Dynamic, state-dependent thresholds for the perception of single-element apparent motion: Bistability from local cooperativity

Previous studies have indicated that the formation of coherent patterns for multielement motion displays depends onglobal cooperative interactions among large ensembles of spatially distributed motion detectors. These interactions enhance certain motion directions and suppress others. It is reported here that perceiving one element moving between two nearby locations likewise is subject to cooperative influences (possibly facilitating and inhibiting interactions within alocal ensemble of overlapping detectors). Thresholds depending on luminance contrast were measured for a generalized singleelement apparent-motion stimulus, and evidence for spontaneous switching and hysteresis effects indicated that motion perception near the 50% threshold was bistable. That is, for conditions in which motion and nonmotion were perceived half the time, the two percepts were distinct; when one was perceived, it clearly was discriminable from the other. These results indicated that (1) single-element apparent-motion thresholds depended on the immediately preceding state of the ensemble of motion detectors responding to the stimulus, and (2) the stimulus activation of individual motion detectors always might be influenced by recurrent, cooperative interactions resulting from the detectors’ being embedded within interconnected ensembles.     

Lexical Acquisition in Probable Alzheimer''s Disease

Patients with probable Alzheimer's disease (pAD) were exposed to a new verb in a naturalistic fashion. We probed their knowledge of the word's semantic and grammatical characteristics for several minutes following this exposure, and compared this with their performance on parallel measures assessing known words. Significant differences were seen between pAD patients and controls in the acquisition of the new verb's semantic meaning and its argument structure, but pAD patients did not differ from controls in the acquisition of the new word's grammatical form class. Individual patient analyses demonstrated parallel deficits restricted to the semantic meaning and argument structure of the new word and known words in several pAD patients, suggesting that a selective language impairment contributed to their word learning deficit. This pattern is consistent with an intimate relationship between semantic meaning and argument structure in semantic memory. Other pAD patients had difficulty learning about all aspects of the new word, despite good performance with known words, suggesting that compromised memory may have limited their lexical acquisition.     

Single parenting: Interventions in the transitional stage

Following divorce or separation, many mother-headed families need to mourn losses, including reduced economic resources. They need to reestablish family rituals, confront such issues as time management and structural changes that can result in scapegoating or over-reliance on a parental child. Normalizing difficulties associated with parenting is important because single parents tend to internalize societal attribution of family difficulties to inadequate family structure rather than developmental stages, limited economic resources, and negative expectations about the capacity of women to head families.     

Time out from Stress: Camp Program and Parenting Groups for Homeless Mothers

This paper describes a camp program for homeless families and parenting groups aimed at discussing issues related to parenting while homeless. In groups and individual interviews, the women shared stories about multiple problems that negatively impacted parent/child relationships and their ability to maintain employment and residential stability. These problems included domestic violence, sexual abuse, and substance abuse. Evaluation of the camp program indicated that services available in the community and those provided by shelters were limited and mothers often had difficulties utilizing services.     

Feminist attitudes and mother-daughter relationships in adolescence

In spite of the growing amount of research on women's issues, there are few empirical studies of mother-daughter relationships, and almost none on the effects of the major women's movement of our times on relationships between mothers and daughters. In this study of late adolescent daughters' perceptions of their relationships with their mothers, two alternative hypotheses are examined: (1) feminism, with its emphasis on bonding among women, strengthens relations between adolescent daughters and their mothers, or (2) feminism as a force of social change, both attitudinal and behavioral, weakens the adolescent daughter-mother relationship. Based on 102 questionnaires completed by university-age women in the winter of 1983, it was found that the majority of daughters who have a good relationship with their mothers see both themselves and their mothers as feminist. However, these daughters do not attribute their positive mother-daughter relationship explicitly to feminism. For the minority of daughters who claim to have a poor relationship with their mothers, they attribute the problems to feminism.     

Effects of elaboration and relational distinctiveness on sentence memory

Memory for normal and distinct target sentences in elaborated and isolated contexts was examined in two experiments. Distinctiveness was operationalized as the uniqueness of the stated relation among the elements (words) of the sentence. In both experiments distinct target sentences were recalled significantly better than normal target sentences. Robust elaboration effects emerged only in Experiment 2, however, when care was taken to construct elaborations that were causally related to the target sentences. Further, the positive mnemonic effects of elaboration in Experiment 2 combined additively with the distinctiveness effects. These results demonstrate that text manipulations emphasizing both relational distinctiveness and causal elaboration facilitate memory performance. Several possible theoretical mechanisms underlying this facilitation are outlined.     

Multiple processes in prospective memory retrieval: factors determining monitoring versus spontaneous retrieval

Theoretically, prospective memory retrieval can be accomplished either by controlled monitoring of the environment for a target event or by a more reflexive process that spontaneously responds to the presence of a target event. These views were evaluated in Experiments 1-4 by examining whether performing a prospective memory task produced costs on the speed of performing the ongoing task. In Experiment 5, the authors directly tested for the existence of spontaneous retrieval. The results supported the multiprocess theory (M. A. McDaniel & G. O. Einstein, 2000) predictions that (a) spontaneous retrieval can occur and can support good prospective memory and (b) depending on task demands and individual differences, people rely to different degrees on monitoring versus spontaneous retrieval for prospective remembering.     

TREATMENT OF PICA THROUGH MULTIPLE ANALYSES OF ITS REINFORCING FUNCTIONS

We conducted functional analyses of the pica of 3 participants. The pica of 1 participant appeared to be maintained by automatic reinforcement; that of the other 2 participants appeared to be multiply controlled by social and automatic reinforcement. Subsequent preference and treatment analyses were used to identify stimuli that would compete with the automatic function of pica for the 3 participants. These analyses also identified the specific aspect of oral stimulation that served as automatic reinforcement for 2 of the participants. In addition, functional analysis-based treatments were used to address the socially motivated components of 2 of the participants' pica. Results are discussed in terms of (a) the importance of using the results of functional analyses to develop treatments for pica and (b) the advantages of developing indirect analyses to identify specific sources of reinforcement for automatically reinforced behavior.