Software Agent 인지 구조
John R. Anderson, "Human Symbol Manipulation Within an Integrated Cognitive Architecture,"
Cognitive Science, vol. 29, no. 3, pp. 313–341, 2005
4 주차 : 제 1 발제 인지구조 / 발제자 : 최봉환
Outline
• Introduction• ACT-R• Use of brain imaging• The capacity for re-representation: A uniquely human trait?
Introduction
• Overview of ACT-R theory– illustrative application of it to algebra equation solving
• Algebra equation solving– uniquely human cognitive activity– "what is unique about human cognitive?"
• Comparing human brain with ACT-R– preliminary mapping ACT-R component to brain
functional fMRI
ACT-R Theory
• ACT-R– Adaptive Control of Thought–Rational
= cognitive architecture
• Theory– for "how human cognition works"
ACT-R Architecture
• RoleInput = Problem repre-
sentation(3x - 5 = 7)
Mental representa-tion
(3x = 12)
Communication,Procedural Control
Goal : Strategy decision(unwind stratage)
Retrieve Critical In-formation(7+5=12)
Output(x=4)
massive parallelism & central bottle neck
Algebra equation manipulation
• Why algebra equation solving problem– substantial complexity– tractably characterized and studied
• unlike many human accomplishments (cf : Natural language)
• Problem–
– solved by unwind strategy
The ACT–R model
• General instruction–
The ACT–R model : speedup
• Speedup– Compilation
• collapse multiple steps into single step
– Reduction of retrieval times• subsymbolic learning
– instruction strongly encoded during day0• arithmetic fact repeated major learning happening at the symbolic
level – production rules
Regions of interest
Caudate procedural
prefrontal retrieval Anterior cingulate
goal
Paretal problem state or
imaginalmotormanual
Measuring activity
• Measuring activity– BOLD : blood-oxygen-level-dependent
• measure neural activity directly have been attempted
– profile of activity in modules
• t = time, s = scales the time, a = determines the shape of BOLD response,m = govern magnitude
• f(x) = engage function
Characterizing the differences among the brain regions
Assessing goodness of fit
• Measure the degree of mismatch against the noise in the data
–
토의 제안
• 인간과 동일한 구조를 모사하는 것의 의미는 ?– 인간과 동일할 필요가 있는가 ?
• 인간에게 원하는 것과 컴퓨터에게 원하는 것이 다를 것 같은데 ..
– 인간과 동일한 것을 증명할 필요는 있는가 ?• 1+3 = 4 = 2+2=4 라면 내부구조의 의미는 ?
• 성능은 ?– 간단한 문제라서 잘 풀리는 것이 아닌지 ?– 수학적인 문제 혹은 논리적인 문제에만 적용 가능한 건 아닌지
• 모호함에 대한 해결책은 ?– ACT-R 은 Deliberative Agent 인듯한데 모호한 정의에 대한 묘사는
어떻게 ?– Goal based Agent 로 구성되어 있는데 목적지는 어떻게 찾을 것인가 ?