I.         Brain BBC video – (revised 3/11/11)

II.     Brain size of humans vs apes

A.    Why haven’t chimps with relatively big brains and good hands refined their tool use over generations?

III.Role of prefrontal cortex (PFC)-2X in humans

A.    Clinical case- effects of PFC damage

1.        Phineas Gage too

B.    Imaging of PFC

1.        Lots of early lesion studies on PFC using monkeys and apes (Becky & Betty?).  Lobotomies were one result of this.

2.        Currently lots of imaging studies exploring changes in activity levels as tasks change.

C.    Functions

1.        Planning

a)       Keeping overall goals in mind

2.        Social relationships

3.        Control and inhibition of behaviors (JL)

IV.                 Compare with chimps

A.    Maze solution—is it really deep planning? Don’t you or the chimp just look ahead?

B.    Can chimps really “plan” even a few days ahead?  There is little analogy to mazes here because the maze is always visible—no representation is needed. Planning is relevant but easy if goal can be maintained.

V.   Language?

A.    Function in culture?

1.        Social relations

2.        Transmission of specific information as culture

3.        Component to intra-personal cognitive processes, e.g. thought, memory, consciousness?

B.    Brain regions?

1.        Cause-Effects of stroke—failure of blood supply- rupture, clot..

2.        Old localization ideas

a)       Left hemisphere

b)      Broca & Wernicke’s area

3.        Aphasia

a)       Physicist’s stroke

(1)  Good grief! Take an aspirin and call 911! Don't fly to L.A!
(2)  Effects of stroke – loss of oxygen, fuel, exhaust destroy neurons in minutes.

b)      Sherrington--Penfield-like probes during epileptic surgery (Ojemann).  This works as brain has no pain receptors.

4.        New localization of brain function ideas

a)       Old ideas statistically reliable but…

b)      Neural Networks devoted to specifics

c)        Lots of individual differences

5.        Laterality of brain function --obvious in humans, less so in apes


6.  Recent genetic findings show humans have undergone several language-related gene mutations with the last 5 to 50K years –- not to mention the previous 7 million year split from a common chimp-human

ancestor -- including those related to vocalization (FOXP2) and hearing.

C    Using human-based codes with apes—the Georgia chimps

                        1. there’s no question that these bonobos can communicate with symbols and limited comprehension of spoken English.

                        2. It is important not to lose perspective however—no matter what S. S. Rumbaugh says.  These apes are about at the level of 18 month old kids and that is a gross comparison.  The idea that they comprehend like children of 5 to 7 years is ridiculous.  Vocabulary of the apes seems about a few hundred while that of children at 5 years might be 5-8 thousand and climbing.

                        3. there are many functions of human L, even in 2-3 year olds that chimps seem clueless about.


D- human language and the left hemisphere—the split brain view

                        1. Gazzaniga argues a recent mutation specialized the human left hemisphere, enabling it (the “interpreter”) to tell causal stories about experiences.  It remains unclear whether this is caused directly by human language or is somehow just associated with it.