Effort

A Behavioral Neuroscience Perspective on the Will

Jay Schulkin

• Publisher: Psychology Press
• Year: 2020
• ISBN:
  9781000149432
• Edition: 1
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

In Effort: A Behavioral Neuroscience Perspective on the Will, author Jay Schulkin presents a two-fold thesis: there is no absolute separation of the cognitive and non-cognitive brain, and there are diverse cognitive systems, many of which are embodied in motor systems that underlie self-regulation. Central to this thesis is that dopamine is the one neurotransmitter that underlies the diverse senses of effort, and is apparent in most everyday activity, whether solving a problem in our head or moving about. As scientific literature abounds with studies of decision-making and effort, this book emphasizes the importance of demythologizing our understanding of cognitive systems in order to link motivation, behavioral inhibition, self-regulation, and will. Effort will benefit researchers and students in neuroscience, behavioral neuroscience, cognitive psychology, clinical psychology, social psychology, as well as anyone with interest in this topic.

1 Neuroscience and Interdisciplinary Inquiry

The neural sciences, though quite young, have dramatically altered the intellectual landscape during the past 50 years. From the time of the formation of the Institute of Neurological Sciences, for example, at the University of Pennsylvania in 1953, the neural sciences have been interdisciplinary. The institute was the brainchild of Louis Flexner, a biochemist who had done work in the area of memory formation. Louis Flexner, nephew of Abraham and Simon Flexner, understood that this new branch of science would require biologists, chemists, anatomists, psychologists, and psychiatrists, and the institute’s faculty accordingly represented this broad spectrum of experts drawn from throughout the university (Fig. 1.1). The Institute of Neurological Sciences was to set the context for a number of other such institutes and departments of neuroscience that were to emerge in the succeeding 50 years (Morrison, 1982).

FIG. 1.1. Three early Directors of the Institute of Neurological Sciences at the University of Pennsylvania: Louis Flexner (middle), James Sprague, and Eliot Stellar (sitting, 1991).

Eliot Stellar (in Fig. 1.1) had written the classic article on “The Physiology of Motivation” (Stellar, 1954, 1960). The concept of motivation is knotted to effort and forms the basis for the origins of what we call the will (chap. 2). The study of motivational systems, like most other behavioral studies, is inherently interdisciplinary and found a home, at that time, in the neurosciences.

Why should the study of neuroscience be so interdisciplinary? The study of the mind means, in part, studying the brain. In the 1970s, philosophical questions were focused on how to characterize the mind in the neural sciences. The idea that the mind is nothing more than neurons, in any language imaginable, is still a scientific dream, a good dream, better to discern functional relationships between mental functions and physical realizations (c. f. Block, 1978; Descombes, 2001; Hebb, 1949; Parrott & Schulkin, 1993; Weissman, 2002). Simplicity in science and elsewhere is a virtue, and a thing of beauty. But simplicity, though a normative goal, is no end.

In this chapter, I orient the reader to the general themes of the book, namely, the emphasis of mind as part of biological adaptation, cognitive systems being endemic to the organization of action, and the fundamental role of central dopamine in the organization of action and thought.

MIND AND BIOLOGY

The brain is a biological organ. We know that cognitive subsystems in the brain are diverse and recruit neural systems across the neural axis from brain stem to cortex (Gazzaniga, 2000; McCulloch & Pitts, 1943; Miller, Galanter, & Pribram, 1960). Thus, the issue is: How do subsystems in the brain perform their functions to produce what we perceive as the actions of the mind? In this regard, a certain amount of reasonable progress has been made over a short period of time. The mind is less a thing, as James (1890/1952) noted, than a collection of embodied behavioral functions. There is often no single physical entity in the brain that corresponds directly to, and is isomorphic with, a mental function. It is one thing to assert that all mental functions are embodied in neural tissue; it is another to conclude that anything that one means by a “mental function” is exhausted in the description of neuronal activity.

The brain has both broad and narrow circuits that have allowed for diverse behavioral adaptations. An example of one of the most important of these adaptations in humans is language (Chomsky, 1972; Pinker, 1994, 1998; Rozin, 1976, 1998). Most concepts, such as “motivation” or “firmness of purpose,” (Lamarck, 1809/1984) or the will, do not have a direct reference to neural structure, but this does not undermine their validity. The will as an expression of the cognitive organization of action is central to understanding who we are as individuals.

To understand the brain and the mind, to understand the organization of action in people and the will, is, in part, to understand a number of specialized mechanisms that evolved to endow us with problem-solving abilities. Information processing means engagement in the everyday sense of trying to figure out what to do and how to understand an event. What is outstanding about the mind/brain is the simplicity of such complex operations.

In the past 10 years within the neurosciences and the cognitive sciences, there has been a resurgence of interest in reenvisioning the body (e.g., Damasio, 1994, 1999; Schulkin, 2004). This new view holds that cognitive systems are endemic to broad-based bodily functions and that the mind is no longer on one side and bodily functions on the other. Cognitive capacity also permeates our considerations of the motor systems. Motor control and expression and cognitive capacity are not separate or opposed to each other; they are embedded within one another. The organization of the motor system, long a neuroscientific object of study (Nauta & Freitag, 1986; Swanson, 2000b; 2003), is integrated with cognitive functions (Georgopoulos, 1994, 2000; Graybiel, Aosaki, Flaherty, & Kimura, 1994; Knowlton, Mangels, & Squire, 1996; Lieberman, 2000; Linas, 2001; Ullman, 2004).

As Lakoff and Johnson (1999) suggest, “brains tend to optimize” and “the embodiment of reason via the sensor-imotor system is of great importance. It is a crucial part of the explanation of why it is possible for our concepts to fit so well with the way we function in the world” (p. 41). Cognitive systems pervade all that we do as human beings. There is no one part of the brain that is purely sensory or motor that does not have a cognitive component. There are still, nonetheless, motor and sensory and integrative neurons. One just recognizes, perhaps, that cognition is not on one side of the equation and sensory and motor events on the other.

There are diverse ways in which cognitive systems underlie our sense of action, of effort—the doing and perceiving of things. Lakoff and Johnson (1999) indicated the following:

1. Representing as doing

2. Communicating as showing

3. Searching as knowing

4. Imagining as moving

5. Attempting to gain knowledge as searching

6. Becoming aware as noticing

7. Impediments to knowledge as impediments to vision

These events are all cognitive and can require effort, resolute purpose, and staying toward a goal (e.g., searching as knowing [Heelan & Schulkin, 1998]). On the neural side, evidence suggests that performing an action and looking at another perform it can activate many of the same neural systems (e.g., Buccino et al., 2004; Decety & Grèzes, 1999; Jeannerod, 1985, 1988; Rizzolatti, Fogassi, & Gallese, 2000). The sight of others, watching them and discerning their intentions, plans, and goals activates something Jackson and Decety (2004) call “motor cognition.” One recent study, interestingly, has shown that words about action (e.g., looking at action words) and the action itself activate human motor and premotor cortex. In an fMRI (functional magnetic resonance imaging) to measure brain activity, subjects were shown action words or were asked to perform a simple action. The study found that in addition to other cortical areas, motor and premotor cortex are activated by the sight of these words or the action itself (Hauk, Johnsrude, & Pulvermuller, 2004; see also Martin & Chao, 2001; Fig. 1.2). In other words, the sight of the word is enough to activate motor and premotor areas linked to the movements themselves. Cognitive systems (looking at a word) are inherent in cortical (and perhaps subcortical, basal ganglia) motor systems.

FIG. 1.2. Action words activate frontal-central motor regions (as well as other cortical sites; Hauk et al., 2004). Reprinted from Neuron, 41, G. Hauk, I. Johnsrude, & F. Pulvermaller, Somatotropic representation of action words in human motor and premotor cortex, 301–307, copyright © 2004, with permission from Elsevier.

CHEMICAL CODING, NEURAL CIRCUITS, AND BEHAVIOR

Dopamine is a fundamental neurotransmitter that underlies the organization of effort and the will, and that figures in virtually every chapter of this book. Dopamine is a catecholamine and is produced in the adrenal gland and in core structures of the brain (Fig. 1.3). It is an ancient molecule that underlies diverse behavioral functions. Dopamine is just one neurotransmitter among others (this will be repeated), but it is an important one for the organization of cognitive systems and for action (Cools & Robbins, 2004; Dreisbach et al., 2005).

FIG. 1.3. Dopamine inthe brain, and dopaminefrom the adrenal gland.

Dopamine is a fundamental neurotransmitter for diverse cognitive functions, for example, language (Ullman, 2001); and probability computations (Schultz, 2002); it is fundamental also in the organization of drive and reward (Hoebel, 1998). It may be fundamental in the development of behavioral inhibition (Diamond, 2001). Both excess and depletion of this transmitter are reflected in diverse forms of pathology (e.g., Parkinson’s disease). The regulation of this transmitter, for behavior, is a fundamental event.

Dopamine, as well as serotonin and norepinephrine, are amines. They are represented in specific neuronal sites in the brain stem and forebrain (e.g., Brown et al., 1976, 1979). From small clusters of cell bodies, a diverse array of fiber pathways connects to a large part of the brain; this is true of all the amines (e.g., dopamine; Mogenson, Yang, Yim, 1991; Simon, Scatton, & LeMoal, 1980; Spanagel and Weiss, 1999). For example, dopaminergic pathways from the substantia nigra innervate the putamen and caudate nucleus of the striatum (Swanson, 1988, 2000a, 2000b). This is the nigrostriatal system, which is involved in subcortical motor control. Dysfunction of this system is associated with certain movement disorders, such as Parkinson’s disease (Parkinson, 1817) and tardive dyskinesia (Marsden, Merton, Adam, & Hallet, 1978). The initiation of movement and the organization of thought are important functions of the nigrostriatal system and are illustrated by the characteristics of Parkinson’s disease (Marsden, Merton, Adam, & Hallet, 1978; Marsden & Obeso, 1994). In other words, there are diverse kinds of data that associate a decrease of cognitive performance along with the well-known movement impairments in Parkinson’s disease (e.g., Mochi et al., 2004).

The mesocorticolimbic dopamine system includes the brain systems that are important for the ingestion of food, water, drugs, and social and other rewards (Berridge & Robinson, 1998; Kelley, 1999, 2004; Spanagel & Weiss, 1999; Wise, 2005; Worsley et al., 2000). This system can be subdivided into two systems, the mesolimbic system and the mesocortical system. The mesolimbic system consists of dopaminergic projections from the midbrain ventral tegmental area to the limbic forebrain areas, including the nucleus accumbens, stria terminalis, lateral septal nuclei, amygdala, and limbic areas of the striatum (Brodal, 1981; Spanagel & Weiss, 1999, 2005; Swanson, 2000a, 2000b). In the mesocortical dopamine system, the dopamine cell bodies are also located in the ventral tegmental area. Subsets of dopaminergic projections terminate in the prefrontal cortex, anterior cingulate, and entorhinal cortex (Tzchentke, 2000).

Dopamine levels are linked to diverse motivated behaviors (e.g., Kelley, 1999, 2004). These links have led a number of investigators to connect dopamine to reward (e.g., Becker et al., 2001; Hollerman et al., 2000; Lucas, Pompei, & McEwen, 2000; Spanagel & Weiss 1999; Tzchentke, 2001). But dopamine neurons are activated under a number of diverse conditions, including duress. Dopamine, like the other amines in the brain, is also essential for the broad-based coordination for adaptive responses and is tied to the organization of thought and action, central to both the activation of behavior and the inhibition of behavior. Dopamine is neutral with regard to function; it is just essential for the organization of behavior, the organization of effort (e.g., solving a math problem, running, persevering, inhibiting behavior).

Dopamine is a broadly based neurotransmitter with a number of receptors that are regulated by different transcription factors. Dopamine is one neurotransmitter that is closely linked to the concept of the will. It underlies the feeling of effort, the organization of action, and the rational prioritizing of our goals. The important thing to note at the onset is the hypothesis that dopamine is neutral; dopamine is active, I suggest, under both positive and negative conditions. It is essential to have dopamine elevated and regulated during the organization of thought and the organization of action, not just during positive reward or the inhibition of behavior.

CONCLUSION

Our sense of effort figures in the consideration of motivation, behavioral inhibition, delayed gratification, and decision making. These core features are knotted to, what...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• Introduction: Self-Preservation and Effort
• 1 Neuroscience and Interdisciplinary Inquiry
• 2 Central Motive States
• 3 Willing to Believe: Reenvisioning Cognitive/ Motor Control
• 4 Self-Control and Behavioral Inhibition
• 5 Afflictions
• 6 Choice, Control, and the Brain
• Conclusion: An Understanding of Effort and the Will
• References
• Author Index
• Subject Index