Different methods of lexical access for words presented in the left and right visual hemifields

Right-handed adults were asked to identify by name bilaterally presented words and pronounceable nonwords. For words in the normal horizontal format, word length (number of letters) affected left visual hemifield (LVF) but not right visual hemifield (RVF) performance in Experiments 1, 2, 3, 5, and 6. This finding was made for words of high and low frequency (Experiment 6) and imageability (Experiment 5). It also held across markedly different levels of overall performance (Experiments 1 and 2), and across different relative positionings of short and long words in the LVF and RVF (Experiment 3). Experiment 4 demonstrated that the variable affecting LVF performance is the number of letters in a word, not its phonological length. For pronounceable nonwords (Experiment 7) and words in unusual formats (Experiment 8), however, length affected both LVF and RVF performance. The characteristics identified for RVF performance in these experiments also hold for the normal reading system. In this (normal) system the absence of length effects for horizontally formatted words is generally taken to reflect the processes involved in lexical access. Length effects in the normal reading system are thought to arise when lexical access for unusually formatted words and for the pronunciation of nonwords requires the short-term storage of information at a graphemic level of analysis. The characteristics of LVF performance indicate that horizontally formatted words presented to the right cerebral hemisphere can only achieve lexical access by a method that requires the short-term storage of graphemic information. This qualitative difference in methods of lexical access applies regardless of whether the right hemisphere is seen as accessing words in the left hemisphere's lexicon or words in a lexicon of its own.     

I. Validity of WISC-R factor scores in predicting achievement and attention for four sociocultural groups

The predictive validity of WISC-R factor scores was examined with samples from the four sociocultural groups of Anglo, Black, Chicano, and native American Papago. The Full Scale IQ and Verbal Comprehension (VC) factor scores were significantly better predictors of achievement as measured by teacher ratings and the Metropolitan Achievement Test. The Perceptual Organization and Freedom from Distractibility (FD) factor scores were also significantly related to achievement, but at a lower level than Full Scale and VC. The correlations of the WISC-R and achievement measures were nearly the same for three of the four groups (exception was native American Papago). The relationship of the FD factor score to ratings of attention was statistically significant, but relatively low. Cautions in interpreting FD as a measure of attention were recommended due to overlap of distributions and low proportion of variance in attention accounted for by FD.     

Conceptual preference for thematic or taxonomic relations: A nonmonotonic age trend from preschool to old age

Two experiments examined the development of conceptual preference for either thematic (functional) or taxonomic relationships in a match-to sample task. In Experiment 1 twenty subjects from each of five age groups—preschool to old age—completed a method of triads preference test where they were forced to choose a thematic or taxonomic match. Young and old individuals preferred the thematic parings while school age and college adults preferred the taxonomic matches. Although the Age × Preference relation was pronounced, the majority of subjects at all ages could provide adequate justification of both the preferred and nonpreferred relationship. In addition, kindergarten subjects in Experiment 2 could readily be trained to respond on the basis of the nonpreferred mode. These data suggest that the pervasive shift in conceptual responding from syntagmatic to paradigmatic, thematic to taxonomic, etc., represents a change in preference rather than a shift to a fundamentally new way of organizing knowledge.     

The Shattered Microcosm: Imperatives for Improved Family Therapy in Africa in the 21st Century

This paper provides an in-depth socio-political analysis of the basis for the limits of family therapy in Africa in the last 40 years. The goal is to make more visible the economic, social, political, and cultural factors that have combined to complicate and frustrate our macro-environments of practice. The conclusion is that family therapy in Africa cannot achieve any meaningful progress in the present millenium unless the structures of underdevelopment under which we live and work are dismantled and in their place the important preconditions for successful practice of modern family therapy are entrenched. The list of imperatives to be addressed is offered to suggest the direction along which we must move if we are to effect this adaptation.     

Thanks, but no thanks: The role of personal responsibility in the experience of gratitude

Current theories of gratitude suggest that individuals feel grateful when they perceive someone else to be responsible for a desired outcome. However, it is unclear whether individuals must also feel a lack of personal responsibility in order to feel gratitude. This paper provides evidence that in achievement contexts, without the belief that they are responsible for their success, individuals do not experience gratitude, even when they acknowledge the help they have received. In two studies, the more helpful participants thought an experimenter had been, the more grateful they felt, but only if they also spontaneously felt responsible for (Study 1) or were induced to feel responsible for (Study 2) their outcomes.     

Conditioned reinforcement and response strength

Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration.     

《周易》的“生态学”解读——从“还原”的角度

对于《周易》的研究,当代学者已从人文、象数、哲学乃至科学等角度进行解读,并取得了丰硕的成果。事实上,作为"天人之学"的《周易》蕴含了丰富的生态思想,其对生命的重视,对人与自然关系的认定乃至"与天与一"的宇宙观皆凸显了深层的生态关怀。无疑,在环境日益恶化的当下,回归经典寻求智慧不失为一种有益的探索。     

On the development and mechanics of delayed matching-to-sample performance

Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100-150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible.     

Resistance to change of operant variation and repetition

A multiple chained schedule was used to compare the relative resistance to change of variable and fixed four-peck response sequences in pigeons. In one terminal link, a response sequence produced food only if it occurred infrequently relative to 15 other response sequences (vary). In the other terminal link, a single response sequence produced food (repeat). Identical variable-interval schedules operated in the initial links. During baseline, lower response rates generally occurred in the vary initial link, and similar response and reinforcement rates occurred in each terminal link. Resistance of responding to prefeeding and three rates of response-independent food delivered during the intercomponent intervals then was compared between components. During each disruption condition, initial- and terminal-link response rates generally were more resistant in the vary component than in the repeat component. During the response-independent food conditions, terminal-link response rates were more resistant than initial-link response rates in each component, but this did not occur during prefeeding. Variation (in vary) and repetition (in repeat) both decreased during the response-independent food conditions in the respective components, but with relatively greater disruption in repeat. These results extend earlier findings demonstrating that operant variation is more resistant to disruption than is operant repetition and suggest that theories of response strength, such as behavioral momentum theory, must consider factors other than reinforcement rate. The implications of the results for understanding operant response classes are discussed.     

The Institute on Human Values in Medicine: Its Role and Influence in the Conception and Evolution of Bioethics

For ten years, 1971–1981, the Institute onHuman Values in Medicine (IHVM) played a keyrole in the development of Bioethics as afield. We have written this history andanalysis to bring to new generations ofBioethicists information about the developmentof their field within both the humanitiesdisciplines and the health professions. Thepioneers in medical humanities and ethics cametogether with medical professionals in thedecade of the 1960s. By the 1980s Bioethics wasa fully recognized discipline. We show the rolethat IHVM programs played in defining thefield, training faculty and helping schools todevelop programs. We review the beginnings ofthe IHVM in the crucible of social andtechnological change that led to theestablishment of the IHVM's parentorganization, the Society for Health and HumanValues. We then turn to the IHVM programsthrough which Faculty members receivedfellowships to explore new crossovers betweenthe humanities and the health professions. Wehave not only described the Fellows Program asit existed in 1973–1980, but have completed asurvey of the fellows a quarter of a centuryafter they held their fellowships. We describeother IHVM programs designed to facilitate theinitiation and development of new humanitiesprograms, to explore conceptual issues betweenmedicine and five humanities fields, to conductissue driven or educational method conferencesand to advance humanities programs intograduate education through the Directors ofMedical Education.