title: On Sequence Learning Models: Open-loop Control Not Strictly Guided by Hick's Law.
abstract: According to the Hick's law, reaction times increase linearly with the uncertainty of target stimuli. We tested the generality of this law by measuring reaction times in a human sequence learning protocol involving serial target locations which differed in transition probability and global entropy. Our results showed that sigmoid functions better describe the relationship between reaction times and uncertainty when compared to linear functions. Sequence predictability was estimated by distinct statistical predictors: conditional probability, conditional entropy, joint probability and joint entropy measures. Conditional predictors relate to closed-loop control models describing that performance is guided by on-line access to past sequence structure to predict next location. Differently, joint predictors relate to open-loop control models assuming global access of sequence structure, requiring no constant monitoring. We tested which of these predictors better describe performance on the sequence learning protocol. Results suggest that joint predictors are more accurate than conditional predictors to track performance. In conclusion, sequence learning is better described as an open-loop process which is not precisely predicted by Hick's law.
authors.affiliation: Universidade Federal do Rio Grande do Norte, Instituto do Cérebro, Natal, 59056-450, Brazil.|Universidade de São Paulo, Instituto de Biociências, São Paulo, 05508-090, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Pavão
authors.affiliation: Universidade de São Paulo, Instituto de Biociências, São Paulo, 05508-090, Brazil.
authors.forename: Joice P
authors.initials: JP
authors.lastname: Savietto
authors.affiliation: Universidade Federal do ABC, Centro de Matemática, Computação e Cognição, Santo André, 09210-580, Brazil.
authors.forename: João R
authors.initials: JR
authors.lastname: Sato
authors.affiliation: Universidade de São Paulo, Instituto de Biociências, São Paulo, 05508-090, Brazil.
authors.forename: Gilberto F
authors.initials: GF
authors.lastname: Xavier
authors.affiliation: Universidade de São Paulo, Instituto de Biociências, São Paulo, 05508-090, Brazil.
authors.forename: André F
authors.initials: AF
authors.lastname: Helene
mesh_terms: D000293:Adolescent; D000328:Adult; D002755:Choice Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008962:Models, Theoretical; D010775:Photic Stimulation; D011336:Probability; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D035501:Uncertainty; D055815:Young Adult