Aition

The Emotional Brain

! only captured chapter 1 (the summary)

 Chapter 1

 Functional Frame

...the proper level of analysis of a psychological function is the level at which that function is represented in the brain. ... We shouldn’t mix findings about different emotions all together independent of the emotion that they are findings about. Unfortunately, most work in psychology and brain science has done this.

 Homeostasis

All animals, including people, have to satisfy certain conditions to survive in the world and fulfill their biological imperative to pass their genes on to their offspring. At a minimum, they need to obtain food and shelter, protect themselves from bodily harm, and procreate. This is as true of insects and worms as it is of fish, frogs, rats, and people. Each of these diverse groups of animals has neural systems that accomplish these behavioral goals. And within the animal groups that have a backbone and a brain (fish, amphibians, reptiles, birds, and mammals, including humans), it seems that the neural organization of particular emotional behavioral systems—like the systems underlying fearful, sexual, or feeding behaviors—is pretty similar across species.

 Emotional Experience

...conscious feelings, like the feeling of being afraid or angry or happy or in love or disgusted, are in one sense no different from other states of consciousness, such as the awareness that the roundish, reddish object before you is an apple, that a sentence just heard was spoken in a particular foreign language, or that you’ve just solved a previously insoluble problem in mathematics. States of consciousness occur when the system responsible for awareness becomes privy to the activity occurring in unconscious processing systems. What differs between the state of being afraid and the state of perceiving red is not the system that represents the conscious content (fear or redness) but the systems that provide the inputs to the system of awareness. There is but one mechanism of consciousness and it can be occupied by mundane facts or highly charged emotions.

 Criticality

[Emotions] chart the course of moment-to-moment action as well as set the sails toward long-term achievements. But our emotions can also get us into trouble. When fear becomes anxiety, desire gives way to greed, or annoyance turns to anger, anger to hatred, friendship to envy, love to obsession, or pleasure to addiction, our emotions start working against us. Mental health is maintained by emotional hygiene, and mental problems, to a large extent, reflect a breakdown of emotional order. Emotions can have both useful and pathological consequences.

 Chapter 2

 Functionalism

One of the most important conceptual developments in the establishment of cognitive science was a philosophical position known as functionalism, which holds that intelligent functions carried out by different machines reflect the same underlying process. For example, a computer and a person can both add 2 + 5 and come up with 7. The fact that both achieve the same answer cannot be explained by the use of similar hardware—brains are made of biological stuff and computers of electronic parts. The similar outcome must be due to a similar process that occurs at a functional level. In spite of the fact that the hardware in the machines is vastly different, the software or program that each executes may be the same. Functionalism thus holds that the mind is to the brain as a computer program is to the computer hardware.

 Unconscious Processing

[Unconscious] mental processes are the bread and butter of cognitive science. Cognitive scientists sometimes speak of consciousness as the end result of processing, but are usually far more interested in the underlying processes than in the contents of consciousness that occur during and as a result of the processing. This emphasis on unconscious processes as opposed to conscious content underlies much work in cognitive science.

 Self-Conceptualization

...people normally do all sorts of things for reasons they are not consciously aware of (because the behavior is produced by brain systems that operate unconsciously) and that one of the main jobs of consciousness is to keep our life tied together into a coherent story, a self-concept. It does this by generating explanations of behavior on the basis of our self-image, memories of the past, expectations of the future, the present social situation, and the physical environment in which the behavior is produced. ...

 Limited Conscious Awareness

Although a good deal remains uncertain about the cognitive unconscious, it seems clear that much of mental life occurs outside of conscious awareness. We can have introspective access to the outcome of processing (in the form of conscious content), but not all processing gives rise to conscious content. Stimulus processing that does not reach awareness in the form of conscious content can nevertheless be stored implicitly or unconsciously and have important influences on thought and behavior at some later time. Further, it is worth emphasizing that information can be simultaneously processed separately by systems that do and do not give rise to conscious content, leading to the conscious representation in some and the unconscious representation in other systems.

 Subjective Emotional Experiences

There is really nothing more or less subjective about the experience of an emotion than about the experience of the redness of an apple or the memory of eating one. The study of visual perception or memory has not been held back simply because these brain functions have subjective correlates, and neither should the study of emotion.

 Chapter 3

 Emotional Thoughts

The conversion of emotions into thoughts has allowed emotion to be studied using the tools and conceptual foundations of cognitive science.

 Nonverbal Unconscious

Consciousness and its sidekick, natural language, are new kids on the evolutionary block—unconscious processing is the rule rather than the exception throughout evolution. And the coin of the evolutionarily old unconscious mental realm is nonverbal processing. Given that so much work on unconscious processing (cognitive and emotional) has focused on verbal processes, we probably have a highly inaccurate picture of the level of sophistication of unconscious processes in humans.

 Chapter 5

 Adaptive Primed Action Patterns

Escaping from danger is something that all animals have to do to survive. ... What is important is that the brain have a mechanism for detecting the danger and responding to it appropriately and quickly. The particular behavior that occurs is tailored to the species (running, flying, swimming), but the brain function underlying that response is the same—protection against the danger. ... People run from danger on two legs, but many other land mammals tend to do so on all four: although quadrupeds use more muscles and different patterns of muscle coordination than bipeds, the function performed is the same—escape. Most important, even when the behaviors are very different, the function achieved may be the same. Plutchik puts this nicely: “although a deer may run from danger, a bird may fly from it, and a fish may swim from it, there is a functional equivalence to all the different patterns of behavior; namely, they all have the common function of separating an organism from a threat to its survival.” (Plutchik 1980) Obviously, running, flying, and swimming are different behaviors involving different muscles, but each achieves escape. ... In an influential treatise on mother-child bonding in humans, the psychoanalytic theorist John Bowlby makes a similar point:

The basic structure of man’s behavioral equipment resembles that of infrahuman species but has in the course of evolution undergone special modifications that permit the same ends to be reached by a much greater diversity of means. ... The early form is not superseded: it is modified, elaborated, and augmented but it still determines the overall pattern. ... Instinctive behavior in humans ... is assumed to derive from some prototypes that are common to other animal species. (Bowlby 1969) I don’t mean to minimize the importance of species differences. The things that distinguish one species from another are often things that allowed its ancestors to survive their particular struggle for existence and pass on their traits to their offspring. The kind of body an animal has obviously limits the kinds of behaviors in which the animal can engage. Nevertheless, evolutionary solutions to problems that are common to many species may have some underlying functional equivalence that cuts across the behavioral differences imposed by the uniqueness of body forms.

 Darwin and Evolved Emotions

Darwin’s revolutionary insights into evolution...demonstrated for the first time the inextricable link between an animal’s world and its behavior. His theory of natural selection made it possible to understand why animals are so well endowed with mysterious instincts—why a wasp, for example, gathers food she has never eaten to feed larvae she will never see. Natural selection, Darwin hypothesized, favors animals which leave the most offspring. Through countless generations the survivors of the unceasing struggle for a limited amount of food have to be ever more perfectly adapted to their worlds, both morphologically and behaviorally. ... Carefully programmed behavior like that of the wasp must provide an enormous competitive advantage for animals.
James Gould, 1982

In The Expression of the Emotions in Man and Animals, Darwin proposed that "the chief expressive actions, exhibited by man and by the lower animals, are now innate or inherited,—that is, have not been learnt by the individual." As evidence for emotional innateness, he noted the similarity of expressions both within and between species. In humans, Darwin was particularly impressed with the fact that the bodily expressions (especially of the face) occurring during emotions are similar in people around the world, regardless of racial origins or cultural heritage. He also pointed out that these same expressions are present in persons born blind, and thus lacking the opportunity to have learned the muscle movements from seeing them in others, and are also present in very young children, who also have had little opportunity to learn to express emotions by imitation.
...
[Darwin] pointed out how common it is for animals of all varieties, including humans, to urinate and defecate in the face of extreme danger. And many animals erect body hair in dangerous situations, presumably to make themselves look more vicious than they otherwise would. Piloerection, according to Darwin, is probably one of the most general of the emotional expressions, occurring in dogs, lions, hyenas, cows, pigs, antelopes, horses, cats, rodents, bats, to name a few. Darwin suggested that goose bumps, a mild form of piloerection in humans, occur as a vestige of the more dramatic displays in our mammalian cousins.
...
Darwin gave many other examples of common emotional expression in different species. For example, he equated the snarl of an angry human with similar behaviors in other creatures. Again turning to literature for support, he quotes Dickens’ description in Oliver Twist of a furious mob witnessing the capture of an atrocious murderer on the streets of London: “the people as jumping up one behind another, snarling with their teeth, and making at him like wild beasts.” Darwin goes on to note that “Everyone who has had much to do with young children must have seen how naturally they take to biting, when in a passion. It seems as instinctive in them as in young crocodiles, who snap their little jaws as soon as they emerge from the egg.” He also quotes from Dr. Maudsley, who specialized in human insanity and for whom the renowned Maudsley Hospital in London is named: “whence come ‘the savage snarl, the destructive disposition, the obscene language, the wild howl, the offensive habits, displayed by some of the insane? Why should a human being, deprived of his reason, ever become so brutal in character, as some do, unless he has the brute nature within him?’ ” In response, Darwin says, “This question must, as it would appear, be answered in the affirmative.” ... Within the general class of innate emotions, Darwin suggested that some have older evolutionary histories than others. He noted that fear and rage were expressed in our remote ancestors almost as they are today in humans. Suffering, as in grief or anxiety, though, he placed closer to human origins. Nevertheless, Darwin was well aware of the pitfalls of such ideas about the time of origin of different emotions and noted: "It is a curious, though perhaps an idle speculation, how early in the long line of our progenitors the various expressive movements, now exhibited by man, were successively acquired."

 Disparate Emotional Bases

...modern researchers have gone into remote areas of the world to firmly establish with scientific methods that at least some emotions have fairly universal modes of expression, especially in the face. On the basis of this kind of evidence, the late Sylvan Tomkins proposed the existence of eight basic emotions: surprise, interest, joy, rage, fear, disgust, shame, and anguish. (Tomkins 1962) These were said to represent innate, patterned responses that are controlled by “hardwired” brain systems. A similar theory involving eight basic emotions has been proposed by Carroll Izard. (Izard 1977; Izard 1992a) Paul Ekman has a shorter list, consisting of six basic emotions with universal facial expression: surprise, happiness, anger, fear, disgust and sadness.(Ekman 1984) Other theorists, like Robert Plutchik(Plutchik 1980) and Nico Frijda (Frijda 1986) do not rely exclusively on facial expressions, but instead argue for the primacy of more global action tendencies involving many body parts. Plutchik points out that as one goes down the evolutionary scale there are fewer and fewer facial expressions, but still lots of emotional expressions involving other bodily systems. Plutchik’s emotions list overlaps with the others, but also diverges to some extent—it is similar to Ekman’s, with the addition of acceptance, anticipation, and surprise. Philip Johnson-Laird and Keith Oatley approach the problem of basic emotions by looking at the kinds of words we have for talking about emotions. (Johnson-Laird and Oatley 1992) They come up with a list of five that overlaps with Ekman’s six, dropping surprise. Jaak Panksepp has taken a different approach, using the behavioral consequences of electrical stimulation of areas of the rat brain to reveal four basic emotional response patterns: panic, rage, expectancy, and fear. (Panksepp 1982) Other theorists have other ways of identifying basic emotions and their lists also overlap and diverge from the ones already described.(Arnold 1960; Fehr and Russell 1984; J.A. Gray 1982.)

 Blended Emotions

Most basic emotions theorists assume that there are also nonbasic emotions that are the result of blends or mixes of the more basic ones. ... The mixing of basic emotions into higher order emotions is typically thought of as a cognitive operation. According to basic emotions theorists, some if not all of the biologically basic emotions are shared with lower animals, but the derived or nonbasic emotions tend to be more uniquely human. Since the derived emotions are constructed by cognitive operations, they could only be the same to the extent that two animals share the same cognitive capacities. And since it is in the area of cognition that humans are believed to differ most significantly from other mammals, nonbasic, cognitively constructed emotions are more likely than basic emotions to differ between humans and other species. Richard Lazarus, for example, proposes that pride, shame, and gratitude might be uniquely human emotions. (C.A. Smith and R.S. Lazarus 1990)

 Fundamental Life Tasks

Modern evolutionarily minded emotions theorists, like Ekman, argue that emotions deal with “fundamental life tasks.” (Ekman 1992a) A similar point is made by Johnson-Laird and Oatley, who say that each emotion “prompts us in a direction which in the course of evolution has done better than other solutions to recurring circumstances.” (Johnson-Laird and Oatley 1992) And Tooby and Cosmides argue that emotions involve situations that have occurred over and over throughout our evolutionary history (escaping from danger, finding food and mates) and cause us to appraise present events in terms of our ancestral past—that the structure of the past imposes an interpretive landscape on the present. (Tooby and Cosmedies 1990) ... In a sense, coming up with a list of the special adaptive behaviors that are crucial to survival would essentially be a list of basic emotions.

 Neural Structure of Emotions

At the neural level, each emotional unit can be thought of as consisting of a set of inputs, an appraisal mechanism, and a set of outputs. The appraisal mechanism is programmed by evolution to detect certain input or trigger stimuli that are relevant to the function of the network. Well call these "natural triggers" [or "sign stimuli"]. The sight of a predator is a good example. It is not uncommon for prey species to recognize predators the first time they see them. Evolution has programmed the prey brain so that certain features of the way the predator looks, sounds, or smells will be automatically appraised as being a source of danger. But the appraisal mechanism also has the capacity to learn about stimuli that tend to be associated with and predictive of the occurrence of natural triggers. These well call “learned triggers.” The place where a predator was seen last, or the sound it made when it was charging toward the prey are good examples. When the appraisal mechanism receives trigger inputs of either type, it unleashes certain patterns of response that have tended to be useful in dealing with situations that have routinely activated the appraisal mechanism in ancestral animals. These networks evolved because they serve the function of connecting trigger stimuli with responses that are likely to succeed in keeping the organism alive. And because different kinds of problems of survival have different trigger stimuli and require different kinds of responses to deal with them, different neural systems are devoted to them.

 Pathological Fear

While fear is a part of everyone’s life, too much or inappropriate fear accounts for many common psychiatric problems. Anxiety, a brooding fear of what might happen, was at the core of Freud’s psychoanalytic theory. Phobias are specific fears taken to extreme. Phobic objects (snakes, spiders, heights, water, open places, social situations) are often legitimately threatening, but not to the extent believed by the phobic person. Obsessive-compulsive disorder often involves extreme fear of something, like germs, and the patients will engage in compulsive rituals to avoid the feared object or event or to rid themselves of the fear object once it is encountered. Panic disorder involves the rapid onset of a host of physical symptoms and often the overwhelming fear that death is near. Post-traumatic stress disorder (PTSD), previously referred to as shell shock, often occurs in war veterans, who can be sent into intense distress by a stimulus that has some resemblance to events associated with battlefield trauma. Thunderclaps and the sound of a car backfiring are common examples.

 Defensive Strategies

All animals have to protect themselves from dangerous situations in order to survive, and there are only a limited number of strategies that animals can call upon to deal with danger. Isaac Marks, who has written extensively on fear, summarizes these as withdrawal (avoiding the danger or escape from it), immobility (freezing), defensive aggression (appearing to be dangerous and/or fighting back), or submission (appeasement).(Marks 1987) The extent to which these strategies apply across the various vertebrates is striking.
Consider the following description of human defense by Caroline and Robert Blanchard, pioneers in fear research:

If something unexpected occurs—a loud noise or sudden movement—people tend to respond immediately...stop what they are doing...orient toward the stimulus, and try to identify its potentiality for actual danger. This happens very quickly, in a reflex-like sequence in which action precedes any voluntary or consciously intentioned behavior. A poorly localizable or identifiable threat source, such as a sound in the night, may elicit an active immobility so profound that the frightened person can hardly speak or even breathe, i.e. freezing. However, if the danger source has been localized and an avenue for flight or concealment is plausible, the person will probably try to flee or hide. ... Actual contact, particularly painful contact, with the threat source is also likely to elicit thrashing, biting, scratching, and other potentially damaging activities by the terrified person. (D.C. Blanchard and R.J. Blanchard 1989)

 Chapter 6

 Temporality of Learned Fear

Not only is fear conditioning quick, it is also very long lasting. In fact, there is little forgetting when it comes to conditioned fear. The passing of time is not enough to get rid of it (Campeau, Liang, and Davis 1990; Gleitman and Holmes 1967). Nevertheless, repeated exposure to the CS [(conditioned stimulus, or learned trigger)] in the absence of the US [(unconditioned stimulus, or natural trigger)] can lead to “extinction.” That is, the capacity of the CS to elicit the fear reaction is diminished by presentation of the CS over and over without the US. If our thirsty but fearful rabbit has only one watering hole to which it can go, and visits it day after day without again encountering a fox, it will eventually act as though it never met a fox there.
But extinction does not involve an elimination of the relation between the CS and US. Pavlov observed that a conditioned response could be completely extinguished on one day, and on the next day the CS was again effective in eliciting the response. He called this “spontaneous recovery.” (Pavlov 1927) Recovery of extinguished conditioned responses can also be induced. This has been nicely demonstrated in studies by Mark Bouton (Bouton 1994; Bouton and D. Swartzentruber 1991).After rats received tone-shock pairings in one chamber, he put them in a new chamber and gave them the tone CS over and over until the conditioned fear responses were no longer elicited—the conditioned fear reaction was completely extinguished. He then showed that simply placing the animals back in the chamber where the CS and US were previously paired was enough to renew the conditioned fear response to the CS. Extinguished conditioned fear responses can also be reinstated by exposing the animals to the US or some other stressful event (Campbell and Jaynes 1966). Spontaneous recovery, renewal, and reinstatement suggest that extinction does not eliminate the memory that the CS was once associated with danger but instead reduces the likelihood that the CS will elicit the fear response.

 Fear Stimulus Response

...when a conditioned fear stimulus occurs, the subject will typically stop all movement—it will freeze (esp Marks 1987). Many predators respond to movement (Von Uexkull 1934) and withholding movement is often the best thing to do when danger is near (Archer 1979). Freezing can also be thought of as preparatory to rapid escape when the coast clears, or to defensive fighting if escape is not possible. Since the muscle contractions that underlie freezing require metabolic energy, blood has to be sent to those muscles. Indeed, the autonomic nervous system is strongly activated by a conditioned fear stimulus, producing a variety of cardiovascular and other visceral responses that help support the freezing response. These also help the body prepare for the escape or fighting responses that are likely to follow (Cannon 1929; Hilton 1979; Mancia and Zanchetti 1981).Additionally, stress hormones are released into the bloodstream to further help the body cope with the threatening situation (Mason 1968; van de Kar et al 1991). Reactivity to pain is also suppressed, which is useful since the conditioned stimulus often announces a situation in which the probability of bodily harm is high (Bolles and Fanselow 1980; Watkins and Mayer 1982; Helmstetter 1992). And reflexes (like eye-blink or startle responses) are potentiated, allowing quicker, more efficient reactions to stimuli that normally elicit protective movements (Brown, Kalish, and Farber 1951; Davis 1992b; Weisz, Harden, and Xiang 1992).

 Emotional Learning and Cognition

The fact that emotional learning can be mediated by pathways that bypass the neocortex is intriguing, for it suggests that emotional responses can occur without the involvement of the higher processing systems of the brain, systems believed to be involved in thinking, reasoning, and consciousness. But before we pursue this notion, we need to further consider the role of the auditory cortex in fear conditioning.
In the experiments described so far, a simple sound was paired with a shock. The auditory cortex is clearly not needed for this. But suppose the situation is somewhat more complex. Instead of just one tone paired with a shock, suppose the animal gets two similar tones, one paired with the shock and the other not, and has to learn to distinguish between them. Would the auditory cortex then be required? Neil Schneidermann, Phil McCabe, and their colleagues looked at this question in a study of heart rate conditioning in rabbits (Jarrell et al 1987). With enough training, the rabbits eventually only expressed heart rate responses to the sound that had been associated with the shock. And when the auditory cortex was lesioned, this capacity was lost. Interestingly, the auditory cortex lesions did not interfere with conditioning by blocking responses to the stimulus paired with the shock. Instead, the cortically lesioned animals responded to both stimuli as if they had each been paired with the shock. ...Neurons in the area of the thalamus that projects to the primary auditory cortex are narrowly tuned—they are very particular about what they will respond to. But cells in the thalamic areas that project to the amygdala are less picky—they respond to a much wider range of stimuli and are said to be broadly tuned. ... So when two similar stimuli are used in a conditioning study, the thalamus will send the amygdala essentially the same information, regardless of which stimulus it is processing, but when the cortex processes the different stimuli it will send the amygdala different signals. If the cortex is damaged, the animal has only the direct thalamic pathway and thus the amygdala treats the two stimuli the same—both elicit conditioned fear.
...
Although the thalamic system cannot make fine distinctions, it has an important advantage over the cortical input pathway to the amygdala. That advantage is time. In a rat it takes about twelve milliseconds (twelve one-thousandths of a second) for an acoustic stimulus to reach the amygdala through the thalamic pathway, and almost twice as long through the cortical pathway. The thalamic pathway is thus faster. It cannot tell the amygdala exactly what is there, but can provide a fast signal that warns that something dangerous may be there. It is a quick and dirty processing system. ...The information received from the thalamus is unfiltered and biased toward evoking responses. The cortex’s job is to prevent the inappropriate response rather than to produce the appropriate one.... The cost of treating a stick as a snake is less, in the long run, than the cost of treating a snake as a stick. (emphasis added)

 Architectural Overview of Fear

So we can begin to see the outline of a fear reaction system. It involves parallel transmission to the amygdala from the sensory thalamus and sensory cortex. The subcortical pathways provide a crude image of the external world, whereas more detailed and accurate representations come from the cortex. While the pathway from the thalamus only involves one link, several links are required to activate the amygdala by way of the cortex. Since each link adds time, the thalamic pathway is faster. Interestingly, the thalamo-amygdala and corticoamygdala pathways converge in the lateral nucleus of the amygdala. In all likelihood, normally both pathways transmit signals to the lateral nucleus, which appears to play a pivotal role in coordinating the sensory processes that constitute the conditioned fear stimulus. And once the information has reached the lateral nucleus it can be distributed through the internal amygdala pathways to the central nucleus, which then unleashes the full repertoire of defensive reactions. Although I have mainly discussed my own work, research by others (especially Michael Davis, Michael Fanselow, Norman Weinberger, and Bruce Kapp) has also contributed significantly to our understanding of the neural basis of fear conditioning. (Kapp et al (1992); Davis et al (1992); Fanselow (1994) Weinberger (1995). For an alternative interpretation of the role of the thalamic pathway, see Campeau and Davis (1995). For a rebuttal of their interpretation see Corodimas and LeDoux (1995).)

Later (ch 8):

...information about external stimuli reaches the amygdala from two pathways, one subcortical, the other cortical. The subcortical pathway is shorter and faster but imprecise, and the cortical pathway has the opposite attributes.

 Contextual Conditioning

Psychologists have studied contextual conditioning extensively. If you place a rat in a box and give it a few exposures to a mild shock in the presence of a tone, the rat will become conditioned to the tone, as we’ve already seen, but will also get conditioned to the box. So the next time the rat is placed in the box, the conditioned fear responses—freezing, autonomic and endocrine arousal, pain suppression, reflex potentiation—will occur, even in the absence of the tone. The context has become a CS.
...
The interesting thing about a context is that it is not a particular stimulus but a collection of many. For some time it has been thought that the integration of individual stimuli into a context that no longer contains the individual elements is a function of the hippocampus (O’Keefe and Nadel 1978; Nadel and Willner 1980; Eichenbaum and Otto 1992; Sutherland and Rudy 1989). Unlike the amygdala, the hippocampus does not get information from brain regions that process individual sensory stimuli, like lights and tones (Amaral 1987; Van Hoesen 1982). Instead, the sights and sounds of a place are pooled together before reaching the hippocampus, and one job of this brain region is to create a representation of the context that contains not individual stimuli but relations between stimuli (O’Keefe and Nadel 1978; Nadel and Willner 1980; Eichenbaum and Otto 1992; Sutherland and Rudy 1989).

 Amygdala Role

The amygdala is like the hub of a wheel. It receives low-level inputs from sensory-specific regions of the thalamus, higher level information from sensory-specific cortex, and still higher level (sensory independent) information about the general situation from the hippocampal formation. Through such connections, the amygdala is able to process the emotional significance of individual stimuli as well as complex situations. The amygdala is, in essence, involved in the appraisal of emotional meaning. It is where trigger stimuli do their triggering.
...
The point of this discussion is to illustrate that the amygdala seems to do the same thing—take care of fear responses—in all species that have an amygdala. This is not the only function of the amygdala (Aggleton 1992), but it is certainly an important one. The function seems to have been established eons ago, probably at least since dinosaurs ruled the earth, and to have been maintained through diverse branches of evolutionary development. Defense against danger is perhaps an organism’s number one priority and it appears that in the major groups of vertebrate animals that have been studied (reptiles, birds, and mammals) the brain performs this function using a common architectural plan.

 System 2

...no matter how useful automatic reactions are, they are only a quick fix, especially in humans. Eventually you take control. You make a plan and carry it out. This requires that your cognitive resources be directed to the emotional problem. You have to stop thinking about whatever you were thinking about before the danger occurred and start thinking about the danger you are facing (and already responding to automatically). Robert and Caroline Blanchard call this behavior "risk assessment" (D.C. Blanchard and R.J. Blanchard 1988). This is something we do all the time. We’re always sizing up situations and planning how to maximize our gains and minimize our losses. Surviving is not just something we do in the presence of a wild beast. Social situations are often survival encounters.

 Chapter 7

 Dual Learning

[Cohen and Squire] (1980, 1984; Squire, Cohen, and Nadel 1984) called these two processes declarative and procedural memory. A similar dichotomy was offered by Daniel Schacter of Harvard, who distinguished between explicit and implicit memory (Schacter and Graf 1986). Conscious awareness of the basis of performance occurs in explicit memory, but in implicit memory performance is guided by unconscious factors. Skill learning, priming, and classical conditioning are all examples of implicit or procedural learning. These are each intact in temporal lobe amnesia and involve brain areas other than the temporal lobe memory system. Other memory dichotomies have been proposed over the years (Tulving 1983; O’Keefe and Nadel 1978; Olton, Becker, and Handleman 1979; Mishkin, Malamut, and Bachevalier 1984), but the distinction between conscious, explicit, declarative memory, on the one hand, and unconscious, implicit, procedural memory, on the other, has had the greatest impact on current thinking and will be emphasized here.

 Representation of Environment

...the major link between the hippocampus and the neocortex is the transition cortex. This region receives inputs from the highest stages of neocortical processing in each of the major sensory modalities. So once a cortical sensory system has done all that it can do with a stimulus, say a sight or a sound, it ships the information to the transition region, where the different sensory modalities can be mixed together. This means that in the transition circuits we can begin to form representations of the world that are no longer just visual or auditory or olfactory, but that include all of these at once. We begin to leave the purely perceptual and enter the conceptual domain of the brain. The transition region then sends these conceptual representations to the hippocampus, where even more complex representations are created.

 Temporal Differences in Memory

...the implicit emotional memory system would have to be less forgetful than the explicit memory system. Two facts suggest that this may be the case. One is that the explicit memory system is notoriously forgetful and inaccurate (as we’ll see below). The other is that conditioned fear responses exhibit little diminution with the passage of time. In fact, they often increase in their potency as time wears on, a phenomenon called “the incubation of fear” (Eysenck 1979). It is possible to decrease the potency of a conditioned response by presenting the learned trigger; the CS, over and over again without the US. However, so-called extinguished responses often recur on their own and even when they don’t they can be brought back to life by stressful events (Jacobs and Nadel 1985). Observations like these have led us to conclude that conditioned fear learning is particularly resilient, and in fact may represent an indelible form of learning.

 Flashbulb Memory

Psychologists describe this phenomenon as a “flashbulb memory,” a memory that is made especially crisp and clear because of its emotional implications (R. Brown and J. Kulik 1977; Christianson 1989). Recent findings, described below, by Jim McGaugh and his colleagues at the University of California at Irvine, together with the idea of separate systems for detecting the emotional memory, help us understand the biological basis of flashbulb memories.
McGaugh’s laboratory has long been concerned with the role of peripheral hormones, like adrenaline, in the solidification of memory processes (McGaugh et al 1995; Cahill et al 1994; McGaugh et al 1993; McGaugh 1990). His studies show that if rats are given a shot of adrenaline right after learning something, they show an enhanced memory of the learning situation. This suggests that if adrenaline is released naturally (from the adrenal gland) in some situation, that experience will be remembered especially well. Since emotional arousal usually results in the release of adrenaline, it might be expected (as suggested by the flashbulb idea) that the explicit conscious memory of emotional situations would be stronger than the explicit memory of nonemotional situations. It would also be expected that blockade of the effects of adrenaline would neutralize the memory-enhancing effects of emotional arousal.

 Contextual Memory

Learning that takes place in one situation or state is generally remembered best when you are in the same situation or state (Bower 1992).

 Chapter 8

 Fear and Anxiety

Anxiety and fear are closely related. Both are reactions to harmful or potentially harmful situations. Anxiety is usually distinguished from fear by the lack of an external stimulus that elicits the reaction—anxiety comes from within us, fear from the outside world. The sight of a snake elicits fear, but the remembrance of some unpleasant experience with a snake or the anticipation that you may encounter a snake are conditions of anxiety. Anxiety has also been described as unresolved fear (Öhman 1992; Epstein 1972). Fear, according to this view, is related to the behavioral acts of escape and avoidance in threatening situations, and when these actions are thwarted, fear becomes anxiety.

 Fear Disorders

The characteristic features of these disorders are intense feelings of anxiety and avoidance of situations that are likely to bring on these feelings.15 Phobias are fears of specific stimuli or situations that are in excess of the actual threat posed. Exposure to the phobic object or situation reliably elicits a profound state of anxiety. The person will go to great lengths to avoid the object or situation.

 The Utility of Anxiety

(whole is a block quote from Mowrer)

By and large, behavior that reduces anxiety also operates to lessen the danger that it presages. An antelope that scents a panther is likely not only to feel less uneasy (anxious) if it moves out of the range of the odor of the panther but also likely to be in fact somewhat safer. A primitive village that is threatened by marauding men or beasts sleeps better after it has surrounded itself with a deep moat or a sturdy stockade. And a modern mother is made emotionally more comfortable after her child has been properly vaccinated against a dreaded disease. This capacity to be made uncomfortable by the mere prospect of traumatic experiences, in advance of their actual occurrence (or reoccurrence), and to be motivated thereby to take realistic precautions against them, is unquestionably a tremendously important and useful psychological mechanism, and the fact that the forward-looking, anxiety-arousing propensity of the human mind is more highly developed than it is in lower animals probably accounts for many of man’s unique accomplishments. But it also accounts for some of his most conspicuous failures. (Mowrer 1939)

 Fear Target Transitivity

The avoidance response seemed, as Mowrer had suggested, to be maintained by the anticipation of shock, by the fear elicited by the warning signal. ...
...Just as a rat could learn any response that allowed it to escape from or avoid an anxiety-provoking situation, humans learn all sorts of instrumental responses that allow them to escape or avoid anxiety and guilt caused by neurotic conflict (Hall and Lindzey 1957). ... ...avoidance conditioning extinguishes quickly if the animal is prevented from making the avoidance response and alternative solutions for escape or avoidance are not provided.

 Maladaptive Specifc Threats

In a relatively stable environment, it is generally a good bet that the dangers a species faces will change slowly. As a result, having a ready-made means of rapidly learning about things that were dangerous to one’s ancestors, and theirs, is in general useful. But since our environment is very different from the one in which early humans lived, our genetic preparation to learn about ancestral dangers can get us into trouble, as when it causes us to develop fears of things that are not particularly dangerous in our world.
...conditioned fear (measured by autonomic nervous system responses) was more resistant to extinction with fear-relevant than with fear-irrelevant stimuli. Further, when modern fear-relevant stimuli (guns and knives) were used, no evidence for resistance to extinction was found, suggesting that evolution has not yet had enough time to build these dangers in. He also showed that phobies respond to a greater degree when they see stimuli relevant to their own phobia than when they see other fear-relevant stimuli—snake phobies gave bigger conditioned responses to snake pictures than to spider pictures and spider phobies did the reverse. This is consistent with his contention that phobies are super-prepared genetically to respond to the objects of their phobia.

 Hormonal Stress

...stressful events can cause malfunctons in the hippocampus. ...
When people or other animals are exposed to a stressful situation, the adrenal gland secretes a steroid hormone into the bloodstream (J. A. Gray 1987; McEwen and Sapolsky 1995). Adrenal steroids play an important role in helping the body mobilize its energy resources to deal with the stressful situation. ...
It has been recognized for some time that the hippocampal steroid receptors are part of a control system that helps regulate how much adrenal steroid hormone is released (Jacobson and Sapolsky 1991). When the hormone binds to receptors in the hippocampus, messages are sent to the hypothalamus to tell it to tell the pituitary and adrenal glands to slow down the release. In the face of stress, the amygdala keeps saying “release” and the hippocampus keeps saying “slow down.” Through multiple cycles through these loops the concentration of the stress hormones in the blood is delicately matched to the demands of the stressful situation.
If stress persists too long, the hippocampus begins to falter in its ability to control the release of the stress hormones, and to perform its routine functions. Stressed rats are unable to learn and remember how to perform behavioral tasks that depend on the hippocampus (Diamond and Rose 1994; Diamond and Rose 1993; Diamond et al 1994; Luine 1994). For example, they fail to learn the location of the safe platform in the water maze task described in the last chapter. Stress also interferes with the ability to induce long-term potentiation in the hippocampus (Shors et al 1990; Pavlides, Watanabe, and McEwen 1993; Diamond et al 1994; Diamond and Rose 1994), which probably explains why the memory failure occurs. Importantly, stress also impairs explicit conscious memory functions in humans (McNally et al 1995; Bremner et al 1993; Newcomer et al 1994; Wolkowitz, Reuss, and Weingartner 1990; McEwen and Sapolsky 1995). ...
...if the stress is discontinued these changes are reversible. However, with prolonged stress, irreversible changes take place. Cells in the hippocampus actually begin to degenerate. When this happens, the memory loss is permanent. ... ... One of the consequences of excess life stress is depression, and depressed persons sometimes have poor memory. It is quite possible that the memory disturbances that occur in depression are closely tied up with the effects of stress on the hippocampus.

 Stress-Fear Spirals

The finding that stress hormones can amplify conditioned fear responses has an important implication for our understanding of anxiety disorders, and in particular for understanding why these sometimes seem to occur or get worse after unrelated stressful events (Jacobs and Nadel 1985). During stress, weak conditioned fear responses may become stronger. The responses could be weak either because they were weakly conditioned, or because they were previously extinguished or were otherwise treated into remission. Either way, their strength might be increased by stress. For example, a snake phobic might be in remission for years but upon the death of his spouse the phobia returns. Alternatively, a mild fear of heights, one that causes few problems in everyday life, might be converted into a pathological fear under the amplifying influences of stress. The stress is unrelated to the disorder that develops and is instead a condition that lowers the threshold for an anxiety disorder, making the individual vulnerable to anxiety, but not dictating the nature of the disorder that will emerge. The latter is probably determined by the kinds of fears and other vulnerabilities that the person has lurking inside.

 Fear Extinction

...the visual cortex might be a necessary link between the visual world and other higher order cortical areas that are necessary for extinction. ... ...Extinction appears to involve the cortical regulation over the amygdala, and even unprepared conditioned fear can be resistant to extinction when the amygdala is freed from these cortical controls.
One of the hallmarks of frontal lobe damage in humans is perseveration, the inability to stop doing something once it is no longer appropriate (Luria 1966; Fuster 1989; Nauta 1971; Damasio 1994; Stuss 1991; Petrides 1994; Stuss 1991; Shimamura 1995; Milner 1964). For example, when frontal lobe patients are performing a task in which a rule must be followed, they have great difficulty in changing their behavior when the rule is switched. ... Sometimes they even know what they should do, but can’t make their behavior match their knowledge. They are rigid and inflexible, and perseverate in their ways, even when it is obvious that the behavior is not appropriate to the situation. This seems to characterize their behavior in real life as well. ...Since prolonged stress results in a breakdown in this negative feedback control function, it may be the case that both the prefrontal cortex and hippocampus are adversely affected. A stress-induced shutdown of the prefrontal cortex might release the brakes on the amygdala, making new learning stronger and more resistant to extinction, and possibly allowing previously extinguished conditioned fears to be expressed anew. ...extinction prevents the expression of conditioned fear responses but does not erase the implicit memories that underlie these responses (LeDoux, Romanski, and Xagoraris 1989). Extinction, in other words, involves the cortical control over the amygdala’s output rather than a wiping clean of the amygdala’s memory slate.

 Species-Specific Amygdala Sensitivity

...the amygdala is particularly responsive to stimuli that serve as species-specific emotional signals, with stimuli that support prepared learning being a prime example of these. ...In fact, the amygdala of all creatures may be prepared to respond to species-relevant cues. For example, faces are important emotional signals in the lives of primates, and neurons in the monkey amygdala respond briskly to the sight of monkey faces (Rolls 1992a; Allman and Brothers 1994).

 Response Habituation

The avoidance responses that so typify anxiety disorders fall somewhere between what I described earlier as innate emotional reactions and voluntary emotional actions. Avoidance responses are instrumental responses that are learned because they are reinforced. ... These responses, once learned, prevent emotional arousal. They are performed automatically, without conscious decision. They become habits, ways of automatically responding to stimuli that routinely warn of danger. Like conditioned fear responses, they are performed automatically, but they are learned rather than innate responses.

 Anxiolytics

Many of the leading drugs for treating anxiety have been developed because of their efficiency in reducing avoidance behavior in animals.

 Connective Assymetry

Interestingly, it is well known that the connections from the cortical areas to the amygdala are far weaker than the connections from the amygdala to the cortex (Amaral et al 1992). This may explain why it is so easy for emotional information to invade our conscious thoughts, but so hard for us to gain conscious control over our emotions.

 Chapter 9

 Emotional Experience Framing

To my way of thinking, then, emotional experience is not really a problem about emotion. It is, instead, a problem about how conscious experiences occur. Because the scientific study of emotions has mostly been about conscious emotional experiences, scientists who study emotions have set things up so that they will not understand emotions until they’ve understood the mind-body problem, the problem of how consciousness comes out of brains, arguably the most difficult problem there is and ever was (Churchland 1984; Boring 1950; Gardner 1987; Jackendoff 1987; Rorty 1979; Searle 1992; Eccles 1990; Picton and Stuss 1994; Chalmers 1996; Humphrey 1992).

 Amygdala Spirals

The amygdala, it should be noted, is also the recipient of arousal system axons, so that amygdala activation of arousal systems also helps keep the amygdala aroused. These are self-perpetuating, vicious cycles of emotional reactivity. Arousal locks you into whatever emotional state you are in when arousal occurs, unless something else occurs that is significant enough and arousing enough to shift the focus of arousal.

 Further References to Research

  • 1977, Richard Nisbett and Timothy Wilson published an extremely interesting paper, “Telling More Than We Can Know: Verbal Reports on Mental Processes.” -- people making up reasons for preference between identical objects
  • Wolpe on panic / anxiety?
  • Feeling and Thinking: Preferences Need No Inferences. Robert Zajonc "preferences (which are simple emotional reactions) could be formed without any conscious registration of the stimuli. This, he said, showed that emotion has primacy over (can exist before) and is independent of (can exist without) cognition." (esp subuliminal mere exposure effect)
    • what amount of racism exists independently of grand narratives and the exposure effect?
  • Robert Bornstein 1992
    • As expected, they were unable to identify which ones they had seen before, but when asked to rate how much they liked the pictures, the preexposed ones received more positive ratings. Mere exposure works for faces.
    • Bornstein later performed what is called a “meta-analysis” of subliminal mere exposure research
  • !! "computer simulations of appraisal and other emotional processes": Dyer (1987); K.R. Scherer (1993b); Frijda and Swagerman (1987); Sloman (1987); Grossberg (1982); Armony et al (1995).
    • Some AI proponents assume that emotional feelings and other states of consicousness could be programnmed into a computer if we could just get the right algorithm. For example, see: Newell (1980); Minsky (1985); Sloman and Croucher (1981). For a rebuttal to the notion that computers might have feelings or other conscious states, see Searle (1984).
  • see Ch 5 Disparate Emotional Bases
  • see Ch 5 Fundamental Life Tasks
  • find original: "William James once said that nothing marks the ascendancy of man from beast more clearly than the reduction of the conditions under which fear is evoked in humans." James 1890
  • The Hippocampus as a Cognitive Map, O'Keefe & Nadel 1978, "place cells" / place fields
    • also O’Keefe (1993).
    • also McNaughton and Barnes (1990); Barnes et al (1995); Wilson and McNaughton (1994).
    • also Olton, Becker, and Handleman (1979).
    • also Morris (1984); Morris et al (1982).
    • also Kubie, Muller, and Bostock (1990); Kubie and Ranck (1983); Muller, Ranck, and Taube (1996).
  • Cognition in emotion: concept and action. In C.E. Izard, J. Kagan, and R.B. Zajonc, eds., Emotions, Cognition, and behavior 1984
    • associative network models of memory (esp emotional)
updated Jun 2, 2022