Interactions Between the Nucleus Accumbens and Auditory Cortices Predict Music Reward Value
When you hear an unfamiliar tune, how do you wind up either tapping your foot or plugging your ears? A study finds that a specific brain region gives the song a thumbs up or down.
….values participants assigned to songs were associated with:
– activity in the nucleus accumbens, a section of the brain’s pleasure center.
– For more popular tunes, this region was more active and communicated more with the brain region that stores auditory information. Continue reading
“We borrow the term valence from chemistry. Instead of referring to an atom’s positive or negative charge, we use it to describe the positive or negative perception associated with an image.
Valence is simpler than emotion, or preference, or value; it should be thought of as a very rough, very rapid and automatic snapshot of perception that the brain computes in order to estimate likability of an object. Instead of thinking about what constitutes valence, it is perhaps more helpful to think why we even see valence.
…In the lab, we have shown that most people detect a negative valence as early as 17 milliseconds after the participant sees the gun. Continue reading
The Stress-Response Cycle
The human stress-response cycle is a complex neuroendocrine response triggered by perceived or real threats from the environment or internal stimuli. The sympathetic nervous system and the hypothalamus-pituitary-adrenal (HPA) axis are primarily responsible for the
physiological changes associated with a stressful state (Selye, 1937). The initial catecholamine response triggered from the sympathetic nervous system involves a rapid release of epinephrine and norepinephrine into the bloodstream and throughout the body, inducing the changes characteristic of the ‘fight or flight’ response—increased heart rate and respiration, pupil dilation, and more blood flow to the skeletal muscles, vigilance, and so forth…… Continue reading
Taken together, our neuronal and behavioral findings demonstrate that:
- High childhood stress and trauma
- Is related to lower MPFC activation during both rest and the self-oriented task.
- This is behaviorally manifested as an abnormal shift from internally to externally guided decision making, even in situations where internal guidance is required.
This is called “parasite load” and is correlated with most social behaviors around groups.
“The forest region of central Africa is the disease epicentre of the universe! HIV from chimps, bats carrying rabies, Ebola, SARS, insect vectors carrying malaria and parasitic diseases like river blindness and elephantitis, loads of fecal-oral diseases… It’s described as ‘pathogen rain’,” says Walsh.
“You live in a big group with lots of (inter-group) social interaction, and one of you gets Ebola – everybody dies. So it doesn’t make evolutionary sense in such places”.
Walsh suggests that the region’s ‘pathogen rain’ could have stunted early human development, as limited interactions due to fear of disease meant that ideas and innovations were unable to spread and build, leaving our first ancestors languishing in the forest for thousands of years.
“In disease hotbeds, people have much stronger group identification, which makes them much more hostile – part of the behavioural immune system. You see the same in gorillas.”
“Science is a continuous challenge to common sense….Science is about challenging our a priori concepts of the world…the way we think and our mental vision of the world. We keep changing our image of the world, to find a new one that works a little bit better…The past knowledge is always less. We trust our past knowledge but we are always ready to modify our conceptual structure of the world.…Science is not about certainty. Science is about finding the most reliable way of thinking at the present level of knowledge. Science is extremely reliable but not certain…Science ideas are credible because they have survived all the critics of the past…The core idea of science is that we have wrong ideas and prejudices and ingrained ideas in our grasping of reality – that we have to revise…”
My reading of the bench science is that the emphasis on brain “plasticity” is mainly an ideological reaction to the increasing evidence for genetic/developmental determinism from birth of most brain functions. So naturally, an active denialism has become popular.
“Plasticity is just learning at the neural level, and learning is not an alternative to innate motives and learning mechanisms. Plasticity became an all-purpose fudge factor in the 1990s Continue reading