טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentChuntonov Olga
SubjectIndividual Differences in Control Processes
DepartmentDepartment of Industrial Engineering and Management
Supervisor Professor Emeritus Daniel Gopher
Full Thesis textFull thesis text - English Version


Abstract

The objective of the present research is to explore the existence and consistency of individual differences in control abilities. More specifically, the study investigates individual differences in the ability to switch and to focus attention. It combines the “task switching” and the “flankers” paradigms to elucidate the sources of focusing difficulties and problems of switching. Using individual differences methodology, we try to shed light on one of the main questions in the field of human information processing, the centrality of the control system.

Studies of individual differences in executive control until now suggest the existence of stable individual differences and there is evidence that control functions are not completely independent. This consistent finding across a variety of studies creates the possibility of using this data to try and infer on the basic structures involved.

Our experimental results showed consistent individual differences in focusing and switching abilities across training and tasks. The correlation between the ability of a person to perform switching and his ability to focus was almost 0.9, as if the two functions were variants of the same ability or strongly connected. PCA supported this finding, revealing a distinction between univalent and bivalent response sets. A single factor, explaining most of the variance was found in the bivalent condition, with both the repeat and switch trials loaded on it. In the univalent condition, there were two factors, explaining about the same amount of variance, with the switch trials loaded on one of them and the repeat trials loaded on the other.

Summing up the findings, our results suggest existence of a common mechanism that enables people to perform acts of control. The abilities to switch and to focus are highly explained by this mechanism. It also appears that a person that performs well in focusing situations will also perform well when switching control is required. We may refer to the two processes as variants of the same ability; at least as long as we are using tasks that involve a single bivalent response set. When the tasks used one common response set - the functions of switching and focusing are associated with one mechanism, while when the tasks were separated not only on stimuli-set level, but also on the response-set level, those processes are distanced from each other. It is possible that other manipulations exist that may create even further separation of those control functions.