What makes us
HUMAN?
When you work on a definition
question, explain the concept and
examples do not hurt.
When you answer a significance
question, you must think on why this
this concept is important (e.g.
missing heritability is important
because knowing all genomic
associations do not clarify the link
between phenotype and genotype).
What characteristics set homo sapiens apart from other primates?
Figure 4.1: Simplified hominin phylogeny. After Lewin and Foley (2004) p. 17
Calendar of Hominin Evolution
10 - 5 mya
~ 5-7 mya
4.4- 1.1 mya
2.4 - 1.5 mya
1.9 - 0.3 mya
800 - 50 kya
300 - 30 kya
200kya - pres.
Cooler climate in Africa replacing tropical forests with open
habitats
Hominini separated from Panini
Australopithecus species
Homo habilis
Homo erectus
Archaic Homo sapiens (Homo heidelbergensis)
Homo neanderthalensis
Modern Homo sapiens
10kya - pres.
Agriculture
Check out eSkeletons to compare extant primate species!
Figure 5.10: Muscles that move the human thumb. From Sussman R. (1994)
Science 265: 1570-1573
Muscles unique to humans are in color.
Kalthoff 2010
~3.4Ma
Human brain anatomy
• Cerebral cortex
– Neocortex
•
•
•
•
•
Sensory perception
Motor commands
Spatial reasoning
Consciousness
Language
– Allocortex
• Hippocampus
Cerebellum
– Spatial navigation
– Consolidation of short and long
term memory
• Amygdala
– Emotional memory
– Long term memory consolidation
• Corpus callosum
– Connects left & right hemisphere
• Cerebellum
– Motor control
http://www.brain-map.org/
Human brain anatomy
Somatosensory representation of the human
body in the cortex
Why do humans have large brains?
Allometric hypothesis
• Non-adaptive
– Allometric hypothesis: large
brains are a consequence of
having a larger body size
• Adaptive
– Ecological Brain Hypotheses
1.
2.
3.
Resource dispersion
Mental maps
Extractive foraging
– Social Brain Hypotheses
1.
2.
3.
4.
Individual recognition
Relationship memory
Emotional competence
Relationship management
Could you explain the encephalization quotient from the 'brain evolution' lecture?
Is the human brain special?
• Humans don’t have the
largest brain among
mammals
• Encephalization quotient:
brain mass corrected for
body mass
– Does a small brained
animal with a large EQ
have greater cognitive
ability than a large brained
animal with a small EQ?
• Neuron number
– does not always correlate
with brain mass
Is the human brain special?
•
The total number of neurons in the
human brain is actually what you would
predict for our body size
–
–
•
The relative number of neurons in the
cerebral cortex is similar to other primates
–
•
82% of brain mass, but only 19% of the neurons!
The energetic cost per neuron is not
unusual
–
•
a 75 kg primate would be expected to have 78
billion neurons
Humans have 86 billion, within 10% of the
expected from body mass
6 kCal per billion neurons per day
Humans have a very large brain, but its
just a scaled up version of the typical
primate brain
–
Caveat: the relative size of functional cortical
areas, the volume of prefrontal white matter or
the size of specific portions of the cerebellum may
impact human cognition
©2012 by National Academy of Sciences
Herculano-Houzel PNAS 2012;109:10661-10668
Is the human brain special?
•
The total number of neurons in the
human brain is actually what you would
predict for our body size
–
–
•
The relative number of neurons in the
cerebral cortex is similar to other primates
–
•
82% of brain mass, but only 19% of the neurons
The energetic cost per neuron is not
unusual
–
•
a 75 kg primate would be expected to have 78
billion neurons
Humans have 86 billion, within 10% of the
expected from body mass
6 kCal per billion neurons per day
Humans have a very large brain, but its
just a scaled up version of the typical
primate brain
–
Caveat: the relative size of functional cortical
areas, the volume of white matter or the size of
specific portions of the cerebellum may impact
human cognition
©2012 by National Academy of Sciences
Herculano-Houzel PNAS 2012;109:10661-10668
In the 'brain evolution' lecture, it is mentioned that a larger neocortex is associated with more
parvocellular cells. Does this support the hypothesis that primates with more frugivorous diets
have a larger neocortex ratio than folivorous primates?
Ecological Brain
Resource Dispersion Hypothesis
•
•
Hypothesis: Temporally or spatially ephemeral resources select for greater cognitive function
Prediction: Primates with more frugivorous (fruit eating) diets should have a larger neocortex
ratio than folivorous (leaf eating) primates
-> A larger neocortex is associated with more parvocellular cells
(color processing region of the cortex)
Dunbar 1998
Ecological Brain
Mental Maps Hypothesis
•
•
Hypothesis: Spatial learning selects for greater cognitive function
Prediction: Primates with larger home ranges should have a larger neocortex ratio
-> Range size does correlate with hippocampus size
-> Migrating animals (birds, butterflies) have small brains
Dunbar 1998
Remember, to answer: Why do humans have large
brains? There are these hypotheses
• Non-adaptive
– Allometric hypothesis: large
brains are a consequence of
having a larger body size
• Adaptive
– Ecological Brain Hypotheses
1.
2.
3.
Resource dispersion
Mental maps
Extractive foraging
– Social Brain Hypotheses
1.
2.
3.
4.
Individual recognition
Relationship memory
Emotional competence
Relationship management
What is the faculty of language?
HCF have argued that most if not all of FLB is shared with other species
While FLN may be unique to humans
(This represents a hypothesis in need of further empirical investigation)
FLN evolved for reasons other than language, the comparative analysis should
demonstrate this
Hypotheses For Human Language Evolution
• Hypothesis 1: FLB (including FLN) is strictly
homologous to animal communication.
• Hypothesis 2: FLB is a derived, uniquely
human adaptation for language.
• Hypothesis 3: Only FLN is uniquely human.
Hauser et al 2002
What are the differences between the broad and narrow sense of the faculty of language?
“FLB includes a sensory-motor system, a conceptual-intentional system, and the computational
mechanisms for recursion, providing the capacity to generate an infinite range of expressions
from a finite set of elements. We hypothesize that FLN only includes recursion and is the only
uniquely human component of the faculty of language”
Hauser et al 2002
•
•
•
•
Hauser et al 2002
To understand the evolution of language
we are not interested in the language per
se but the ability to use it.
FLB includes FLN plus two other
components, the sensory motor aspects
and the conceptual intentional aspects.
Sensorimotor = capacity to perceive and
produce sound
Conceptual-intentional = mental
representations of an idea
4. What does "FLN generates internal representations and maps them onto
sensory motor and conceptual-intention interface" mean? (language ppt #12)
So….. What is recursion?
Wikipedia: Recursion is the process of repeating items in a self-similar way. For instance,
when the surfaces of two mirrors are exactly parallel with each other, the nested images that
occur are a form of infinite recursion.
Recursion in R language and programing!
The abstract [Hauser et al 2002] makes the very strong
proposal that the narrow language faculty “only includes
recursion and is the only uniquely human component of
the faculty of language.”
Recursion refers to a procedure that calls itself, or to a
constituent that contains a constituent of the same kind.
The authors suggest that “most, if not all, of FLB is based
on mechanisms shared with non-human animals..
In contrast, we suggest that FLN—the computational
mechanism of recursion—is recently evolved and unique
to our species”
“We propose in this hypothesis that FLN comprises only
the core computational mechanisms of recursion as they
appear in narrow syntax and the mappings to the
interfaces” (i.e. the interfaces with mechanisms of speech
perception, speech production, conceptual knowledge,
and intentions).
The authors go on to speculate that the recursion
mechanism, defining what is special about language, may
not even have evolved for language itself but for other
cognitive abilities such as navigation, number, or social
relationships.
Steven Pinker
FLB = Faculty of Language (Broad sense)
FLN = Faculty of Language (Narrow sense)
Hauser et al 2002
Can you go over the different parts of the brain and the associated function of each?
Campbell’s
monkeys
also
produce alarm calls in response
to predators and other
disturbances.
•
•
•
Six different alarm calls types
Call given in different contexts.
Adding an ‘‘oo’’ unit to ‘‘hok’’
indicated that the male was
aggressively motivated
Fig. 2. Composition of call sequences in different behavioral
contexts. ‘‘Alarm’’ indicates leopard or eagle alarm calls given
by sympatric Diana monkeys.
Could you give us examples of the four types of operant conditioning. (Behavior ppt #13)
PRINCIPLES OF THE STANDARD SOCIAL
SCIENCES MODEL
• Learning is the mechanism
generating fidelity within and
differences between cultures in
human behavior.
– “Behaviorism”
• Humans are learning machines
– Any behavior can be learned through
reward and punishment
• Skinner’s operant conditioning: Behaviors
not followed by reinforcement (or
punishment) are not repeated.
• Culture is thus free to vary in any
direction.
Look at this video if you can:
https://www.youtube.com/watch?v=Mt4N9GSBoMI
Operant conditioning
Taken from http://examples.yourdictionary.com/operant-conditioning-examples.html
Positive Reinforcement
Positive reinforcement is giving something pleasant after a behavior. This increases the probability that the behavior will continue. Examples are:
Having a job and going to work every day to receive a paycheck.
Receiving praise after a musical performance would increase the amount that you perform.
A teacher complimenting students when they answer correctly will increase that behavior.
At a gym, customers receive a discount if they work out a certain number of times and eat healthy.
In the Skinner Box experiment, a rat got food as a reward for acceptable behavior, such as pressing a lever.
Negative Reinforcement
Negative reinforcement is taking away something unpleasant as a result of the behavior that is acceptable. This is also meant to increase the behavior.
Examples are:
It is very noisy outside so you turn on the television to mask the noise. Turning on the radio decreased the unpleasant noise.
A teacher exempts student from the final test if they have perfect attendance. So, the teacher is taking away something unpleasant to increase behavior.
At a store, a child throws a tantrum because he did not get a candy bar. Dad finally gets him one. He stopped the tantrum so he took away something
unpleasant and Dad’s behavior of getting candy bars will increase.
In the Skinner box experiment, a loud noise continuously sounded inside the cage until the rat did what Skinner wanted him to do. When he did, the noise
stopped, so the unpleasant noise was taken away.
In a biology class, students who made an "A" on the test did not have to dissect a frog.
Positive Punishment
Positive punishment is used to decrease a behavior and is presenting something unpleasant after the behavior. Examples are:
An employee exhibits bad behavior at work and the boss criticizes him. The behavior will decrease because of the boss’s criticism.
When a student misbehaves in class, she receives a time out.
A child gets a spanking when he puts his hand in the cookie jar.
When a child does not out his clothes in the hamper, he has to do ten extra minutes of chores.
In an experiment, the subject received a slight electric shock when they got an answer wrong.
Negative Punishment
Negative punishment is also used to decrease a behavior and is removing something pleasant after the behavior. Examples are:
An employee is habitually late for work so begins losing the privilege of listening to music while working. The behavior will decrease because of losing a
privilege.
A child doesn’t put his bike away so the parents lock it up for a certain time. The parents took away something pleasant to decrease behavior.
Ted gets a $500 fine and suspension of his driving license for driving under the influence. Money and his license were removed to decrease behavior.
A family has a "swear jar." Every time someone swears, they have to put a dollar in the jar. This is taking away money, which is something pleasant, and
decreases the behavior of swearing.
Kevin trashes his sister’s room and Mom told him he could not go camping with his friends.
When talking about evolutionary psychology, what is genetic determinism in the strict
sense? (Behavior ppt #13)
PRINCIPLES OF EVOLUTIONARY PSYCHOLOGY
• The brain is an information processing device
•
– A physical system that can be studied, not a “black box”
– Receives inputs, enacts a decision rule and outputs
behavior/emotions/physiological responses.
Does not assume genetic determinism of behavior in the strict sense
– Output is dependent upon specific environmental contingencies.
• If E1 occurs, do x; if E2 occurs, do y, if E1 & E2 occurs, do z.
– “Darwinian algorithms”: the mind has evolved to process many different
environmental contingencies and produce an adaptive response.
– Algorithms can be modified by the environment, but this is also an evolved
capacity constrained by the pre-existing algorithms.
Inputs
Decision Rules
Outputs
What does it mean when it says that humans and dolphins can imitate in > 1 sensory
modality and do dolphins and songbirds just regurgitate the imitated sounds without them
having any meaning?
Imitation: The sensory-motor system
• Imitation is a precondition for FLB
to evolve
• Imitation not unique to humans
– Highly developed in songbirds
and dolphins.
– But virtually absent in apes and
monkeys
• can learn several hundred hand
signs but requires years of
training
• Only humans and dolphins
can imitate in >1 sensory
modality
On slide #12 of the "bipedalism and tool making" powerpoint, it states that male have a
preference for high waist to hip ratio. However, from the mate choice lecture, we learned
that the preference is for lower waist/hip ratio. What is the reason for this discrepancy?
It depends on the point of view….. Lower than .65 has lower preferences
Cooperation
Kin Selection
Directed
reciprocation
Indirect reciprocity
Byproduct
cooperation
There were not questions on this….. If I get more before Monday I will update this ppt