טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBaram Avichay
SubjectThe Comparative Effects of Inter-stimulus-interval on
Immediate Recall of Visual and Haptic Sequences
DepartmentDepartment of Industrial Engineering and Management
Supervisors Professor Emeritus Daniel Gopher
Ms. Maria Korman
Full Thesis textFull thesis text - English Version


Abstract

 

Temporal effects on working memory (WM) have been widely studied in visual and auditory modalities; yet its effects on WM of the haptic (active touch) modality are as yet unclear. In particular, the relationship between presentation rate of haptic stimuli and the duration of haptic exploration, and how these variables contribute to storage and maintenance of information in haptic working memory, need to be elucidated.

In the current thesis, we examined (1) the effect of presentation times and interstimulus interval (ISI) length on haptic WM and visual WM; and (2) how manipulation of these variables affects strategy choice while performing a similar task in visual and haptic modalities. 

To achieve these aims, we investigated the impact of various temporal effects on visual or haptic memory for multiple items presented serially. We designed a unique memory task in which subjects examined sequences of stimuli which were encoded either haptically or visually, and modulated by the degree of stiffness (haptics) or luminance (visual) of stimuli. The ISI between stimuli was manipulated within and between practice and transfer sessions.

Results suggest that (1) recall (measured as performance level) under visual conditions was generally superior to that of haptic conditions; (2) varying ISI lengths between practice and transfer sessions affected performance level in the haptic, but not visual, modality, in terms of memory capacity; (3) varying ISI lengths affected the amount of time invested in stimuli exploration in the haptic, but not visual, condition. However, preparation time, defined as the time until commencing exploration, showed no major differences between modalities.

Thus, the current study presents important differences between haptic and visual WM, in particular for capacity. This may be due to the different role that haptic exploration plays in memory processes, compared to visual exposure. The possible relationship between our findings is further discussed in the context of capacity limitations and strategy choice under various modality conditions.