Politics in Madison, WI

I spend the spring, summer, and fall months in Madison, WI., writing this blog from my university office there, and so have been closely following the theatrical union busting efforts of the new Republican majority.  With all the agonizing over long term debt incurred by the states, I thought this graphic from yesterday's NY Times Magazine, from an article on New Jersey governor Christie, was revealing (click on figure to enlarge): 

Improving your cognitive toolkit - V

Continuation of my abstracting of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":

Daniel Dennett - Look for the Cycles

A good rule of thumb...when confronting the apparent magic of the world of life and mind is: look for the cycles that are doing all the hard work....it turns out that all the "magic" of cognition depends, just as life itself does, on cycles within cycles of recurrent, re-entrant, reflexive information-transformation processes from the biochemical scale within the neuron to the whole brain sleep cycle, waves of cerebral activity and recovery revealed by EEGs. Computer programmers have been exploring the space of possible computations for less than a century, but their harvest of invention and discovery so far includes millions of loops within loops within loops. The secret ingredient of improvement is always the same: practice, practice, practice.

Andy Clark - We are engines of prediction

The basic idea is simple, the brain is basically an engine of prediction. To perceive the world is to successfully predict our own sensory states. The brain uses stored knowledge about the structure of the world and the probabilities of one state or event following another to generate a prediction of what the current state is likely to be, given the previous one and this body of knowledge. Mismatches between the prediction and the received signal generate error signals that nuance the prediction or (in more extreme cases) drive learning and plasticity.

Some Implications:

First, the notion of good ('veridical') sensory contact with the world becomes a matter of applying the right expectations to the incoming signal...Second, the time course of perception becomes critical. Predictive coding models suggest that what emerges first is the general gist (including the general affective feel) of the scene, with the details becoming progressively filled in as the brain uses that larger context — time and task allowing — to generate finer and finer predictions of detail...Third, the line between perception and cognition becomes blurred. What we perceive (or think we perceive) is heavily determined by what we know, and what we know (or think we know) is constantly conditioned on what we perceive (or think we perceive)...Fourth, if we now consider that prediction errors can be suppressed not just by changing predictions but by changing the things predicted, we have a simple and powerful explanation for behavior and the way we manipulate and sample our environment. In this view, action is there to make predictions come true.

A potpuorri of almost-posts

As I scan journals' tables of contents and abstracts of articles looking for potential MindBlog posts, I accumulate a list of post candidates. Most never make it into a post, yet are very interesting chunks. My list now is 30 pages long, and I though I would begin to dispel that list by selecting a few to pass as a list of links, hoping that a few readers might find an item useful to them.

Writing about testing worries boosts exam performance.

Memory formation without the hippocampus.

Temporary suppression of fear memories during adolescence.

Solving the cocktail party problem.

Your Brain on Improv....to be creative, you have to have this weird dissociation in your frontal lobe. One area turns on, and a big area shuts off, so that you're not inhibited, so that you're willing to make mistakes, so that you're not constantly shutting down all of these new generative impulses.

Control your spotlight.

Retracted Autism Study.

Past adversity strengthens.

Courage.

Your brain on technology.

Krugman - The New Voodo.

Oliver Sachs - Change your brain.

How stress damages or enhances different aspects of our vision

Richie Davidson, Alex Schackman and colleagues report a fascinating study that demonstrates that stress (painful, but not harmful, random electric shocks delivered to informed consent study participants) makes us more sensitive to our external surroundings as a way of learning where or what a threat may be, but interferes with our ability to do more complex thinking:

Stress can fundamentally alter neural responses to incoming information. Recent research suggests that stress and anxiety shift the balance of attention away from a task-directed mode, governed by prefrontal cortex, to a sensory-vigilance mode, governed by the amygdala and other threat-sensitive regions. A key untested prediction of this framework is that stress exerts dissociable effects on different stages of information processing. This study exploited the temporal resolution afforded by event-related potentials to disentangle the impact of stress on vigilance, indexed by early perceptual activity, from its impact on task-directed cognition, indexed by later postperceptual activity in humans. Results indicated that threat of shock amplified stress, measured using retrospective ratings and concurrent facial electromyography. Stress also double-dissociated early sensory-specific processing from later task-directed processing of emotionally neutral stimuli: stress amplified N1 (184–236 ms) and attenuated P3 (316–488 ms) activity. This demonstrates that stress can have strikingly different consequences at different processing stages. Consistent with recent suggestions, stress amplified earlier extrastriate activity in a manner consistent with vigilance for threat (N1), but disrupted later activity associated with the evaluation of task-relevant information (P3). These results provide a novel basis for understanding how stress can modulate information processing in everyday life and stress-sensitive disorders.

Uncertainty increases romantic attraction

Another interesting bit of work from Daniel Gilbert and collaborators:

This research qualifies a social psychological truism: that people like others who like them (the reciprocity principle). College women viewed the Facebook profiles of four male students who had previously seen their profiles. They were told that the men (a) liked them a lot, (b) liked them only an average amount, or (c) liked them either a lot or an average amount (uncertain condition). Comparison of the first two conditions yielded results consistent with the reciprocity principle. Participants were more attracted to men who liked them a lot than to men who liked them an average amount. Results for the uncertain condition, however, were consistent with research on the pleasures of uncertainty. Participants in the uncertain condition were most attracted to the men—even more attracted than were participants who were told that the men liked them a lot. Uncertain participants reported thinking about the men the most, and this increased their attraction toward the men.

Strategies for remembering.

Two recent articles offer different perspectives on retaining information. The interesting NYTimes magazine article by world class memory athlete Joshua Foer describes an ancient memory training tradition that flourished in ancient Greece before the invention of printing.  Brain imaging of  memory athletes who have engaged this training (who are of ordinary intelligence in virtually all other respects) shows more activation of brain areas known to be involved in spatial memory during memory tasks. The training derives from discoveries of Simonides of Ceos in the fifth century B.C.,

...who reasoned that just about anything could be imprinted upon our memories, and kept in good order, simply by constructing a building in the imagination and filling it with imagery of what needed to be recalled. This imagined edifice could then be walked through at any time in the future. Such a building would later come to be called a memory palace...a short Latin rhetoric textbook called “Rhetorica ad Herennium,” written sometime between 86 and 82 B.C. It is the only comprehensive discussion of the memory techniques attributed to Simonides to have survived into the Middle Ages. The techniques described in this book were widely practiced in the ancient and medieval worlds. Memory training was considered a centerpiece of classical education in the language arts, on par with grammar, logic and rhetoric...What distinguishes a great mnemonist...is the ability to create lavish images on the fly, to paint in the mind a scene so unlike any other it cannot be forgotten. And to do it quickly. Many competitive mnemonists argue that their skills are less a feat of memory than of creativity.

Both ancient and more recent memory enhancement techniques focus on the processing that occurs when we encode knowledge. A recent fairly simple experiment by Karpicke and Blunt suggests the effectiveness of another strategy that emphasizes practice.  From their introduction:

It is beyond question that activities that promote effective encoding, known as elaborative study tasks, are important for learning. However, research in cognitive science has challenged the assumption that retrieval is neutral and uninfluential in the learning process. Not only does retrieval produce learning, but a retrieval event may actually represent a more powerful learning activity than an encoding event. This research suggests a conceptualization of mind and learning that is different from one in which encoding places knowledge in memory and retrieval simply accesses that stored knowledge. Because each act of retrieval changes memory, the act of reconstructing knowledge must be considered essential to the process of learning.

Their abstract:

Educators rely heavily on learning activities that encourage elaborative studying, whereas activities that require students to practice retrieving and reconstructing knowledge are used less frequently. Here, we show that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping. The advantage of retrieval practice generalized across texts identical to those commonly found in science education. The advantage of retrieval practice was observed with test questions that assessed comprehension and required students to make inferences. The advantage of retrieval practice occurred even when the criterial test involved creating concept maps. Our findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes. Retrieval practice is an effective tool to promote conceptual learning about science.

Improving your cognitive toolkit - IV

Continuation of my abstracting of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":

Charles Seife - Random events in the aggregate behave predictably.

Randomness is daunting; it sets limits where even the most sophisticated theories can not go, shielding elements of nature from even our most determined inquiries. Nevertheless, to say that something is random is not equivalent to saying that we can't understand it. Far from it...Randomness follows its own set of rules — rules that make the behavior of a random process understandable and predictable...These rules state that even though a single random event might be completely unpredictable, a collection of independent random events is extremely predictable — and the larger the number of events, the more predictable they become. The law of large numbers is a mathematical theorem that dictates that repeated, independent random events converge with pinpoint accuracy upon a predictable average behavior. Another powerful mathematical tool, the central limit theorem, tells you exactly how far off that average a given collection of events is likely to be. With these tools, no matter how chaotic, how strange a random behavior might be in the short run, we can turn that behavior into stable, accurate predictions in the long run.

The rules of randomness are so powerful that they have given physics some of its most sacrosanct and immutable laws. Though the atoms in a box full of gas are moving at random, their collective behavior is described by a simple set of deterministic equations. Even the laws of thermodynamics derive their power from the predictability of large numbers of random events; they are indisputable only because the rules of randomness are so absolute...Paradoxically, the unpredictable behavior of random events has given us the predictions that we are most confident in.

Emanuel Derman - Distrust Pragmamorphism

Anthropomorphism means attributing the characteristics of human beings to inanimate things or animals...I have invented the word pragmamorphism as a short-hand extension for the attribution of the properties of inanimate things to human beings...One of the meanings of the Greek word pragma is a material object...It's pragmamorphic to equate material correlates with human psychological states, to equate PET scans with emotion. It's also pragmamorphic to ignore human qualities you cannot measure.

We have discovered useful metrics for material objects -- length, temperature, pressure, volume, kinetic energy, etc. Pragmamorphism is a good word for the attempt to assign such one-dimensional thing-metrics to the mental qualities of humans...IQ, a length scale for intelligence, is a result of pragmamorphism. Intelligence is more diffuse than linear...The utility function in economics is similar. It's clear that people have preferences. But is it clear that there is a function that describes their preferences?

Nicholas Carr - Respect your cognitive load

...our brains can hold only about seven pieces of information simultaneously. Even that figure may be too high. Some brain researchers now believe that working memory has a maximum capacity of just three or four elements...The amount of information entering our consciousness at any instant is referred to as our cognitive load. When our cognitive load exceeds the capacity of our working memory, our intellectual abilities take a hit. Information zips into and out of our mind so quickly that we never gain a good mental grip on it...The information vanishes before we've had an opportunity to transfer it into our long-term memory and weave it into knowledge. We remember less, and our ability to think critically and conceptually weakens. An overloaded working memory also tends to increase our distractedness.

...it's important to remember that, when it comes to the way your brain works, information overload is not just a metaphor; it's a physical state. When you're engaged in a particularly important or complicated intellectual task, or when you simply want to savor an experience or a conversation, it's best to turn the information faucet down to a trickle.

Empire at the End of Decadence

Since MindBlog seems to be doing a political weekend, I'm thinking I should, after yesterday's pointer to George Lakoff, also note the excellent summary by Charles Blow in Friday's NYTimes on the eroding American Empire. Here is the graphic (you should be able to read the small print if you click on the image.)

What conversatives really want.

A great essay from George Lakoff on the real significance of what is going on back in my Madison Wisconsin home.

A Sunday School Hymn - Evolution Made Us All

From The Laughing Squid site, a spoof of a sunday school hymn:


Evolution Made Us All from Ben Hillman on Vimeo.

Suppressing emotions correlates with larger prefrontal cortical area

I'm a "keep calm and carry on" kind of guy, always suppressing my emotional reactivity in charged situations (which is probably why my colleagues said I was a good university department chair back when...). Kühn et al suggest that this might mean that the grey matter (nerve cell) volume of my dorsomedial (top, toward the middle) prefrontal cortex is a bit larger than that of those exploding around me:

There is a growing appreciation that individuals differ systematically in their use of particular emotion regulation strategies. Our aim was to examine the structural correlates of the habitual use of expressive suppression of emotions. Based on our previous research on the voluntary suppression of actions we expected this response-focused emotion regulation strategy to be associated with increased grey matter volume in the dorsomedial prefrontal cortex (dmPFC). On high-resolution MRI scans of 42 college-aged healthy adults we computed optimized voxel-based-morphometry (VBM) to explore the correlation between grey matter volume and inter-individual differences in the tendency to suppress the expression of emotions assessed by means of the Emotion Regulation Questionnaire (Gross & John, 2003). We found a positive correlation between the habitual use of expressive suppression as an emotion regulation strategy and grey matter volume in the dmPFC. No other brain area showed a significant positive or negative correlation with the Emotion Regulation Questionnaire scores. The association between the suppression of expression of emotions and volume in the dmPFC supports the behavioural stability and biological foundation of the concept of this particular emotion regulation strategy within an age-homogenous sample of adults.

Placebo in 3 minutes

This sent by a loyal blog reader, pulled from this Australian site:

Blue-enriched light keeps us alert...

I think I've mentioned before that I used to put natural spectrum florescent lights (with more blue wavelengths) in my research laboratory, because I found it promoted my relaxation and alertness, and my graduate students and post-docs reported the same effect. Chellappa et al. offer yet another study that documents this effect, and relates it to suppression of melatonin levels by blue wavelengths. The observations can be made by simply comparing commercially available compact fluorescent lamps that provide correlated lamp colour temperature in kelvin (K), that indicate the relative proportion of warm versus cool colours in a light source. The authors found that 2-hour exposure to light in the evening with compact fluorescent light at 6500K (blue shifted) will attenuate the expression of endogenous melatonin levels, and also promote an augmentation of subjective and objective alertness levels when compared with lights at 2500K and at 3000K (more yellow). The light with more blue wavelengths has the overall effect of enhancing alertness and performance in cognitive tasks specifically associated with sustained attention.

Skeuomorphs - why innovation is also a throwback

Joshua Brustein writes a nice piece on how innovation usually doffs an old hat, maintaining superfluous marks of its evolution (skeuomorphs - from the Greek words for tool and form) to ease people's comfort with the transition to the new.

Digital cameras produce a reassuringly retro but artificial shutter snap when you push the button to take a photograph; cellphones have keyboards with layouts originally meant to keep typewriters from jamming; and blue jeans have pockets that are a throwback to a time when watches dangled from chains...Designers in all fields are regularly confronted with versions of this choice: whether to incorporate cues to keep people grounded in what has come before, or scrap convention completely. In transportation, for instance, the power of steam engines was initially described in relation to that of horses, a practice that has continued to the present day. Automobile designers have incorporated visual cues suggesting carriages; for example, adding nonfunctional spokes on wheels...This tension is palpable in many efforts to create new digital media experiences. The Daily, Rupert Murdoch’s publication designed specifically for tablet computers, incorporates video and interactivity into what is essentially a newspaper. At the same time, it is designed to show up on a reader’s digital doorstep once a day, a concept that seems as old-fashioned as pocket watches when compared with Web sites that are updated continually...Apple, probably the best symbol of the march into a new digital era, also encourages designers to incorporate analog references in its devices. On the iPad, users enter appointments into a calendar that is encased in an on-screen leather ledger, scrawl notes on what looks like a legal pad and advance through digital books by swiping their fingers across the screen, prompting an animation that actually looks like a page being turned.

Sleep enhances memories relevant to the future.

Here is a fascinating bit of work from Wilhelm et al., which possibly explains why in my first moments of starting to awaken, I notice that finger sequences of piano pieces I am studying to perform are playing in my head....

The brain encodes huge amounts of information, but only a small fraction is stored for a longer time. There is now compelling evidence that the long-term storage of memories preferentially occurs during sleep. However, the factors mediating the selectivity of sleep-associated memory consolidation are poorly understood. Here, we show that the mere expectancy that a memory will be used in a future test determines whether or not sleep significantly benefits consolidation of this memory. Human subjects learned declarative memories (word paired associates) before retention periods of sleep or wakefulness. Postlearning sleep compared with wakefulness produced a strong improvement at delayed retrieval only if the subjects had been informed about the retrieval test after the learning period. If they had not been informed, retrieval after retention sleep did not differ from that after the wake retention interval. Retention during the wake intervals was not affected by retrieval expectancy. Retrieval expectancy also enhanced sleep-associated consolidation of visuospatial (two-dimensional object location task) and procedural motor memories (finger sequence tapping). Subjects expecting the retrieval displayed a robust increase in slow oscillation activity and sleep spindle count during postlearning slow-wave sleep (SWS). Sleep-associated consolidation of declarative memory was strongly correlated to slow oscillation activity and spindle count, but only if the subjects expected the retrieval test. In conclusion, our work shows that sleep preferentially benefits consolidation of memories that are relevant for future behavior, presumably through a SWS-dependent reprocessing of these memories.

Foundations of religious belief

Judith Shulevitz reviews James Kugel's "In the Valley of the Shadow - on the Foundations of Religious Belief." The book rose from the author's experience of still being alive seven years after being told he would die of cancer within a few years. His points on the utility of religious belief (even it if is a cognitive error) remind me of last Friday's MindBlog post on the utility of the size-weight illusion in throwing. Here are a few clips from the review:

...the recent debates about religion — is it a force for good or for evil, intrinsically violent or intrinsically peaceful? — have on the whole been a bit “narrow.” Too many pundits, anthropologists and evolutionary biologists fail to imagine their way into the rich, elusive mental condition called “believing in God” or “being religious.” They dismiss it as a neurosis, a superstition or a mistake. An otherwise appealing evolutionary theory of religion, for instance, holds that God and the gods are ghostlike entities created by a “hyperactive agent detection device” in the brain — that is, a hair-trigger response to unusual stimuli that evolved to protect us from danger, but wound up making us mistakenly attribute intention and even divinity to things that have none.

Kugel asks whether it’s the skeptics who are being willfully blind to the ancient truths bundled into these apparent errors. Consider the band of prehistoric hunter-gatherers made aware of their fragility by the magnitude of what they were up against. “This little group was endlessly overshadowed by all that was outside of them, forever on the receiving end of whatever You — immanent in the great Outside all around — happened to be dishing out,” he reminds us. To call their brains “hyperactive” because they identify that “You” as a mindful agent, Kugel says, is “ludicrous.” The “great Outside” was nearly all-powerful: why shouldn’t it mean to make things happen? “On the contrary,” Kugel writes, “it would require some sort of extraordinarily twisted spirit to look up and not see You, Your hand gloved in cloud and sky, Your voice mingling with cricket song and crashing waves, doing all the things that impinged on the little band’s existence. You were practically everything, and You completely overwhelmed their own little reality.”

Believing in God, Kugel suggests — possibly being a tad ahistorical — originally meant aligning yourself with the force of the universe, of humbly opening yourself up to its grandeur, more than it meant asserting faith in a particular deity. Kugel reviews the literature on epilepsy and the “God spot,” the “verbal conceptual association area” where various lobes of the brain come together. When stimulated, as in epileptic seizures, it has been shown to lead to visions of God or at least a sense of what one researcher called “connection with an overwhelmingly powerful being.” You could say the God spot proves that religion is a matter of brain malfunction, Kugel observes. Or you could call the epileptic’s aura “a privileged moment, an opening of the mind to something it cannot normally perceive.”

To the religious — or at least to Kugel and his sources — religion is an experience more than a cosmology. “It is not God’s sovereignty over the entire universe that is at issue so much as his sovereignty over the cubic centimeter of space that sits just in front of our own noses,” he writes. “That is to say, religion is first of all about fitting into the world and fitting into one’s borders. There may indeed be something ‘mythic’ about it, but it pales before the mythic quality of our own clumsy, modern selves.”

Improving your cognitive toolkit - part III

CContinuation of my abstracting of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":

Sean Carroll - The Pointless Universe

Things happen because the laws of nature say they will — because they are the consequences of the state of the universe and the path of its evolution. Life on Earth doesn't arise in fulfillment of a grand scheme, but rather as a byproduct of the increase of entropy in an environment very far from equilibrium. Our impressive brains don't develop because life is guided toward greater levels of complexity and intelligence, but from the mechanical interactions between genes, organisms, and their surroundings.

None of which is to say that life is devoid of purpose and meaning. Only that these are things we create, not things we discover out there in the fundamental architecture of the world. The world keeps happening, in accordance with its rules; it's up to us to make sense of it and give it value.

Rudy Rucker - The World is Unpredictable

The media cast about for the proximate causes of life's windfalls and disasters. The public demands blocks against the bad and pipelines to the good. Legislators propose new regulations, fruitlessly dousing last year's fires, forever betting on yesterday's winning horses...A little-known truth: Every aspect of the world is fundamentally unpredictable. Computer scientists have long since proved this.

At a personal level, even if the world is as deterministic as a computer program, you still can't predict what you're going to do. This is because your prediction method would involve a mental simulation of you that produces its results slower than you. You can't think faster than you think. You can't stand on your own shoulders...It's a waste to chase the pipedream of a magical tiny theory that allows us to make quick and detailed calculations about the future. We can't predict and we can't control. To accept this can be a source of liberation and inner peace. We're part of the unfolding world, surfing the chaotic waves.

Anniversary of Deric's MindBlog

I just realized that Feb. 6 marked the start of year 6 of this blog. We've now clocked ~2,500 Posts, and there are roughly 2,000 subscribers (The green line in the FeedBurner summary plot) to the blog's RSS feed.

Last year's birthday notice indulged in a writing identity crisis which I will spare you from this year.

The Net Delusion

I've been meaning to point to Lee Siegel's review of Evgeny Morozov's new book "The Net Delusion - The Dark Side of Internet Freedom." A few clips:

Contrary to the “cyberutopians,” as he calls them, who consider the Internet a powerful tool of political emancipation, Morozov convincingly argues that, in freedom’s name, the Internet more often than not constricts or even abolishes freedom...He quotes the political blogger Andrew Sullivan, who proclaimed after protesters took to the streets in Tehran that “the revolution will be Twittered.” The revolution never happened, and the futilely tweeting protesters were broken with an iron hand... What was broadcast on Twitter and elsewhere was repression of the revolution. The Iranian regime used the Web to identify photographs of protesters; to find out their personal information and whereabouts (through Facebook, naturally); to distribute propagandistic videos; and to text the population into counterrevolutionary paranoia.

As Morozov points out, don’t expect corporations like Google to liberate anyone anytime soon. Google did business in China for four years before economic conditions and censorship demands — not human rights concerns — forced it out. And it is telling that both Twitter and Facebook have refused to join the Global Network Initiative, a pact that Morozov describes as “an industrywide pledge . . . to behave in accordance with the laws and standards covering the right to freedom of expression and privacy embedded in internationally recognized documents like the Universal Declaration of Human Rights.”

Morozov urges the cyberutopians to open their eyes to the fact that the ­asocial pursuit of profit is what drives social media. “Not surprisingly,” he writes, “the dangerous fascination with solving previously intractable social problems with the help of technology allows vested interests to disguise what essentially amounts to advertising for their commercial products in the language of freedom and liberation.” In 2007, when he was at the State Department, Jared Cohen wrote with tragic wrongheadedness that “the Internet is a place where Iranian youth can . . . say anything they want as they operate free from the grips of the police-state apparatus.” Thanks to the exciting new technology, many of those freely texting Iranian youths are in prison or dead. Cohen himself now works for Google as the director of “Google Ideas.”

The size weight illusion is not an illusion for throwing.

Zhu and Bingham offer an interesting bit of work that suggests that human throwing and speaking abilities developed in a manner that is consistent with their evolutionary history (Accurate long distance throwing ability is unique to humans):

Long-distance throwing is uniquely human and enabled Homo sapiens to survive and even thrive during the ice ages. The precise motoric timing required relates throwing and speech abilities as dependent on the same uniquely human brain structures. Evidence from studies of brain evolution is consistent with this understanding of the evolution and success of H. sapiens. Recent theories of language development find readiness to develop language capabilities in perceptual biases that help generate ability to detect relevant higher order acoustic units that underlie speech. Might human throwing capabilities exhibit similar forms of readiness? Recently, human perception of optimal objects for long-distance throwing was found to exhibit a size–weight relation similar to the size–weight illusion; greater weights were picked for larger objects and were thrown the farthest. The size–weight illusion is: lift two objects of equal mass but different size, the larger is misperceived to be less heavy than the smaller. The illusion is reliable and robust. It persists when people know the masses are equal and handle objects properly. Children less than 2 years of age exhibit it. These findings suggest the illusion is intrinsic to humans. Here we show that perception of heaviness (including the illusion) and perception of optimal objects for throwing are equivalent. Thus, the illusion is functional, not a misperception: optimal objects for throwing are picked as having a particular heaviness. The best heaviness is learned while acquiring throwing skill. We suggest that the illusion is a perceptual bias that reflects readiness to acquire fully functional throwing ability. This unites human throwing and speaking abilities in development in a manner that is consistent with the evolutionary history.