In my opnion the reaon why use animal is1 for information on human cognition, mental illness, memory disorders, drug addiction, and how the body’s sensory system and central nervous system work, animals are subjected to experiments on vision, hearing, pain perception, hunger, thirst, reproduction and fetal development, fear, stress, aggression, learned helplessness, maternal deprivation, cigarette use, drug and alcohol abuse and dependence, and environmental toxins, to name a few. In research relating to the central nervous system, animals are used to study the process of recovery after neural damage biological correlates of fear, anxiety, and other forms of stress; subjective and dependence-producing effects of psychotropic and mechanisms that control eating and other motivational processes.

To create an animal model of depression, anxiety, posttraumatic stress, obsessive-compulsive disorder, alcoholism, autism, schizophrenia, anorexia, drug addiction, or spinal cord injury, a facsimile of the conditions of the disorder or disease is induced in an animal. This is accomplished by manipulation of the animal’s behavior and environment, invasive procedures to the brain and body, or genetic engineering. Animals are subjected to food, water, and sleep deprivation, sensory deprivation or overload, long-term physical restraint, social isolation, maternal separation, electric shocks, limb amputation, and brain damage and manipulation through the use of electrodes surgically implanted into the brain.

To study behaviors and experiences, psychology research typically requires animals to be conscious and aware, and as such may be considered the cruelest of animal experiments due to the high degree of pain and suffering involved. Animals can remain in distress for a long length of time, since they are often subjected to invasive procedures that they then must recover from