‘Blind to change’ or just ‘mostly blind’?

The New York Times Science section has a recent article, Blind to Change, Even as It Stares Us in the Face, by Natalie Angier (you can access it without charge by signing up to their site). The article follows along some of the lines laid out by Jeremy Wolfe of Harvard Medical School, at a symposium on Art and Neuroscience.

Angier discusses Wolfe’s use of Ellsworth Kelly’s ‘Study for Colors for a Large Wall’ to illustrate what is typically called ‘change blindness’: ‘the frequent inability of our visual system to detect alterations to something staring us straight in the face.’ Kelly’s painting is an 8×8 grid of coloured squares, and Wolfe apparently showed repeatedly slides of the picture, sometimes with the colours of squares altered. When he first showed the slide, Angier writes: ‘We drank it in greedily, we scanned every part of it, we loved it, we owned it, and, whoops, time for a test.’ After the test, when the audience was thoroughly uncertain about its ability to recall even the basic patterns of colours; ‘By the end of the series only one thing was clear: We had gazed on Ellsworth Kelly’s masterpiece, but we hadn’t really seen it at all,’ Angier reports.

Change blindness is a fun phenomenon to put into research design. Researchers get away with some really amazing manipulations without their subjects recognizing them. Some experiments report that subjects fail to notice, as Angier details, whole stories of buildings disappearing or that ‘one poor chicken in a field of dancing cartoon hens had suddenly exploded.’

Dr. Wolfe also recalled a series of experiments in which pedestrians giving directions to a Cornell researcher posing as a lost tourist didn’t notice when, midway through the exchange, the sham tourist was replaced by another person altogether.

I’ve also seen discussions of experiments in which subjects watched a videotape and failed to notice a guy in a gorilla suit walking through the middle of the video because they were asked to pay attention to other details.

But is it that we’re blind to change, or that we just trust the world to remember for us, and we’re really good at getting the information we need?
Continue reading “‘Blind to change’ or just ‘mostly blind’?”

Smell, fear and sensory learning

Blogging on Peer-Reviewed ResearchWen Li, James D. Howard, Todd B. Parrish, and Jay A. Gottfried have a fascinating article in the most recent edition of Science, ‘Aversive Learning Enhances Perceptual and Cortical Discrimination of Indiscriminable Odor Cues.’ The researchers trained subjects to discern between the aroma of chemicals that initially were indistinguishable using electric shocks (!) coupled with one of the two aromas. The research is a great example of perceptual learning, a form of neural enculturation that I think is absolutely essential to understanding cultural difference but little appreciated in anthropology.

Subjects in the experiment were given a test of their ability to discern between very closely related chemicals: ‘On each trial, subjects smelled sets of three bottles (two containing one odorant, the third containing its chiral opposite) and selected the odd stimulus.’ Before the training, subjects selected the odd odor out 33% of the time — no better than random. After the repeated association of one chemical with shocks, subjects’ ability to discriminate the smells improved markedly, showing that negative reinforcement training could ‘enhance perceptual discriminability between initially indistinguishable odors.’ Moreover, the neural representation of the smells changed, as found with fMRI.

From their abstract:

We combined multivariate functional magnetic resonance imaging with olfactory psychophysics to show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after aversive conditioning, paralleling the spatial divergence of ensemble activity patterns in primary olfactory (piriform) cortex. Our findings indicate that aversive learning induces piriform plasticity with corresponding gains in odor enantiomer discrimination, underscoring the capacity of fear conditioning to update perceptual representation of predictive cues, over and above its well-recognized role in the acquisition of conditioned responses. That completely indiscriminable sensations can be transformed into discriminable percepts further accentuates the potency of associative learning to enhance sensory cue perception and support adaptive behavior.

Continue reading “Smell, fear and sensory learning”

Wednesday Round Up #4


Dr. Ginger Campell and her Brain Science Store
Ginger provides a handy Amazon collection of the books covered in her podcasts

Greg Mortensen and David Oliver Relin, Three Cups of Tea: One Man’s Mission to Promote Peace… One School at a Time
Building schools amid the Taliban, Americans and more…  Recently covered in the Diane Rehm show.  800+ reviews on Amazon, averaging in at the max 5 stars

Brian Fagan, The Great Warming: Climate Change and the Rise and Fall of Civilizations
Drought is our great historical enemy, especially in dense populations… Recently reviewed in the NY Times

Sandra Blakeslee & Matthew Blakeslee, The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better
One reviewer: “The brain and the body are not separate entities, but are intertwined, interdependent, and interfunctional. Understanding this fact is essential to understanding how and why body maps work. This book explains that lucidly.”

Stephen Kern, A Cultural History of Causality: Science, Murder Novels, and Systems of Thought
Literary murder and social history—how we view the causes of ourselves

Melody Petersen, Our Daily Meds: How the Pharmaceutical Companies Transformed Themselves into Slick Marketing Machines and Hooked the Nation on Prescription Drugs
Pharmaceuticals killing people, and companies marketing them more.  See an illuminating review here


Cognitive Daily, Fun With Point-Light Displays—And What That Says About The Visual System
Creating order out of dots… includes some good QuickTime videos

Mixing Memory, Language, Neuroscientific Evidence for the Influence of Language on Color Perception
Critique of imaging, importance of evidence, and our visual system


Cordelia Fine, Will Working Mothers’ Brains Explode? The Popular New Genre of Neurosexism
Critique of the at times popular view that gender differences are “hard wired”

Brandon Keim, Brain Scanner Can Tell You What You’re Looking At
Functional imaging and a good computational program can “decode” the different photographs people see, reconstructing the content.   Worth a look!

Continue reading “Wednesday Round Up #4”

Wednesday Round Up #3


The New York Times, How Race Is Lived In America
Series of articles focused on how race relations are defined by “daily experience, in schools, in sports arenas, in pop culture and at worship, and especially in the workplace”

American Anthropological Association, RACE: Are We So Different?
“Looking through the eyes of history, science and lived experience, the RACE Project explains differences among people and reveals the reality – and unreality – of race.”

The New York African Burial Ground
“Return to the past to build the future”

Also check out the lead researcher’s report, “An Examination of Enslaved Lives, A Construction of Ancestral Ties

Jennifer Eberhardt, Imaging Race (pdf)
American Psychologist article on brain imaging and the “social psychological responses associated with race”

Barack Obama’s Speech on Race
Full transcript here; Video, with comments across the spectrum, here

And for those people coming here, seeking more commentary on Obama’s speech, I now have a post on Obama and Race.

Embodiment & Sense Making

20/20, Blind People Who Interact with the World like Dolphins & Bats
Humans can echolocate!  Absolutely amazing.

Mind Matters, Thinking With The Body
, Movement, and Embodied Cognition

CF Kurtz & DJ Snowden, The New Dynamics of Strategy: Sense-making in a Complex and Complicated World
Challenging three basic assumptions—order, rational choice, and intent—in decision making

Continue reading “Wednesday Round Up #3”

Trust your hand, not your eyes

Blogging on Peer-Reviewed ResearchDaniel forwarded me a link to the story, The Hand Can’t Be Fooled, Study Shows, from Science Daily. The story is a short piece about research by Ben-Gurion University of the Negev Psychologist Tzvi Ganel and his colleagues on how the “Ponzo” illusion affects visual perception. The “Ponzo” illusion occurs when two equal line segments appear to be of different lengths because they are superimposed on a pair of converging lines; like two lines hovering over train-tracks disappearing into the distance appear to be of different lengths, as you can see from this illustration I took from the BBC. Ponzo illusion

Ganel and his colleagues ‘hooked participants’ index finger and thumb to computerized position tracking equipment and asked them to grasp the objects with their fingers. Even thought the object appeared to be larger (or smaller) than it really was, the size of their grasp reflected the object’s real rather than apparent size. For good measure, the researchers arranged the illusion so that the object that appeared to be the smaller of the two was actually the larger of the two.’

Ganel argues that the experiment provides compelling support for the ‘two visual systems’ hypothesis put forward by Mel Goodale and David Milner about a decade ago (see Goodale and Milner 1992; Milner and Goodale 1995; for an overview, see Goodale and Humphrey 2001). According to Goodale and Milner, one visual system processes input for object and color recognition, recognizes objects no matter what the perspective of the viewer, and uses conscious parts of the brain; another visual system judges spaces, movement and object trajectories in egocentric space in order to control body movement, and does not necessarily access conscious thought. I’ve written about the two visual systems hypothesis elsewhere in a book chapter that just came out (Downey 2008), so Daniel probably recognized that I’m a bit of a fan of the ‘tectopulvinar’ (motion control) visual system. (For a quick overview of the two systems, this is a good set of diagrams and explanation.)

Continue reading “Trust your hand, not your eyes”

Time Globalized

Blogging on Peer-Reviewed ResearchStefan Klein has an editorial, Time Out of Mind, in today’s New York Times, where he writes “the quest to spend time the way we do money is doomed to failure, because the time we experience bears little relation to time as read on a clock. The brain creates its own time, and it is this inner time, not clock time, that guides our actions.”

 He elaborates on this argument as follows:

Inner time is linked to activity. When we do nothing, and nothing happens around us, we’re unable to track time… To measure time, the brain uses circuits that are designed to monitor physical movement. Neuroscientists have observed this phenomenon using computer-assisted functional magnetic resonance imaging tomography. When subjects are asked to indicate the time it takes to view a series of pictures, heightened activity is measured in the centers that control muscular movement, primarily the cerebellum, the basal ganglia and the supplementary motor area. That explains why inner time can run faster or slower depending upon how we move our bodies — as any Tai Chi master knows.Time seems to expand when our senses are aroused. Peter Tse, a neuropsychologist at Dartmouth, demonstrated this in an experiment in which subjects were shown a sequence of flashing dots on a computer screen. The dots were timed to occur once a second, with five black dots in a row followed by one moving, colored one. Because the colored dot appeared so infrequently, it grabbed subjects’ attention and they perceived it as lasting twice as long as the others did. 

Klein then links this argument to stress: “Believing time is money to lose, we perceive our shortage of time as stressful. Thus, our fight-or-flight instinct is engaged, and the regions of the brain we use to calmly and sensibly plan our time get switched off. We become fidgety, erratic and rash… Tasks take longer. We make mistakes — which take still more time to iron out. Who among us has not been locked out of an apartment or lost a wallet when in a great hurry? The perceived lack of time becomes real: We are not stressed because we have no time, but rather, we have no time because we are stressed.”

 His conclusion? “The remedy is to liberate ourselves from Franklin’s equation. Time is not money but ‘the element in which we exist,’ as Joyce Carol Oates put it more than two decades ago (in a relatively leisurely era). ‘We are either borne along by it or drowned in it’.”

 By coincidence, Kevin Birth, professor of anthropology at Queens College-CUNY, wrote us about our blog recently, highlighting his own work on time, anthropology and biology.  Birth has a recent article, “Time and the Biological Consequences of Globalization (full pdf).”  Given that we live on a “rotating globe where each locale has its own cycles of day and night,” our present globalized economic system produces some severe contradictions that people struggle with in everyday life: “temporal conflicts between locations on the globe, desynchronization of biological cycles, and lack of correspondence between those cycles and social life.”

Continue reading “Time Globalized”