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.     

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.     

The hydra-headed Mueller-Lyer effect: A theoretical puzzle

Three experiments were conducted to examine the effects of multiple fins on the magnitude of the Mueller-Lyer illusion. All studies showed that the multiple form of the elongation illusion was greater than the average of the components and that the multiple form of the shrinkage illusion was smaller than either of the components. The pattern of results failed to support either simple addition models or more complex averaging theories of illusions. A cross-attribute summation hypothesis and a filled space hypothesis were proposed as possible explanations for the results.     

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.     

The perception of melodies distorted by splitting into several octaves: Effects of increasing proximity and melodic contour

Splitting up the familiar tune “Yankee Doodle” by placing successive notes in different octaves makes it very difficult to recognize. The present experiments generalize this finding to more than one familiar tune and to presentation by actual musical instruments. Tunes differ in the degree to which their recognizability is affected by scrambling into different octaves, but recognition of all 10 tunes investigated was substantially diminished by the distortion. Increasing pitch proximity of temporally adjacent notes by leaving pairs or triples of successive notes intact within the same octave increases recognizability of at least some scrambled tunes. Leaving the melodic contour (the pattern of ups and downs) intact while splitting up the melody increases recognizability for subjects informed of the preservation of contour, though recognition is still worse than for undistorted versions.     

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.