Prefrontal Cortex

Adam GanikJulia Piskova Kevin Ilango

LocationLocation

• Front of Brain• Located in the

frontal lobes area of the brain

•  Lies in the motor and premotor areas

Functions of the Prefrontal CortexFunctions of the Prefrontal Cortex

The Skull of Phineas Gage, a case that first established

the functions of the Prefrontal Cortex

• Responsible for executive functions (goal-directed behavior) which are:

• Decision making• Initiation and control over the execution

of deliberate actions• Targeting attention• Problem solving• Planning initiation of activities• Processes in Working memory• Social Behavior/Reasoning

• When an action is executed, the prefrontal cortex is informed, & allows appropriate monitoring

• Feedback-feedforward loop helps judge activity & reveals possible deficiencies

StudiesStudies

 

Nieder & Diester (2007) Nieder & Diester (2007)

 

AimAim

• To determine which part of the brain would be activated when monkeys associated an

Arabic numeral to the corresponding number of dots.

ProcedureProcedure

• Two rhesus monkeys were trained to associate a number of dots to the corresponding Arabic numeral

• Monkeys pulled a lever when they saw a picture of dots and the corresponding numeral

• Researchers scanned 692 randomly selected neurons in the prefrontal cortex and 437 neurons in the parietal cortex

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ResultsResults

• 23% of prefrontal cortex neurons showed increased activity as compared to 2%

• Groups of neurons in the prefrontal cortex were tuned to certain numbers

• If the monkey was about to make an incorrect decision, prefrontal neurons displayed a different pattern than when they were correct

Koenigs et al. (2007) Koenigs et al. (2007)

 

AimAim

•To determine the effect of damage to the ventromedial prefrontal cortex on solving a

moral dilemma.

““The Ultimatum Game”The Ultimatum Game”

• A pair of players is offered a sum of money

• Player A proposes some division of the money with Player B;

• If Player B rejects the proposed division, neither of them gets any money.

• Player B’s best option is to accept any proposal, since rejection means no gain at all.

ResultsResults

• Players with damage to the ventromedial prefrontal cortex rejected imbalanced offers more than the control group

Limb & Braun (2008)Limb & Braun (2008)

AimAim

• To determine if change in neural activity in the prefrontal cortexes of Jazz musicians’ was due to creativity and not the complexity of a given task.

ProcedureProcedure• fMRI scans were done on highly trained jazz

musicians while they played a simple major C scale, then they attempted improvisation

• They then played a memorized Jazz piece, and improvised after that, however, this time, the Jazz piece was being played to them while they improvised and came up with their own notes.

ResultsResults

• The scans determined that improvisation didn’t increase the neural activity, but rather the Jazz piece did as it was the more creative task.

• The study supported that the dorsolateral prefrontal cortex shuts down during improvisation and the medial gets more active because the medial is more active during creative actions and processes like self-initiated thoughts

What happens when the What happens when the prefrontal cortex is dysfunctional?prefrontal cortex is dysfunctional?• No effect on basic cognitive abilities

• Social Behavior (Phineas Gage)

• Decision making, weighing of risks and consequences

• Defective response to punishment

• Dysfunction linked to schizophrenia

• Relationship between smaller prefrontal cortex and ADHD

Works Cited

“ADHD Gets Some Attention.” University of Washington. N.p., n.d. Web. 6 Apr. 2010. <http://faculty.washington.edu/ chudler/

adhd.html>.Anderson, Steven W., et al. “Impairment of social and moral behavior

related to early damage in human prefrontal cortex .” Nature Neuroscience. N.p., 1999. Web. 6 Apr. 2010.

<http://www.nature.com/ neuro/ journal/ v2/ n11/ abs/ nn1199_1032.html>.

Koenigs, Michael, et al. “Damage to the prefrontal cortex increases utilitarian moral judgements.” Nature. N.p., 19 Apr. 2007. Web. 7

Apr. 2010. <http://www.nature.com/ nature/ journal/ v446/ n7138/ abs/ nature05631.html>.

Limb, Charles J., and Allen R. Braun. “Neural Substrates of Spontaneous Musical Performance: An fMRI Study of Jazz Improvisation.” PLoS ONE. N.p., n.d. Web. 6 Apr. 2010.

<http://www.plosone.org/ article/ info:doi/ 10.1371/ journal.pone.0001679>.

Works Cited (cont’d)

Moll, Jorge, and Ricardo Oliveira-Souza, de. “When Morality is Hard to Like.” Scientific American Mind. N.p., 6 Aug. 2007. Web. 6 Apr. 2010. <http://www.scientificamerican.com/ blog/ post.cfm?id=when-

morality-is-hard-to-like>.Perlstein, WM, et al. “Relation of prefrontal cortex dysfunction to working memory and symptoms in schizophrenia.” PubMed. N.p.,

July 2001. Web. 6 Apr. 2010. <http://www.ncbi.nlm.nih.gov/ pubmed/ 11431233>.

“Study: Prefrontal Cortex In Jazz Musicians Winds Down When Improvising.” Scientific Blogging. N.p., 26 Feb. 2008. Web. 6 Apr.

2010. <http://www.scientificblogging.com/ news_releases/ study_prefrontal_cortex_in_jazz_musicians_winds_down_when_impr

ovising>.Swaminathan, Nikhil. “How the Brain Maps Symbols to Numbers .”

Scientific American Mind. N.p., 31 Oct. 2007. Web. 6 Apr. 2010. <http://www.scientificamerican.com/ article.cfm?id=how-the-brain-

maps-symbol>.