Functional magnetic resonance imaging: Overview and methods for psychological research

Functional magnetic resonance imaging (fMRI) allows noninvasive imaging of hemodynamic changes related to neural activity. This technique can be used in single-subject designs and can provide millimeter spatial resolution and temporal resolution in the range of 5–10 sec. This paper provides a brief introduction to MRI techniques and their application to functional neuroimaging, focusing on methodological issues that are of particular concern to psychologists, including methods for presenting computerized stimuli to subjects without disrupting the scanner, experimental design issues, and statistical analysis and image processing procedures. To illustrate methodological issues, recent results from a series of studies looking at the topographic organization of visual cortex are presented. General issues concerning limitations in this technique, future directions in its development, its relationship to other neuroimaging techniques, and the role of functional neuroimaging in psychological research are addressed in the Discussion.     

Screen display and timing synchronization on the Apple IIe and Apple Ilgs

The logic of the vertical blanking interval (VBL) Softswitch in the Apple Ilgs is the reverse of the logic of the VBL in the Apple IIe. Programs written for the Apple IIe that synchronize the videoscan with the experiment control program timing by sensing the VBL pulse will therefore function incorrectly when run on an Apple Ilgs. Procedures for modifying existing synchronization routines are discussed. A flexible alternative program that senses the type of computer on which it is running and accordingly adjusts the logic of the synchronization routine is described.     

A sustained analysis of the behaviors of schooling

Educationally significant behaviors of students, teachers, and supervisors were directly assessed daily for a fiscal year in a residential school in which the results of behavior analysis research are applied to all levels of schooling. The variables assessed included those found to be concomitantly related to effective schooling as determined by the educational research literature, and functionally related to effective teaching as determined by the literature of behavior analysis. Weekly summaries of the following variables were analyzed for each of two daily shifts of teachers and supervisors: (a) number of trials presented and correct number of trials, (b) number of instructional sessions conducted, (c) number of learning objectives achieved, (d) percentage correct in each of three curricular areas, (e) weekly teacher observation scores, and (f) the total and rate per hour of supervisors' task accomplishments. There were strong positive correlations between: (a) instructional sessions and learning objectives, (b) teachers use of behavioral techniques in weekly observations by supervisors and students' achievement, (c) number of supervisor tasks completed and number of instructional sessions conducted by teachers, (d) number of teacher observations by supervisors and teachers' performance during observations, and (e) number of student objectives attained and number of tasks completed by supervisors. The assessment is the most comprehensive and sustained analysis of the daily behaviors of schooling. The relationships found between students and teacher behaviors replicate the effects of numerous experiments but do so in a total school setting. The relationships found between supervisor and student behavior have not been demonstrated in prior research. There is a need for similar school wide assessments in other types of schools to determine the generality of the relationships obtained in the present article.     

An evaluation of statistical software for research and instruction

A variety of microcomputer statistics packages were evaluated. The packages were compared on a number of dimensions, including error handling, documentation, statistical capability, and accuracy. Results indicated that there are some very good packages available both for instruction and for analyzing research data. In general, the microcomputer packages were easier to learn and to use than were mainframe packages. Furthermore, output of mainframe packages was found to be less accurate than output of some of the microcomputer packages.     

Further investigations of inhibitory mechanisms in attention

Three experiments employed a discrete-trials version of the Stroop task to investigate further the claim that there are inhibitory mechanisms in selective attention (Neill, 1977). The results indicated that the evidence supporting the inhibitory theory (i.e., the diminished availability of distractor responses) cannot be explained by subjects’ attempts to physically match successive stimuli (Lowe, 1979). In light of all the available evidence, it was suggested that the suppression effect does not index attentional inhibition, but may be attributed to a problem of code coordination (Keele & Neill, 1978).     

Lexical representation of fact and opinion

This research investigated the lexical properties underlying comprehension that a word represents fact or opinion. In Experiment 1 subjects reliably identified words as either fact or opinion. Bivariate correlations and multiple regression showed that fact/opinion judgments were predicted primarily by ratings of the ease of verifiability of a word's referent and secondarily by the word's literalness, but not by several other lexical attributes: abstractness-concreteness, vagueness-preciseness, and evaluation. Experiment 2 extended the results of the first experiment to an implicit fact/opinion judgment, i.e., the identification of headlines as originating from a newspaper's front page (presumably based primarily upon fact) or from the editorial page (presumably based upon opinion). The headline judgments, also made reliably by subjects, were predicted by the same variables found significant in the first experiment, i.e., by verifiability and literalness, but not by the other lexical properties. Thus, the results of both experiments indicate that the identification of a word as representing fact or opinion is rooted in a word's verifiability and literalness.     

Reliability and validity of children's reports of migraine headache symptoms

The present study was concerned with whether children's responses to a questionnaire correspond with parents' reports of the child's headache symptoms and whether these responses correlate with self-monitored headache activity. Twenty-eight children, ages 7 years–16 years, participated in the study. Using a questionnaire format, data on a wide variety of headache characteristics were gathered from parents and children. During the subsequent 4 weeks, children monitored their headache activity and medication usage. Results were generally supportive of the validity and reliability of children's reports via a questionnaire format. The responses to the frequency of headache and medication usage were found to predict the responses over the next month, whereas the response on the duration of headache did not. Significant correlations for most headache-symptom items indicated that children and parents agree on their presence and severity. This investigation is the first step in developing a systematic assessment procedure for childhood headache.