Damage to the lateral distraction center releases inhibition on the medial allowing behaviors to be overly tenacious. This produces the dorsolateral syndrome which is a pseudo-depression where the patient loses the ability to initiate new behaviors. Yet when behaviors can be induced after much effort they tend to persist without stopping. In severe cases the patient will lie passively in bed, neither eating nor drinking.
Patients with this syndrome are no longer bothered by pain even though they can describe the pain they feel just like normal people. Laughing gas does the same thing. This means valuation is a separate independent conscious sensation from the underlying feeling. Conscious experiences themselves are not inherently good or bad. Some just seem to have inherent valuations (like bad smells) due to evolution and context.
Most of these patients will also have anosognosia in which they are unable to perceive their limitations because they cannot place a valuation on it. As a result they have no motivation to undergo rehabilitation exercises. Minor or slowly developing dorsolateral syndromes can be very hard to recognize in people because their friends assume that the person is becoming lazy or simply becoming disinterested in things due to age.
A stroke patient with mostly dorsolateral syndrome but who also had damage to her middle (medial) part of her prefrontal cortex is described by Antonio Damasio.
She suddenly became motionless and speechless, and she would lie in bed with her eyes open but with a blank facial expression.... Her body was no more animated than her face. She might make a normal movement with arm and hand, to pull her bed covers for instance, but in general, her limbs were in repose. When asked about her situation she usually would remain silent, although after much coaxing she might say her name, or the names of her husband and children, or the name of the town where she lived....She never became upset with my insistent questioning, never showed a flicker of worry about herself or anything else.Months later, as she gradually emerged from this state of mutism and akinesia (lack of movement), and began to answer questions, she would clarify the mystery of her state of mind. Contrary to what one might have thought, her mind had not been imprisoned in the jail of her immobility. Instead it appeared that there had not been much mind at all, no real thinking or reasoning. ... At this later date she was certain about not having felt anguished by the absence of communication. Nothing had forced her not to speak her mind. Rather, as she recalled, “I really had nothing to say.” (Damasio 1994, page 72)The patients with dorsolateral syndrome still have conscious experiences but they are unable to form goals and reason to achieve those goals because the valuation signal has been stripped off the underlying feelings.
In contrast to the dorsolateral syndrome, damage to the medial tenacity center causes the orbitofrontal syndrome. This is a condition in which the patient lacks any sort of tenacity. The patient is emotionally dis-inhibited and impulsive. They are not able to defer immediate gratification and cannot see the consequences of their actions. They will say what is on their minds without regard to the social consequences (Goldberg 2001, page 144). The earliest celebrity example of this was Phineus Gage who had a railroad tamping iron go through the middle of his brain in 1848.
A patient with orbitofrontal syndrome from a cancerous tumor was reported on by clinical neurologist Oliver Sacks. This patient, one Mrs. B, was a female research chemist. She seemed to realize she had lost her sense of valuation about social situations. Oliver Sacks says this:
When I saw her she seemed high-spirited, volatile - ‘a riot’ (the nurses called her) - full of quips and cracks, often clever and funny.‘Yes, Father,’ she said to me on one occasion. ‘Yes, Sister,’ on another‘Yes, Doctor,’ on a thirdShe seemed to use the terms interchangeably. ‘What am I?’ I asked, stung, after a while.I see your face, your beard,’ she said, ‘I think of an Archimandrite Priest. I see your white uniform - I think of the Sisters. I see your stethoscope - I think of a doctor.‘You don’t look at all of me? ’‘No, I don’t look at all of you. ’‘You realize the difference between a father, a sister, a doctor?’I know the difference, but it means nothing to me. Father, sister, doctor - what’s the big deal?’Thereafter, teasingly, she would say: ‘Yes father-sister. Yes, sister-doctor,’ and other combinations.Testing left-right discrimination was oddly difficult, because she said left or right indifferently (though there was not, in reaction, any confusion of the two, as when there is a lateralizing defect of perception or attention). When I drew her attention to this, she said: ‘left/right. Right/left. why the fuss? What’s the difference?’‘Is there a difference?’ I asked.‘Of course,’ she said, with a chemist’s precision. ‘You could call them enantiomorphs of each other. But they mean nothing to me. They’re no different for me. Hand … Doctors …. Sisters ...’ she added, seeing my puzzlement. ‘Don’t you understand? They mean nothing - nothing to me. Nothing means anything … at least to me.‘And … this meaning nothing ...’ I hesitated, afraid to go on. ‘This meaninglessness … does this bother you? Does this mean anything to you?’‘Nothing at all,’ she said promptly, with a bright smile, in the tone of one who makes a joke, wins an argument, wins at poker.’ (Sacks 1998, page 116)Dr. Sacks went on to concluded: ‘Mrs. B., though acute and intelligent, was somehow not present - ‘de-souled’ - as a person.Valuation is also dependent on perceptual context which suggests that it is easily changeable via emotional propagation. Heterosexual men find a perceived touch by a woman more enjoyable than that from a man. If men can be fooled by an experiment into thinking a woman is doing the touching then a man's touch is just as enjoyable. This perceptual valuation effect even shows up in their brain scans (Gazzola and all, 2012).
Consciousness experiences comes in two varieties because of how goal paths are created in space. The space we experience is not a network like a road map but is continuous. Deep experiences provide valuation about the goal itself as in whether we want to get it or if we want to flee from it. These we call our deep feelings. Shallow experiences are constraints which help guild our path (whole body or hand) toward or away from a goal. These conscious experiences are involved in spatial perception, vision, body position, etc.
Laughing gas affects the valuation of pain and other things and often induces light heartedness like that seen in patient Mrs. B above. My college roommate went to the dentist and experienced a light dose saying it "hurt like hell but I didn't care." The underlying conscious experience was there but not its valuation.
Damasio, Antonio (1994) Descartes’ Error, Emotion, Reason, and the Human Brain . Penguin BooksGazzola, V., Spezio, M.L., Etzel, J.A., Castelli, F., Adolphs, R., and Keysers, C. (2012) Primary somatosensory cortex discriminates affective significance in social touch. Proceedings of the National Academy of Sciences, June 4, 2012 DOI: 10.1073/pnas.1113211109Goldberg, Elkhonon (2001) The Executive Brain, Frontal Lobes and the Civilized Mind. Oxford University PressSacks, Oliver (1998) The Man who Mistook His Wife for a Hat and Other Clinical Tales, Touchstone, New York
