Primates cognition brain size and structure Flashcards
What factors of an organism need to be considered when studying cognition? Why?
- Life history and ecology - tells us why brains and cognition are needed.
- Morphology - tells us how the organism interacts with the natural environment and other organisms. This is linked to their behaviour and cognition.
- Evolution - this places constraints on the organism. The way they live now is different to that of many years ago.
- Life span - primates have a longer life span and this reflects level of cognition.
Why does cognition between different taxonomic groups differ?
Each organism has to solve problems, and each taxonomic group does this in a different way. Despite this, the same outcome is reached.
Describe the cognition of a primate.
- Flexible and visual learning.
- Have some adaptable motor input.
- Problems are solved using the brain, eyes and hands. There are no specialised adaptations involved.
Describe the life history and ecology of primates.
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.
Describe the morphology of primates.
- 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.
Name differences between monkeys and apes in terms of foraging.
- Monkeys are more generalist and have no specific gut adaptations.
- Apes are more cognitive but don’t have morphological specialisms.
How are apes able to be more cognitive when foraging?
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.
How does social learning and foraging affect the brain?
This causes memory and learning to occur, which causes structural plasticity within the brain.
Advantages and disadvantages of cognitive foraging over general foraging.
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.
What consequences does the morphology and life history have on the problem solving of primates?
- The long life and broad niche mean there are not morphological specialisations.
- Therefore, problem solving is dependent on behavioural flexibility.
How does relative brain size change in primates?
Increases from monkey < gibbon < orangutan < gorilla < chimpanzee < humans.
What part of the brain is involved in growth?
The neocortex - this is the top part.
What change in brain size is being increasingly seen over the last 30 years?
Reduction by around 20%.
What other group of animals do primates share brain features with? What are the similarities?
Mammals
- Both have a layered cortex for an increased SA.
What are the differences between mammalian and primate brains? Why are these differences important?
- Primates have smaller and more densely packed neurons.
- This allows for an increased SA. - Primates have an expanded and
a extensively folded neocortex.
- Increases SA. - Primates have a larger brain:body ratio.
- Allows for more neural circuits.
Which parts of the cortex are particularly expanded?
- The visual cortex.
- In particular, the posterior parietal cortex. - The motor cortex.
- The pre-frontal cortex.
Importance of expanding visual cortex, particularly the posterior parietal cortex.
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.
Importance of expanding motor cortex.
This is specialised for dexterity.
Importance of expanding pre-frontal cortex.
This is associated with higher cognition and complex social behaviour. It relies on both sensory inputs and past events.
Which primate has the most expanded granular frontal cortex?
Humans.
What is the function of the neocortex?
Involved in executive functions of learning, including planning and flexible decision making
What is the function of the cerebellum?
Involved in sensory-motor functions, controlling movement and co-ordination.
How are the neocortex and cerebellum connected?
It is believed that they are closely connected in function and are co-evolved.
- Have strong neuronal connections which are constantly changing.
What are the general features of primate cognition?
- Rapid learning.
- Good working memory capacity enhanced by learning.
- Flexible behaviour.
- Social learning.
- Meta-cognition (thinking about thinking).
What is abstract learning?
Learning about concepts which are not linked to specific properties of objects. Includes reasoning by exclusion i.e. referring to things that are absent.
In which species is abstract learning mostly studied?
Humans.
How do apes reason about absence? Experiment and result.
- 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.
Do monkeys show reason about absence?
No, in the plate experiment, they will eat whatever food is present.
How does tool use differ in populations of the same species?
Tool use differs depending on the culture and environment of the animal.
- Tool use is flexible.
Why are humans thought to be the dominant species?
They have the ability to imagine as well as social learning.
How does social cognition differ between humans and apes?
Humans and apes perform ~ the same.
- However, children are better than apes.
What are factors which determine the route taken by apes to find food?
- The ripeness of a tree.
- The location of the best tree.
How do apes fight for the best food?
- 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.
How does visual stimuli affect the brain?
Has a positive effect on the cerebellum and hippocampus as it causes memory and new experience neurons to fire.
What is metacognition?
Having access to our own private knowledge and competence.
What does metacognition allow for? Good and bad.
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.
What experiment was done to test if non-human primates show metacognition?
- 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.
What were the outcomes of the experiment testing metacognition in rhesus monkeys?
The task was declined more as it became more difficult.
- This suggests declining when there is uncertainty due to metacognition.
What factors allow for flexible cognition in primates? Including their ability to plan ahead.
- 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.
What is one reason why human cognition is different to other primate cognition, despite the similar brain structures?
Humans have the ability to imagine things, this allows us to choose how we use our brains.
