Further experiments on the olfactory thresholds of pure chemical substances, using the “Sniff-Bottle method”

“Sniff-Bottle” method of determining olfactory thresholds under conditions of adaptation to a second olfactory stimulus, as described by Cheesman and Mayne (1953), has been further developed. Their study was limited to the mutual adaptation effects of three substances. The original matrix of nine quantities, described as degrees of community of odour property, has been revised and extended to include a fourth stimulus-substance. It is suggested that the matrix now obtained shows a definite pattern characteristic of consistent mutual relationships between the substances. A number of shortcomings in the original technique are discussed, and the appropriate emendations described.     

Influence of correlated visual cues on auditory signal detection

Two experiments investigated the effects on auditory signal detection of introducing visual cues that were partially correlated with the signal events. The results were analyzed in terms of a detection model that assumes that such cue-signal correlations will not affect sensitivity, but will instead cause the subject to develop separate response biases for each cue. The model specifies a functional relationship between the asymptotic values of these cuecontingent biases. The overall results of the experiments supported the detection assumptions of the model and the general bias learning assumption, but indicated a more complex learning process than that specified by the model.     

Self-terminating versus exhaustive processes in rapid visual and memory search: An evaluative review

A major issue in elementary cognition and information processing has been whether rapid search of short-term memory or a visual display can terminate when a predesignated target is found or whether it must proceed until all items are examined. This study summarizes past and recent theoretical results on the ability of self-terminating and exhaustive models to predict differences in slopes between positive (target-present) and negative (target-absent) set-size functions, as well as position effects. The empirical literature is reviewed with regard to the presence of slope differences and position effects. Theoretical investigations demonstrate that self-terminating models can readily predict the results often associated with exhaustive processing, but a very broad class of exhaustive models is incapable of predicting position effects and slope differences typically associated with self-termination. Because position effects and slope differences are found throughout the rapid search literature, we conclude that the exhaustive processing hypothesis is not tenable under common experimental conditions.     

Beyond the Myth of the Nietzschean Ideal‐Type

This paper furthers the understanding of Nietzsche's project of increasing the prevalence of higher individuals. I do this by opposing the dominant tendency in Nietzschean scholarship of constructing a single ideal‐type. I argue that Nietzsche actually describes multiple higher types, with incommensurable physiological and psychological characteristics, and that attempts to collapse these into one type obscure the nuance and richness of his thought. Furthermore, I claim that higher types are not ahistorical ideals; instead, their emergence relates closely to existing psychological and physiological conditions in society. The artistic‐genius type, for example, is characterised by his sensitivity to stimuli and plays a vital role in injecting creativity into culturally uniform societies. He is, however, a counter‐productive role model for diverse modern societies, characterised by an abundance of stimuli and widespread reactivity. In response to such conditions, Nietzsche extols the virtue of a peculiarly anti‐modern type, who cultivates independence from stimuli. Interpreting higher types as multiple and historically situated is vital to carrying out the normative aspect of Nietzsche's philosophy. This role is performed by the philosophical‐physician, who surveys the physiological and psychological conditions of his own age and attempts to exploit these conditions to produce future higher individuals.     

The development of attentional orienting during the school‐age years

This study was designed to assess the development of spatial attentional orienting during the school‐age years. To that end, we used a cost‐benefit attentional cueing task with short (100 ms) and long (800 ms) cue‐to‐target intervals to examine attentional processing independent of motor skills and perceptual processing in 200 7–17‐year‐olds and 40 adults. We found that orienting attention, disengaging attention and visual processing in an unattended location, were all progressively more accurate and faster with increasing age. Our data thus suggest that the efficiency of attentional orienting improves in an age‐related manner throughout the school‐age years.     

Studying visual search using systems factorial methodology with target—distractor similarity as the factor

Systems factorial technology (SFT) is a theory-driven set of methodologies oriented toward identification of basic mechanisms, such as parallel versus serial processing, of perception and cognition. Studies employing SFT in visual search with small display sizes have repeatedly shown decisive evidence for parallel processing. The first strong evidence for serial processing was recently found in short-term memory search, using target-distractor (T-D) similarity as a key experimental variable (Townsend & Fifi?, 2004). One of the major goals of the present study was to employ T-D similarity in visual search to learn whether this mode of manipulating processing speed would affect the parallel versus serial issue in that domain. The result was a surprising and regular departure from ordinary parallel or serial processing. The most plausible account at present relies on the notion of positively interacting parallel channels.     

A Systematic Review of the Relationship between High School Dropout and Substance Use

A systematic review of peer-reviewed, empirical literature published between 1990 and 2006 was undertaken to determine whether existing research could provide evidence, and a deeper understanding of the relationship between dropping out of high school and the use of substances such as tobacco, alcohol, cannabis/marijuana and other illicit drugs. Forty-six articles were reviewed. The review describes the heterogeneity of theoretical frameworks employed, as well as the limited ability of any one to adequately explain the relationship between high school dropout and substance use. A refinement of the many confounding and mediating variables into coherent conceptual categories would aid more robust theory building and theory integration. In spite of differences in dropout definitions and diverse measures of substance use across studies, the main findings point to a largely consistent relationship between dropping out of high school and substance use. However, socially disadvantaged and poor persons, dropouts, and drug users are over-represented in some of the loss to follow-up groups in longitudinal studies surveyed. More rigorous mechanisms to retain participants in longitudinal studies should be employed. Suggestions for future research include comparisons between urban and rural populations, employing qualitative research methods, and research in developing countries, which have the least favourable school outcomes and a dearth of research on high school dropout.