bispebjerg Hospital was set to become the first institution where functional brain imaging would become routine.

In collaboration with Drs. Seymour Kety and Louis Sokoloff at the National Institutes of Health, Drs. Lassen and Ingvar helped pioneer methods used to demonstrate that local cerebral blood flow changes commensurate with metabolic and electric nerve cell activity under normal physiological conditions. Based on this discovery, colleagues at Bispebjerg Hospital would be able to demonstrate later that visual mental imagery, e.g. the navigation of visual scenes in front of the mind's eye, activated many regions of cortex that are ordinarily engaged in the processing of visual input (Roland and Friberg, 1985). They would be able to identify cortical areas activated during the retrieval of memory. One compelling discovery Dr. Ingvar described in his essay in Human Neurobiology was that the same regions in the frontal lobes of cerebral cortex that were activated when people remember episodes in their past were also active when they were asked to make plans for the future. He concluded that there can be no planning of future actions without memory of the past. He called this process forming memories of the future.

Dr. Ingvar's insights inevitably posit that any human invention, any creative process, any idea we form of something unprecedented from mere mental concept to actual implementation hinges on our declarative memory. Indeed, with this wonderful gift we can make dreams come true. Hence, declarative memory must constitute another pillar of a Theory of Mind.

Related Posts

• Prologue to A Theory of Mind
• Theory of Mind I: Feral Children & Language Development
• A Theory of Mind III: Emotions

Addenda

• On occasion of H.M.'s passing, informative reports appeared in The New York Times on Dec. 4, 2008 (Bendict Carey's article entitled "H. M., an Unforgettable Amnesiac, Dies at 82"), and in the Economist on Dec. 18, 2008 ("Henry Molaison, a man without memories, died on December 2nd, aged 82").
• National Public Radio's Weekend Edition broadcast a segment on H.M. by Brian Newhouse's with the title "H.M.'s Brain and the History of Memory" on Feb. 24, 2007.
• In support of Dr. Ingvar's hypothesis, Hassabis and others (2007) observed that amnesic patients with hippocampal damage were unable to imagine future experiences.
• Joshua Foer tells us about constructing memory palaces in his latest book with the title "Moonwalking with Einstein: The Art and Science of Remembering Everything" just published by Penguin Press, New York. Building memory palaces constitutes an intriguing strategy for retaining excellent memories and may possess profound bearing on a sharper mind. The method was developed in the classical age and rediscovered during the Renaissance. Perhaps, the extraordinary explosion of creativity in the arts and the sciences during that period depended on such strategies to memorize facts in a time when books were still inaccessible to most (03/08/11).

References

• Ingvar DH (1985) "Memory of the future": an essay on the temporal organization of conscious awareness. Hum Neurobiol 4:127-136.
• Lassen NA (1985) Cerebral blood flow tomography with xenon-133. Semin Nucl Med 15:347-356.
• Roland PE, Friberg L (1985) Localization of cortical areas activated by thinking. J Neurophysiol 53:1219-1243.
• Scoville WB, Milner B (1957) Loss of recent memory after bilateral hippocampal lesions. J Neurol Neurosurg Psychiat 20:11-21.

Example for the Memory of the Future at Work: Treehouse

Son's Idea

Dad's Implemention

Humans perfected this method over generations!

Theory of Mind I: Feral Children & Language Development

The human mind is quite robust. We can compensate for the loss of any sense and learn to behave normally. People who cannot see or cannot hear from birth can perfectly graduate with advanced academic degrees, provided they are afforded the necessary help. The brain reorganizes. Cortical regions deprived of dominant sensory input may be recruited in the processing of information of other sensory modalities. Detailed reviews of scientific studies examining the neural basis of such reorganization can be found in the book entitled "Blindness and Brain Plasticity in Navigation and Object Perception."

However, if we are deprived of most social contact in early childhood, our development appears irrevocably impaired. The etiology of only few feral children is documented in depth. Kaspar Hauser is one such case. In Werner Herzog's wonderfully detail-oriented movie "The Enigma of Kaspar Hauser," Bruno S. plays the role of Kaspar so astonishingly real that the movie strikes us as a documentary. This may come as no surprise. Herzog is a brilliant cinematic portrait artist, and Bruno Schleinstein seems predestined for this role, when we learn about his life. Michael Kimmelman published a passionate, yet distanced account on this man in The New York Times on Dec. 24.

Bruno S. possesses the great natural gift to act in one role, that is, as the feral child Kaspar Hauser. In Herzog's epic description of bucolic life in a small town in nineteenth century southern Germany, the story of Kaspar teaches us that we may not be able to attain the language skills necessary to grasp the intricacies of human relations when barred extensively from interacting with others in early childhood. As long as we find sufficient access to language, our mind will develop fine. Social relationships play a fundamental role in this process. The inability to express ourselves in language both constitutes and reflects a disability of thought, hindering the ordinary development of self-awareness. Hence, a meaningful Theory of Mind must consider abstract thought expressed in language and detached from senses as one bearing pillar of our psyche.

Two areas on the left cortical hemisphere are known to play fundamental roles in the processing of language. In an oversimplification, Wernicke's area appears instrumental in the comprehension of speech; Broca's area is crucial for speaking. Functional magnetic resonance imaging studies on the cerebral activation of Braille readers that my colleagues and I carried out (Melzer and others, 2001) suggest that, in addition, regions where visual, auditory, and somatic sensory association areas meet may be engaged in the phonetic and semantic processing of symbolic language. In his book "Language and Mind",Noam Chomsky proposes that language originates from innate roots. A vivid discussion of his ideas with Michel Foucault can be found here. Forkhead box P2 genes, FOXP2 genes for short, have been identified to substantially affect the development of language skills. Recent research provides evidence that these genes may have been expressed already in Neanderthals (Krause and others, 2007). Therefore, hereditary boundaries are set for the nerve cell mechanisms that underlie the development of language. These limitations need to be explored in depth and a valid Theory of Mind must take them into consideration.

Addenda

• A second installment for a Theory of Mind has been posted (02/20/2009).
• FOXP2 genes encode transcription factors. That is, their protein products control the expression of other genes, influencing cascades of developmental events. In a letter to this week's issue of the journal Nature, Konopka and others (2009) report that the product of chimpanzee FOXP2 differs only in two building blocks (amino acids) from that found in humans. Inserting the chimpanzee gene into the DNA of cultured human nerve cells resulted in distinct modifications of the proteins the cells synthesized. The observed differences may be relevant for the development of a speech apparatus (11/11/09).
• In his new book with the title "Through the Language Glass: Why the World Looks Different in Other Languages", Guy Deutscher gives great examples for the fashion in which our language shapes our mind and vice versa? An excerpt of his book can be found in this weeks' New York Times Magazine entitled "Does Your Language Shape How You Think?". The author convincingly demonstrates in astounding examples that language distinctly reflects differences in the perception of space and geographic position in cultures that use an absolute system of reference, that cardinal points (East, West, North, South), as opposed to a relative system, that is body-centric reference (left, right, in front, behind). Lera Boroditsky provides more details in her essay for The Wall Street Journal with the title "Lost in Translation" published online  Jul. 23, 2010. Self-conscience seems to differ accordingly. In a culture using absolute reference, the individual is not surrounded by her/his environment, but situated in it (08/28/10).
• Neanderthals were not that different from us. It is not unreasonable to assume that they were able to speak to each other. The Smithsonian Institution recently unveiled MEanderthal, a face morphing mobile application that may drive this point home (09/03/10)
• You may wish to listen to this interview with Werner Herzog by Tom Ashbrook with the title "Filmmaker Werner Herzog", originally broadcast on National Public Radio's On Point Dec. 11, 2009 (09/06/10).
  
• In this interview by Steve Inskeep on National Public Radio's Morning Edition with the title "From Werner Herzog, Three DVDs Worth A Close Look" aired today, Werner Herzog recommends three movies for us to watch (09/16/10):

• This comprehensive review by Kuhl (2010) provides detailed insight into recent findings on early language and brain development, using the latest technology (10/10/2011)

References

• Chomsky N (2006) Language and the Mind. Cambridge Univ Press, Cambridge, UK.
• Deutscher G (2010) Through the Language Glass: Why the World Looks Different in Other Languages. Metropolitan Books, New York, USA.
• Konopka G, Bomar JM, Winden K, Coppola G, Jonsson ZO, Gao F, Peng S, Todd M. Preuss TM, Wohlschlegel JA, Geschwind DH (2009) Human-specific transcriptional regulation of CNS development genes by FOXP2. Nature 462:213-217.
• Krause J, Lalueza-Fox C, Orlando L, Enard W, Green RE, Burbano HA, Hublin J-J, Hänni C, Fortea J, de la Rasilla M, Bertranpetit J, Antonio Rosas A, Pääbo (2007) The Derived FOXP2 Variant of Modern Humans Was Shared with Neandertals. Curr Biol 17:1908-1912.
• Kuhl PK (2010) Brain Mechanisms in Early Language Acquisition. Neuron 67:713-727.
• Melzer P, Morgan VL, Pickens DR, Price RR, Wall RS, Ebner FF (2002) Cortical activation during Braille reading is influenced by early visual experience in subjects with severe visual disability: a correlational fMRI study. Human Brain Mapp 14:186-195.

Related Posts

• Prologue to A Theory of Mind
• A Theory of Mind II: H.M.'s Memory
• A Theory of Mind III: Emotions