Chapter 2: Animal Research HL

Question 1

Comparative Psychology

Answer 1

they focus on a particular species or compare this species to humans

Question 2

Animal models

Answer 2

a concept that refers to using animal research to test a certain cause-effect hypothesis about a certain human behavior.
An example would be stress models (explain depression due to exposure to stressful situations), separation models (separation from others causing depression), medical models (chemical imbalances in the brain), etc.

Question 3

Premack (2007)

Answer 3

The idea is that the deeper brain structures can be found in animals as well and the further down you go the further down evolution you see (MacLean (1990).
This led some scientists to argue that the comparison of brain differences might not give us a full understanding of how animals are psychologically similar to humans and that we need to compare psychological functions as well.

Premack (2007) carried out such a comparison. He says that whenever we find a similarity, we need to find a dissimilarity.

Question 4

Principles of animal research

Answer 4

Animal research is to some extent generalizable to humans, as the physiology and genetic set-up of humans and animals are similar
Animal research may inform our understanding of human behavior
Behavior is the product of physiology and behavior can be genetically inherited

Question 5

Advantages of animal research and ways of keeping it ethically right

Answer 5

Ethical considerations that can be applied:

• Anesthesia and euthanasia for more humane treatment.
• Guidelines and healthy benevolent treatment for nonhuman animals.
• Non-invasive methodologies and experimental techniques. E.g. behavioral observation

Advantages:

• Easy gene modification for research
• Animals are easy to control.
• (Potential) medical discoveries
• Increased understanding and development of treatments for neurological and psychological disorders
• Many similarities between mice and humans
• Animals live shorter lives, which allows for studying the full lifespan.
• Inexpensive

Question 6

Disadvantages and ethical considerations

Answer 6

• Trivial findings are likely as non-human animals are different than humans in many areas. (E.g. drugs can affect nonhuman animals differently).
• Even if humans and animals are similar in some biological aspects, they can still differ psychologically.
• Animals can’t tell us what they want - they have no saying in their own destiny.
• Environmental (laboratory) and other specific effects will not be taken into consideration when researching phenomena such as depression. - social psychology
• Problems with transferability (to humans).
• An animal model is never going to be 100 percent representative of human anatomy, physiology, cognition or behavior.

Question 7

Three main groups of research purposes

Answer 7

• Compare species to humans (comparative psychology).
• Use the study of animals as models of human beings hoping that the findings will be universal and generalizable.
• To understand human conditions such as diseases

Question 8

Main experimental manipulation types used in animal models

Answer 8

• Genetic manipulation (when animals are bred in a certain way)
• Invasive manipulations with the nervous system (brain parts are stimulated with electrodes, lesioned, or removed)
• Invasive manipulations with other body parts (by substances or damage)
• Behavioral and environmental manipulations (e.g. electric shocks for maze training of rats)

Question 9

MacLean (1990)

Answer 9

The idea that the deeper we go into the brain, the more “primitive” structures we will find, and that this is seen in animals as well as humans. The Triune Brain proposed by MacLean (1990) divides the human brain into three parts:

• reptilian complex
• paleomammalian complex (limbic system)
• neocortex.

However, the evolution of brain structure is more complex than simply it building newer structures upon old structures, which has been discovered by comparative neurobiology that showed that neurons in humans and animals are different.

Question 10

Ethical guidelines (APA)

Answer 10

Any animal study should be justified with a clear scientific purpose. It should increase scientific knowledge of behavior, our understanding of a particular species, or have beneficial results for humans or animals.

It should be ensured that the chosen species is the best choice, the minimum number of them is used, and what pain is caused.

Study proposals must be sent to the Ethics Committee.

Researchers must know the normal behavior of the species.

Lab animals must be given humane care.

Studies should always try to minimize discomfort for animals.

If in much pain, the animal should be euthanized.

Lab animals must not be released into the wild.

Question 11

Karl Lashley

Answer 11

Topic:
Brain and behavior (localization).

Study:
Lashley’s experiments with rats: removing varying portions of the cortex to see if the memory of the maze disappears

Findings:
Performance deterioration depends on the percentage of cortex destroyed but not on the location of the destroyed cells. This challenges the idea of localization of function for memory.

Question 12

Merzenich et al (1984)

Answer 12

Topic:
Brain and behavior (neuroplasticity)

Study:
Merzenich et al (1984): cortical representations of the hand in adult owl monkeys

Findings:
There was re-specialization of brain matter responsible for one digit so that it became responsible for other, adjacent digits.

Question 13

Romero et al (2014)

Answer 13

Topic:
Hormones and behavior

Study:
The role of oxytocin in promoting social bonds in mammals in non-reproductive contexts

Findings:
Dogs were placed in a room with their owner and another dog. Dogs sprayed with oxytocin showed higher affiliation towards their owner. Similar results were observed for the other dog in the room: affiliation and approach behaviors were more frequent in the oxytocin condition.

Question 14

Weaver et al (2004)

Answer 14

Topic:
Genetics and behavior (epigenetics)

Study:
Weaver et al (2004): epigenetic research on how the type of nurturing rats receive from their mothers in early life affects the way their brain responds to stress in later life.

Findings:
Less nurturing in early life was linked to the suppression of the glucocorticoid receptor gene. The genetic sequences themselves did not differ. This study demonstrates the effeCts of gene suppression on behavior.

Question 15

Hetherington and Ranson (1942)

Answer 15

Lesioned the ventromedial hypothalamus in order to see the role of the part of the brain on eating behavior, which found that rats increased their food intake (and often doubled their weight), and as such concluded that the hypothalamus acted as a brake on eating. Later research showed that since lesioning can be imprecise, the actual part of the brain responsible was not the VMH

Question 16

Rosenzweig, Bennet & Diamond’s (1972)

Answer 16

Studied the role of environmental stimuli on brain plasticity, and concluded (by killing the animal) that there was a cause and effect relationship between the two (which they argued because their experiment was highly controlled)

Question 17

Brady (1958)

Answer 17

Ulcers in Executive Monkeys was a study into the effects of stress. Joseph Brady subjected one group of monkeys to regular electric shocks every 20 seconds for six-hour shifts. Another group of “executive monkeys” had the same schedule, except that they could prevent the shocks by pressing a lever in each 20 second period.

Question 18

(Warren & Marshall, (1983)

Answer 18

showed that humans develop ulcers from bacteria, not from stress alone. Stress lowers one’s immune system. This, in turn, increases the level of bacteria in the stomach – which then eats through the stomach lining, leading to ulcers. Regardless of one’s level of stress, if you don’t have the bacteria, you won’t develop ulcers.

Question 19

Robert Sapolsky, case study

Answer 19

In this case study, Sapolsky used observations, physiological tests and experiments in a troop of baboons in order to find the role of one’s place in the hierarchy on cardiovascular health. Sapolsky’s research was longitudinal and naturalistic. The baboons were observed over a period of 25 years in their natural habitat in Western Kenya. His findings showed that long-term exposure to stress, determined by being at the bottom of the baboon social hierarchy, leads to higher levels of glucocorticoids (such as cortisol), which results in higher levels of heart disease, lower rates of fertility and lower life expectancy. Study is high in external validity, as no animals were harmed and were observed in their natural habitat.

Question 20

Shively & Day (2015)

Answer 20

a longitudinal case study on the health of female macaque monkeys. They found that those lower in the hierarchy suffered from twice the level of atherosclerosis – a plaque that builds up on the walls of the arteries – than higher-ranking monkeys. Atherosclerosis is the usual cause of heart attacks, strokes, and cardiovascular disease. High in external validity.

Question 21

Transgenic [mice] (selective breeding)

Answer 21

Modern research using selective breeding often uses transgenic mice – that is, a mouse that has had a single gene changed or removed. In 2007 Mario Capecchi, Oliver Smithies and Martin Evans won the Nobel Prize in Physiology for developing this procedure. These mice are also sometimes referred to as “knockout mice.”

Question 22

Harry Harlow’s Total Isolation in Monkeys (1965)

Answer 22

Harlow’s studies on dependency in monkeys – attachment and affection – create fearful situations, where the monkeys would either seek comfort in a wire mother or a cloth mother.