The effects of stimulus dimensionality on the rate of gain of information

Hick's paradigm as extended to an absolute judgment task by Doherty was used to study the effects of dimensionality on the rate of stimulus identification in two experiments. Two undimensional conditions, size and brightness, and two bidimensional conditions, size-brightness redundant and size-brightness non-redundant, were employed. The significant linear components of the regression of choice reaction time on transmitted information for the undimensional and bidimensional stimuli supported and extended Hick's law. The finding of nearly identical slopes for the two undimensional and redundant bidimensional condition regression lines suggests a stage of processing which has a constant capacity in bits/s and which is independent of stimulus dimensionality. An increase in slope for the non-redundant condition is attributed to a difference in response requirements.     

Recall of semantic clusters in primary memory

An experiment is reported which investigated the use of semantic relatedness as a retrieval cue in the primary memory component in a free recall task. Six-word semantically related clusters were placed in the middle and end positions of free recall lists. Retention was measured immediately after the list presentation and after a filled retention interval of 15 sec. Pure primary memory functions were calculated. The results indicated that semantic cues are useful in retrieval from secondary memory but played no part in recall from primary memory.     

Proactive personality and the successful job search: a field investigation with college graduates

The current article tests a model of proactive personality and job search success with a sample of 180 graduating college students. Using structural equation modeling, the authors tested a theoretical model that specified the relations among proactive personality, job search self-efficacy, job search behaviors, job search effort, and job search outcomes. Job seekers were surveyed at 2 separate points in time, once 3-4 months prior to graduation and once 2-3 months following graduation. The results suggest that proactive personality (a) significantly influenced the success of college graduates' job search, (b) was partially mediated through job search self-efficacy and job search behavior, and (c) was independent of self-esteem and conscientiousness. The findings are discussed in terms of their general implications for understanding the nature of the process through which distal personality factors, such as proactive personality, affect the nature and success of an individual's job search.     

When logic fails: Implicit transitive inference in humans

Transitive inference (TI) in animals (e.g., choosing A over C on the basis of knowing that A is better than B and B is better than C) has been interpreted by some as reflecting a declarative logical inference process. We invert this anthropomorphic interpretation by providing evidence that humans can exhibit TI-like behavior on the basis of simpler associative mechanisms that underlie many theories of animal learning. In this study, human participants were trained on a five-pair TI problem (A+B-, B+C-, C+D-, D+E-, E+F-) and, unlike in previous human TI studies, were prevented from becoming explicitly aware of the logical hierarchy, so they could not employ logical reasoning. They were then tested with three problems: B versus D, B versus E, and C versus E. Participants only reliably chose B over E, whereas the other test conditions yielded chance performance. This result is inconsistent with the use of logical reasoning and is instead consistent with an account developed to explain earlier TI studies with rats that found the same pattern of results. In this account, choice performance is based on differential associative strengths across the stimulus items that develop over training, despite equal overt reinforcement.     

Menstrual cycle effects on perceptual closure mediate changes in performance on a fragmented objects test of implicit memory

Healthy premenopausal women with regular menstrual cycles were assessed on a fragmented objects test of implicit memory. Testing took place at either the low estrogen (n=17) or the high estrogen (n=16) stages of the menstrual cycle. Concentrations of ovarian hormones were confirmed by saliva assays. Both groups of women exhibited a priming effect, in that primed objects were identified faster and at greater fragmentation than unprimed objects. There was no evidence that high estrogen inhibits perceptual object priming. However, women at the menstrual phase were able to identify both primed and unprimed objects at a more degraded level of fragmentation. Changes in perceptual closure over the menstrual cycle may be the basis for the changes in performance on the fragmented objects test observed in previous studies.     

Intact visual discrimination of complex and feature-ambiguous stimuli in the absence of perirhinal cortex

The perirhinal cortex is known to be important for memory, but there has recently been interest in the possibility that it might also be involved in visual perceptual functions. In four experiments, we assessed visual discrimination ability and visual discrimination learning in severely amnesic patients with large medial temporal lobe lesions that included complete lesions of perirhinal cortex. Experiment 1 tested complex visual object perception. Experiments 2a and 2b tested in two different ways the ability to discriminate between feature-ambiguous images, which was reported to be impaired in monkeys with perirhinal lesions. Experiment 3 involved images that were successfully discriminated in Experiment 2a and asked patients to learn across 20 trials which of the images had been designated as "correct." Patients performed as well as controls in Experiments 1, 2a, and 2b, but one of the patients had difficulty in Experiment 3 when the task required remembering from trial to trial which image was "correct." These findings indicate that perirhinal cortex is not needed for visual perception across a wide range of visual perceptual tasks.     

Novel treatments for autistic spectrum disorders

In no area of developmental pediatric practice is there more controversy regarding the choice of treatment than related to children with autistic spectrum disorders (ASD). Complementary and alternative medical therapies (CAM) are often elected because they are perceived as treating the cause of symptoms rather than the symptoms themselves. CAM used for autism can be divided by proposed mechanism: immune modulation, gastrointestinal, supplements that affect neurotransmitter function, and nonbiologic intervention. Secretin as a therapy for autism is discussed as an example of how a clinical observation rapidly grew to a widespread treatment before well-designed studies demonstrated absence of effect. The plausibility for behavioral effect was not substantiated by clinical studies. CAM used for treatment of autism is examined in terms of rationale, evidence of efficacy, side effects, and additional commentary. Families and clinicians need access to well-designed clinical evidence to assist them in choice of therapies.     

ANOTHER LOOK AT THE EFFECTS OF APPEARANCE, GENDER, AND JOB TYPE ON PERFORMANCE-BASED DECISIONS

The present study attempted to replicate and extend Heilman and Stopeck's (1985a) Lack of Fit Model. Using the Lack of Fit Model's proposal that attractiveness enhances perceived gender characteristics, we examined the effects of attractiveness and performance evaluations of persons in jobs rated as masculine, feminine, and neutral. Results were not consistent with the Model and did not replicate the results of the earlier study. Instead, attractiveness emerged as an asset regardless of job type or gender of employee. Attractive men and women were given higher overall ratings in all three jobs. In addition, attractive ratings were related to masculinity–femininity ratings. These findings are discussed in light of demographic and attitudinal changes in the workplace.     

Editing a book on the World-Wide Web with 29 collaborators in 8 countries in 12 months: A case in survival tactics

We describe the techniques that we devised to enable authors who had never met physically to collaborate on a large-scale writing project. The goal was to use the Internet to simulate the close interactions that are possible in a traditional conference to foster cross-fertilization of ideas and to increase the coherence of the book we were writing. We discuss areas that should concern those who consider using the Internet for collaborative work.