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Small-animal imaging has emerged as a powerful technique to determine the pharmacokinetics and molecular effects of new drugs. Computer tomography (CT), magnetic resonance imaging (MRI), optical, single photon emission computed tomography (SPECT), and positron emission tomography (PET) can all be used to study these compounds or their effects directly. The methods all have varying sensitivities and resolutions and can be used to track events down to the molecular level. Around six orders of magnitude separate cellular and molecular events. Cell radii are around 10−5 m, whereas a small-molecular-weight compound (1 kDa) will have a molecular radius of around 10−10 m. Although MRI can have a resolution of below 10−4 m, the sensitivity of magnetic resonance spectroscopy is quite poor, at 10−4 molar. Conversely, PET and SPECT have lower resolutions of around 10−3 m, but the sensitivities are down to 10−12 molar and depend on the specific activity of the tracer used. Small-animal imaging is a valuable tool to investigate new drugs and validate their potential in vivo. CT and MRI are good methods for anatomical and functional imaging, but cannot be reliably used for molecular imaging since they require potentially pharmacologically active doses of drugs. Optical methods of imaging can be performed at the tracer level using bioluminescence and fluorescent imaging techniques, but they can only offer planar images which cannot give quantitative data. Small-animal imaging with PET and SPECT permits the non-invasive study of novel drugs as well as their effects in animals over substantial periods of time. The methods are directly transferable into the clinic and offer a rapid and cost effective way of developing new therapeutic strategies.

Publisher Summary This chapter presents social psychological perspectives on language. Despite the existence of a number of studies prior to the 1960s on social aspects of language use, the study of language behavior in its social context only really emerged as a distinct field with its own label, sociolinguistics, about the mid-1960s. In part, it developed as a reaction to the asocial linguistics and psycholinguistics prevalent at that time that was attempting to provide understandings of language use without due concern for the context of situation in which it was spoken; it was as if context was considered a static given. Language is also an independent source of input for cognitive organization.

Listeners gave their impressions of psychologically androgynous, feminine, masculine and undifferentiated male and female speakers, who were tape-recorded reading a short prose passage. Speakers were judged on items relevant to Femininity (F), Masculinity (M), Social Competence (C) and Social Attractiveness (A). Listeners' attributions of F and M were not only consistent and systematic, but correspond closely to speakers' self-assessed gender identities. Attributions of C and A were also systematically related to the three independent variables. These encouraging results suggest that the attribution of sex stereotypical characteristics to people is not simply determined by their sex, and that speech cues are capable of mediating between the expression and perception of conformity to sex stereotypes.