Predicting stress patterns in an unpredictable stress language: The use of non-lexical sources of evidence for stress assignment in Russian

The main goal of this research was to examine how readers of Russian assign stress to disyllabic words. In particular, we tested the claim that the process of stress assignment in Russian can only be accomplished lexically. Eleven potential non-lexical sources of evidence for stress in Russian were examined in regression and factorial studies. In Study 1, onset complexity, coda complexity, the orthography of the first syllable (CVC1), of the second syllable (CVC2), and of the ending of the second syllable (VC2) were found to be probabilistically associated with stress in Russian disyllables. In Studies 2 and 3, it was shown that Russian speakers do use 3 of these cues (CVC1, CVC2, and VC2) when making stress-assignment decisions. These results provide evidence against the idea that the nature of stress in the Russian language is so unpredictable that stress assignment can only be accomplished lexically. These results also suggest that any successful model of stress assignment in Russian needs to contain mechanisms allowing these 3 orthographic cues to play a role in the stress-assignment process.     

Pilocarpine seizures cause age-dependent impairment in auditory location discrimination

Children who have status epilepticus have continuous or rapidly repeating seizures that may be life-threatening and may cause life-long changes in brain and behavior. The extent to which status epilepticus causes deficits in auditory discrimination is unknown. A naturalistic auditory location discrimination method was used to evaluate this question using an animal model of status epilepticus. Male Sprague-Dawley rats were injected with saline on postnatal day (P) 20, or a convulsant dose of pilocarpine on P20 or P45. Pilocarpine on either day induced status epilepticus; status epilepticus at P45 resulted in CA3 cell loss and spontaneous seizures, whereas P20 rats had no cell loss or spontaneous seizures. Mature rats were trained with sound-source location and sound-silence discriminations. Control (saline P20) rats acquired both discriminations immediately. In status epilepticus (P20) rats, acquisition of the sound-source location discrimination was moderately impaired. Status epilepticus (P45) rats failed to acquire either sound-source location or sound-silence discriminations. Status epilepticus in rat causes an age-dependent, long-term impairment in auditory discrimination. This impairment may explain one cause of impaired auditory location discrimination in humans.     

Distinguishing Between Causes and Enabling Conditions—Through Mental Models or Linguistic Cues?

The mental model theory of naive causal understanding and reasoning (Goldvarg & Johnson-Laird, 2001, Cognitive Science, 25, 565–610) claims that people distinguish between causes and enabling conditions on the basis of sets of models that represent possible causal situations. In the tasks used to test this hypothesis, however, the proposed set of models was confounded with linguistic cues that frame which event to assume as given (the enabling condition) and which to consider as responsible for the effect under this assumption (the cause). By disentangling these two factors, we were able to show that when identifying causes and enabling conditions in these tasks, people rely strongly on the linguistic cues but not on the proposed set of models and that this set of models does not even reflect people's typical interpretation of the tasks. We propose an alternative explanation that integrates syntactic and causal considerations.     

Sublexical and morphological information in speech processing

Three experiments investigated the impact of syllabic boundary information and of morphological structure on performance in a sequence-monitoring task. In sequence monitoring, participants detect pre-specified sequences of phonemes in spoken carrier words. Sequences corresponded to the first syllable of the carrier word, to its first morpheme, or simultaneously to both. The data from Experiments 1 and 2, using different variants of the monitoring task, showed a strong impact of syllable boundary cues on monitoring latencies. An effect of morphological match between targets and carrier words was also evident. Experiment 3, in which parts of the spoken carrier words were cross-spliced, revealed that syllabic boundary information takes precedence over morphological information. The results are in line with an early process of speech processing, in which syllabic cues are used to aid lexical access. The morphological effect is better understood as a later, probably lexical, contribution of morphological decomposition to monitoring performance.     

The Effects of Early English Learning on Auditory Perception of English Minimal Pairs by Taiwan University Students

Auditory perception of English minimal pairs was tested with or without noise background. Each subject was interviewed after the test to collect information regarding their early experience on learning English as a foreign language. This study was designed to examine the differential effects of learning English at three age-starting points and two learning durations. This study hopes to determine how childhood experience of English learning (which is not mandatory in public elementary schools) has affected the auditory competence of university students in distinguishing English minimal pairs. Results showed that age effects were salient only under condition of noise background. Without the interference of background noise, most subjects performed well enough to obliterate any potential differences.     

Second-order schedules with paired auditory brief stimuli

Pigeons were exposed to multiple second-order schedules of paired and unpaired brief stimuli in which responding on the main key was reinforced according to a fixed-interval thirty-second schedule by a brief stimulus (a tone in the paired schedule) and advancement to the next segment of the second-order schedule. In Experiment 1, a response on the second key was required during the tone in its fourth and final presentation to produce food. Responses during earlier brief stimuli indicated the extent to which the final brief stimulus was discriminated from preceding ones. Responding was comparable during all tones, extending prior findings with visual paired brief stimuli and weakening explanations of subjects' failure to discriminate between brief-stimulus presentations in terms of elicited responding. In Experiment 2 the number of fixed-interval segments comprising the second-order schedules varied from one through eight. Although main-key response rates increased across segments in both experiments, they increased much less sharply with a variable number of segments. These results suggest that the increase in main-key response rates across segments is due primarily to a degree of temporal discrimination not reflected on the second key. Main-key response rates were higher on paired auditory brief-stimulus schedules than on unpaired visual brief-stimulus schedules, especially in Experiment 2, thus further extending findings with visual brief stimuli to second-order schedules with auditory brief stimuli.     

TEACHING CHILDREN WITH AUTISM TO USE PHOTOGRAPHIC ACTIVITY SCHEDULES: MAINTENANCE AND GENERALIZATION OF COMPLEX RESPONSE CHAINS

We used a graduated guidance procedure to teach 4 boys with autism to follow photographic activity schedules to increase on-task and on-schedule behavior. The multiple baseline across participants design included baseline, teaching, maintenance, resequencing of photographs, and generalization to novel photographs phases. The results indicated that photographic activity schedules (albums depicting after-school activities) produced sustained engagement, and skills generalized to a new sequence of photographs and to new photographs. The acquisition of schedule-following skills enabled these children with severe developmental disabilities to display lengthy response chains, independently change activities, and change activities in different group home settings in the absence of immediate supervision and prompts from others.     

Context specificity of operant discriminative performance in pigeons: II. Necessary and sufficient conditions

Six experiments were performed to explore the necessary and sufficient conditions for producing context specificity of discriminative operant performance in pigeons. In Experiment 1, pigeons learned a successive discrimination (red S+/blue S−) in two chambers that had a particular odor present and between which they were frequently switched. The birds subsequently learned the reversal (blue S+/ red S−) in one of these chambers with a different odor present. When switched to the alternative chamber, although the odor and the reinforcement contingency were still appropriate to the reversal, performance appropriate to the original discrimination recurred in subjects for which the houselights were on during training and testing but not for those for which the houselights were off. This indicated the importance of visual contextual cues in producing context specificity. Experiment 2 showed that the frequent switching between boxes in initial training was of no consequence, presumably because the apparatus cues were highly salient to the subjects. Experiment 3 showed significantly less context specificity when odor cues were omitted. Experiment 4 showed that simply using a different reinforced stimulus in each phase of training was ineffective in producing context specificity. Experiment 5 showed that the generalization test procedure used in Experiment 4 was sensitive to context specificity when discrimination-reversal training was used with different odors in the two training phases. Experiment 6 replicated the results of Experiment 4, but then showed that when different odors accompanied the two training phases, context specificity was obtained with the single-stimulus paradigm. Thus in both single-stimulus and discrimination-reversal paradigms, redundant odor cues potentiated learning about apparatus cues.     

AUDITORY SUCCESSIVE CONDITIONAL DISCRIMINATION AND AUDITORY STIMULUS EQUIVALENCE CLASSES

This paper describes an experimental demonstration of stimulus equivalence classes consisting entirely of auditory stimuli. Stimuli were digitized arbitrary syllables (e.g., “cug,” “vek”) presented via microcomputer. Training and testing were conducted with a two-choice auditory successive conditional discrimination procedure. On each trial, auditory samples and comparisons were presented successively. As each comparison was presented, a response location (a rectangle) appeared on the computer screen. After all stimuli for a trial were presented, subjects selected one of the response locations. Six subjects acquired the conditional discrimination baseline, 4 subjects demonstrated the formation of three-member auditory equivalence classes resulting from sample-S+ relations, and 1 subject demonstrated equivalence classes resulting from sample-S— relations. Four subjects received additional training and subsequently demonstrated expansion of the three-member classes to four members each.     

Group affiliation and confidence in denominational categorization in Northern Ireland

The effects of group affiliation on group categorization confidence were examined in Northern Ireland. Subjects were presented with stereotypic name, school and location cues and a group affiliation scale devised by Brown, Condor, Mathews, Wade and Williams (1986). The results suggest that group affiliation has no effect on subjects' confidence in making denominational categorizations.