Components of the reaction time stroop-task

Summary The Stroop-phenomenon in its single-trial reaction-time version is analyzed in terms of Donders's additive-components approach. The complete set of component tasks forms an incomplete factorial design, and so, for resolving reaction times into their component parts multiple regression with dummy coding is used. The results of two independent experiments confirm the asymmetry of the incongruence effect in naming and reading, but contradict the redundancy hypothesis for congruent items. This finding is consistent with the linear approach which in Exp. 1 accounts for about 45%, and in Exp. 2 for about 30%, of total reaction-time variance. In a third experiment reaction times for the detection of colours/words and for congruence/incongruence are measured. These data confirm the estimation of both the basic constant and the assumed matching component in the first two experiments. Finally it is proposed that the data can be interpreted on the assumption that a matching process is responsible for the incongruence effect in naming. Reading interference does not normally occur because of faster processes or fewer stages in a parallel reading channel. Different strategies in coping with the Strooptask (reading vs inhibition) may explain differences between Exps. 1 and 2 and the absence of the redundancy effect from the data. The constraints on such assumptions in the context of reaction-time measurement are discussed.Parts of the data analyzed here were reported at the 18th Congress of Experimental Psychology in April 1976 at Bochum. K.P. Muthig, now at the Free University of Berlin, Dpt. 12, helped in the performance and analysis of the first and third experiments.I gratefully acknowledge the helpful comments of O. Neumann (Bochum) and of three anonymous reviewers of an earlier version of this paper.     

A head-mounted scene holder for eye movement research

An inexpensive head-mounted scene holder is described. In contrast to the usual biteboard/fixed-head approach, the present apparatus allows head movements without introducing substantial artifact. This enables eye movement investigations of brain-damaged or psychiatric subjects who often cannot maintain prolonged head immobility; also, the unit makes possible subjects’ verbal reports coincident with visual scanning.     

ISSUES AND IMPLICATIONS OF ESTABLISHING GUIDELINES FOR THE USE OF BEHAVIORAL TECHNIQUES

Several guidelines surrounding the use of behavioral procedures have recently appeared, the best of which is that of the National Association of Retarded Citizens (NARC). Some issues and implications of the establishment of guidelines are briefly reviewed in the context of the NARC guidelines. Issues include the factual versus opinion bases for guidelines and the need to continue the development of explicit behavioral criteria for assessing staff competence. Implications for programs include the impact of guidelines on professional boundaries, administrative decision-making, and budgeting, together with the dangers of expanding the regulatory bureaucracy. Several miscellaneous impacts are noted, including a potential for curbing innovative behavioral technology.     

Between-theory and within-theory conflict in explaining context effects in impression formation

Research on context effects in impression formation has taken the form of testing competing predictions from the averaging model and the meaning shift model. This between-theory conflict has been unprofitable because neither theory has yet acquired the degree of specificity necessary to generate unequivocal predictions in this area. The research has been useful, however, in identifying each theory's capacity to generate self-contradictory predictions. Future research on this topic can most profitably be addressed to resolving these within-theory conflicts.     

N=1: An alternative research strategy for school psychologists

Single subject (N=1) research strategies deserve increased emphasis in the training of school psychologists. Single subject methodology has demonstrated credibility in research and in monitoring effects of professional interventions, but school psychology programs have typically not provided systematic training in this area. This paper suggests that N=1 research paradigms offer a promising supplement and, in some cases, an alternative to traditional large N between group strategies in school-based research; it reviews some examples of N=1 research design and methodology; it discusses some advantages and limitations of N=1 research strategies; and it argues that school psychology training programs must train graduate students in N=1 research and encourage this form of research methodology in practice.     

Laterality differences and practice effects under central backward masking conditions

Two experiments were conducted to examine laterality differences and practice effects under various central backward masking conditions. Critical stimulus onset asynchrony (SOA) was determined for subjects on 3 consecutive days using single letters as target stimuli (TS) and a pattern masking stimulus (MS). There was a right visual field (RVF) advantage on Day 1 but no difference between the visual fields on following days. The decline in the RVF advantage appeared to be dependent upon prior experience with laterally located letters, to be independent of initial experience with a particular set of letters, and to be more pronounced for females than for males. In addition, large improvements in performance were found, particularly between the first and second testing sessions. These practice effects were discussed in terms of the possible development of strategies for enhancing TS features or attenuating MS features.     

Fitting cross-classification table data to models when observations are subject to classification error

Individuals are classified in a cross-classification table where two behavioral observations on each individual determine the classification. The problem is to test certain structural models assumed to underlie the cross-classified observations. A minimum chi-square test procedure is proposed.