HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Binder, M. Articles by Urbanik, A. S. Search for Related Content PubMed PubMed Citation Articles by Binder, M. Articles by Urbanik, A. S.

Material-dependent Activation in Prefrontal Cortex: Working Memory for Letters and Texture Patterns—Initial Observations¹

¹ From the Department of Psychophysiology, Institute of Psychology (M.B.) and Department of Radiology, Collegium Medicum (A.S.U.), Jagiellonian University, 19 Kopernika St, 31-501 Kraków, Poland. Received September 20, 2004; revision requested November 24; revision received February 2, 2005; final version accepted February 28. Address correspondence to A.S.U. (e-mail: aurbanik{at}mp.pl).

View larger version (13K): [in a new window]   Figure 1a: Examples of stimuli trains used during (a) zero-back task with letters, (b) two-back task with letters, (c) zero-back task with patterns, and (d) two-back task with patterns. Arrows indicate relevant stimuli that required positive responses from subjects; a motor response to each stimulus was required.

View larger version (14K): [in a new window]   Figure 1b: Examples of stimuli trains used during (a) zero-back task with letters, (b) two-back task with letters, (c) zero-back task with patterns, and (d) two-back task with patterns. Arrows indicate relevant stimuli that required positive responses from subjects; a motor response to each stimulus was required.

View larger version (47K): [in a new window]   Figure 1c: Examples of stimuli trains used during (a) zero-back task with letters, (b) two-back task with letters, (c) zero-back task with patterns, and (d) two-back task with patterns. Arrows indicate relevant stimuli that required positive responses from subjects; a motor response to each stimulus was required.

View larger version (46K): [in a new window]   Figure 1d: Examples of stimuli trains used during (a) zero-back task with letters, (b) two-back task with letters, (c) zero-back task with patterns, and (d) two-back task with patterns. Arrows indicate relevant stimuli that required positive responses from subjects; a motor response to each stimulus was required.

View larger version (13K): [in a new window]   Figure 2: Diagram shows the block design used in the study.

View larger version (92K): [in a new window]   Figure 3: Selected transverse MR image sections overlaid with statistical maps show results of stimulation with nonverbal (patterns) and verbal (letters) versions of the working memory task in the dorsolateral prefrontal cortex. When the stimuli were letters, activation showed up in the left hemisphere, whereas memorization of patterns was correlated with bilateral activation within the prefrontal regions. Background images are a template derived from a high-spatial-resolution (1-mm isotropic voxels) low-noise data set that was created by registering 27 images obtained with T1-weighted gradient-echo sequence (18/10; flip angle, 30°) in the same individual in stereotactic space where they were subsampled and averaged for signal intensity (29). Images are shown in radiologic convention (ie, left side of each image corresponds to subject's right side).

View larger version (52K): [in a new window]   Figure 4: Three-dimensional cortical surface maps illustrate the overall cortical distribution of activation in verbal (letters) and nonverbal (patterns) versions of n-back task. Background images are a template derived from a high-spatial-resolution (1-mm isotropic voxels) low-noise data set that was created by registering 27 images obtained with T1-weighted gradient-echo sequence (18/10; flip angle, 30°) in the same individual in stereotactic space where they were subsampled and averaged for signal intensity (29).