Neuropsychology


23
Dec 06

Compulsive addiction to language

WNYC runs a series called Radio Lab, a curious investigative exploration of the world that distinguishes itself with an immersive layering of sound and narration. I recently listened to the Radio Lab podcast, specifically show number 202, Musical Language, originally aired on April 21, 2006. Jad Abumrad and Robert Krulwich host a trip looking at how the brain processes sound, and a fascinating trip it is.

Our hosts focus on how we perceive music and how language is actually very close to song. Most of us are verbally expressive and we are expert in changing the execution of our speech to communicate overtones and undertones. They interview a series of academics to explore what we understand about sound and how it is understood.

Diana Deutsch, is a professor in University of San Diago’s psychology department studying tone languages, where the same word has different meanings depending on the tone they are spoken in. Anne Fernald, Stanford Associate Professor of Development Psychology, has looked at how specific tones communicate to young infants – universal across languages. “Sound is more like touch at a distance.” Tone is a fundamental component in communication and it begs the question – What happens if you are tone deaf? Does a person of perfect pitch understand language differently?

Jonah Lehrer, author and Rhodes Scholar with a degree in neuroscience, helps us understand how sound transmits from speaker to ear. The voice box compresses air, sends waves to the eardrum, vibrating the bones, rippling fluid in the ear, releasing electricity and then our brain interprets that as sound. Mark Jude Tramo, Harvard Assistant Professor of Neurology, actually listens to the electricity and even at this low level, pleasant sounds have consistent meter, while unpleasant sounds have inconsistent meter. The word pleasant is obviously subjective, but establishes a point for discussion, after all people seem to be able to appreciate even the unpleasant – the pleasant can often become pleasant with repetition, time and linking to other highly valued experiences.

What happens when you cannot hear? Obviously, these electrical pulses are not stored along with other information in the brain. Yet it is common to read how people with disabilities develop higher sensitivity with their other senses. Considering that these tuned senses reflect the human potential, can everyone develop heightened senses, or do we need to lose one to gain development in another? Do people who do not have the use of one sense store additional information – understand and experience at a richer level, or is it just different – can it be richer if it is missing a key sense such as smell?

What is it that we find pleasant and why is it that we can so easily shift the unpleasant to the pleasant? Lehrer describes how our brains are always trying to assimilate foreign changes in audio input. Can we extrapolate that to other senses? People have different pain thresholds, derive a certain level of enjoyment from it – an outdoor hot tub in the winter can be particularly biting, but relaxing all the same. Different types of alcohol require an acquired taste – whisky is not exactly hot chocolate. Almost all alcohol varieties cultivate experts that can discern even the most subtle elements from seeing, smelling and tasting. One person’s Syrah is another person’s Sancerre, yet to a new wine drinker both might offend.

Another question: What is it when we develop addictions and what are we addicted to – the signals to the brain or the experiences we engage in? What does it mean to abuse an experience? Society tends to see harmful behavior, such as smoking and excessive drinking as addictive and abusive. If my addiction is to coffee, reading or love then it is generally accepted, even though I might actually be damaging something unknown or unseen. I am not convinced that there is anything substantially different from one compulsive behavior to another – our brains (and our bodies through our brains) create custom drug cocktails of pleasure and the vices we have affinity for might very well be arbitrary.


27
Oct 06

Feeling conscious

Neuropsychology could have easily been my first profession. My fascination for the brain and appreciation for how little and much we know of it has always captivated my logical and imaginative thought.

I just finished the book, Wider Than The Sky: The Phenomenal Gift of Consciousness, where Gerald Edelman, M.D., Ph. D. covers an impressive amount of information refuting that consciousness is solely metaphysical. While anyone can argue there is mystery to the brain, Edelman’s work is persuasive – there are neurological constructs which give rise to consciousness.

Quale (IPA [ ˈkwɑːle]) is the way something feels, an experienced conscious moment. The definition’s subtly fails to describe the complex recipe that comprises a feeling –

sensory input, consequences of motor activity, imagery, emotions, fleeting memories, bodily sensations and a peripheral fringe. (p. 61)

Our experience, being conscious of being conscious naturally contains all of these things all of the time. It would be trivializing to say it is like a movie where only audio and visual aspects are perceived. Qualia consider the past, the current and the possible future, all at the same moment, all the time, becoming part of the categorized catalog of discriminated conscious states influencing future qualia.

In order to fully understand the data set that is flowing throughout the brain, we would actually need to be that body, that brain. The information outside of that context can only be imagined. An example used was, “what would it be like to be a bat?” illustrating the complexity – it would actually be easier to understand what it would be like to be another human, but is quite literally, impossible.

Recently on CBS Sunday Morning, Mo Rocca questioned if as we live longer and medical technology continues to deliver higher quality transplant and artificial replacement, will you still be you? Assuming that the replacement of an organ is successful, the brain would read the new organ as part of new quale. What happens to the qualia associated with the failed organ? Does the brain simply treat those discriminations as part of a phantom part of a quale – similar to the sensation some people experience when losing a limb, or, is some of the data lost forever? Does the new organ have the ability to read the data stream as part of the body and brain? Does the replacement organ, know something that the failing organ did not?

So, Mo, I think the answer is yes, probably, you will still be you, but a different you.