Introduction to two-dimensional Fourier analysis

The application of two-dimensional Fourier analysis provides new avenues for research in visual perception. This tutorial serves as an introduction to some of the methods used in two-dimensional Fourier analysis and an introduction to two-dimensional image processing in general.     

Toward a science of history

The scientific status of History was compared to other sciences in the critical areas event selection, investigative operations, and theory construction. First, in terms of events studied, history is regarded as a quasi-scientific study of past events. However, viewed from the science of behavior's perspective of what historians actually do, history becomes a study of current records. As a study of currently existing records, not the non-existent past, history has potential to become a science. Second, like other scientists, historians may undertake manipulative investigations: they can locate the presence and absence of a condition in records and thereby determine its relation to other recorded phenomena. A limitation has been the lack of quantification that results from emphasis on the uniqueness of things rather than on their communality. Scientific training would facilitate viewing similar things as instances of a larger class that could be counted. Another limitation that cannot be easily overcome is the inability to produce raw data. This limitation has created problems in theoretical practices, the third area of comparison, because theoretical constructions have frequently been substituted for missing data. This problem too could be reduced through scientific training, particularly in other behavior sciences. An authentic science of history is possible.     

Towards a model of stress and human performance

An outline is presented of a model that aims to relate energetical and structural mechanisms of human information processing and to incorporate an interactionally defined stress notion in performance research. The first section summarizes objections to unidimensional notions of arousal and stress. It is concluded that further progress requires the analysis of joint cognitive-energetical processing structures. In the second section two current performance models - in terms of linear stages and resources - are briefly reviewed. Despite a number of problems and objections, it is decided to base the model upon linear stage notions of information processing. This is further elaborated in the third section. In accord with Pribram and McGuinness (1975) three energetical supply systems are proposed which are selectively related to specific cognitive processing mechanisms. Stress is defined as a state of imbalance in the energetical supply which is difficult to restore or to compensate. The final section is devoted to the discussion of some lines of evidence and to suggestions for future research.     

Focus shift and individual differences in the Sternberg memory-search task

One consistent finding in research using the memory search task developed by Sternberg (1966) is that negative set size has no effect on search reaction time, even when the negative set contains fewer items than the positive set. Such inefficient behavior appears to result from an intense positive focus generated by standard memory search task instructions. The present research was designed to explore the conditions under which a subject will switch focus to a smaller negative set. Two experiments were carried out using standard Sternberg instructions. The first experiment examined the effects of making the contents of the negative set explicit. The result was a shift to negative focus when the negative set was much smaller than the positive set. In the second experiment the size of the positive set was increased systematically to induce a shift to negative focus. The second experiment also examined the relationship between focus shift and measures of intelligence (Raven Progressive Matrices) and information storage capacity (digit span). The results are evidence that negative set size can affect reaction time in the memory search task, and that individual differences in ability to shift focus are related to intelligence.     

Halos vs. stigmas: long-term effects of parent's death or divorce on college students' concepts of the family

College students from families of divorce, of death of a parent, and of intact families rated the meaning of six concepts of the family: mother, father, I myself, marriage, family, and divorce. The Semantic Differential was used to assess four dimensions of meaning of family concepts: evaluation, potency, activity, and general cultural favorability. Children of divorce rated father less favorably than did children of death of a parent or of intact families; however, children of divorce rated divorce more favorably than the remaining two groups. Also, children of divorce evaluated the family concepts that were rated here more negatively than, but equally as potent and active as, children of death of a parent and of intact families. Thus, several long-term stigmas attach to family among children of divorce, but no evidence was found of a halo effect for children of death of a parent.