Exam 3: Primate Brains, Cognition, and Behavior Flashcards

1
Q

Are Primates Especially Intelligent?

A

Primates are behaviorally plastic -> Cultural traditions

Primates are “intelligent” if defined by:

  • Negotiate life in complex social systems
  • Solve difficult ecological problems
  • Exceptional learning capacities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Evidence for unique primate intelligence?

A

Primates have a # of anatomical & physiological features which may relate to behavioral plasticity.
** The most important of course are BRAINS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Comparing Brains:

A
  • many same basic “parts”

- HUMANS: have larger overall & more cortical folding than other primates = MORE NEURONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Paul D. Macleans “Triune Brain” - thought to describe the “evolution” of the mammalian brain (1960s)

A

Three Parts:

  1. Reptilian Brain: basic instinctual behavior like mating, aggression
  2. Paleomammalian Brain (aka Limbic): Emotions/memory
  3. Neomammalian Brain: Abstract thought & cognition

However now thought to be too simplistic & many nonmammals have these abilities w/out the same “parts”

EX: Bird Brains: organized diff from primate brains. Mammals & bird brains have been evolving down separate paths over 300 million yrs

**Brain areas important for high-level cognition such as long term memory & problem solving are wired up to other regions of the brain in a similar way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Relative Brain Size - Another Story

body wt/brain wt

A

Primate brains are RELATIVELY LARGE in comparison to most other vertebrates

  • Humans are above the red line which suggests something is going on
  • However *SOCIAL ANIMALS like Cetaceans (porpoises), crows, wolves also show this pattern

**Absolute brain size vs Relative brain size => matters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Encephalization Quotient (EQ):

A

ratio btwn actual brain mass & predicted brain mass for an animal of a given size

  • *HOWEVER neither brain size alone, nor brain size in relation to body size (EQ) may be the whole story
  • We can also look at the relative size of DIFFERENT PARTS of the brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Parts of the Brain:

A
  • Reptilian Brain: Survive, react, repeat, repeat
  • Midbrain: Feel, remember, interact w/others
  • Neocortex: Abstract thought - talk - think- move- create- learn
  • Cerebellum: doesnt change alot among diff species

*NOT all parts of the brain do the SAME thing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neocortex vs Body size

A
  • Neocortex is the most recent evolved portion of the cerebral cortex
  • Where info from diff senses is integrated; controls conscious thought.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The neocortex where conscious thought occurs:

A
  • 30-40% of brain vol. in most mammals

- 50-80% in primates -> more emphasized in primates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Phylogenetic effects : Relative size of neocortex to medulla (part of the primitive brain)

A
  • Insectivorous mammals: neocortex same size as medulla
  • Strepsirrhine primates : neocortex 10x larger
  • Haplorrhine primates: neocortex 20-50x larger
  • Humans - neocortex: 105x larger
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

AND Primate brains are NOT all the same!!

A

Phylogenetic effects exist in size & capacity

  • Strepsirrhines have smaller relative brain size, small neocortex than happlorrhines
  • Happlorrhines have higher neuron density
  • Apres have larger relative brain size than most monkeys (except Capuchins**)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why Big Brains?

A

Difficult to answer since brains are so expensive:

  • around 8x the cost of muscle tissue
  • In humans: the brain accts for 2% of body mass & about 20% energy expenditure
  • Big brain is NOT always Beneficial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Natural Selection

A

Only allows for big brain if beneficial over small brain

  • cant spend energy elsewhere
  • tradeoffs w/other needs

ex: weird bat: Brains vs Testes
- Promiscuous: small brain, large testes
- Monogamous: big brain, small testes
* Tradeoff: reproduction vs smarts!!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Brain size is correlated w/ a # of variables

A

diet, social structure, longevity, locomotion…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

TWO major reasons for big brains:

A
  1. Ecological Hypothesis

2. Social Hypothesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ecological Explanations

A

> No non-human primate stores food they must find it

  • Food must be found efficiently
  • Primates do not move randomly
  • They use the most direct path to food - even if not visible

> Frugivores: have larger brains relative to body size than folivores:

  • Fruits more challenging to find (competition)
  • seasonal distribution (only ripe certain times/places)
  • patchily distributed which means larger home ranges

> Primates & other animals are able to do basic math:
-FORAGING strategy : why stay in one area vs another?
if can ct you can determine where to focus your energy

17
Q

Ecology: Extractive Foragers

A

All have big brains & all engage in extractive foraging (Aye-aye, Capuchin, Chimp)

EXTRACTIVE Foraging: locating & processing foods encased w/in some other matrix

ex: Aye-Aye:
Brain size as an important life history factor - brain size & aye-aye life history:
-largest brain to body wt of all lemurs
Despite being a strepsirrhine, aye-ayes:
-have relatively larger brain
-wean their infants later using this time to teach their young how to forage
-have females who become reproductive at a later age

**Ecological learning maybe linked to the larger brain & thus a “slow” life history

18
Q

Social Explanations:

A

A larger brain allows one to manage social relationships

  • Neocortex size correlates w/sociality
  • Large groups = many interactions ! You need to keep track of both positive and negative interactions

TRIADIC Awareness if rank & friendship in some species

  • is A better friends w/B than A is w/ me?
  • Matters if I have a fight w/B & ask A for help
  • Capuchins & baboons have triadic awereness of this kind

Chimp kin recognition found chimps can match mother-son but not mother daughter pairs because a migrating female should probably not settle into a community in which many males look like their mother, as these males might be related to her

19
Q

Machiavellian Intelligence?

A

Is primate intelligence an adaptation to the special complexities of their social lives, rather than to ecological problems such as finding food?

  • Manipulate other for personal gain
  • make (& break) alliances and friendships to meet ones own personal needs
20
Q

Theory of Mind

-Social Manipulation & Deception

A

Ability to understand the presence of mental states: Beliefs, feelings, intentions, knowledge

Takes two Forms:
1- understand what YOU are thinking
2-Understand what OTHERS are thinking
**Theory of Mind allows predictions of what the other is thinking..how they feel…what they know… & what they will do

21
Q

Mirror Recognition: Tests of Self

A

Monkeys & apes differ in their response to mirrors

  • Monkeys respond as if it is another monkey or act confused
  • Apes eventually use mirror to inspect self (butt)
  • Human children dont pass until 1 yrs old

**Not taxon specific - dolphins, giant manta rays, Eurasian magpies, cleaner wrasse (a fish), and some ant species. Few do pass though

Problems? Focuses on visual sense (what about olfaction?) Problems with testing - does it really mean anything?

22
Q

-Chimp dolls -> capacity for imagination?

A

Cultural Component:

  • Executive brain ratio = vol of neocortex relative to the rest of the brain
  • Life History : long lifespans, cultural buffer, social species = allows emphasis on social learning - driving enhanced brain to store info?
23
Q

Ecology & Social Influences Together?

A

EX: Chimp hunting an ex of an extremely complicated behavior:

  • needs extreme cooperation & planning
  • requires “theory of mind” & social learning as well as ecological knowledge
  • need understanding of what others “deserve” after the hunt
  • requires as least a complex brain

**Brains have been selected for their ability to store & manage info via some combo of individual (asocial) or social learing -> CULTURAL BRAIN HYPOTHESIS