Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Fear ---- Pleasure

Pleasure is a key factor in controlling the motivated behavior of humans. (Kandel; Principles of Neural Science, 1007)

Stimulation of the nucleus accumbens in humans elicits smiling, laughter, pleasurable feelings, happiness, even euphoria. (Cardoso; Hardwired for Happiness, 173)

Amygdala and its connections to the prefrontal cortex and basal ganglia are likely to influence the selection and initiation of behaviors aimed at obtaining rewards and avoiding punishments. (Purves; Neuroscience, 701)

Orbital cortex may be especially involved in working memories about rewards and punishments. (LeDoux; Emotional Brain, 285)

Nucleus accumbens -- part of a network of structures involved in feelings of pleasure and reward, whether it is through eating, having sex, or listening to pleasurable music. (Levitin; Your Brain on Music, 89)

Link to — Pain and Pleasure Systems

Research study — Hippocampal CA3 Link to Ventral Tegmental Area

All feelings contain some aspect of pain or pleasure as a necessary ingredient. (Damasio; Looking for Spinoza, 123)

Some parts of the mind register the attainment of increments of fitness by giving us a sensation of pleasure. (Pinker; How the Mind Works, 524)

Pain is the perception of a sensory representation of local living tissue dysfunction. (Damasio; Feeling of What Happens, 76)

Pleasures associated with eating or drinking. (Damasio; Feeling of What Happens, 77)

Thwarting of the consummation may actually cause anger. (Damasio; Feeling of What Happens, 77)

Alleviation or suspension of the state of pain may cause the emergence of pleasure and positive emotions. (Damasio; Feeling of What Happens, 77)

More than two emotions, some aligned with pain, some aligned with pleasure, mostly with pain. (Damasio; Feeling of What Happens, 77)

Pleasure leads an organism to attitudes and behavior that are conducive to the maintenance of its homeostasis. (Damasio; Feeling of What Happens, 77)

Science 13 February 2009: Vol. 323. no. 5916, pp. 890 - 891

Pains and Pleasures of Social Life

Matthew D. Lieberman and Naomi I. Eisenberger

Department of Psychology, 1285 Franz Hall, University of California at Los Angeles, Los Angeles, CA 90095-1563, USA.

Neuroscientists have identified neural systems responsible for experiences of pain and pleasure.

The cortical pain network consists primarily of the dorsal anterior cingulate cortex (dACC), insula, and somatosensory cortex, with subcortical contributions from the periaqueductal gray and thalamus. Whereas the somatosensory cortex is associated with sensory aspects of cutaneous physical pain (e.g., its location on the body), the dACC is associated with the distressing aspect of pain.

The brain's reward circuitry consists of neural structures receiving the neurotransmitter dopamine from the ventral tegmental area, and responds to physically rewarding stimuli such as food, drugs, and sexual activity. The nucleus accumbens in ventral striatum plays a critical role in reward learning and pleasurable states, while the ventromedial prefrontal cortex and amygdala are also major dopaminergic targets that have been implicated in reward processes

Rewards and Punishers as primary reinforcers

Pleasure systems

A key motivator of our lives, pleasure is central to learning, for you must find things like food, water, and sex rewarding in order to survive and pass our genetic material to the next generation. (Linden; Compass of Pleasure, 2)

Release of dopamine onto the nucleus accumbens appears to underlie all reward feelings. (Johnston; Why We Feel, 116)

Feelings of pleasure and anticipation of desirable outcomes are associated with circuits of neurons that employ the neurotransmitter dopamine, running from the ventral tegmental area through the nucleus accumbens to the prefrontal cortex. Such brain circuits are reciprocal, with many feedback loops. (Thagard; Brain and the Meaning of Life, 96)

Dopamine levels rise in the nucleus accumbens in response to natural rewards (food, water, and sexual stimuli), and conditioned incentives (stimuli associated with rewards). (LeDoux; Synaptic Self, 247)

Pleasurable feelings that accompany actions such as eating chocolate, laughing, smiling, touching, meditating, singing, listening to good music, and even orgasm are partially attributed to the brains release of endorphins. (Cardoso; Hardwired for Happiness, 174)

EEG recordings from various parts of the brain during orgasm. Slow, high-amplitude waves similar to those in epilepsy appear, principally in the septum. Orgasm for man and for woman is the supreme ecstasy, intense waves of pleasure and emotion. Acetylcholine in the septum of a female provoked intense sexual pleasure, culminating in repeated orgasm. (Changeux; Neuronal Man, 111-113)

Fear and Anxiety

Amygdala is the area of the brain most involved in fear. (Ratey; User's Guide to Brain, 233)

Amygdala interacts with the medial prefrontal cortex (anterior cingulate and orbital regions). Cognitive functions in prefrontal regions regulate the amygdala and its fear reactions. (LeDoux; Synaptic Self, 217)

Prefrontal cortex and amygdala are reciprocally related. (LeDoux; Synaptic Self, 217)

Amygdala is an important interface between visual and auditory emotionally competent stimuli and the triggering of emotions, in particular, though not exclusively, fear and anger. (Damasio; Looking for Spinoza, 60)

Fear becomes anxiety, desire gives way to greed, annoyance turns to anger, anger to hatred, friendship to envy, love to obsession, or pleasure to addiction. (LeDoux; Emotional Brain, 20)

Fear conditioning is quick and very long lasting; there is little forgetting with conditioned fear. (LeDoux; Emotional Brain, 145)

Fear conditioning is an evolutionarily old solution to the problem of acquiring and storing information. (LeDoux; Emotional Brain, 147)

Direct thalamic input to the amygdala allow the cortex to be bypassed. (LeDoux; Emotional Brain, 158)

Subregion of the amygdala -- central nucleus has connections with brain stem areas controlling heart rate and autonomic nervous system responses. (LeDoux; Emotional Brain, 158)

Implicit, fear-conditioned memory, 'emotional memory' (LeDoux; Emotional Brain, 182)

Once the fear system is turned on, it's hard to turn it off; this is the nature of anxiety. (LeDoux; Emotional Brain, 289)

Can't have a complete feeling of fear without the activation of the amygdala. (LeDoux; Emotional Brain, 298)

There are separate output pathways from the amygdala for different fear related responses. (Rolls; Emotion Explained, 161)

Lateral nucleus of amygdala is a key site of plasticity during fear learning. (LeDoux; Synaptic Self, 124)

Nature 454, 600-606 (31 July 2008)

Switching on and off fear by distinct neuronal circuits

Cyril Herry, Stephane Ciocchi, Verena Senn, Lynda Demmou, Christian Müller, Andreas Lüthi

Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland

Switching between exploratory and defensive behaviour is fundamental to survival of many animals. The amygdala is a key brain structure mediating defensive behaviour in states of fear and anxiety. Such states can be induced by classical auditory fear conditioning, in which an initially neutral auditory stimulus (the conditioned stimulus, CS) comes to elicit a fear response after pairing with an aversive foot shock (the unconditioned stimulus, US). Subsequent repetitive presentations of the CS alone induce a progressive decrease in the fear response, a phenomenon called extinction. Whereas firing of amygdala neurons is critical for the retrieval of conditioned fear memories, their firing after the extinction of conditioned fear is thought to be constrained by local inhibitory circuits activated by the medial prefrontal cortex (mPFC), Converging evidence from animal studies indicates, however, that the basolateral complex of the amygdala (BLA), comprising the lateral (LA) and the basal (BA) nuclei, actively participates in fear extinction. Although fear extinction is an active learning process eventually leading to the formation of a consolidated extinction memory, it is a fragile behavioural state that is readily influenced by context. Changing context results in the immediate recovery of the previously conditioned fear response, a process known as fear renewal. In vivo pharmacological studies indicate that the hippocampus, which is reciprocally connected to the BLA, processes contextual information during fear conditioning, extinction and renewal. Thus, bi-directional changes in fear behaviour during extinction and context-dependent renewal are likely to be encoded within a distributed network containing the BLA, the mPFC and the hippocampus.

Fear and Expectation of Pleasure drive Motivation

Interactions between the amygdala and nucleus accumbens contribute to motivation. (LeDoux; Synaptic Self, 250)

Return to — Emotion