Temporal integration and vibrotactile backward masking

Subjects were presented with vibrotactile target patterns to their left index fingertips. The target patterns varied in the number of line segments that they contained and were presented in the presence or absence of a backward-masking stimulus. The stimulus onset asynchrony (SOA) between the target and masker was varied. In an identification task, subjects' errors indicated that the effect of the masker at brief SOAs was to increase the perceived number of line segments in the target. This effect diminished with increasing SOA, and at the longest SOAs subjects confused targets with patterns containing the same number of line segments but varying in how the line segments were related. In an estimation task, the effect of the masker was to increase the number of line segments estimated to be contained in the target pattern. The effect of the masker at brief SOAs is discussed in terms of an integration theory of vibrotactile backward masking. At longer SOAs, the results suggest that the masker may interfere with the extraction of relational information in the target pattern.     

Modeling feature perception in brief displays with evidence for positive interdependencies

Recent studies have begun to test certain fundamental assumptions underlying popular models of feature perception. This research is continued here. It was discovered that every basic assumption that was open to test in the present study was disconfirmed. However, several new characteristics of line and curve feature perception were discovered: (1) Feature perception sensitivity was inversely related to the number of features present in a stimulus pattern, and the decision criteria for reporting a feature decreased with the number of features contained in a pattern; (2) the decrements in sensitivity reported in (1) were greater for features lying inside a pattern than for those on the exterior; and (3) feature perception sensitivity actually improved if another feature was known to be correctly perceived during the same trial. Likewise, feature sensitivity decreased if another feature was missed on any trial. At the present time, a system that first extracts global and then local (more detailed) featural information provides a basis that qualitatively accounts for our findings and is also compatible with several other studies in the literature.     

Self-reinforcement: Impact of instructions,criterion setting,and tangible rewards

This investigation was designed to ascertain the effects of instructions, criterion setting, and the presence of tangible rewards on the self-reinforcement process. Fifty-two third- and fourth-grade subjects were assigned to one of four treatment groups: (a) stringent instructions/criterion setting/tangible reward, (b) stringent instructions/criterion setting/no tangible reward, (c) nonstringent instructions/criterion setting/tangible reward, and (d) nonstringent instructions/no tangible reward. In the stringent-instruction conditions, subjects received social reinforcement for selecting stringent performance criteria, whereas in the non-stringent-instruction conditions, social reinforcement was withheld. Subjects in the tangible-reward groups were allowed to select a prize following the successful completion of their self-selected work performance. Subjects in the no-tangible-reward groups received no prizes for their work. All subjects performed an arithmetic task in which the number of correct problems completed, number of problems attempted, and time at task served as dependent variables across five reinforcement and two extinction trials. The results suggest that the condition of stringent instructions, criterion setting, and tangible reward was more effective in producing behavior change than the other three conditions. Perceived task difficulty and previous achievement on arithmetic task performance were shown to affect criteria selected and mathematical performance. The results are discussed in light of the contributory role of instructions, criterion setting, and tangible rewards on the self-reinforcement procedure.This study is based on a doctoral dissertation submitted to the Faculty of Arts and Sciences at the University of Pittsburgh by Helen L. Evans. Dr. Russell T. Jones was the dissertation committee chairperson. It was partially funded by an American Psychological Association Minority Fellowship awarded to the first author. Special thanks are extended to the committee members, Drs. Lloyd Bond, Robert Glaser, Johnny Matson, and Samuel M. Turner, for their assistance. The authors would like to thank Thomas DeVoge, Paul Karoly, and Samuel M. Turner for reading and commenting on an early draft of this study. Portions of this paper were presented at the 1982 APA convention.     

Further evaluation of prompt density,rate of reinforcement,and the persistence of manding

Previous research has evaluated the effects of prompt rates on the rate of communicative behavior. More recent research has suggested that dense prompting can result in communicative behavior that is more resistant to change. However, existing research has not considered the impact that higher response rates had on reinforcement rate, a variable known to impact response persistence. The current study systematically replicated previous research by evaluating communicative responding in contexts associated with dense- and lean-prompt schedules and extended existing research by (a) holding reinforcement rates similar across the two prompting schedules (lean and dense), and (b) evaluating the persistence of communicative responding in the contexts associated with each prompting schedule. The results for Experiment 1 clearly replicated and extended previous research. The results for Experiment 2 were equivocal and suggested that previous reinforcement history and response class size impacted outcomes.     

The role of affinity for prosumption experiences and values

Prosumers are individuals who produce goods they consume themselves. The prosumption literature suggests that prosumption can be enhanced through knowledge sharing, creativity and innovation, and developing expertise. In this article, we investigate the relationships between prosumption experiences, prosumption values, and affinity with a prosumption activity. We use a structural equation model approach to evaluate the relationships between these constructs and assume that affinity can mediate the relationship between prosumption experiences and values. We collect empirical data from prosumers who homebrew their own beer and confirm that prosumption experiences and values are positively related, and that affinity mediates the relationship between experiences and values. Implications deriving from these findings are discussed along with directions for future research.     

Factor structure of the mobility inventory for agoraphobia: A validational study with australian samples of agoraphobic patients

This study examines the factor structure of the Mobility Inventory for Agoraphobia and attempts to validate the inventory, using an Australian sample of agoraphobic patients, by comparison with other scales. One hundred twentyfour panic disorder with agoraphobia patients were studied. Factor analysis showed that a two-factor solution was the most suitable both when subjects were accompanied (accompanied condition) and when alone (alone condition). Factor I represented public, crowded, or social situations including department stores, supermarkets, restaurants, theaters, and panics and social gatherings. Factor II reflected enclosed or riding situations such as elevators, parking garages, enclosed spaces, and riding in subways or airplanes. These two factors accounted for 46.6% and 44.3% of the variance on the accompanied condition and the alone condition, respectively. The Mobility Inventory was significantly correlated with the Agoraphobia factor of the Fear Questionnaire and the Social Avoidance and Distress scale. These results indicated that the Mobility Inventory is a valid instrument to measure agoraphobic behavior.     

Practices and representations of child care and motor development among West Africans in Paris

Massage techniques and postural manipulation used by West African women immigrants in Paris were studied, with the aim of demonstrating that culturally regulated caretaking practices have an influence on infant motor development. Twenty-five infants were observed between the ages of 3 and 12 months and 9 and 15 months. Frequency of massage and its accompanying set of physical exercises were found to be related to age at onset of independent walking. The findings show that infants receiving daily massage walk significantly earlier than infants who do not receive massage, thus confirming other reports that vestibular and postural stimulation have a positive effect on motor development. These results are discussed in relation to the observed frequencey of contact and of physical games with the caregiver for a smaller sample of three infants, and to parental expectations about the age of acquisition of certain cognitive and motor abilities. African immigrant mothers expect their infants to sit and to walk earlier than French mothers. The conclusion emphasizes the contribution of social anthropology, which shows that in all cultures, physical development and body changes elicit symbolic practices and a search for explanation.