Understanding the central processing limit in consistent-mapping visual search tasks

Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972).     

Difference and ratio information in children's and adults' memory representations.

A study was made of the choice reaction times of 8-, 10-, 12-year-olds and adults in order to investigate whether length information stored in memory was coded to preserve numerical relations between stimuli. Subjects learned unique line length-color associations and were later presented with pairs of colors and were instructed to choose the color that had been associated with the longer line. For all age groups, choice reaction times were related to both differences and ratios. These results were interpreted as supporting the analog theory of representation.     

Reducing smoking among pregnant adolescents

Pregnant adolescents who smoke present a double obstetrical risk. Not only is the adolescent mother at risk from the biological, social, educational, and economic factors associated with childbearing at a young age, she and her developing infant also risk the complications associated with maternal smoking. This paper describes a psychosocial intervention designed to reduce smoking in a group of pregnant adolescents. Five modules are presented. Each is designed to: (1) heighten awareness of the issue, (2) provide motivational messages, (3) enhance the adolescent's social skills, and (4) teach specific smoking-cessation skills.     

A further validation of the bem sex role inventory: A multitrait-multimethod study

The present study used a multitrait-multimethod technique [D.T. Campbell and D. W. Fiske (1959) “Convergent and Discriminant Validation by the Multitrait-Multimethod Matrix,” Psychological Bulletin, 56, 81–105] to examine Bem's [(1974) “The Measurement of Psychological Androgyny,” Journal of Consulting and Clinical Psychology, 42, 152–162] use of an instrumental-expressive dichotomy to conceptualize the Masculinity and Femininity scales of the Bem Sex Role Inventory as statistically orthogonal constructs. Results indicate that while perhaps reliable, masculinity and femininity lack clear convergent and discriminant validity. Therefore, Bem's contention that masculinity and femininity are orthogonal constructs is questioned. Results are discussed in light of trait- vs. method-driven research.     

Bystander Responses to Public Episodes of Child Abuse

Bystander responses to public episodes of child abuse were surveyed among 269 self reported witnesses. Respondents completed an 80-item self-report questionnaire which inquired into a broad range of events, experiences, and behaviors surrounding naturally occurring incidents of perceived child abuse witnessed in public places. Almost one-half of the sample reported having witnessed at least one event of child abuse in public, but only one out of four witnesses acted to intervene. Data analyses identified 40 statistically significant variables across four categories: characteristics of the bystander, situation, victim, and perpetrator. Results were generally consistent with predictions and findings from previous research on bystander intervention, but a number of new and significant variables were identified that characterized intervention events. Direct and indirect forms of intervention were also distinguished. Implications of the findings are discussed, and educating people to intervene on behalf of abused children is proposed.     

The Assessment of Limb Apraxia: An Investigation of Task Effects and Their Cause

To test the effects of variations in the structure of tasks used to assess limb apraxia, eight tasks—differing in their modes of elicitation (tactile, verbal, visual, imitation) and/or types of movement elicited (transitive, intransitive, meaningless)—were administered to 25 carefully selected subjects with idiomotor limb apraxia. When standardized scores (based on the performance of 10 nonneurologically impaired control subjects) were used to measure the differences between tasks, no clinically significant task effects were found. Additional investigation was made of two causal hypotheses regarding the processes underlying limb apractic performance. The results of factor analyses and a search for double dissociations among individual subjects were consistent with the (severity) hypothesis that differences in task performances (raw scores) reflect degrees of task difficulty; and they failed to support the (disconnection) hypothesis that posits separate and independent neural/mental processes underlying task performances.     

An analysis of performance by pre-school children on the KRISP and on a length discrimination task

The speed and accuracy of judgements made by pre-school children on the Kansas Reflection-Impulsivity Scale for Pre-schoolers (KRISP - Wright 1971, 1973) and on a two-choice length discrimination task were investigated. If subjects were relatively accurate on the KRISP then correct responses tended to be faster than errors while if subjects were relatively inaccurate errors were the faster. It is inferred that accurate subjects respond asymptotically in terms of a speed-accuracy tradeoff while inaccurate subjects set a less demanding criterion. Accurate subjects showed a tendency to increase inspection time as a function of item difficulty. This relation did not hold for inaccurate subjects.However, groups classified by means of the KRISP did not differ in either the speed of correct responses or accuracy of line length discriminations. For all groups judgement times were significantly related to stimulus differences and to stimulus ratios. There was no evidence that so-called impulsive children engage in less efficient and less detailed processing than other children.It is argued, contrary to the view of Kagan and his co-workers (e.g. Kakan 1966), that speed and accuracy of responding may not reflect a stable trait dimension. Rather children appear to be able to change their strategies according to the particular demands, implicit or explicit, of the task.     

Modification of cooperation and aggression through teacher attention to children's speech

Two experiments were performed in the naturalistic setting of a preschool classroom in order to assess the effects on children's social behavior of nonevaluative teacher attention to children's cooperative or aggressive speech. In Experiment 1, teachers attended to the children's spontaneous cooperative speech for two weeks. Observation of the children's free-play behaviors revealed an increase over baseline levels in both verbal and physical cooperative behaviors as well as a decrease in both verbal and physical aggressive behaviors. In Experiment 2, teachers attended first to the children's spontaneous aggressive speech for one week and then switched their attention to the children's cooperative speech for a second week. Teacher attention to aggressive speech in the first week led to an increase over baseline levels in the children's verbal aggressive behavior as well as a decrease in both verbal and physical cooperative behaviors; however, physical aggression remained unchanged. Teacher attention to cooperative speech in the following week served to reverse the effects of the first week's treatment. The findings were discussed in terms of the sequential relationship between verbal and nonverbal components of cooperative and aggressive social behaviors and the teacher's role in modifying children's performance on these behaviors in the classroom.     

Parental and Child Characteristics Predicting Asian immigrants’ Feeding Practices

To explore parenting style, child effortful control, parenting stress, and their associations with maternal use of pressure to eat among Asian U.S. immigrant families with preschoolers. One hundred and nine Asian immigrant mothers with 3-to-5-year-old children in Maryland, United States rated their authoritative and authoritarian parenting styles, frequency of pressuring their child to eat, perceived parenting stress, and child’s effortful control. Two proposed moderated mediation models were tested using conditional process modeling. Effortful control mediated the association between authoritative parenting style and pressure to eat practices, αβ?=??0.07, p?<?0.05, and the association between authoritarian style and pressure to eat, αβ?=?0.12, p?<?0.05. Moreover, parenting stress moderated the association between child effortful control and maternal pressure to eat in the authoritarian style model, but not in the authoritative style model. Specifically, higher effortful control was associated with less use of pressure to eat at low and mean levels of parenting stress. Our findings revealed potential mechanisms underlying the associations between parenting styles and controlling feeding practices. Importantly, information learned from the present study may guide transdisciplinary efforts to design and implement culturally sensitive and family-based interventions targeting Asian immigrants’ wellbeing and obesity in the United States.