tag:blogger.com,1999:blog-88841431211536268062012-01-28T10:12:34.915-08:00unconditionally devoted to understanding the biological basis of the mindLizzienoreply@blogger.comBlogger421100tag:blogger.com,1999:blog-8884143121153626806.post-77412965757126661022007-08-01T12:40:00.001-07:002008-05-12T15:12:39.300-07:00

The first Alzheimer’s diseased brain I ever touched looked horrific. The cortex was shriveled, the ventricles were large, cavernous voids, and when I stained the sample I saw a galaxy of proteinaceous tangles and masses. The brain had clearly been degenerating steadily for over a decade, and it was difficult to imagine how the patient could have functioned. I was shocked to discover that,

Lizzienoreply@blogger.com346tag:blogger.com,1999:blog-8884143121153626806.post-65597321824884561052007-07-17T11:11:00.001-07:002008-05-12T15:16:27.986-07:00

My life, though generally fortunate, has been peppered by a small number of somewhat serious injuries: broken hand, broken collarbone, broken wrist, torn meniscus, ruptured anterior cruciate ligament (ACL). The hand and collarbone were consequences of my big sister tripping and crushing me, respectively, but the rest I managed to accrue on my own. (Even though I sustained these latter injuries

Lizzienoreply@blogger.com183tag:blogger.com,1999:blog-8884143121153626806.post-7379144269614225252007-07-16T12:31:00.000-07:002007-07-17T11:46:15.025-07:00

Images like the one above are familiar to any of us who have ever used webmail, Ticketmaster, or any other web service that wants to prevent automated spammers and scalpers from exploiting their systems. The distorted, fuzzy letters don't provide a challenge to humans, but are indecipherable to the most sophisticated computer algorithms. Our genius is facilitated by our "invariant" perceptual

Lizzienoreply@blogger.com165tag:blogger.com,1999:blog-8884143121153626806.post-21691723537644968352007-07-13T10:17:00.001-07:002007-07-16T14:43:42.505-07:00

In my first post ever, I discussed how specialized circuits in the spinal cord (called "central pattern generators," or CPGs) coordinate the intricate motions and muscle patterns involved in running and walking, without significant input from the brain. The autonomy of these circuits allows animals to run and walk while their mental efforts are otherwise engaged; for example, we can talk on the

Lizzienoreply@blogger.com154tag:blogger.com,1999:blog-8884143121153626806.post-27560467735719778532007-07-10T11:13:00.000-07:002007-07-16T14:44:57.262-07:00

As a young brown-eyed, brown-haired girl growing up in Orange County, CA, I found this "stereotype" repeatedly, bewilderingly, validated. Although I defended myself with Van Morrison and a sizeable artillery of blonde-jokes, behind my façade of self-assurance I continued to wonder: why are blonde hair and blue eyes "prettier"? Now, as a slightly more mature brunette with a more comprehensive

Lizzienoreply@blogger.com261tag:blogger.com,1999:blog-8884143121153626806.post-3210709685551385542007-07-09T20:48:00.000-07:002007-07-13T15:00:58.763-07:00

There's a great article by David Dobbs in the New York Times Magazine about Williams Syndrome (WMS), a condition with a diverse and remarkable array of cognitive symptoms. I have vivid memories of my first exposure to WMS--watching a documentary hosted by Oliver Sacks for my "Psychology of Music" class. In one of the first scenes, Dr. Sacks introduces himself to a 6-year old girl with WMS, who

Lizzienoreply@blogger.com30tag:blogger.com,1999:blog-8884143121153626806.post-41051926727233475022007-07-05T12:16:00.001-07:002007-07-05T14:15:00.349-07:00

From The Globe and Mail: Babies aren't as innocent as they look, according to new research out of the United Kingdom.Sweet little infants actually learn to deceive before they can talk, says University of Portsmouth psychology department head Vasudevi Reddy in a study that challenges traditional notions of innocence while

Lizzienoreply@blogger.com31tag:blogger.com,1999:blog-8884143121153626806.post-63777275148336350152007-07-04T16:01:00.001-07:002007-07-05T11:58:48.315-07:00

Animal communication is wonderfully diverse, ranging from the dance of a bee, to written language, to a dog urinating on a tree. For many (all?) animal species, the majority of animal communication is strategically targeted with one goal in mind: sex. Most species lack our oratory competence, yet seem to be procreating rather successfully, able to wordlessly identify and attract mates with

Lizzienoreply@blogger.com14tag:blogger.com,1999:blog-8884143121153626806.post-51547909315061123072007-06-28T15:24:00.000-07:002007-07-05T21:10:25.132-07:00

Well, no, but according to a recent news article in Science, the addition of meat and cooked foods to the Homo erectus diet may have led to the dramatic expansion of our ancestors' brains and cognitive abilities.Between 1.9 million and 200,000 years ago, the brains of our ancestors tripled in size (from 500 cc in Australopithecus to about 1500 cc in Neanderthals), a feat that required a massive

Lizzienoreply@blogger.com13tag:blogger.com,1999:blog-8884143121153626806.post-72782808663847495842007-06-27T01:45:00.000-07:002007-07-13T15:03:38.086-07:00

As women advance in age, pregnancy and childbirth become increasingly dangerous and destructive. Perhaps to protect us, we women have evolved to be infertile later in life: our ovaries stop producing estrogen, causing our reproductive systems to gradually cease operations. Thus rendered barren, we can devote our maternal resources to mentoring and supporting our children and grandchildren. The

Lizzienoreply@blogger.com17tag:blogger.com,1999:blog-8884143121153626806.post-726432052237252862007-06-23T01:44:00.001-07:002007-06-25T00:23:56.914-07:00

Scientific American, the oldest continuously published magazine in the United States, is unveiling a new, "appealingly bright, colorful design" and giving away the July issue for free (until June 30). Among the highlights of this issue: neuronal codes and memory formation, gravitational waves, and a debate between Richard Dawkins and Lawrence Krauss on the coexistence of faith and

Lizzienoreply@blogger.com13tag:blogger.com,1999:blog-8884143121153626806.post-41516566554753029852007-06-23T00:04:00.000-07:002007-06-25T16:12:13.811-07:00

A new study in Science reports that the eldest children in families tend to have slightly higher IQs than their younger siblings. The report (brought to my attention by, not surprisingly, my older sister) concluded that the small but significant difference (2.3 IQ points) was not a result of biology, but rather social upbringing.From The New York Times:Norwegian epidemiologists analyzed data on

Lizzienoreply@blogger.com26tag:blogger.com,1999:blog-8884143121153626806.post-83268058892705756672007-06-20T14:01:00.000-07:002007-06-21T16:11:06.664-07:00

The world offers an awesome, indescribably magnificent profusion of sensory riches. For our meager mortal brains, however, trying to process this deluge of information is akin to taking a drink from Iguaçu Falls: it's tremendously inefficient, and you will likely be violently ripped from your precipice and vanish in a ferocious torrent of natural wonder.Because the world is too rich for our

Lizzienoreply@blogger.com11tag:blogger.com,1999:blog-8884143121153626806.post-27223620658923569122007-06-14T16:57:00.001-07:002007-06-14T17:31:31.786-07:00

If you're looking to mix some education into your procrastination, the Society for Neuroscience website has a series of free online newsletters "explaining how basic neuroscience discoveries lead to clinical applications." The articles are brief and quite accessible, and include a wide variety of interesting topics, like narcolepsy, phobias, memory enhancers, pheromones, and artificial vision.

Lizzienoreply@blogger.com19tag:blogger.com,1999:blog-8884143121153626806.post-76924658937860115132007-06-08T00:53:00.000-07:002007-06-08T12:14:20.683-07:00

Imagine being home on a moonless night when the power unexpectedly goes out. You are shrouded by silent darkness, instantly blind to your surroundings. Yet despite this sensory deprivation, you can navigate somewhat effortlessly around the futon, through the doorway of the kitchen, and across to the middle drawer where your lighter is stored, avoiding walls, furniture, and other familiar

Lizzienoreply@blogger.com10tag:blogger.com,1999:blog-8884143121153626806.post-61493981133651967202007-06-07T02:52:00.000-07:002007-06-07T12:22:16.543-07:00

Humans are constantly making decisions with uncertain outcomes—betting on a poker hand, predicting the weather, and selecting a lane of traffic, for example. Because the consequences of such decisions are not guaranteed, we must base our decisions on clues from the environment, determining the probabilities of potential outcomes before deciding on a rational course of action.How does the brain

Lizzienoreply@blogger.com28tag:blogger.com,1999:blog-8884143121153626806.post-40918159543318156632007-06-01T19:13:00.001-07:002007-06-01T19:39:26.134-07:00

I've posted on memory a few different times, but thus far I've shied away from going into great molecular detail; in fact, I've pretty much avoided molecular and cellular neuroscience altogether on this "blog." This sidestepping results, to be honest, from laziness; it is easier to make gambling and ventriloquism widely appealing than it is to spice up intracellular mechanisms like gene

Lizzienoreply@blogger.com14tag:blogger.com,1999:blog-8884143121153626806.post-46924953286167330742007-06-01T18:31:00.000-07:002007-06-01T19:24:09.461-07:00

This is Part II of a two-part series; click here for Part I.Now for some neurobiological background on memory, on the biological changes that occur at synapses when "internal representations" are modified. A key experimental paradigm to understand is called long term potentiation (LTP), which is thought to simulate what happens in the brain during learning. Basically, experimenters take a slice

Lizzienoreply@blogger.com6tag:blogger.com,1999:blog-8884143121153626806.post-15991769916580683902007-05-25T22:49:00.000-07:002007-05-26T10:05:50.868-07:00

In 1954, RCA released the first color television set, transforming shades of gray into rich, dazzling hues at dinner tables around the country. Imagine experiencing that tantalizing technicolor transformation when you hear a piece of music, or look at everyday objects like numbers, letters, and days of the week? There is a rare condition in which people do experience the world in this

Lizzienoreply@blogger.com61tag:blogger.com,1999:blog-8884143121153626806.post-4966717896619938092007-05-23T17:19:00.002-07:002007-05-23T18:07:19.294-07:00

I recently posted on neuroeconomics, which attempts to understand the neural basis for human decision-making. One of the primary motivations of the field is understanding the irrationality of our decisions; i.e. why they are often contrary to the logical choices that would maximize one's personal outcome. Mind Hacks has a post on a recent Scientific American article that discusses "how [some

Lizzienoreply@blogger.com13tag:blogger.com,1999:blog-8884143121153626806.post-74634845465838480012007-05-23T11:40:00.000-07:002007-05-23T12:13:57.365-07:00

From the San Francisco Chronicle:A female hammerhead shark was mysteriously born at Omaha's Henry Doorly Zoo in December 2001, in a tank that held three adult, female hammerheads but no males. Although the three females had been caught before they reached sexual maturity and held in captivity for more than three years, researchers initially thought one of them had stored sperm from a male

Lizzienoreply@blogger.com21tag:blogger.com,1999:blog-8884143121153626806.post-22514653079219884102007-05-21T14:17:00.001-07:002007-05-23T22:49:51.352-07:00

The biology of brain plasticity, including adult neurogenesis, synaptic plasticity, axon regrowth, and synaptic reorganization, is currently one of the most intensively studied areas of neuroscience. One of the burgeoning avenues of research for this field explores how altered plasticity may account for some of the behavioral and neural changes afflicting the aging brain, and is leading to

Lizzienoreply@blogger.com20tag:blogger.com,1999:blog-8884143121153626806.post-66141689678132435102007-05-21T13:09:00.001-07:002007-05-21T13:09:53.605-07:00

Aloha and welcome to the 23rd installment of Encephalon, a blog carnival devoted to the study of the nervous system and the understanding of thought, emotion, and behavior. I received a lovely diversity of posts, and I've made a mildly successful attempt at categorizing them to help guide you in your explorations. Enjoy!Approaches to understanding the mindChris at Developing Intelligence has an

Lizzienoreply@blogger.com122tag:blogger.com,1999:blog-8884143121153626806.post-76790414578645780772007-05-18T15:13:00.000-07:002007-05-19T12:28:52.155-07:00

As we grow older, we experience a number of cognitive changes, such as poorer working memory, declining ability to encode new memories, and slower processing speeds. By contrast, a number of critical abilities (short-term memory, autobiographical memory, semantic knowledge) remain stable. One of the major avenues of research for the cognitive neuroscience of aging explores how these behavioral

Lizzienoreply@blogger.com18tag:blogger.com,1999:blog-8884143121153626806.post-77092991213028807332007-05-17T00:52:00.000-07:002007-05-22T02:17:28.025-07:00

Over the centuries since Adam Smith, economists have developed mathematical frameworks for maximizing economic success. However, despite the intellectual power of these theories and the often simple logic involved in their calculations, humans continue to amass credit card debt, default on loans, fail to save for retirement, and on the whole refuse to do what these rational, reward-maximizing

Lizzienoreply@blogger.comtag:blogger.com,1999:blog-8884143121153626806.post-19335813593990090112007-05-15T19:00:00.000-07:002007-05-15T19:02:06.604-07:00

Aloha!The 23rd biweekly installment of Encephalon, a blog carnival devoted to neuroscience, will be hosted here on Monday, May 21, which also marks the birthdays of Alexander Pope, Henri Rousseau, Laurence Tureaud (Mr. T), Jeffrey Dahmer, and Christopher George Latore Wallace (The Notorious B.I.G.), and the wedding anniversary of Humphrey Bogart and Lauren Bacall. To join these legendary

Lizzienoreply@blogger.com9tag:blogger.com,1999:blog-8884143121153626806.post-26704338433856799222007-05-15T09:17:00.000-07:002007-05-15T09:39:58.847-07:00

From Mind Hacks:The Technology, Entertainment, Design conference has strayed from its original focus and now hosts a wide-ranging set of talks, including a number on 'How the Mind Works', all of which are available online as streamed video....Helen Fisher talks about the psychology and biology of love, Daniel Gilbert talks about happiness and why we are so bad at understanding it, Ray Kurzweil

Lizzienoreply@blogger.com6tag:blogger.com,1999:blog-8884143121153626806.post-52732525379774258352007-05-13T14:46:00.000-07:002007-05-13T19:49:49.615-07:00

Neurogenesis--the birth and integration of neurons--occurs in the adult brains of all mammals, including humans. I've posted on the phenomenon of adult neurogenesis here and here, and it happens to the focus of my thesis in grad school. One of the major issues in the field is how the generation of new neurons translates into a functional change in the brain. Birth is the first of a number of

Lizzienoreply@blogger.com12tag:blogger.com,1999:blog-8884143121153626806.post-50583439145744909802007-05-04T12:44:00.000-07:002007-05-05T16:27:19.343-07:00

The first animals to evolve on Earth did not have nervous systems. They spent their days and nights sitting on the sea floor, passively filtering water for food particles, a lifestyle that continues in their extant descendants: the sponges. Their lifestyle does not require movement or the ability to sense and respond to the environment, making a nervous system a useless ornamentation.Clearly,

Lizzienoreply@blogger.com54tag:blogger.com,1999:blog-8884143121153626806.post-81780846414744780442007-04-17T03:22:00.000-07:002007-05-22T02:15:24.843-07:00

As a pledge-signing member of my elementary school's rigorous D.A.R.E. program, I was regularly exposed to horrific photographs of blackened lungs and deteriorating hearts, and was utterly convinced that cigarettes ravaged and destroyed everything they touched. Thus when my dad started smoking when I was about 5, I (with my mom's encouragement) flushed pack after pack down the toilet until he

Lizzienoreply@blogger.com102tag:blogger.com,1999:blog-8884143121153626806.post-13899227154105873072007-04-12T16:01:00.000-07:002007-04-13T11:17:00.714-07:00

The wonderfully diverse repertoire of animal behaviors is, to a great extent, motivated by a universal desire: to acquire or avoid a particular outcome. Such "goal-directed" behavior is contingent upon learning associations between our actions and the predicted consequences, and, as the name implies, using these associations to direct our behavior. For example, many people drink alcohol because

Lizzienoreply@blogger.com4tag:blogger.com,1999:blog-8884143121153626806.post-9266703940271119062007-04-07T00:42:00.001-07:002007-04-07T11:14:09.292-07:00

For some background on vision, particularly color vision, read my previous post.Millions of years ago, before the dinosaurs roamed, the remote ancestors of mammals probably had magnificent color vision. When the dinosaurs came to ecological power, these ancestors (mammal-like reptiles), were banished from the daylight hours and became creatures of the night. During this period, their visual

Lizzienoreply@blogger.com26tag:blogger.com,1999:blog-8884143121153626806.post-59966796385686616932007-04-06T19:23:00.001-07:002007-04-08T10:27:13.833-07:00

My trichromatic mouse post was way too long, so I decided to take all the background information on the visual system, which some of you may not need, and put it in a different post, thus breaking it into more digestible bits. This intro focuses on topics relevant to the article (photoreceptors and the initial processing stages of color vision), so although I would love to discuss physical

Lizzienoreply@blogger.com11tag:blogger.com,1999:blog-8884143121153626806.post-58721487549039223462007-03-14T16:39:00.000-07:002007-05-22T02:20:27.165-07:00

Imagine a game of dodgeball, in which your attention is consumed by whizzing balls and the warlike cries of aggressive athletes, all reverberating off the gymnasium walls. Suddenly, you hear someone on the opposing side yell to his teammates that his next shot will be aimed at you. At that instant, you look over at his side of the court and see three hostile-looking boys holding dodgeballs,

Lizzienoreply@blogger.com41tag:blogger.com,1999:blog-8884143121153626806.post-49614717649864875302007-03-09T19:23:00.000-08:002007-05-22T02:19:51.084-07:00

The invasion of the land by animals was an astonishing evolutionary feat, necessitating a number of substantial changes to the body: limbs with digits, structures for obtaining oxygen from the air, a relatively waterproof covering to prevent dehydration, and sturdy structures to support the body in a medium much less buoyant than water, to name a few. When these pilgrims first bridged the

Lizzienoreply@blogger.com32tag:blogger.com,1999:blog-8884143121153626806.post-22344134996757785652007-03-07T22:26:00.000-08:002007-03-08T10:23:12.242-08:00

I remember when my body was so chemically-inexperienced that half a cup of coffee would transform me into a screaming ball of energy, bouncing indefatigably off the walls. Age, college finals, and early morning soccer games have dramatically altered my requirements for sufficient stimulation, but luckily, the beverage and drug industries seem to have co-evolved to meet my ever-increasing

Lizzienoreply@blogger.com47tag:blogger.com,1999:blog-8884143121153626806.post-56926080517307031432007-03-06T14:49:00.001-08:002007-03-06T14:54:11.525-08:00

This post is devoted to my favorite invertebrate, Apis mellifera, the Western honeybee. The honeybee genome is the most recent genome to be fully sequenced (published October of 2006), and I have heard many demean this development as pointless and superfluous. I feel otherwise; as eusocial insects, these little critters lead fascinating lives, which may help us understand the evolution of

Lizzienoreply@blogger.com34tag:blogger.com,1999:blog-8884143121153626806.post-11630478361752438262007-03-06T01:59:00.000-08:002007-03-06T09:26:12.831-08:00

The adult brain has long been seen as a stable circuit, often compared with computer hardware in that the components (neurons) are connected in an elaborate architecture that is not amenable to structural change. It was thought that learning occurred by altering the way the neurons communicated with each other, without any need to modify the composition of the system. As I discussed in an

Lizzienoreply@blogger.com31tag:blogger.com,1999:blog-8884143121153626806.post-83841782403910641402007-02-25T15:59:00.000-08:002007-02-28T17:05:36.654-08:00

The animal kingdom is full of noisy beasts. Screeching monkeys, barking dogs, squawking chickens…animals use sounds to communicate with each other, both friends and foes. These sounds are instinctual, and although the animals may learn, through observation, when a particular sound is appropriate, the quality of the sounds is not learned; the vocalizations are acoustically innate. What about

Lizzienoreply@blogger.com13tag:blogger.com,1999:blog-8884143121153626806.post-44016035094948198262007-02-23T10:53:00.000-08:002007-05-22T02:17:45.841-07:00

Imagine a coin toss in which you could win $50 for heads, but would lose $50 for tails. Would you take that bet?What about winning $1,000,000 for heads, or losing $50 for tails?Winning $75 or losing $50?Most of us would not accept the first bet, but would certainly accept the second. The third option is a bit more ambiguous. Even though the potential gain is 50% greater than the potential loss,

Lizzienoreply@blogger.com34tag:blogger.com,1999:blog-8884143121153626806.post-17927716568602741782007-02-16T13:38:00.000-08:002007-03-08T12:50:07.575-08:00

When I was a child, my mother told me never to head the ball during a soccer game. She believed the impact would kill brain cells, thus leading to an irreversible drop in my neuron count because the brain is incapable of forming new neurons after birth. Luckily, she was wrong. Like my overprotective mother, many people are under the impression that we are born with all of the neurons we will

Lizzienoreply@blogger.com12tag:blogger.com,1999:blog-8884143121153626806.post-65601064136693618682007-02-07T19:25:00.000-08:002007-07-13T10:25:04.142-07:00

When's the last time you walked? Most of us, excepting those with disabilities, probably walked relatively recently. Walking is a routine behavior that's very routine, learned at an early age and performed without much mental effort. So a more difficult question: when's the last time you thought about what our bodies do when we walk? If you take the time to consider the behavior, walking is a

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