The Evolution of Music

In the May 15 issue of Nature Josh McDermott discusses ideas about the evolution of music:

The mere presence of music in every known culture implies some genetic basis. But music varies dramatically from culture to culture, and many aspects of musical behaviour seem at best only weakly constrained by genetics. Whereas our ability to hear pitch intervals, for instance, could well be biologically rooted in the hardware of the auditory system, our emotional response to particular scales or chords seems likely to be acquired from exposure to a particular culture. Interactions between genes and environment are complex, and unravelling their contributions is not easy, but studies of music in different cultures and of musical development offer some hope.

A number of interesting music-related traits emerge in human infants with fairly minimal musical input, providing some evidence for innate constraints. Babies notice when the notes of a melody are reordered, but not when they are shifted to a different pitch range. Infants, like adults, are sensitive to the relationships between notes, which is preserved in transposition, but altered by reordering. Infants also tend to be captivated by music relative to many other stimuli. Not all music is equivalent to them — they prefer combinations of notes that are judged by adults to sound pleasing, or consonant (the perfect fifth, for instance), over combinations that are less pleasing, or dissonant (a minor second). Infants may even extract metre from music: they react when the rhythm changes from a march to a waltz.
Universal appeal

Features of music that occur repeatedly around the world despite the substantial cultural variation in music also provide clues to genetically constrained mechanisms. Lullabies seem to qualify as a rare universal — nearly every culture has a genre of music geared towards infants, and there is considerable consistency in how they sound, generally being slow, repetitive and featuring descending pitch contours. Other features that are common, if not completely universal, among cultures include the inclination to dance to music, musical metre, and the hierarchical organization of pitch, giving structural prominence to particular notes over others.

Neurobiology of trust

The June 2008 issue of Scientific American has an article by Zak on the neurobiology of trust, and the hormone oxytocin. I've previously mentioned Zak's work, and if you enter 'oxytocin' in MindBlog's search box in the left column you will pull up numerous previous posts on oxytocin, trust, and affiliative behaviors, some of which the Zak article mentions (for example, inhaling a nasal spray containing oxytocin increases trusting behaviors). I thought I would show one graphic from the article relevant to the fact that trust is among the strongest known predictors of a country’s wealth. Nations with low levels tend to be poor. Societies with low levels are poor because the inhabitants undertake too few of the long-term investments that create jobs and raise incomes. Such investments depend on mutual trust that both sides will fulfill their contractual obligations.

Brief Bach, and its piano and windows

A Bach two-part invention (No. 8)

Do chimpanzees have a theory of mind? 30 years later

Call and Tomasello offer a review in the May issue of Trends in Neuroscience on the controversial question of how much our nearest relatives understand about the minds of others:

On the 30th anniversary of Premack and Woodruff's seminal paper asking whether chimpanzees have a theory of mind, we review recent evidence that suggests in many respects they do, whereas in other respects they might not. Specifically, there is solid evidence from several different experimental paradigms that chimpanzees understand the goals and intentions of others, as well as the perception and knowledge of others. Nevertheless, despite several seemingly valid attempts, there is currently no evidence that chimpanzees understand false beliefs. Our conclusion for the moment is, thus, that chimpanzees understand others in terms of a perception–goal psychology, as opposed to a full-fledged, human-like belief–desire psychology.

Here is one description of an experimen showing that Chimpanzees infer a human's intentions:

Buttelmann et al. [Dev. Sci. 10 (2007 pp. F31–F38]...tested six human-raised chimpanzees in the so-called rational-imitation paradigm. The chimpanzees were shown how to operate an apparatus to produce an interesting result (e.g. lights or sounds), and then they were given a turn. The most natural behavior for them in all cases was to operate it with their hands. But this obvious behavior was never demonstrated for them; they always saw a human manipulate the apparatus in a novel way with some other body part. The idea was that in some cases the physical constraints of the situation dictated that the human (referred to as ‘E’ in the figure) had to use that unusual body part; for example, he had to turn on a light with his head because his hands were occupied holding a blanket or he had to operate a light with his foot because his hands were occupied with a heavy bucket (see Figure I). When the chimpanzees saw this forced use of the unusual body part, they mostly discounted it and used their hands as they normally would (because the constraints were not present for them). However, when they saw the human use the unusual body part when there was no physical constraint dictating this, they quite often copied the unusual behavioral means themselves. If we interpret this experiment the way it is interpreted for human infants, the conclusion is that the chimpanzees understood not only what the experimenter was trying to do (his goal) but also why he was doing it in the way he was doing it – the rationality behind the choice of the plan of action toward the goal. According to Tomasello et al. [Behav. Brain Sci. 28 (2005), pp. 675–691], an understanding of the action plan chosen toward a goal constitutes an understanding of the intention.

Models of cognitive control in prefrontal cortex.

In the May issue of Trends in Cognitive Sciences David Badre reviews different models of the cognitive controls in our prefrontal cortex that support flexible behavior by selecting actions that are consistent with our goals and appropriate for our environment. I thought I would pass on two nice graphics from the papers, showing the structures and models involved. They do make the point that we have a long way to go before figuring out how the system works.

Figure (click to enlarge). Schematic of major anatomical sub-divisions in the frontal lobes. Boundaries and Brodmann areas (BA) are only approximate. Arrows indicate anatomical directions of anterior/rostral (front) versus posterior/caudal (back) and dorsal (up) versus ventral (down). From caudal to rostral, labeled areas include motor cortex, dorsal (PMd) and ventral premotor cortex, dorsal (pre-PMd) and ventral aspects of anterior premotor cortex, ventro- (VLPFC) and dorsolateral PFC (DLPFC), and lateral frontal polar cortex (FPC).


Figure: (Click to enlarge) Theoretical accounts of the rostro–caudal gradient in the PFC. (a) From a working memory perspective, rostral and caudal PFC can be distinguished on the basis of processing domain general versus specific representations. Hierarchical versions of this perspective propose that domain-specific posterior frontal regions can be modulated by the maintenance domain general rules in anterior DLPFC and FPC. (b) Relational complexity proposes a gradient in the PFC with respect to evaluation of simple stimulus properties, first-order relationships among the properties, and second-order relationships among relationships. (c) The cascade model proposes four levels of control that are distinguished by temporally disparate control signals, either sensory, context, episodic or branching. (d) Abstract representational hierarchy proposes that regions of the PFC are distinguished by the level of abstraction at which representations compete in a hierarchy of action representations.

Music becoming a monoculture...

David Huron writes an interesting essay in the May 22 issue of Nature noting the fact that as millions of musical recordings have become available over the web, there has been a

...collapse in the diversity of musical minds. A Nigerian group might sing in Yoruba, but the harmonies are thoroughly Western. Native American Navajo singers make valiant efforts to preserve their traditions, but to the trained musicologist, their singing bears the unmistakable imprint of Western scales. The casual listener hears a wealth of variety; the musicologist detects a rapidly spreading monoculture — albeit expressed in many forms.
...Linguists know how fast languages disappear. Musical cultures may be an order of magnitude more fragile. It will be many centuries before the whole world speaks Mandarin. Meanwhile Western music has swept the globe faster than aspirin. Robust musical cultures remain in China, India, Indonesia and the Arab world, but even in these regions, most people are thoroughly acquainted with Western music through film and television. Less robust musical cultures are disappearing rapidly or are showing deep infiltration by Western musical foundations. Many have already disappeared. There remain only a few isolated pockets, such as the highlands of Papua New Guinea and Irian Jaya.

What and Where pathways in auditory brain

The visual cortex has parallel processing streams that deal mainly either with the location of an image (the dorsal stream) or its identity (the ventral stream). It now appears that auditory cortex (in cats) has similar parallel processing of the location and identity of sounds. Here is the abstract from Lomber and Malhotra and a graphic from the summary by Sumner and Moore.

Studies of cortical connections or neuronal function in different cerebral areas support the hypothesis that parallel cortical processing streams, similar to those identified in visual cortex, may exist in the auditory system. However, this model has not yet been behaviorally tested. We used reversible cooling deactivation to investigate whether the individual regions in cat nonprimary auditory cortex that are responsible for processing the pattern of an acoustic stimulus or localizing a sound in space could be doubly dissociated in the same animal. We found that bilateral deactivation of the posterior auditory field resulted in deficits in a sound-localization task, whereas bilateral deactivation of the anterior auditory field resulted in deficits in a pattern-discrimination task, but not vice versa. These findings support a model of cortical organization that proposes that identifying an acoustic stimulus ('what') and its spatial location ('where') are processed in separate streams in auditory cortex.

Legend: The effects of cooling posterior and anterior regions of auditory cortex are doubly disassociated, with anterior regions being important for discriminating between sounds and posterior parts being important for localizing them.

Meeting George Bush versus Meeting Cinderella

The rest of the title of this article by von Cramon and Schubotz is "The Neural Response When Telling Apart What is Real from What is Fictional in the Context of Our Reality." Our ability to distinguish fact from fiction emerges early during our development, and by the age of 5, we not only differentiate reality from fiction but can also distinguish between different fictional worlds. The neural correlates underlying this ability are unknown. The authors obtain fMRI images showing significant difference in brain activity while processing real versus fictional conditions. The graphic is from the paper just to include a pretty picture, I'll spare you the details, because they really don't add all that much to the bottom line:

The processing of real and fictional scenarios activated a common set of regions including medial-temporal lobe structures. When the scenarios involved real people, brain regions associated with episodic memory retrieval and self-referential thinking, the anterior prefrontal cortex and the precuneus/posterior cingulate, were more active. In contrast, areas along the left lateral inferior frontal gyrus (shown in the graphic), associated with semantic memory retrieval, were implicated for scenarios with fictional characters. This implies that there is a fine distinction in the manner in which conceptual information concerning real persons in contrast to fictional characters is represented. In general terms, the findings suggest that fiction relative to reality tends to be represented in more factual terms, whereas our representations of reality relative to fiction are colored by personal subjectivity. What modulates our understanding of the relative difference between reality and fiction seems to be whether such character-type information is coded in self-relevant terms or not.

The authors note their agreement with the statement of William James: "In the relative sense, then, the sense in which we contrast reality with simple unreality, ... reality means simply relation to our emotional and active life

Older adults have a broader attention span

An article by Reistad-Long describes studies suggesting that a broader attention span may enable older adults to ultimately know more about a situation and the indirect message of what’s going on than their younger peers. For example, older people take longer to read passages that are interrupted with unexpected words or phrases, but are more likely to be successful at answering questions for which the out-of-place words might be answers. This might yield advantages in the real world, where it is not always clear what information is important, or will become important. Maybe we think of older people as wiser because they take in more information from a situation, and are able to combine it with a comparatively greater store of general knowledge.

Lotus therapy

Yet another article on benefits of mindfulness meditation in this morning's NYTimes science section.

Blogging as self-medication

Maybe I've found one of the reasons I do this blog (other than to keep me off the streets): An article by Jessica Wapner in the June issue of Scientific American discusses studies on the therapeutic value of blogging. Blogging is claimed to provide physiological benefits similar to those that have been shown for expressive writing (serving as a stress-coping mechanism, improving memory and sleep, and boosting immune cell activity.) Blogging may act as a "placebo for getting satisfied." The blogosphere offers an antidote to social isolation. (Checking out my 'mdbownds' YouTube video postings reveals that the Debussy Reverie video has been viewed 98,739 times and 157 comments made; this mindblog gets 500-600 visitors each day. While this is social connection, I totally don't know any of you people, except for a handful of friends.) I find fleeting virtual world contacts a pallid substitute for real life huggable friends, and sometimes fret that my time spent hunkering over a keyboard provides too convenient an excuse for the harder work of being a robust member of real (versus virtual) social groups.

Another reason for being gay?

Ever alert for the latest speculation on a possible biological basis for why I might be gay, I come across this little gem on fruitflies: genetic manipulation that enhances dopamine levels in males makes them more likely to court with other males.

A Chopin Nocturne...

Chopin Nocturne Op. 27 No. 2, recorded on my Steinway B at Twin Valley.

For your memorial day holiday hangover

Check out this article by Joan Acocella in the May 26 issue of The New Yorker, "A Few Too Many - Is there any hope for the hung over?"

Tones of Ancient Greece

I found this brief commentary from "Random Samples" in the May 16 issue of Science so interesting that I wanted to pass it on in its entirety:

The strings of a helikon, a gadget invented by Ptolemy to probe musical scales, sounded last week for the first time in almost 2 millennia at the University of Cambridge in the U.K....Andrew Barker, a musicologist at the University of Birmingham, U.K., built the instrument from a description in Harmonics, Ptolemy's 2nd century treatise on the mathematics of music. Ancient scholars considered the study of harmonics vital in understanding the mathematical rules that they believed governed the universe. He unveiled it as part of Cambridge's Science of Musical Sound Project.

Barker says the 1-meter-long wooden instrument with eight metal strings allows scientists to test "complete scales constructed on the basis of mathematical principles." The helikon creates different pitches with a calibrated sliding bridge, which can be inserted diagonally to shorten strings to different lengths. Strings can also be moved crosswise to raise or lower the range of pitches. Barker, who showed how the adjustments produce different intervals when the gadget is plucked, admits that it's not designed for musicmaking. Still, he says he was delighted that it worked at all.

Cambridge historian Torben Rees, a professional jazz singer, called Barker's presentation "a fascinating account of ancient thinking concerning harmonics." Music, he says, was regarded as "the sensible expression of the order of the cosmos. This conception of the universe … was essentially the birth of mathematical physics."

Most popular consciousness papers

Here is the list of the five most downloaded papers from the ASSC archive for April, 2008:

1. Destrebecqz, Arnaud and Peigneux, Philippe (2005) Methods for studying
unconscious learning. In: Progress in Brain Research. Elsevier, pp. 69-80.
1877 downloads from 23 countries. http://eprints.assc.caltech.edu/170/
2. Koriat, A. (2006) Metacognition and Consciousness. In: Cambridge handbook
of consciousness. Cambridge University Press, New York, USA. 1297 downloads
from 23 countries. http://eprints.assc.caltech.edu/175/
3. Dehaene, Stanislas and Changeux, Jean-Pierre and Naccache, Lionel and
Sackur, Jérôme and Sergent, Claire (2006) Conscious, preconscious, and
subliminal processing: a testable taxonomy. Trends in Cognitive Science, 10
(5). pp. 204-211. 880 downloads from 16 countries.
http://eprints.assc.caltech.edu/20/
4. Sagiv, Noam and Ward, Jamie (2006) Crossmodal interactions: lessons from
synesthesia. In: Visual Perception, Part 2 - Fundamentals of Awareness:
Multi-Sensory Integration and High-Order Perception. Progress in Brain
Research, Volume 155. Elsevier, pp. 259-271. 868 downloads from 13
countries. http://eprints.assc.caltech.edu/224/
5. Tsuchiya, Naotsugu and Koch, Christof (2005) Continuous flash suppression
reduces negative afterimages. Nature Neuroscience, 8 (8). pp. 1096-1101. 762
downloads from 13 countries. http://eprints.assc.caltech.edu/35/

Are you a morning person? - mood and body clocks

From from PJH at editor's choice, Science Magazine.

Some neurotransmitters, such as dopamine, have been implicated in adjusting a person's mood. The circadian clock mechanisms, meanwhile, keep the organism's physiology tuned for appropriate responses to day or night. Hampp et al. have demonstrated how the molecular signaling pathways for circadian rhythms might intersect with the brain's establishment of general mood. They found that the promoter of the gene encoding monoamine oxidase A (Maoa), which stabilizes some aspects of mood and breaks down dopamine and serotonin, contains binding sites for several clock proteins and showed that circadian oscillation was driven by the Maoa promoter in neuroblastoma cells. Mice lacking Per2, a gene that stabilizes circadian rhythms, showed damped expression from the Maoa promoter. Observations of the Per2 mutant mice in response to an unavoidable problematic situation--taken as a proxy for despair in humans--showed correlations with disorders of mood.

Tranquility...

A MindBlog reader suggests that I pass along this link on "50+ Simple 30-Second Ways to Bring Tranquility To Your Life"... Hmmmm, good luck.

Brain imaging of belief, disbelief, and uncertainty

A fascinating fMRI study by Sam Harris and colleagues has used functional magnetic resonance imaging (fMRI) to study the brains of 14 adults while they judged written statements to be true (belief), false (disbelief), or undecidable (uncertainty). (Yes, this is the same Sam Harris who wrote "The End of Faith" and "Letter to a Christian Nation."). To characterize belief, disbelief, and uncertainty in a content-independent manner, they included statements from a wide range of categories: autobiographical, mathematical, geographical, religious, ethical, semantic, and factual. They show that belief, disbelief, and uncertainty are mediated primarily by regions in the medial PFC, the anterior insula, the superior parietal lobule, and the caudate. The acceptance and rejection of propositional truth-claims appear to be governed, in part, by the same regions that judge the pleasantness of tastes and odors.

...the final acceptance of a statement as true or its rejection as false appears to rely on more primitive, hedonic processing in the medial prefrontal cortex and the anterior insula. Truth may be beauty, and beauty truth, in more than a metaphorical sense, and false propositions may actually disgust us.
...When compared with both belief and uncertainty, disbelief was associated in our study with bilateral activation of the anterior insula..., a primary region for the sensation of taste. The anterior insula has been regularly linked to pain perception and even to the perception of pain in others. This region, together with left frontal operculum (also active in the contrast disbelief - belief), appears to mediate negatively valenced feelings such as disgust. Studies of olfaction have shown that the left frontal operculum is engaged when subjects are required to make active judgments about the unpleasantness of odors. Thus, regions that have been regularly implicated in the hedonic appraisal of stimuli, often negative, appeared in our study to respond preferentially when subjects rejected written statements as false. Our results appear to make sense of the emotional tone of disbelief, placing it on a continuum with other modes of stimulus appraisal and rejection.
...Several psychological studies appear to support Spinoza’s conjecture that the mere comprehension of a statement entails the tacit acceptance of its being true, whereas disbelief requires a subsequent process of rejection...Understanding a proposition may be analogous to perceiving an object in physical space: We seem to accept appearances as reality until they prove otherwise...subjects assessed true statements as believable faster than they judged them as unbelievable or undecidable. Further, because the brain appears to process false or uncertain statements in regions linked to pain and disgust, especially in judging tastes and odors, this study gives new meaning to a claim passing the “taste test” or the “smell test.”

MindBlog becomes a drop-out student at a brain enhancement site

When the folks at happy-neuron.com offered me a free log in to check out their brain enhancement/preservation exercises I said "Sure, I'll try it out and do a review." The site offers a brief discussion of the science of brain fitness is offered, and the scientific contributors have reasonable credentials. Several have associations with gerontology and aging programs, as is the case with other brain enhancements sites. The single study I was pointed to testing the effects of the happy-neuron exercises was a pilot effort carried out by Robert Bender, a geriatrics and family practice physician in Des Moines, Iowa. He did not respond to my email requesting information on the study.

Well.... to do a proper review one really has to get into it, and I tried, but simply was unable to do this. One could just pick directly from ~ 35 classic style tests (of memory, attention, language, executive function, and visual spatial skills) with a thin video game veneer, or let a "coach" present you with 20 minutes worth of exercises. I chose the "coach" option which chooses exercises for you, monitors your progress, strengths and weaknesses, etc. (It didn't tell me what my strengths and weaknesses were, but perhaps I didn't stick with it long enough for it to get back to me...) The exercises were mildly engaging and indeed left me feeling 'brain tired' after 20 minutes. I did get a bit tired of variations on the towers of Hanoi game (classic form, then basket balls in hoops, then bells in cathedral towers, etc.) I found the 'exit' or 'next' buttons sometimes blanked out or froze the browser window.

I found it difficult to get hooked on the system in a daily basis (I came along before the video game revolution on which my kids were raised). The exercises soon took on an "eat your spinach" aspect. I suspect my motivation might have been greater to pursue them if had been accumulating more striking evidence of my own impending cognitive decline.

I did find it very interesting to pursue the exercises to the point of brain fatigue, which my brain was clearly saying "enough of this, dammit, I'm tired." However, I have not found exercise to the point of fatigue useful or relevant in the daily gym routine to which I am addicted (varying combinations of running, swimming, weights at the Univ. of Wisconsin gym). I feel it would take a similar sort of addiction process to bind me to the routine performance of games like these, and I did not get reinforcement from the "coach" that might have nudged me in that direction ("Hey, you're doing great on executive function and rotating visual images, but your short term memory sucks...")

I may continue to putter with this as well as other brain exercise sites, and if lightning strikes and I get enthusiastic, I'll report back to you.