Primates cognition brain size and structure

Question 1

What factors of an organism need to be considered when studying cognition? Why?

Answer 1

1. Life history and ecology - tells us why brains and cognition are needed.
2. Morphology - tells us how the organism interacts with the natural environment and other organisms. This is linked to their behaviour and cognition.
3. Evolution - this places constraints on the organism. The way they live now is different to that of many years ago.
4. Life span - primates have a longer life span and this reflects level of cognition.

Question 2

Why does cognition between different taxonomic groups differ?

Answer 2

Each organism has to solve problems, and each taxonomic group does this in a different way. Despite this, the same outcome is reached.

Question 3

Describe the cognition of a primate.

Answer 3

• Flexible and visual learning.
• Have some adaptable motor input.
• Problems are solved using the brain, eyes and hands. There are no specialised adaptations involved.

Question 4

Describe the life history and ecology of primates.

Answer 4

Long life and broad niche:

• There are 14 families and around 350 species of primate.
• They are primarily arboreal (found in the trees) and are mostly diurnal (awake during daytime).
• They have a wide range of diet which does not change.
• They mate in a broad range, e.g. life-long, temporary.
• Have flexible behaviour, today is different to years ago.
• Live long.
• Show social learning: children often stay with the mother for a long time.

Question 5

Describe the morphology of primates.

Answer 5

• Their eyes are frontal and allow for binocular vision. Eyesight is their main sense.
• See in colour and view the world in a similar way to humans.
• Have dexterous hands with thumbs which allow for grasping. Those primates which don’t (spider monkeys) have the equivalent of a thumb on the end of their tail.
• Have a large brain.
• No real specialised structures.

Question 6

Name differences between monkeys and apes in terms of foraging.

Answer 6

• Monkeys are more generalist and have no specific gut adaptations.
• Apes are more cognitive but don’t have morphological specialisms.

Question 7

How are apes able to be more cognitive when foraging?

Answer 7

They rely on social learning to learn what to eat and avoid.

• Vision distinguishes between edible parts.
• Hands and brain finds and processes foods, including removing seeds.

Question 8

How does social learning and foraging affect the brain?

Answer 8

This causes memory and learning to occur, which causes structural plasticity within the brain.

Question 9

Advantages and disadvantages of cognitive foraging over general foraging.

Answer 9

Advantages:
- Provides more energy as better foods are being consumed.

Disadvantages:

• There is a longer learning period where reproduction cant occur.
• e.g. orangutans have a reproductive gap of 8 years for learning to occur.

Question 10

What consequences does the morphology and life history have on the problem solving of primates?

Answer 10

• The long life and broad niche mean there are not morphological specialisations.
• Therefore, problem solving is dependent on behavioural flexibility.

Question 11

How does relative brain size change in primates?

Answer 11

Increases from monkey < gibbon < orangutan < gorilla < chimpanzee < humans.

Question 12

What part of the brain is involved in growth?

Answer 12

The neocortex - this is the top part.

Question 13

What change in brain size is being increasingly seen over the last 30 years?

Answer 13

Reduction by around 20%.

Question 14

What other group of animals do primates share brain features with? What are the similarities?

Answer 14

Mammals

- Both have a layered cortex for an increased SA.

Question 15

What are the differences between mammalian and primate brains? Why are these differences important?

Answer 15

1. Primates have smaller and more densely packed neurons.
   - This allows for an increased SA.
2. Primates have an expanded and
   a extensively folded neocortex.
   - Increases SA.
3. Primates have a larger brain:body ratio.
   - Allows for more neural circuits.

Question 16

Which parts of the cortex are particularly expanded?

Answer 16

1. The visual cortex.
   - In particular, the posterior parietal cortex.
2. The motor cortex.
3. The pre-frontal cortex.

Question 17

Importance of expanding visual cortex, particularly the posterior parietal cortex.

Answer 17

This has key roles in sensorimotor activities such as climbing and grasping, which are vital in primates. There is a strong link between grip and the brain; primates grip first and grip is the last thing that is lost when they are sedated/awaken.

Question 18

Importance of expanding motor cortex.

Answer 18

This is specialised for dexterity.

Question 19

Importance of expanding pre-frontal cortex.

Answer 19

This is associated with higher cognition and complex social behaviour. It relies on both sensory inputs and past events.

Question 20

Which primate has the most expanded granular frontal cortex?

Answer 20

Humans.

Question 21

What is the function of the neocortex?

Answer 21

Involved in executive functions of learning, including planning and flexible decision making

Question 22

What is the function of the cerebellum?

Answer 22

Involved in sensory-motor functions, controlling movement and co-ordination.

Question 23

How are the neocortex and cerebellum connected?

Answer 23

It is believed that they are closely connected in function and are co-evolved.
- Have strong neuronal connections which are constantly changing.

Question 24

What are the general features of primate cognition?

Answer 24

• Rapid learning.
• Good working memory capacity enhanced by learning.
• Flexible behaviour.
• Social learning.
• Meta-cognition (thinking about thinking).

Question 25

What is abstract learning?

Answer 25

Learning about concepts which are not linked to specific properties of objects. Includes reasoning by exclusion i.e. referring to things that are absent.

Question 26

In which species is abstract learning mostly studied?

Answer 26

Humans.

Question 27

How do apes reason about absence? Experiment and result.

Answer 27

• Apes are provided with 2 plates of food, one empty and one with okay food.
• -> The ape will point to the empty plate and won’t touch the plate with okay food as they would rather wait for the great food.

Question 28

Do monkeys show reason about absence?

Answer 28

No, in the plate experiment, they will eat whatever food is present.

Question 29

How does tool use differ in populations of the same species?

Answer 29

Tool use differs depending on the culture and environment of the animal.
- Tool use is flexible.

Question 30

Why are humans thought to be the dominant species?

Answer 30

They have the ability to imagine as well as social learning.

Question 31

How does social cognition differ between humans and apes?

Answer 31

Humans and apes perform ~ the same.

- However, children are better than apes.

Question 32

What are factors which determine the route taken by apes to find food?

Answer 32

• The ripeness of a tree.

- The location of the best tree.

Question 33

How do apes fight for the best food?

Answer 33

• They will take detours to get to the best tree first.
• They will wake up earlier to get their preferred breakfast.
• They will go to further trees for their preferred food.
• They will go past more nutritious food in order to get their preferred food.
• They will make a new nest to be closer to their preferred fruit tree.

Question 34

How does visual stimuli affect the brain?

Answer 34

Has a positive effect on the cerebellum and hippocampus as it causes memory and new experience neurons to fire.

Question 35

What is metacognition?

Answer 35

Having access to our own private knowledge and competence.

Question 36

What does metacognition allow for? Good and bad.

Answer 36

Good:

• Allows for situations to be imagined and judged in terms of risk and consequence.
• -> Tells us if a task should be carried out or not.

Bad:
- By judging this imaginary situation, facts are ignored. Therefore, the bad consequences lead to a task not being done even though the likelihood of this consequence is ~0.

Question 37

What experiment was done to test if non-human primates show metacognition?

Answer 37

• Experiment was done in rhesus monkeys.
• Tests how they deal with a new task.
• If the monkeys decline the task (showing risk assessment and declining the task), then no reward is given.
• Reward for responding to the task correctly.

Thus, if the monkeys decline a new task, despite not getting a reward, metacognition is inferred.

Question 38

What were the outcomes of the experiment testing metacognition in rhesus monkeys?

Answer 38

The task was declined more as it became more difficult.

- This suggests declining when there is uncertainty due to metacognition.

Question 39

What factors allow for flexible cognition in primates? Including their ability to plan ahead.

Answer 39

• The complex and dynamic environment they live in: evolution of cognition.
• Majority visual and somatosensory processing within the brain: allows reasoning in absence of object/event and planning ahead.
• Social learning: allows for more sophisticated learning.

Question 40

What is one reason why human cognition is different to other primate cognition, despite the similar brain structures?

Answer 40

Humans have the ability to imagine things, this allows us to choose how we use our brains.