Stimulus recognition and the mere exposure effect.

A meta-analysis of research on Zajonc's (1968) mere exposure effect indicated that stimuli perceived without awareness produce substantially larger exposure effects than do stimuli that are consciously perceived (Bornstein, 1989a). However, this finding has not been tested directly in the laboratory. Two experiments were conducted comparing the magnitude of the exposure effect produced by 5-ms (i.e., subliminal) stimuli and stimuli presented for longer durations (i.e., 500 ms). In both experiments, 5-ms stimuli produced significantly larger mere exposure effects than did 500-ms stimuli. These results were obtained for polygon (Experiment 1), Welsh figure (Experiment 2), and photograph stimuli (Experiments 1 and 2). Implications of these findings for theoretical models of the mere exposure effect are discussed.     

Identification and adaptation of hue: Parallels in the operation of mechanisms that underlie categorical perception in vision and in audition

Summary Four experiments were conducted to examine processes in identification and selective adaptation of hues in color perception that exactly parallel processes in identification and adaptation of auditory detectors that provide information for phonemic perception. The first experiment demonstrated an effect of adaptation on identification of blue and green when a hue category center was used as the adaptor; this experiment also assessed recovery from adaptation. Adaptation to one hue was found to shift identification to favor the alternative hue, implicating a single detector underlying hue categorization. The second experiment demonstrated similar effects of adaptation between green and yellow. The third experiment compared the magnitudes of shift following adaptation with a category center, a near-boundary hue, and variously graded adaptation series. Adaptation was found to be related to the category representativeness of the adaptor(s). Results of the third experiment also provided support for the view that adaptation, rather than response bias, is responsible for shifts in the position of identification functions following extended stimulus exposure. The fourth experiment explored the neural loci of adaptation by an interocular transfer test. Hue adaptation was found to occur at both central and peripheral loci. In the four main experiments, reaction times to identify hues in unadapted and adapted states were also analyzed and compared. Subsidiary experiments assessed the effects of stimulus luminance on the magnitude of adaptation. General principles of categorical perception and its underlying bases, including the sweep, magnitude, and symmetry of adaptation, are discussed. The principal findings of these studies provide new data on hue perception which strikingly parallel findings in speech perception.     

Discriminant validity of the General Behavior Inventory: an outpatient study

Recent studies have provided strong support for the convergent validity of the General Behavior Inventory (GBI), a case identification inventory for chronic subsyndromal affective disorders (cyclothymia and dysthymia). Fewer data are available, however, on the ability of the GBI to distinguish chronic subsyndromal affective disorders from other forms of psychopathology. In order to address this issue, outpatients with cyclothymia (n = 9), dysthymia (n = 26), nonchronic major depression (n = 16), and nonaffective psychiatric disorders (n = 30) were compared on the GBI. Diagnoses were derived blind to GBI scores using structured diagnostic interviews and DSM-III criteria. The inventory significantly discriminated cyclothymes and dysthymes from patients with nonchronic major depressions and nonaffective disorders. Using the cutoff score that maximized GBI-diagnosis concordance, the inventory correctly classified 88% of the sample. All of the cyclothymes, 92% of the dysthymes, 87% of the patients with nonaffective psychiatric disorders, and 75% of the nonchronic major depressives were correctly classified by the inventory. These data provide strong support for the discriminant validity of the GBI.     

The effects of polydrug use with and without cocaine on mother-infant interaction at 3 and 6 months

The face-to-face interactions of 43 polydrug-with-cocaine-using mothers and their infants at 3 and 6 months were compared to 17 non-cocaine-but other-drug-using mothers and 21 mothers who used no drugs during their pregnancy. Coders blind to mothers' drug use status scored 3 min of face-to-face interactions for 16 measures of maternal and infant interactive behaviors. A principal component of 7 behaviors formed a measure of maternal attentiveness; a principal component of 5 behaviors formed a measure of mother-infant dyadic organization; and a principal component of 4 behaviors formed a measure of infant readiness to interact. A measure of maternal interruption was computed as the mean standard score of 3 additional interruptive behaviors. At 3 and 6 months, polydrug-with-cocaine-using mothers were less attentive to interactions, and polydrug-with-cocaine-using mothers and their infants engaged in fewer dyadic interactions than either non-cocaine or non-drug-using mothers. Compared to 3 months, polydrug-with-cocaine-using mothers at 6 months were less attentive to interactions and more frequently interrupted interactions by looking away, redirecting the infant, or withdrawing, whereas non-cocaine-using and non-drug- using mothers showed no change or an improvement in attentiveness to interactions and a decrease in interruptions. No differences emerged in the interactive behaviors of the infants of polydrug- with-cocaine-using, non-cocaine-using, or non-drug-using mothers. Cocaine use represents a significant risk for diminished parental attentiveness and responsiveness to infants and for diminished interactiveness in infants.     

Antecedents of information-processing skills in infants: Habituation, novelty responsiveness, and cross-modal transfer

Three skills which characterize cognitive functioning in human infants in the middle of the first year of life—habituation, novelty responsiveness, and cross-modal transfer—predict mental ability in later childhood. Antecedents of each skill at 5 months postnatal were examined in a short-term prospective longitudinal study of infant ability and maternal intelligence and interaction style. Infant perceptuocognitive performance at 2 months, maternal intelligence, and maternal responsiveness at 5 months relate to the expression of the three infant cognitive skills, but in different ways. Variation in infant information-processing abilities can be explained by specific child and maternal factors that are evident soon after birth.     

Extra-legal factors and product liability: The influence of mock jurors' demographic characteristics and intuitions about the cause of an injury

Two experiments were performed to investigate the role of extra-legal factors in a simulated product liability trial. In cases where the factual evidence was identical, subjects' liability judgments varied as a function of the case-specific factor of the alleged source of the plaintiffs injury. In deciding cases differently depending on the alleged cause, subjects relied on intuitions about what injury sources are more or less likely to cause a certain kind of injury. Juror-specific factors also influenced subjects' verdicts. There was no difference between students and non-students, but race and SEC—factors that are often correlated with student status—did affect subjects' verdicts. Low-SES and minority subjects were more likely to find the defendant liable than high-SES and white subjects. The results are considered in terms of general decision-making processes, and the implications for jury selection and mock jury research are discussed.     

Track-draw: A graphical interface for controlling the parameters of a speech synthesizer

In this report we describe a graphical interface for generating voiced speech using a frequency-domain implementation of the Klatt (1980) cascade formant synthesizer. The input to the synthesizer is a set of parameter vectors, calledtracks, which specify the overall amplitude, fundamental frequency, formant frequencies, and formant bandwidths at specified time intervals. Tracks are drawn with the aid of a computer mouse that can be used either inpoint-draw mode, which selects a parameter value for a single time frame, or inline-draw mode, which uses piecewise linear interpolation to connect two user-selected endpoints. Three versions of the program are described: (1) SYNTH draws tracks on an empty time-frequency grid, (2) SPECSYNTH creates a spectrogram of a recorded signal upon which tracks can be superimposed, and (3) SWSYNTH is similar to SPECSYNTH, except that it generatessine-wave speech (Remez, Rubin, Pisoni, & Carrell, 1981) using a set of time-varying sinusoids rather than cascaded formants. The program is written for MATLAB, an interactive computing environment for matrix computation. Track-Draw provides a useful tool for investigating the perceptually salient properties of voiced speech and other sounds.     

Visual behavior of the young human infant: Relationships between chromatic and spatial perception and the activity of underlying brain mechanisms

Two experiments investigated visual attention in human infants. In one experiment, babies looked longer at more than at less saturated colors. In a second experiment, babies looked longer at gratings aligned along the horizontal and vertical orthogonals than along the obliques. Because saturated colors and orthogonal stimulation elicit greater activity in visual system neurons and greater amplitude evoked potentials than desaturated colors or oblique stimulation, these two experiments support the hypothesis that the simple visual stimuli to which infants preferably attend are those that are particularly appropriate in stimulating the geniculostriate or primary visual system. The ethological significance of this taxic mechanism and its utility and function in perception, cognition, and aesthetics are underscored.     

APPLICATION OF A SOCIAL SKILLS TRAINING PROGRAM IN THE MODIFICATION OF INTERPERSONAL DEFICITS AMONG RETARDED ADULTS: A CLINICAL REPLICATION

Six mentally retarded adults, equally divided into two treatment groups, were provided with individualized social skills training programs. Treatment, evaluated via a multiple-baseline design strategy, was sequentially and cumulatively applied across target behaviors over a four-week intervention period. Behavioral observation probes and social validation measures served as the primary dependent variables. Results indicated that (a) treatment was effective for virtually all behaviors across all subjects, (b) improvements occurred for both training and generalization scenes, and (c) behavioral performance was maintained one month following the termination of treatment.