The effect of social feedback contingent upon a non-social response in seven- and ten-month-old infants

Summary Acquisition of a manipulative response under contingent and non-contingent maternal social stimulation was examined in seven- and ten-month-old infants. Response acquisition was reliably deomonstrated in the case of the ten-month-old infants, but not in the case of the seven-month-old infants. However, despite no acquisition, the performance of the younger infants did differ from that obtained under non-contingent scheduling Examination of visual behaviour to the manipulandum and the feedback source revealed comparable profiles for both ages. The findings are interpreted in terms of the greater difficulty of mixed social/non-social contingency situations and discussed in the context of cognitive constraints on response acquisition in infancy.The conduct of this study was supported by a grant from the United Kingdom Social Science Research Council to H.R. Schaffer, and undertaken whilst the author was a Research Fellow in Psychology at the University of Strathclyde, Glasgow, Scotland.The author is grateful to W.M. Cheyne for advice and to Norman Sharp and Margaret Hunter who assisted with the data collection and analysis.     

Minicomputer presentation of speech stimuli

A brief introduction to minicomputer control of speech stimuli is presented. Several techniques that have proven useful in this area are described.     

Perception of syllable-final stop consonants by 2-month-old infants

Previous research has shown that infants are capable of perceiving many phonetic distinctions between initial segments of syllables. The present study demonstrates that 2-month-old infants have the ability to distinguish syllables differing only in their final segments. Infants were found to be sensitive to place-of-articulation differences for stop consonants in final segments of both consonant-vowel-consonant (CVC) and vowel-consonant (VC) syllable pairs. Contrary to previous reports for older infants (Shvachkin, 1973), there was no indication that 2-month-olds have any more difficulty with contrasts of final-stop consonant:3 than they do with initial ones.     

Operant conditioning of the EEG in two patients with epilepsy: Methodologic and clinical considerations

Methodologic and clinical considerations are discussed in sensorimotor rhythm (SMR) biofeedback research on two dissimilar but severe epileptic males. The first case, an akinetic epileptic who prior to feedback training experienced 80–100 clinical seizures every 10 hours, showed considerable seizure reduction after 6 months of SMR and epileptiform training. A number of methodologic and instrumentation advances were pioneered with the akinetic patient: (1) development of and ultra-sharp band-pass filter; (2) use of epileptiform inhibit and feed-back circuitry; (3) use of monetary rewards as additional incentive; (4) use of correlational analysis for evaluation of acquisition in the major dependent variables and; (5) use of noncontingent feedback and rein-forcement as control techniques. The second case, a psychomotor epileptic, also showed therapeutic benefit from SMR training. Clinical information regarding the effect of anticonvulsant medications on the course and therapeutic outcome of SMR training are described. In conjunction with operant conditioning of 12 Hz activity, corresponding changes for other EEG parameters are examined.     

Judgment of duration relations: Simultaneous and sequential presentation

Four groups of subjects gave category ratings of total duration, average duration, or difference in duration of pairs of temporal intervals presented either simultaneously or successively. The results indicated that temporal information is combined in very different ways, depending on whether the members of the pairs must be monitored in parallel or sequentially. While judgments of successively presented intervals were reasonably consistent with the predictions of the appropriate linear models, judgments of simultaneously presented intervals were not. The latter judgments conformed more closely to the predictions of a vector sum model. These results appear to be in conflict with a model of duration perception recently proposed by Eisler (1975) based on the assumption that judgment of temporal intervals involves a simultaneous monitoring of two intervals even when the intervals to be compared are presented successively.     

Concurrent validity of Holland's theory for college degreed working women

The study was designed to explore two areas: (1) the concurrent validity of Holland's theory for employed college degreed women using two different operational definitions (Vocational Preference Inventory and the Self-Directed Search) of vocational orientation; and (2) the relationships among same named scales across the VPI and the SDS. Concurrent validity was studied by administering the VPI and the SDS to 179 women workers in occupational environments consistent with Holland's six vocational environments. In general, the findings indicate that the VPI and SDS scales tend to effectively discriminate among the occupational groups consistent with Holland's theoretical framework. In addition, the correlation coefficients for same named scales for the two inventories were all found to be significant. In sum, the results of the study lend some support to the concurrent validity of Holland's theory for employed college degreed women.