Simplified learning in complex situations: knowledge partitioning in function learning

The authors explored the phenomenon that knowledge is not always integrated and consistent but may be partitioned into independent parcels that may contain mutually contradictory information. In 4 experiments, using a function learning paradigm, a binary context variable was paired with the continuous stimulus variable of a to-be-learned function. In the first 2 experiments, when context predicted the slope of a quadratic function, generalization was context specific. Because context did not predict function values, it is suggested that people use context to gate separate learning of simpler partial functions. The 3rd experiment showed that partitioning also occurs with a decreasing linear function, whereas the 4th study showed that partitioning is absent for a linearly increasing function. The results support the notion that people simplify complex learning tasks by acquiring independent parcels of knowledge.     

Lower region: a new cue for figure-ground assignment

Figure-ground assignment is an important visual process; humans recognize, attend to, and act on figures, not backgrounds. There are many visual cues for figure-ground assignment. A new cue to figure-ground assignment, called lower region, is presented: Regions in the lower portion of a stimulus array appear more figurelike than regions in the upper portion of the display. This phenomenon was explored, and it was demonstrated that the lower-region preference is not influenced by contrast, eye movements, or voluntary spatial attention. It was found that the lower region is defined relative to the stimulus display, linking the lower-region preference to pictorial depth perception cues. The results are discussed in terms of the environmental regularities that this new figure-ground cue may reflect.     

Contents Volume 111 2002

Volume Contents

Contents Volume 110 2002     

Perceptual match effects in direct tests of memory: the role of contextual fan

The aim of the present study was to determine whether physical attributes of a memory representation would affect explicit memory performance and, if so, what type of factors would affect the size of a perceptual match effect. Subjects studied words in different, uncommon fonts and were later asked whether the word had been studied earlier. Words could be re-presented in the original font, a font studied with another word, or a font not seen earlier. In two additional experiments, we varied the numbers of words studied in the same unusual font (1 vs. 12 words per font). Recognition memory for the words was better if the test and study fonts matched, and this effect was larger for fonts not shared with other words. Moreover, old judgments were most likely to be classified as remember responses when words were re-presented in the same font when it had not been studied with other words. Although we found a significant effect of levels of processing, this factor did not interact with whether the font matched between study and test. These results are consistent with the predictions of the source of activation confusion model of memory and suggest that perceptual information operates according to the same memory principles as conceptual information.     

Phenomenal characteristics of guided imagery,natural imagery,and autobiographical memories

Research indicates that guided imagery experiences can be mistaken for actual experiences under some circumstances. One explanation for such effects is that memory representations of guided imagery and actual events contain similar phenomenal characteristics such as sensory and contextual details, making the source of the events less distinguishable. This study examined this prediction, comparing memory characteristic ratings for guided imagery experiences with those for memories of perceived and natural imagery events (e.g., fantasies). Results replicated previous findings for the difference between perceived and natural imagery memories. Guided imagery ratings were also lower than those for perceived memories for most sensory details (sound, smell, and taste) and temporal details. However, guided imagery ratings for reflective details were lower than both perceived and natural imagery memory ratings. Thus, guided imagery was similar to natural imagery with respect to sensory details, but similar to perceived memories with respect to reflective details.     

Ethical considerations in neuroimaging and its impact on decision-making for neonates

Neuroimaging can now provide information about structure and function. Despite new and improved neuroimaging technologies applicable to the newborn, predictions about later cognition, learning, social and emotional behavior, and neuromuscular capabilities, based on images of a fetus inside or a newborn outside the womb, are fraught with difficulties that go beyond technical ones. The interpretation of neuroimages may be necessary but it is not sufficient for decision-making related to the withholding or withdrawing of medical support for neonates. As the explanatory reach of neuroimaging increases, there will still need to be consideration of ethical issues as they relate to the best interests of the neonate and the neonate's parents, the quality of life of the neonate and non-beneficial treatment. Once this is appreciated, the boundary between the technical and the ethical will be less often disputed.     

Memory for multidimensional source information

Source memory may comprise recollection of multiple features of the encoding episode. To analyze the simultaneous representation and retrieval of those multiple features, a multinomial memory model is presented that measures memory for crossed dimensions of source information. The first experiment investigated the validity of the new model. The model showed an excellent statistical fit to empirical data, and the parameters of multidimensional source memory were sensitive to manipulations of source similarity on distinct dimensions. The second experiment used the model to test the hypothesis that source memory for individual context attributes is stochastically related in the case of conscious recollection but independent in the case of familiarity-based recognition judgments. The prediction was supported by the introduction of a "remember"-"know" distinction in a multidimensional source memory test.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

Social attention orienting integrates visual information from head and body orientation

Subjects were asked to detect visual, laterally presented reaction signals preceded by head-body cue stimuli in a spatial cueing task. A head rotated towards the reaction signal combined with a front view of a body resulted in shorter reaction times in comparison to the front view of a head and body. In contrast, a cue showing the head and body rotated towards the reaction signal did not result in such a facilitation in reaction times. The results suggest that the brain mechanisms involved in social attention orienting integrate ventrally processed visual information from the head and body orientation. A cue signaling that the other person, in his or her frame of reference, has an averted attention direction shifts the observer's own attention in the same direction.     

Participation by women in developmental, social, cognitive, and general psychology: A context for interpreting trends in behavior analysis

We examined participation by women in journals devoted to social, developmental, cognitive, and general psychology. Authorship and first authorship by women increased from 1978 to 1997 for most journals. Participation by women on the editorial staff did not keep pace with their increased authorship for social and developmental psychology. Based on these trends, women's participation decreased with increases in the selectivity of the position for social and developmental psychology (a glass ceiling). The development of a glass ceiling suggests that the contributions of men and women are not always treated equally (gender inequity). Because a similar glass ceiling was reported for journals in behavior analysis (McSweeney, Donahoe, & Swindell, 2000; McSweeney & Swindell, 1998), the causes of this inequity appear to be relatively widespread. The failure to find a glass ceiling for general and cognitive psychology suggests that the inequity might be reduced by subtle pressure for diversity in editorial positions and by adopting actions that encourage women to pursue research positions.