TEACHING CHILDREN WITH AUTISM TO USE PHOTOGRAPHIC ACTIVITY SCHEDULES: MAINTENANCE AND GENERALIZATION OF COMPLEX RESPONSE CHAINS

We used a graduated guidance procedure to teach 4 boys with autism to follow photographic activity schedules to increase on-task and on-schedule behavior. The multiple baseline across participants design included baseline, teaching, maintenance, resequencing of photographs, and generalization to novel photographs phases. The results indicated that photographic activity schedules (albums depicting after-school activities) produced sustained engagement, and skills generalized to a new sequence of photographs and to new photographs. The acquisition of schedule-following skills enabled these children with severe developmental disabilities to display lengthy response chains, independently change activities, and change activities in different group home settings in the absence of immediate supervision and prompts from others.     

Context specificity of operant discriminative performance in pigeons: II. Necessary and sufficient conditions

Six experiments were performed to explore the necessary and sufficient conditions for producing context specificity of discriminative operant performance in pigeons. In Experiment 1, pigeons learned a successive discrimination (red S+/blue S−) in two chambers that had a particular odor present and between which they were frequently switched. The birds subsequently learned the reversal (blue S+/ red S−) in one of these chambers with a different odor present. When switched to the alternative chamber, although the odor and the reinforcement contingency were still appropriate to the reversal, performance appropriate to the original discrimination recurred in subjects for which the houselights were on during training and testing but not for those for which the houselights were off. This indicated the importance of visual contextual cues in producing context specificity. Experiment 2 showed that the frequent switching between boxes in initial training was of no consequence, presumably because the apparatus cues were highly salient to the subjects. Experiment 3 showed significantly less context specificity when odor cues were omitted. Experiment 4 showed that simply using a different reinforced stimulus in each phase of training was ineffective in producing context specificity. Experiment 5 showed that the generalization test procedure used in Experiment 4 was sensitive to context specificity when discrimination-reversal training was used with different odors in the two training phases. Experiment 6 replicated the results of Experiment 4, but then showed that when different odors accompanied the two training phases, context specificity was obtained with the single-stimulus paradigm. Thus in both single-stimulus and discrimination-reversal paradigms, redundant odor cues potentiated learning about apparatus cues.     

Prenatal discrimination of a male and a female voice uttering the same sentence

Using a habituation/dishabituation procedure, near-term foetuses (36-39 weeks gestational age) were tested in a low variability HR state, to examine whether they could discriminate between a male and a female voice repeatedly uttering the same short sentence. Prosody and loudness of the two voices were controlled. Once the foetal heart rate (HR) habituated to the first voice, the effect of a second voice was investigated in two experimental conditions: male/female voice and female/male voice. HR variations after the onset of the second voice were compared to those occurring in two control conditions in which the same voice was presented twice (male/female voice and female/female voice). Highly conservative statistical criteria taking each subject's pre-stimulus HR variability into account showed that most foetuses exposed to the voice change displayed decelerative cardiac changes, with no significant difference between the two conditions. These HR decelerations were found in the first seconds following the onset of the new voice, and reached their peak amplitude within 10 s in most subjects. These responses lasted more than 10 s for two-thirds of the experimental subjects. Mostly transient HR accelerations and only a few decelerative changes were recorded in the control subjects. Furthermore, mean amplitudes of these changes were significantly lower than the HR decelerations induced by the new voice in the experimental conditions, suggesting that the latter were not spontaneous HR modifications but rather cardiac responses to the voice change. It is argued that near-term foetuses may perceive a difference between voice characteristics of two speakers when they are highly contrasted for fundamental frequency and timbre.     

Teacher rated problems and school ability tests in relation to preschool problems and parents'' health information at school start. A study of first-graders

The reliability of assessments at four and six years of age in identifying teacher rated problems in behaviour, concentration, motor skill and school achievement was investigated in a study of first-graders. Relationships between preschool data and school ability tests, and between parents' information at school start and teacher ratings were also studied. Problems noted in preschool and school were often present in more than one area. Multiple problems at four and six years were strong predictors of later school problems, but preschool assessments of separate areas could not in general predict problems in corresponding areas in school. However, cross situational concentration deficits at the age of six did reliably identify concentration problems in the first grade, at the age of seven.     

Group affiliation and confidence in denominational categorization in Northern Ireland

The effects of group affiliation on group categorization confidence were examined in Northern Ireland. Subjects were presented with stereotypic name, school and location cues and a group affiliation scale devised by Brown, Condor, Mathews, Wade and Williams (1986). The results suggest that group affiliation has no effect on subjects' confidence in making denominational categorizations.     

A comparison of fixed momentary differential reinforcement of other behavior to variable momentary differential reinforcement of other behavior to reduce challenging behavior

Differential reinforcement of other behavior (DRO) is commonly used to reduce behavioral excesses. Momentary DRO schedules involve delivery of reinforcement contingent upon the absence of the target behavior at a given moment. Two variations of momentary DRO exist: fixed-momentary (FM) DRO and variable-momentary (VM) DRO. In the current study, we directly compared FM-DRO and VM-DRO schedules to reduce challenging behavior maintained by automatic reinforcement exhibited by four children with autism spectrum disorder. The results suggest that both the DRO schedules were equally effective to reduce challenging behavior. A social validity measure showed that most caregivers rated the VM-DRO as a preferred schedule and noted the potential for FM-DRO schedule to become more discriminable over time, which could reduce its effectiveness. However, most caregivers also commented that the FM-DRO schedule was easier to implement.     

Perceiving the inertial properties of actions in anticipation skill

Inertial properties of throwing or striking actions constrain action outcomes, but their role in anticipation skill has not been investigated yet. Therefore, the aim of this study was to systematically investigate the effect of inertial constraints on anticipation skill. Fifteen semi-professional and fifteen novice soccer players were tasked with determining the kick direction of penalty kicks occluded at 160 ms, 80 ms before ball-foot contact, at ball-foot contact, or 80 ms after ball-foot contact. The inertial constraints were manipulated by loading the kicking leg with a 2.25 kg weight around the shank of the kicking leg and were compared with unloaded kicks. Anticipation accuracy of kick direction, response time, and decision confidence were recorded. It was found that loaded kick directions were anticipated more accurately, faster, and at earlier occlusion periods than unloaded kicks. The higher accuracy for the loaded kicks was found in the earlier occlusion conditions in experts compared to novices, as were the positive relationships between accuracy and confidence. It was concluded that the perception of the inertial constraints of the kicking action allowed for earlier anticipation of kick direction. It is proposed that accurate perception of the biomechanical property radius of gyrations in the body segments linking proximal to distal towards the kicking foot may provide this information.     

Reactions to social and non‐social novelties in 2‐year‐olds

The purpose of this study is to investigate the internal structure of behavioural inhibition [cf. Goldsmith, H.H. and Campos, J.J. (1990). Child Development, 61 , 1944–1964]. Observations of 45 2‐year‐olds’ approaching/positive reactions, inhibited/negative reactions, and latencies, when encountering strangers as well as unfamiliar objects, are made in a laboratory setting. The intercorrelations between the six different measures, obtained from the observations, are analysed by means of a multitrait–multimethod matrix. It is concluded, from inspection of the matrix, that aggregations of data into indexes covering different reactions (approaching/positive reactions, inhibited/negative reactions, and latency) and settings (stranger and objects), respectively, are appropriate. To further validate the different indexes, assessments of concurrent variables (separation reactions, reactions to physical intrusion, reactions in a new setting, and maternal ratings of reactions to strangers) are used. The results indicate that all reactions to both social and non‐social novelties can be assigned to one construct, which is in line with the assumption made by Kagan and his co‐workers about behavioural inhibition. Copyright © 1999 John Wiley & Sons, Ltd.     

Cues that chimpanzees do and do not use to find hidden objects

Chimpanzees follow conspecific and human gaze direction reliably in some situations, but very few chimpanzees reliably use gaze direction or other communicative signals to locate hidden food in the object-choice task. Three studies aimed at exploring factors that affect chimpanzee performance in this task are reported. In the first study, vocalizations and other noises facilitated the performance of some chimpanzees (only a minority). In the second study, various behavioral cues were given in which a human experimenter either touched, approached, or actually lifted and looked under the container where the food was hidden. Each of these cues led to enhanced performance for only a very few individuals. In the third study – a replication with some methodological improvements of a previous experiment – chimpanzees were confronted with two experimenters giving conflicting cues about the location of the hidden food, with one of them (the knower) having witnessed the hiding process and the other (the guesser) not. In the crucial test in which a third experimenter did the hiding, no chimpanzee found the food at above chance levels. Overall, in all three studies, by far the best performers were two individuals who had been raised in infancy by humans. It thus seems that while chimpanzees are very good at “behavior reading” of various sorts, including gaze following, they do not understand the communicative intentions (informative intentions) behind the looking and gesturing of others – with the possible exception of enculturated chimpanzees, who still do not understand the differential significance of looking and gesturing done by people who have different knowledge about states of affairs in the world. Received: 8 November 1999 / Accepted after revision: 24 January 2000