The language of social pretend play

The literature dealing with the structure and communication of social pretend play activity in preschool-age children is examined. The two objectives of this review were to determine (1) whether there are any differences in the linguistic forms and expressions children use in pretend as opposed to nonpretend activity and (2) whether age-related differences appear in the language of social pretending over the preschool years. The results of a cross-sectional study of a number of linguistic features occurring in the pretend and nonpretend activities of 35 dyads of children are also presented. The evidence supports the hypotheses that the language of social pretending differs from that of other social activities at several levels of language organization and that some of these differences in the “language of social pretending” appear at different ages during the preschool years. Suggestions are made for further research on the communicative techniques by which social pretend interactions are achieved.     

Visual marking of old objects

Watson and Humphreys (1997) presented evidence that selection of new elements can be prioritized by on-line top-down attentional inhibition of old stimuli already in the visual field (visual marking). The experiments on which this evidence was based always presented old elements in green and new elements in blue. Because of this, instead of prioritizing new objects by inhibiting old objects, selection could have been based on color. The present experiment, which does not contain this confound, showed that visual marking is a strong and robust process that enables subjects to visually mark at least 15 old elements even when these elements have the same color as the new elements. The results indicate that preview of the elements is critical—not the fact that those elements contained a common feature.     

Application of the Generalized Matching Law for Description of Student Behavior in the Classroom

Matching law and theory have applied implications for classroom instruction and student behavior. The Generalized Matching Law (GML) is examined in this exploratory study to assess its utility for quantitatively describing student behavior in the classroom. Data were collected using computer-based observational software. Time-lag sequential analysis was used to identify specific teacher behaviors following specific student behaviors as estimates of reinforcement. Derived rates of student and teacher behaviors were analyzed in a linear regression of the natural logarithmic form of the GML. On average, the GML described over 70% of the variance in two students' behavior in a first-grade regular education classroom. Discussion addresses the potential utility of the GML for observation and intervention in the classroom.     

Offset transients modulate attentional capture by sudden onsets

Recent research with visual search tasks has suggested that stimuli which appear as sudden onsets (new objects) have attentional priority over stimuli that are created by removing segments of premasks (non-onset stimuli). Attentional capture by sudden onsets occurs despite the fact that the appearance of these new objects predicts neither the identity nor the location of the target in the visual search task. In three experiments, we examined the extent to which attentional capture by sudden onsets could be modulated by offset transients used to create non-onset objects. To that end, we systematically manipulated the ratio of non-onset to onset stimuli in the display (display ratio) as well as the ratio of offset to onset segments between the stimulus types (stimulus ratio). Increases in either the stimulus ratio or the display ratio resulted in increases in the visual search slopes for the onset targets. These results suggest that the ability of sudden onsets (new objects) to capture attention is influenced by stimulusdriven factors, such as environmental change. Interestingly, the results also indicated that goal-directed or purposeful search for sudden-onset (new-object) targets was relatively uninfluenced by the amount of change in the visual display. Therefore, it would appear that environmental change has differential effects on goal-directed and stimulus-driven search. These results are discussed in terms of their implications for our understanding of attentional capture.     

An attempt towards differentiating attentional deficits in traumatic brain injury

Attentional deficits in patients suffering traumatic brain injury (TBI) can occur with minor to severe impact to the brain. Based on reviews of both the cognitive and neurobehavioral literature, the following three concepts of attention are addressed: (a) arousal/alertness, (b) selective attention, and (c) energetic aspects of attention, which include such components as effort, resource allocation, and speed of processing. Within each concept, definitions are proposed, the underlying brain mechanisms are identified, and the specific deficits associated with TBI are explored. This review combines theoretical perspectives and clinical findings with the objective of leading toward a diagnostic differentiation that in turn will benefit treatment planning.     

Memory for recent behavior in the pigeon

Variations of the symbolic delayed-matching-to-sample procedure were used to study a pigeon's memory for a small number of pecks. In the first experiment a choice of a left or right sidekey after a delay or retention interval was reinforced if a bird had not pecked at all or had pecked exactly once, before the delay, respectively. In the second experiment a choice of a red or green sidekey, regardless of its position, was reinforced if a bird had not pecked at all or had pecked exactly twice, respectively. In the first experiment a bird could orient toward the correct choice during the delay, whereas it could not in the second experiment. In a third experiment a feature-probing method was used to study a pigeon's memory for a number of pecks in the context of certain other pecks. The results showed that a pigeon can remember a small number of pecks for one-half to one minute or more and that the percent correct is a decreasing function of the log retention interval. When a second number of pecks is different from the first number, memory for the first number lasts only a few seconds. When a second number is the same, memory lasts considerably longer. The more recent number of pecks is remembered better. The results are interpreted in terms of a theory which holds that a reinforcer, in general, may act on a subjects' memory for recent behavior to generate patterns of behavior.