Auditory processing and anxiety in stutterers

This study utilized the Synthetic Sentence Identification/Ipsilateral and Contralateral Competing Message subtests and the State-Trait Anxiety Inventory to examine auditory processing deficits, anxiety levels, and the interaction of these two components in 15 adult stutterers and 15 nonstutterers. Results support brainstem auditory processing deficits in stutterers and equalization of cortical functioning between groups. Group differences were not found in anxiety levels. Nonsignificant correlations between anxiety levels and auditory processing were revealed.     

Reinforcement as positive or negative meaning-extension: An empirical demonstration

According to logical learning theory, a reinforcement involves the extension of meanings predicated by subjects who are asked to perform in a learning task. Based on this theoretical position, it is predicted that subjects who are administered a reinforcement following their successful anticipation of the second member of a paired-associates unit will acquire their liked trigrams more readily than their disliked trigrams (mixed lists). Conversely, it is predicted that subjects who are reinforced following their incorrect anticipations of the second paired-associates member will acquire their disliked trigrams more readily than their liked. College students (divided equally by sex) were exposed to one of three reinforcement conditions: positive reinforcement, negative reinforcement, and no reinforcement (control). Trigrams reliably rated for likability by each subject were used as learnable materials. Although the control condition did not perform as expected, the remaining experimental conditions support the hypotheses.     

Influence of six types of visual structure on complexity judgments in children and adults

Individuals at five grade levels (kindergarten, Grade 2, Grade 4, Grade 6, and college) made pair-comparison judgments of visual complexity. The influence of the presence or absence of six types of visual structure (double symmetry, vertical symmetry, horizontal symmetry, diagonal symmetry, checkerboard organization, and rotational organization) and of amount of contour were examined. Two general developmental trends were revealed: First, the age at which visual structure initially affected complexity judgments varied with the type of structure, independent of amount of contour, within the range of contour values used. Second, there was a uniform increase in the effect of structure on complexity judgments between the fourth and sixth grades. These results are discussed in relation to possible mechanisms of visual pattern encoding and complexity judgment.     

Time errors and differential sensation weighting

Sixteen pairs of successive tones, with different amplitude combinations, were presented with 16 combinations of tone duration and interstimulus interval. A separate group of 12 subjects was assigned to each presentation condition and made comparative loudness judgments for each of the pairs. Perceived within-pair loudness differences were scaled by a Thurstonian method using the subjective width of the "equal" category as the unit. The scale differences were well described by weighted linear combinations of the sensation magnitudes of the tones in the pairs. The time error can be regarded as an effect of this differential weighting. For the longer interstimulus intervals, the weight of the second tone was the greater, causing the usual inverse relation between time error and stimulus intensity level. For the shorter interstimulus intervals, these effects were reversed. An analysis of the pattern of weights led to the development of two models, one of which is a generalization of Michels and Helson's time error model. The weights could be interpreted as reflecting the differential efficiency of the loudness information from the two compared stimuli.     

Effect of posttrial episodes on conditioning in compound conditioned stimuli

The effect of signaled and nonsignaled posttrial episodes (PTEs) on conditioning to the target CS of a preceding compound CS-US trial was examined in two conditioned emotional response (CER) experiments with rats. Experiment 1 revealed that a nonsignaled PTE, a second shock US, interfered with conditioning to the preceding target CS and that the interference effect of the PTE was greater when it occurred 5 sec as opposed to 1,800 sec after the preceding compound CS-US trial. Experiment 2 revealed that if the shock PTE was signaled by a CS, its ability to interfere with conditioning was reduced. This second study also revealed that omission of an "expected" US interfered with conditioning to the target CS. The implications of these data for information processing models of Pavlovian conditioning are discussed.     

Central sources of visual masking: Indexing structures supporting seeing at a single,brief glance

Summary When two briefly exposed, spatially overlapping visual fields are presented dichoptically, the identifiability of the first field is a J-shaped function of the interval separating their onsets. Three distinct sources of central masking are inferred from the selective influence of variables at different onset asynchronies. In integration through common synthesis, two fields presented at or near simultaneous onset yield one iconic representation. The distinctiveness of this source is inferred from the selective influence of eye dominance at and near simultaneous onset. At longer onset asynchronies, the selective influence of variables such as mask contrast and degree of contour overlap imply a second source of masking. This source was identified with the inhibition of sustained channels by transient channels reported elsewhere. Interchannel inhibition is proposed to affect the fidelity of the iconic representation, but here the imprecision is due to loss of form-relevant information on the first field. At yet longer onset asynchronies, where the fields are phenomenally separate, a third set of variables (e.g., words vs. nonwords and left vs. right visual fields) show their influence. These effects are taken as evidence of a replacement principle: the iconic representation of the second field directs attention from that of the first field. Here, first-field identifiability is constrained by time rather than by impoverished data.In a final series of experiments, central three-field interactions are demonstrated. A field, inserted into the temporal gap between two fields, is perceptually impaired even though it is separated from the first and third fields by intervals at which, individually, neither field is an effective mask. This second-field depression is accompanied by a first-field enhancement. The three sources of central masking are hard pressed to account for the three-field effects.     

The Mexican American in Higher Education: Implications for Educators

From a review of literature and an examination of data from the Counseling Services at the University of Texas - El Paso, the authors conclude that Mexican-American students place more emphasis on cooperation and group achievement than on individual achievement, and that the education of Mexican Americans may be enhanced when teachers properly reinforce “successful behavior.” In addition, it seems that problems may arise in using U.S.-based theories of “democratic” leadership styles because the Mexican-American culture places more emphasis on traditional leadership roles.