Selective information use and perseveration in the search behavior of infants and young children

Two experiments examined the early development of selective information use in search. The first experiment tested 9- and 16-month-olds on a modification of Piaget's Stage IV object permanence task. It examined infants' use of information from previous experiences with an object (prior information) and from the most recent hiding (current information) to locate a hidden object. In the second experiment, 2-, $\text{2}\text{1}\text{2}$-, and 4-year-old children received these same sources of information along with new forms of prior and current information: information about the typical locations of objects (location specificity) and verbal information. No systematic perseveration was observed at 9 months, although previous findings related to perseveration were replicated. Perseveration was found at 16 months, but there was also evidence of selectivity at that age. When errors occurred, they tended to be to the prior location, but they were infrequent in comparison to correct searches at the current location. The preschoolers, while continuing to show perseveration, were more consistently selective than the infants. They also showed considerable generality in extending their selectivity to new sources of information.     

Differences in temporal appearance associated with activity in the chromatic and achromatic systems

The temporal appearances of spatially coincident increments that activate the chromatic or achromatic system are different. Whereas near-threshold stimuli that are detected by the chromatic system appear to come on gradually, increments detected by the achromatic system appear to flash or step on. This difference in perception is consistent with previous reports that show differences in the temporal properties of the two systems.     

Preparing dichotic tapes using a digital music synthesizer

Digital music synthesizers represent audio signals in the form of binary coded numbers. These binary coded numbers can be manipulated by the operator, thereby altering the audio signal in a variety of ways. The present article describes how these capabilities can be used to produce perfectly aligned dichotic tapes in which the stimulus items are matched on all extraneous (timbre, amplitude, duration) factors.     

Irrelevant thoughts,emotional mood states,and cognitive task performance

In two experiments, we investigated the relationship shared by irrelevant thoughts, emotional mood states, and cognitive task performance. At an empirical level, irrelevant thoughts were defined as thoughts that did not facilitate successful task performance. We used the same general procedure for both experiments: three groups of college students received happy-, neutral-(control), or sad-mood inductions and performed a memory task. The procedure for obtaining thoughts varied between experiments. The subjects in Experiment 1 listed their thoughts after the memory recall task. In Experiment 2, the subjects were tape-recorded while performing a memory task and producing concurrent verbal protocols. The subjects in both experiments then judged their thoughts in terms of frequency, intensity, and irrelevance. We found a similar pattern of results in both experiments: (1) The proportions of irrelevant thoughts and recall performance were negatively related, and (2) happy and sad students produced reliably greater proportions of irrelevant thoughts than did neutral (control) students.     

Organizational and family systems factors in stress among ministers

Forty-one Protestant ministers completed measures of stress-related symptoms, family of origin contact, church governing body density, history of pastor-parish conflict in the church, and a measure of Bowen's (1959b/1985) concept of emotional triangles. A denominational executive provided ratings of each church's history of pastor-parish conflict. Path analysis using multiple regression showed support for a model in which governing body density and history of conflict predicted emotional triangles, and emotional triangles predicted stress symptoms. Contact with the pastor's family of origin moderated the relationship between emotional triangles and stress symptoms. Results suggest that the organizational and family ecology of the ministerial role can be important in understanding occupational stress among ministers.     

Out-of-home placement of children: Selected issues and prospects for the future

This paper describes the recent trends in the child welfare and children's mental health systems and their implications for public policy. Despite the rhetoric calling for preserving families and treating children and youth in their own homes, the best available evidence indicates that the rates of out-of-home placement are increasing at an alarming rate. More concerted and comprehensive efforts are needed if this trend is to be reversed in the near future.     

Interval and ratio reinforcement of a complex sequential operant in pigeons

Pigeons were required to produce exactly four pecks on each of two keys in any order for reinforcement. Correct response sequences were reinforced on either fixed-interval two-minute or fixed-ratio four schedules, with each correct sequence treated as a single response. Each pigeon developed a particular dominant sequence that accounted for more than 80% of all sequences. Sequence stereotypy was relatively unaffected by the temporal properties of the fixed-interval and fixed-ratio schedules. Response time (time from the first response in each sequence to the last) was also relatively unaffected by the temporal properties of the schedules. In contrast, response latency (time from end of one sequence to the beginning of the next) was markedly affected by the schedules. Latencies were long early in the interreinforcement interval and got shorter as the interreinforcement interval progressed. These data suggest that stereotyped response sequences become functional behavioral units, resistant to disruption or alteration by reinforcement variables that ordinarily influence the temporal spacing of individual responses.     

Verbal ability and mental processing speed

The notion that verbal ability is related to mental processing speed was examined using tasks that systematically varied in semantic content. Subjects' reaction times were measured in five tasks involving arrow matching, physical identity word matching, or taxonomic identity word matching. The findings indicated that matching tasks using different decision rules and different stimuli were all related to verbal ability. In fact, reaction time for subjects required to judge whether two arrows pointed in the same direction was the best predictor of verbal ability. One explanation of the results is that speed of information processing (a general factor) may be the important component of verbal ability which is measured by seemingly different matching tasks.     

The relationship of estimated comprehensibility to the rate of connected speech

The relationship between subjective estimates of the comprehensibility of connected, freerunning speech and rate of speech was investigated for each of two types of time-compressed speech: pitch-varying speeded speech and pitch-normalized compressed speech. The midpoints of the resulting functions approximated the values obtained by a previously described speechrate tracking method. For equivalent degrees of comprehensibility, rates were higher for compressed speech than for speeded speech, indicating that estimates are sensitive to the intelligibility of speech. Subjective estimates of comprehensibility of time-compressed speech provide a means of assessing the itelligibility of connected speech.