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A lie detector test or polygraph measures and records several physiological indices (for example, blood pressure, pulse, respiration, and skin conductivity) while a person is asked and answers a series of questions. The belief underpinning the use…

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from article Anorexia nervosa

Anorexia nervosa is a serious disorder and can have severe health consequences that go far beyond simple weight loss. (Credit: Office on Women's Health, U.S. Department of Health and Human Services)

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from article Anorexia nervosa

Incidence (%) of eating disorders among teenagers (13 to 18 years old) in the United States. Three types of eating disorders are included in the data: anorexia nervosa, bulimia nervosa, and binge eating disorder. Note that female teens are much more…

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from article Speech perception

The perception of speech (as well as the production of speech) involves interactive processes occurring in various regions of the brain. Researchers also have noted the important contribution that vision makes to normal speech perception. (Copyright…

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from article Speech perception

An auditory spectrogram of the word "telephone." (a) The vertical striations in the bands represent amplitude modulation at the frequency of the voice pitch. Such striations are absent from the initial noise portion corresponding to the voiceless…

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from article Dendrochronology

Ring patterns showing complacent and sensitive ring series. (a) Climate has minimal effect on ring widths when trees have ample moisture every year. (b) Maximum ring-width variations occur on sites where growth is limited by factors that vary from…

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from article Dendrochronology

Core being taken from a tree with an increment borer. (Courtesy of Laboratory of Tree-Ring Research, University of Arizona)

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from article Dendrochronology

Chronology building. Chronologies are extended backward in time by matching patterns of wood samples whose ages overlap.

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from article Dendrochronology

Skeleton plot (top) from an idealized tree-ring sequence in a specimen (bottom). Ring widths are represented by vertical lines in inverse proportion; that is, tall lines represent narrow rings. An exceptionally wide ring is designated by the letter…

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from article Dendrochronology

Bristlecone pines, which attain ages of more than 4000 years, form the basis for the second longest chronology yet developed. (Courtesy of Laboratory of Tree-Ring Research, University of Arizona)

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from article Paleoindian

Location of some important North American Paleoindian sites during the late-Pleistocene Ice Age.

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from article Sleep-dependent memory processing

The sleep cycle, memory systems, and memory stages. (a) The human sleep cycle. Across the night, rapid eye movement (REM) sleep and non-REM (NREM) sleep cycle every 90 minutes in an ultradian manner (that is, occurring in cycles that are repeated…

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from article Sleep-dependent memory processing

Sleep-dependent motor skill learning. (a) Wake first. After morning training (10 a.m., clear bar), subjects showed no significant change in performance when tested after 12 hours of wake time (10 p.m., clear bar). However, when tested again…

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from article Sleep-dependent memory processing

Sleep-dependent integration of human relational memory. (a) Delayed inference (associative) memory performance (% correct) in a relational memory task following different offline delays. Immediate testing after just a 20-min offline delay…

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from article Territoriality

The tiger (Panthera tigris) is highly territorial in its behavior. (Credit: Safique Hazarika Photography/Getty Images)

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from article Fossil primates

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from article Fossil primates

Carpolestes simpsoni, a 55.5-million-year-old plesiadapiform from Wyoming: (a) skeleton as recovered, laid out in approximate anatomical position; (b) reconstruction in life stance on a tree branch; elements in dark gray are known; (c) external…

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from article Fossil primates

Cranium of the omomyoid tarsiiform Teilhardina asiatica, from deposits dated approximately 55 MYA in China: (a) dorsal (top) view as found; (b) left lateral reconstruction. (Credit: Xijun Ni)

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from article Fossil primates

Anjohibe (Madagascar) specimen of Palaeopropithecus ingens (an extinct lemur), mounted in a probable habitat posture. (Credit: American Geological Institute)

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from article Fossil primates

Partly reconstructed skeleton (casts) of Paracolobus chemeroni, a 3.2-million-year-old colobine monkey from Kenya, on exhibit at the American Museum of Natural History in New York. (Credit: Eric Delson)

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from article Fossil primates

Reconstructed skeleton of Proconsul heseloni, an early hominoid (23–14 MYA) from East Africa. Known parts are shaded. (Credit: R. L. Ciochon and R. S. Corruccini)

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from article Hunger

Principles of appetite regulation by gut–brain peptides. Tissues and organs, including the pancreas, stomach, small intestine, adipose tissue, and large intestine, are sources of peptides that stimulate or inhibit appetite-regulating neurons in the…

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from article Paleolithic