Inducing blindsight in normal observers

We attempted to induce blindsight in normal observers, in an effort to replicate and extend the findings of Kolb and Braun (1995). In that demonstration, observers were able to localize a target in the absence of visual awareness, indicated by the lack of a correlation between localization accuracy and confidence ratings. Replication of this work seemed essential, given the failed attempt by Morgan, Mason, and Solomon (1997). A key aspect of the present work was the use of a pointing response, which is believed to have access to the unconscious representations subserving blindsight. In the critical rivalrous condition, the display consisted of Gabor patterns presented dichoptically with orthogonal orientation in each eye. Binocular summation of left and right images combined to give the appearance of a uniform plaid, camouflaging the texture-defined target. Our attempt to demonstrate blindsight in normal observers was unsuccessful, in that the localization accuracy of the texture-defined target and the observers’ confidence ratings were positively correlated. Although the replication was unsuccessful, the results are valuable in that they provide closure to this widely publicized but fruitless line of inquiry.     

Phonological memory and vocabulary learning in children with focal lesions

Eleven children with early focal lesions were compared with 70 age-matched controls to assess their performance in repeating non-words, in learning new words, and in immediate serial recall, a triad of abilities that are believed to share a dependence on serial ordering mechanisms (e.g.,; ). Results for the experimental group were also compared with other assessments previously reported for the same children by. The children with brain injury showed substantial impairment relative to controls in the experimental tasks, in contrast with relatively unimpaired performance on measures of vocabulary and non-verbal intelligence. The relationships between word learning, non-word repetition, and immediate serial recall were similar to those observed in several other populations. These results support previous reports that there are persistent processing impairments following early brain injury, despite developmental plasticity. They also suggest that word learning, non-word repetition, and immediate serial recall may be relatively demanding tasks, and that their relationship is a fundamental aspect of the cognitive system.     

Two determinants of the peak shift in human voluntary stimulus generalization

Two hundred and forty college students were divided into two groups, with training stimuli (from the brightness dimension) selected to produce small and large adaptation level shifts between discrimination training (to respond “same” to S+ and “different” to S—) and gen-eralization testing. These were further divided into three groups with discriminations expected to yield positive (toward brighter values), negative (toward dimmer values), or zero post-discrimination peak shifts. Half the subjects received brief discrimination training while half received extended training. A further group of 60 subjects were given exposure to the stimuli comparable to that of the extended training subjects, but were asked to rate the stimuli instead of being given discrimination training. The results indicated that two independent, additive sources of shift were active. One source, occurring in all groups, was interpreted as being due to the change in adaptation level from training to test. The other source of shift, occurring only in the groups with extended discrimination training, was interpreted as due to the establishment of asymmetrical decision criteria; the more traditional interpretation in terms of the interaction between excitatory and inhibitory gradients of response strength was also considered.     

Reliability of the Behavior Problem Checklist with institutionalized male delinquents

Interrater and 2-week test retest reliability coefficients were determined for subscales of the Behavior Problem Checklist on 50 males incarcerated in a state receiving facility for delinquent adolescents. Raters were 22 dormitory counselors, 2 of whom rated each child after 1 week and again after 3 weeks of observing the boys. Interrater reliability ranged from .06 to .68 on the various BPC subscales and was .50 overall, reflecting wide variation in the agreement of raters in rating boys on different dimensions. Test-retest reliability coefficients for the same rater at 2-week intervals were higher (.71 overall) and also varied among subscales. Raters were able to agree best on aggressive, acting-out behaviors. Other personality dimensions tapped by the BPC were rated with less reliability in this particular setting.This research was conducted with the cooperation and support of the Alabama Department of Youth Services, Diagnostic and Evaluation Center, Mt. Meigs, Alabama.     

Therapeutic social influence: sternly strike while the iron is hot

Two studies tested social influence options in symbolic modeling therapy. The first gave a pretreatment interview in which the therapist behaved in a “warm” or “businesslike” manner, and then urged the clients to approach a snake as closely as possible when (immediately afterward) they repeated a prior runway BAT and fear assessment. The “businesslike” group reported less fear than the “warm” group, but differential therapist perceptions did not affect overt avoidance. Study 2 compared directive social influence or its omission when clients performed approach immediately vs. the next week. The strongest BAT gains occurred if social influence was followed by prompt execution of the relevant task, but these differences were not maintained after treatment. The data suggested that timing is critical for applying social influence, which should be given immediately before task demands. Continued efforts to capitalize on initial differences might sustain socially-influenced gains for enduring treatment purposes.     

Strength of instigation as a determinant of the aggression—Attraction relationship

Somewhat surprisingly, previous research has failed to demonstrate what was thought to be an intuitively obvious negative relationship between aggression and attraction toward the victim of aggression. It was proposed that powerful instigation procedures in past research had served to obscure the effects of attraction on aggression. It was therefore hypothesized that aggression toward a stranger occurs as an inverse function of attitudinally induced attraction toward that stranger only when instigation strength is low. Male subjects (N=60) responding on the Buss aggression apparatus were exposed to a similar or dissimilar victim and to one of three levels of instigation: no instigation, a moderately aggressive model, or insulting evaluations. The hypothesized interaction between similarity and strength of instigation was confirmed for shock intensity (p<.02). For shock duration, main effects were found for both similarity (p<.02) and strength of instigation (p<.02). It was concluded that relatively negative feelings about another individual increase the probability of aggressing against him, but that such feelings do not constitute a necessary or sufficient condition for that aggression.This research was supported in part by Research Grant GS-40329 from the National Science Foundation. The authors wish to thank Dr. Don A. Nelson and Dr. Robert A. Baron for their aid in this experiment.     

AN EVALUATION OF TWO METHODS FOR INCREASING SELF-INITIATED VERBALIZATIONS IN AUTISTIC CHILDREN

Three children with autism and mental retardation were treated for deficits in self-initiated speech. A novel treatment package employing visual cue fading was compared with a graduated time-delay procedure previously shown to be effective for increasing self-initiated language. Both treatments included training multiple self-initiated verbalizations using multiple therapists and settings. Both treatments were efffective, with no differences in measures of acquisition of target phrases, maintenance of behavioral gains, acquisition with additional therapists and settings, and social validity.