Behaviors Caused by Hypothalamic and Thalamic Lesions In the field of neuropsychology, the area of the brain that includes the hypothalamus, thalamus, and subthalamus is referred to as the subcortical diencephalon (Kalat 2004). In the following section, lesions in these specific areas will be discussed. The findings of the injuries will be addressed from the perspective of a neuropsychologist. Neuropsychological assessment refers to the objective evaluation of a person's cognitive, linguistic, perceptual, and psychomotor performance with the aim of relating the state of his performance to the structural and functional condition of his brain (Steinhauer, Gruzelier, and Zubin 1991) . Neuropsychological assessment can be approached by an experimental method in which the researcher has greater control of the variables influencing the situation but generalization is more difficult and human subjects cannot be used in studies (Finger 1978). A clinical method is also used, and although this method does not have the advantage of complete control, brain-behavior relationships are much easier to study because human subjects can be used in this method (Finger 1978). Both methods are usually combined to produce more efficient and useful information for the patient. The most important neuropsychological tests include the Wechsler Adult IntelligenceScale, the Halstead-Reitan battery, and the Wechsler MemoryScale (Steinhauer et. al. 1991). These tests provide the opportunity to analyze the components of performance and thus identify likely disabilities that would explain the faulty performance (Steinhauer, et. al. 1991). The main question that will be examined in this section will be the behavioral effects of lesions to specific parts of the hypothalamus and thalamus. The hypothalamus is located near the base of the brain and is ventral to the thalamus (Dimond 1978, Kalat 2004). The hypothalamus is part of the limbic system and is responsible for motivational behaviors including emotions, eating, drinking, sexual activity, anxiety, and aggression (Kalat 2004, Dimond 1978, Isaacson 1982, Beaumont 1983). The hypothalamus has widespread connections with the rest of the forebrain and also with the midbrain (Kalat 2004). The hypothalamus contains a number of distinct nuclei including the lateral nucleus which controls the initiation of eating and drinking, the ventromedial nucleus which controls the cessation of eating and drinking, the paraventricular nucleus which limits the size of the meal, the supraoptic nucleus which controls the secretion of vasopressin, the suprachiasmic nucleus which constitutes the biological clock,
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