Navigation Links
The world is full of darkness, reflected in the physiology of the human retina, Penn researchers say
Date:10/5/2010

n the fact that there is more dark information in the world around us.

Researchers tested the hypothesis by measuring the spatial contrasts in natural images and quantifying the distribution of lightness and darkness. At all scales, the authors found that natural images contain relatively more dark contrasts than light.

"Photoreceptors respond to light," Vijay Balasubramanian, professor of physics and the study's lead author, said. "But a couple of layers deeper down in the retina, cells are responding to changes and differences in the amount of light across the image. The eye is not a digital camera, recording little pixels. The eye doesn't do that. The eye tells the brain that there are differences in light between neighboring points. The brain learns about contrast. And in this case, there is about twice as much brain activity responding to darker spots."

The team confirmed this across a range of spatial scales and traced the origin of this phenomenon to the statistical structure of natural scenes. Researchers showed that the optimal mosaics for encoding natural images are also asymmetric, with off elements smaller and more numerous, thus matching retinal structure. Finally, the concentration of synapses within a dendritic field matches the information content, suggesting a simple principle to connect a concrete fact of neuroanatomy with the abstract concept of "information": equal synapses for equal bits.

Researchers were interested in how the visual system is adapted to the physical structure of the world, an assumption that makes sense from an evolutionary standpoint. The physics of the natural world should correspond to the processing capabilities of the brain and there are many observable incidences of this phenomenon in the human and animal world. For example, frogs eat flies. That fact predicted that frog's eye contains "fly detectors." Flies, in turn, track potential mates in mid-air, predicting specialized
'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert  

Page: 1 2 3

Related biology news :

1. BIO-key(R) International To Exhibit at Oracle OpenWorld
2. World leaders in infectious diseases convene to discuss emerging global viruses
3. Researchers document worlds mammals in crisis
4. Complete Genomics launches, becomes worlds first large-scale human genome sequencing company
5. Europe rallies behind nanotechnology to wean world from fossil fuels
6. Smithsonian perspective: Biodiversity in a warmer world
7. Take advantage of reduced pre-registration rates for the IOF World Congress on Osteoporosis
8. World Food Day brings attention to food security around the globe
9. Fitness in a changing world
10. Researchers uncover worlds oldest fossil impression of a flying insect
11. Providing toilets, safe water is top route to reducing world poverty: UN University
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
The world is full of darkness, reflected in the physiology of the human retina, Penn researchers say
(Date:4/20/2015)... 20, 2015 The announcement comes ... Glenbeigh Records Management (GRM), Ireland,s foremost ... Bank. Having built up an impressive track record of clients ... player within the records management sector in Dubai ... is GCC staffbase and employ a further eight staff members ...
(Date:4/13/2015)... 2015 According to a ... Market Forecast & Opportunities, 2020", the global biometrics market ... 14% till 2020. The biometrics market is garnering ... and review of biometric management systems. The constant ... with greater efficiency, are resulting in increasing installation ...
(Date:4/8/2015)... , April 8, 2015  Infinisource, a ... and services, and Morpho, a leading supplier of ... to produce the market,s most advanced biometrically-enabled time ... iSolved NXG time clock is setting a bold, ... labor data for the small and mid-size employer. ...
Breaking Biology News(10 mins):Glenbeigh Records Management Wins Contract With Dubai Islamic Bank 2Glenbeigh Records Management Wins Contract With Dubai Islamic Bank 3Global Biometrics Market to Cross US$ 21 Billion by 2020: TechSci Research 2iSolved Time Clock Offers Unmatched Accuracy due to Morpho Biometrics 2iSolved Time Clock Offers Unmatched Accuracy due to Morpho Biometrics 3
... by the Duke-NUS Graduate Medical School (Duke-NUS) in Singapore ... key protein linked to stem cell-like behavior in terminal-stage ... drugs that may extend the survival of these patients. ... Proceedings of the National Academy of Sciences , ...
... to reduce by more than half the time it takes ... researchers in Penn State,s College of Agricultural Sciences. The finding ... foodborne illness, allowing epidemiological investigators to identify the exact strains ... more quickly find -- and eliminate -- the source of ...
... long been used for various purposes, like cleaning wastewater at ... handcrafted wickerwork, as means of nutrition and, in traditional medicine, ... Fraunhofer Institute for Building Physics IBP in Valley now want ... to wit, for the insulation of outer walls or ...
Cached Biology News:Singapore research team identifies new drug target in deadly form of leukemia 2Researchers develop a faster method to identify Salmonella strains 2Researchers develop a faster method to identify Salmonella strains 3Using cattails for insulation 2Using cattails for insulation 3
(Date:4/23/2015)... Prospects for Leading Companies in ... Details   We predict the global healthcare ... in 2015 and will grow at a CAGR of 6.3% ... around the world and increasing functional requirements for healthcare packaging ... global healthcare packaging market. A global ageing population, ...
(Date:4/23/2015)... 23, 2015  Metanome, Inc., an industry leader ... has changed its name to Diversigen, Inc.  The ... the single commercial source for the myriad of ... the diverse opportunities of the microbiome.  From the ... – including those that are difficult to handle, ...
(Date:4/23/2015)... ReliantHeart's HeartAssist5® Ventricular Assist Device (VAD) precisely measure ... in real time, and this data is uploaded to ... Machine to Machine (M2M) communications for the Internet of ... can be monitored by a patient’s clinician 24/7, ... a minimum threshold, the patient can be notified immediately. ...
(Date:4/22/2015)... RICHMOND, Calif. , April 22, 2015  Sangamo ... first quarter 2015 financial results and accomplishments. ... reported a consolidated net loss of $5.3 million, or ... $7.6 million, or $0.12 per share, for the same ... Company had cash, cash equivalents, marketable securities and interest ...
Breaking Biology Technology:Healthcare Packaging Market Forecast 2015-2025 2Healthcare Packaging Market Forecast 2015-2025 3Healthcare Packaging Market Forecast 2015-2025 4Healthcare Packaging Market Forecast 2015-2025 5Healthcare Packaging Market Forecast 2015-2025 6Healthcare Packaging Market Forecast 2015-2025 7Healthcare Packaging Market Forecast 2015-2025 8Healthcare Packaging Market Forecast 2015-2025 9Healthcare Packaging Market Forecast 2015-2025 10Metanome Announces Corporate Name Change to Diversigen 2Sangamo BioSciences Reports First Quarter 2015 Financial Results 2Sangamo BioSciences Reports First Quarter 2015 Financial Results 3Sangamo BioSciences Reports First Quarter 2015 Financial Results 4Sangamo BioSciences Reports First Quarter 2015 Financial Results 5Sangamo BioSciences Reports First Quarter 2015 Financial Results 6Sangamo BioSciences Reports First Quarter 2015 Financial Results 7Sangamo BioSciences Reports First Quarter 2015 Financial Results 8
... Scientists engaged in biological research and drug discovery are ... BioInformatics, LLC ( www.gene2drug.com ), the premier research ... released preliminary data from the company,s newest report ... Science Suppliers. In this report, we set out ...
... LOUIS, Feb. 11 Sigma-Aldrich, a leading Life,Science and High ... by 6% to $0.68 from $0.64 in the same quarter ... $510 million in the fourth quarter 2008 declined by 4%,compared ... fourth,quarter grew 3% from a year ago. Fourth quarter organic ...
... Development for Chronic Pain IndicationsLA JOLLA, Calif., Feb. ... TPTX ) today announced that oral administration of ... and well-tolerated in healthy male and female subjects ... successful completion of this Phase I trial demonstrating ...
Cached Biology Technology:Life Science Labs Reacting to the Economic Crisis 2Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 2Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 3Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 4Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 5Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 6Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 7Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 8Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 9Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 10Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 11Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 12Sigma-Aldrich (Nasdaq: SIAL) Reports Fourth Quarter Diluted EPS of $0.68. Ends 2008 With Record Sales and Earnings and Raises Quarterly Cash Dividend by 11.5%. Provides Outlook for 2009. 13First Multiple Dose Clinical Trial of TorreyPines Therapeutics' Oral Compound NGX426 Demonstrates Compound Is Safe and Well-Tolerated 2First Multiple Dose Clinical Trial of TorreyPines Therapeutics' Oral Compound NGX426 Demonstrates Compound Is Safe and Well-Tolerated 3First Multiple Dose Clinical Trial of TorreyPines Therapeutics' Oral Compound NGX426 Demonstrates Compound Is Safe and Well-Tolerated 4
ELF® 97 Immunohistochemistry Kit...
albumin from bovine serum (BSA), Alexa Fluor® 647 conjugate...
Superior homology search software - in all the flavours of blast, with increased sensitivity and speed. Free windows version for academic use....
... bovine, porcine, rat) ... antagonist. This carboxy-terminal VIP fragment ... more potent than any previously ... Storage: Desiccate ...
Biology Products: