9.3.1 Weber's Law Pioneering work on the relationship between ΔI and S was done by the German physiologist, Ernst Weber in the 1830s. Weber found that the increment in stimulation required for a JND was proportional to the size of the stimulus. Weber had subjects lift a small ‘standard’ weight (S) and then lift a slightly heavier ‘comparison’ (T) weight and judge which was heavier. He found that when the difference between the standard and comparison weights was small, the subjects found
7.3 The descending auditory pathway The auditory system transmits information from the cochlea to the auditory cortex. Another system follows a similar path, but in reverse, from the cortex to the cochlear nuclei. This is the descending auditory pathway. In general, the descending pathway may be regarded as exercising an inhibitory function by means of a sort of negative feedback. It may also determine which ascending impulses are to be blocked and which are allowed to pass to other centres in the brain. The olivocochlear bundl
7.2 Coding of information in the higher auditory centres We have seen that in the cochlear nerve, information about sound intensity is coded for in two ways: the firing rates of neurons and the number of neurons active. These two mechanisms of coding signal intensity are found throughout the auditory pathway and are believed to be the neural correlates of perceived loudness. The tonotopic organisation of the auditory nerve is also preserved throughout the auditory pathway; there are tonotopic maps within each of the auditory nerve relay nuclei, the
2.5.1 Summary of Section 2 Desert animals are classified in terms of their body size and physiology into three groups: evaders, evaporators and endurers. The logic for this classification is that the smaller the animal, the larger its surface area to volume ratio. Small animals therefore gain and lose heat faster than large animals, warming rapidly when exposed to intense solar radiation, and cooling rapidly at night. Small endothermic evaders, e.g. kangaroo rats, rest in cool microenvironments, e.g. shade or burrows,
Learning outcomes By the end of this unit you should be able to: define and use, or recognize definitions and applications of, each of the bold terms; give definitions of the terms ‘hibernation’, ‘torpor’ and ‘adaptive hypothermia’, and the three physiological processes that underlie them; give examples of the diversity of the major groups of mammals and birds that contain hibernating species; describe the physiological changes occur
4.3 Type-II superconductors For decades it was assumed that all superconductors, elements and alloys, behaved in similar ways, and that any differences could be attributed to impurities or defects in the materials. However, in 1957, Abrikosov predicted the existence of a different sort of superconductor, and Figure 23 shows direct evidence for the existence of what are now known as type-II superconductors. A comparison of Figures 23 and 22 indicates that the effect of an applied field on a type-II superconductor is rath
3.4 Penetration depth The characteristic length, λ, associated with the decay of the magnetic field at the surface of a superconductor is known as the penetration depth, and it depends on the number density ns of superconducting electrons. We can estimate a value for λ by assuming that all of the free electrons are superconducting. If we set ns = 1029 m−3, a typical free electron density in a metal, then we find that
Optional reading If you are interested in investigating the issues raised by the House of Lords Select Committee report in more detail, you will find a copy of the full report on the web at: http://www.publications.parliament.uk/pa/ld199900/ldselect/ldsctech/38/3801.htm The following references also discuss issues related to key findings from this report: Irwin and Michael (2003, particularly pp. 19–40), Miller (2001) and Gibbons (1999). This overall picture places demands on you as a co
2.1 History The Council of Europe was set up in 1949. It is an intergovernmental organisation (based in Strasbourg, France) set up to protect human rights, promote cultural diversity and to combat social problems such as intolerance. Its creation was seen as a way of achieving a European approach to the protection of certain individual rights. Although presented now as historical events, the horrors of what had taken place in the Second World War were then fresh in the minds of the governments and
1.4.2: Price indices Cast your mind back to why proportions and percentages were introduced in Section 2. It was because using actual price changes is unsatisfactory in comparing how the prices of different items have altered over time when their basic prices are very different. For example, if the price of a new motor car has gone up by £100 and the price of a new bicycle has gone
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1.1.8 Surgical removal of tattoos The final data set in this section is different from the others in that the data are not numerical. So far you have only seen numerical data in the form of measurements or counts. However, there is no reason why data should not be verbal or textual. Table 7 contains clinical data from
4 Your formulas – using a spreadsheet Although there may be many occasions when you are given a formula to use, sometimes you may need to devise your own formulas, for example if you use a spreadsheet on a computer at home or at work. This section looks at the process of devising a formula in more detail. Part of a spreadsheet that has been constructed to record monthly income and expenditure is shown below. It is similar to a balance sheet that you might draw up by hand and includes the monthly income and outgoings, the to
Dutch vocabulary - Fruits (également en français)
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iPhone 5 arrives in China, but market is moving on
Dec. 14 - Apple's latest handset might be a powerhouse globally, fighting Samsung for top rank, but weak distribution and a high price tag are limiting its sales in what's fast becoming the world's largest smartphone market.
TWC9: Year Wrap Up | This Week On Channel 9 This week on Channel 9, Clint and Rick wrap up the year, with a special TWC9.
Stephen Lewis of the Global Commission on HIV and the Law
Stephen Lewis of the Global Commission on HIV and the Law, and author of Race Against Time speaks at The Grandest Challenge Symposium.
Smile Identification via Feature Recognition and Corner Detection
Daniel Volz
Our project accurately detects a face within an image, identifies the person’s mouth, and determines whether or not they are smiling. Given a set of images of a person input into our system, we […]
21F.040 A Passage to India: Introduction to Modern Indian Culture and Society (MIT)
This course introduces students to Indian Culture through films, short-stories, novels, essays, and newspaper articles. The course examines some major social and political controversies of contemporary India through discussions centered on India's history, politics and religion. The focus is on issues such as ethnic tension and terrorism, poverty and inequality, caste conflict, the "missing women," and the effects of globalization on popular and folk cultures. Particular emphasis is on the IT re
Promo - One Minute Romanian
Hello! My name is Roxana and I'd like to welcome you to One Minute Romanian from the Radio Lingua Network. In this podcast I'm going to be teaching you the basics of Romanian. The great thing about this language course is that you'll be learning all you need to know in just 60 seconds - or thereabouts! Each one minute language lesson will equip you with just enough Romanian to help you get by in lots of situations, either on holiday, or on a business trip to Romania, or just to impress your Roma
