A New York Times Article Published on April 24, 2007

question 39

Multiple Choice

A New York Times article published on April 24, 2007, reported the research of Dr.Vallortigara, a neuroscientist at the University of Trieste, Italy.In this study, Dr.Vallortigara assessed whether a dog's tail wags in a preferred direction in response to positive as opposed to negative stimuli.First Dr.Vallortigara recruited 30 dogs that were family pets.While filming a dog's tail from above he allowed the dog to view (through a slot in its cage) its owner, an unfamiliar human, a cat, and an unfamiliar dominant dog.The study found that dogs' tails wagged to the right for the owner and to the left for the unfamiliar dominant dog.What is the dependent variable in this study?

• A) finding that dogs' tails went rightward for the owner and leftward for an unfamiliar dog
• B) the 30 dogs that were recruited for the study
• C) whether the dog wagged its tail to the right or left
• D) the type of visual stimulus provided to the dog

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Definitions:

Spinal Cord

A long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column.

fMRI

Functional Magnetic Resonance Imaging, a neuroimaging procedure that measures brain activity by detecting changes associated with blood flow.

BOLD Signal

Blood Oxygen Level Dependent Signal, a measure used in functional MRI to observe brain activity through changes in blood flow.

Hemoglobin

A protein in red blood cells responsible for transporting oxygen from the lungs to the body's tissues and returning carbon dioxide from the tissues back to the lungs.