Givenness, complexity, and the Danish dative alternation

In this study, we investigated the interaction between givenness and complexity on the choice of syntactic structure, via two experiments using speeded acceptability judgments. Experiment 1 showed that for the Danish dative alternation, given–new orders are only easier to process for double-object or NP constructions, whereas PP constructions are unaffected. This replicates previous findings for the English dative alternation. Experiment 2 revealed that when a long NP precedes a short NP—a suboptimal complexity relation—the effect of givenness is neutralized, whereas givenness remains influential when the complexity relation between the NPs in the sentence is optimal. This is consistent with the view that in online parsing, the actual syntactic structure-building process is primary, whereas any higher-order computations such as discourse linking are secondary. The relative complexity of the NPs in the double-object construction directly affects the structure-building process, whereas the decoding of the discourse structure is a later and less crucial phenomenon, resulting in neutralization of the givenness effect in cases in which the complexity relation is suboptimal.     

Effects of symmetrical and asymmetrical changeover delays on concurrent performances

Two variable-interval 3-min schedules functioned concurrently to arrange reinforcement of a pigeon's pecks on a single key, the main key. Each schedule was associated with a distinct color of the main key; a response on a second key alternated the color and schedule assignment of the main key. A changeover delay, a period of time following schedule and key-color alternation during which reinforcement of responding on the main key could not occur, was arranged with equal or with unequal durations for the two directions of alternation. Durations were varied from 0.33 sec to 27 sec, in addition to no delay. With equal delays for the two directions of alternation, the pigeon alternated the schedules less often the larger the delay duration. When the delays in the two directions of alternation were unequal, it could be shown that alternation of the schedules was reduced both by a delay just incurred by the last alternation and by a. delay to be incurred by the next. The latter delay was more potent in reducing the frequency of alternations.     

The combined effect of context and case alternation on migration

Summary Previous studies have demonstrated the occurrence of perceptual interactions when words are presented simultaneously in a visual display. The interactions, or migrations, consist of the formation of new words from letters in the display. Contextual information can increase the probability of migration. A difference in visual form between the words does not affect the occurrence of migrations.Two experiments are reported that manipulate context and visual form. Both between-word case alternation and within-word case alternation were used. Neither of these two forms of case alternation affected the occurrence of migrations or the interaction of context with migration, although within-word case alternation reduced the accuracy of word identification.     

Proactive interference and spontaneous alternation in rats

Two pairs of trials were given to naive rats in a T-maze. The first trial of a pair was forced to one arm, the second was free, and the delay between trials was 25 min. or 10 hr. Rats left in the maze for 15 sec. following the forced choice showed increased alternation on the second pair of trials at the 25-min. delay as compared with the 10-hr. delay. This was interpreted as due to a decline in alternation with delay on this pair of trials, together with an overall increase in alternation between the first and second pairs, and is consistent with the proactive interference theory of forgetting. Rats left in for 2 min. showed a decline in alternation with delay on the first pair of trials, but not on the second; this is inconsistent with the proactive interference theory.     

Case alternation effect: Two types of word recognition?

Two experiments were conducted to test Besner's (1983) claim that the lexical decision task involves a type of recognition mechanism that simply monitors the visual familiarity of the target without uniquely specifying the word. The experiments tested the combined effects of case alternation and decision type, and case alternation and word frequency in a lexical decision task and in a task requiring speeded decisions about the syntactic usage of target words. Contrary to Besner's proposal, case alternation did not affect word decisions more than nonword decisions in the lexical decision task. Further, the finding of additive effects of case alternation and word frequency in the two tasks was also at odds with the prediction derived from Besner's account. The discrepancy between the results obtained by Besner and the present lexical decision task was discussed in terms of different decision strategies, and it was suggested that under conditions of difficult word-nonword discrimination, the global visual familiarity of the target is not involved in making lexical decisions.     

Perception of motion in equiluminous kinematograms

Two fields of random dots that were identical except for a slight shift in a central square region were presented in rapid alternation. This produced a vivid impression of a square moving back and forth above the background. When the kinematogram is presented in equiluminous red/green, the motion of the central region can still be seen, although over a narrower range of alternation rates, interstimulus intervals, and displacements than for black/white presentation. The perception of motion for equiluminous stimuli indicates that colour and motion can be analyzed conjointly by the visual system. However, as originally reported by Ramachandran and Gregory, the segregation of the oscillating central square from the background is lost at equiluminance. This segregation process therefore appears to be colour-blind.     

Analyzing acoustic interactions in natural bullfrog (Rana catesbeiana) choruses

Analysis of acoustic interactions between animals in active choruses is complex because of the large numbers of individuals present, their high calling rates, and the considerable numbers of vocalizations that either overlap or show close temporal alternation. The authors describe a methodology for recording chorus activity in bullfrogs (Rana catesbeiana) using multiple, closely spaced acoustic sensors that provide simultaneous estimates of sound direction and sound characteristics. This method provides estimates of location of individual callers, even under conditions of call overlap. This is a useful technique for understanding the complexity of the acoustic scene faced by animals vocalizing in groups.     

Visual access and phonological recoding in reading italian

Summary Two experiments were conducted to investigate the accessing of codes used in the comprehension of Italian words. A semantic decision task was used in both experiments. Two models are proposed to explain the experimental results. Both assume that an entry in the lexicon may be located by two parallel routes, one visual and one phonological. When the visual familiarity of the sentences is disrupted by means of case alternation the subjects seem to rely more on the phonological code in accessing the lexicon. The results are compared with those reported for English readers.     

Clever homunculus: is there an endogenous act of control in the explicit task-cuing procedure?

Does the explicit task-cuing procedure require an endogenous a act of control? In 5 experiments, cues indicating which task to perform preceded targets by several stimulus onset asynchronies (SOAs). Two models were developed to account for changes in reaction time (RT) with SOA. Model 1 assumed an endogenous act of task switching for cue alterations but not for cue repetitions. Model 2 assumed no such act. In Experiments 1 and 2, the cue was masked or not masked. Masking interacted underadditively with repetition and alternation, consistent with Model 2 but not Model 1. In Experiments 3 and 4, 2 cues were used for each task. RT was slower for task repetition than for cue repetition and about the same as RT for task alternation, consistent with Model 2 but not Model 1. The results suggest that the explicit task-cuing procedure does not require an endogenous act of control.     

Discrete-trial alternation in the rat

The acquisition and maintenance by rats of single alternation, double alternation, and four other repeating patterns of reinforced and non-reinforced trials was studied in a discrete-trial lever-pressing situation. The rats learned all these patterns in a small number of experimental sessions. Single alternation was learned more rapidly than the more complex patterns. Rate of learning single and double alternation decreased moderately as inter-trial interval increased. Abrupt changes in the scheduling of trials, either by doubling the inter-trial interval or by shifting from fixed to variable trial spacing, temporarily disrupted the patterned performance. Two hypotheses concerned with the means by which the rats could have learned to conform to the pattern were examined: (1) “timing” of the interval between successive reinforcements; and (2) control of responding on a trial by the outcome of preceding trials, depending on the consistency with which these outcomes were associated with reinforced or non-reinforced trials in the pattern and on how many trials back these outcomes occurred. The second hypothesis accounted for the relative frequency of errors on trials at various locations in the sequences, and predicted most of the changes in error frequency observed in experiments in which “inter-trial stimuli” were added to the sequences.     

Neglected Factors Bearing on Reaction Time in Language Production

The input to phonological reasoning are alternations, that is, variations in the pronunciation of related words, such as in electri[k] - electri[s]-ity. But phonologists cannot agree what counts as a relevant alternation: the issue is highly contentious despite a research record of over 50 years. We believe that the experimental setup presented may contribute to this debate based on a kind of evidence that was not brought to bear to date. Our experiment was thus designed to distinguish between alternations where phonological computation plays no role, and those where it has contributed to language production. The design manipulates two factors that to date have not been considered in experimental studies of language production: linguistic complexity and alternation specificity. The former is understood as extra processing demands issued by two types of linguistic activity, morphosyntactic and phonological. Our results show that reaction time latencies are longer when participants are burdened with both morphosyntactic and phonological tasks than when they carry out just a morphosyntactic task, and they are still shorter in absence of both types of demands. These results allowed us to address alternation specificity, that is, the fact that different alternations (within a language or across languages) may be driven by different production routines (an idea that is consensual among linguists but underdeveloped in the psycholinguistic literature). Our study shows that four different alternations in French produce alternation-specific signatures in reaction time latencies. These findings may thus redound to the advantage of psycholinguistic studies by identifying two new factors, as well as produce results that speak to the linguistic quarrels.     

The influence of irrelevant stimulus changes on stimulus and response repetition effects

In this study the influence of irrelevant stimulus changes from one trial to another in a serial reaction time task was investigated. Two experiments were performed in which subjects were required to respond to stimulus colour. Four colours were mapped on two response keys, so that colour and response repetition effects could be dissociated. In Experiment 1, the irrelevant stimulus dimension was location and in Experiment 2 it was shape. Both experiments were performed with a short and a long response-stimulus interval (RSI)-condition. In both experiments, the irrelevant dimension influenced the response repetition effect but not the colour repetition effect. In the reaction times, a response alternation effect was observed only when the irrelevant location of the stimulus changed in the long RSI-condition. The error rates showed a response alternation benefit for both irrelevant dimensions, in the short and the long RSI-condition. The benefit for response alternations is explained in terms of a response bias towards change that is triggered by a changing stimulus feature. We assume that the response bias is stronger for location than for colour and that accuracy is more sensitive to this bias than response latencies.     

Single and double alternation learning in rats: The role of set size and correction

In many experiments, rats have evidenced extreme difficulty mastering alternation patterns. In three experiments, we explored rats’ ability to learn double alternation patterns and possible reasons behind their past difficulties with such patterns. In Experiment 1, rats learned single and double alternation patterns. In the second and third experiment, we explored the role of correction and interference from stimulus set size on rats’ learning of double alternation patterns. Our results showed that rats easily learned both single and double alternation patterns and that stimulus set size had no noticeable effect on learning double alternation patterns. Findings additionally evidenced that correction played an important role in rats’ learning double alternation patterns.     

Enhanced release of norepinephrine in rat hippocampus during spontaneous alternation tests

Recent evidence suggests that release of acetylcholine (ACh) in the hippocampus is associated with performance on a spontaneous alternation task and with enhancement of that performance by systemic and central injections of glucose. The present study extended these findings by examining norepinephrine (NE) release in the hippocampus using in vivo microdialysis while rats were tested for spontaneous alternation performance with and without prior injections (ip) of glucose. Microdialysis samples were collected every 12 min and assayed for NE content by HPLC-ECD. Like ACh, NE release in hippocampus increased during spontaneous alternation testing. As in past experiments, administration of glucose (250 mg/kg) significantly enhanced alternation scores. However, glucose did not influence NE release either during behavioral testing or at rest. These findings contrast with prior evidence showing that glucose augments testing-related increases in ACh release. The findings suggest that norepinephrine is released within the hippocampus while rats are engaged in alternation performance. However, increased release of norepinephrine apparently does not contribute to the enhancement of alternation scores produced by glucose.     

Executive control of cognitive processes in task switching

In 4 experiments, participants alternated between different tasks or performed the same task repeatedly. The tasks for 2 of the experiments required responding to geometric objects in terms of alternative classification rules, and the tasks for the other 2 experiments required solving arithmetic problems in terms of alternative numerical operations. Performance was measured as a function of whether the tasks were familiar or unfamiliar, the rules were simple or complex, and visual cues were present or absent about which tasks should be performed. Task alternation yielded switching-time costs that increased with rule complexity but decreased with task cuing. These factor effects were additive, supporting a model of executive control that has goal-shifting and rule-activation stages for task switching. It appears that rule activation takes more time for switching from familiar to unfamiliar tasks than for switching in the opposite direction.     

Response bias and the measurement of choice alternation

The problem of devising a measure of alternation of choices that is independent of response bias is considered. Previous solutions are equivalent to the correction for chance guessing in the Yes/No experiment of psychophysics, and require an estimate of response bias, usually from choices on the first of two daily trials. This involves the questionable assumption that response bias is homogeneous over time or across subjects. It is suggested that spontaneous alternation is analogous to the two alternative forced choice situation of psychophysics, and the fourfold point correlation is proposed as an index of alternation that is statistically independent of response bias. Implications for interpreting the effect upon spontaneous alternation of hippocampal and other lesions are considered.     

Control of tantrum behavior by operant techniques during experimental verbal training

A technique of controlling undesirable or disruptive behavior during an ongoing program of verbal training with a retardate is described. The technique required that the stimulus materials of the verbal training program be graded according to difficulty, i.e., in terms of the length and complexity of the stimulus materials. (This resulted in an initial grading of the stimulus materials into different levels of probability of reinforcement.) Changes by the experimenter from high-difficulty to low-difficulty stimuli for two trials contingent upon disruptive behavior increased the rate of that behavior; changes from low-difficulty to high-difficulty stimuli for two trials contingent upon disruptive behavior decreased its rate. Thus, contingent alternation of the stimulus materials of the ongoing training program controlled the frequency of undesirable behaviors within the experimental sessions. This technique may comprise an alternative to other procedures which require punishment or timeout from the ongoing program.     

A design comparing free- and forced-trial alternation in the rat at two interchoice intervals

A design is derived which equates the normally differing chance levels of alternation in the free- and forced-trial paradigms. Using 37 rats, this design was used to compare alternation levels in the two paradigms at two interchoice intervals. Forced-trial alternation was found to be significantly higher and longer lasting than free-trial alternation. It is suggested that the methodology presented here be considered by future researchers dealing with the two paradigms.     

Dichotic and bisensory grouping effects

The relationship between the Gray and Wedderburn effect, the channel alternation effect and the class alternation effect was studied in dichotic and bisensory experiments using physically and semantically distinguishable word classes. With dichotic presentation all three effects were found to occur, but with bisensory presentation neither the Gray and Wedderburn effect nor the class alternation effect was detected. There were no significant differences between physically and semantically based grouping. The present investigation provides support for Broadbent's claim that the Gray and Wedderburn effect depends on the occurrence of the class alternation effect. The various dichotic and bisensory grouping effects are explicable in terms of selection by modality-specific processing systems.     

Phonological Bases for L2 Morphological Learning

Two experiments examined the hypothesis that L1 phonological awareness plays a role in children’s ability to extract morphological patterns of English as L2 from the auditory input. In Experiment 1, 84 Chinese-speaking third graders were tested on whether they extracted the alternation pattern between the base and the derived form (e.g., inflate – inflation) from multiple exposures. Experiment 2 further assessed children’s ability to use morphological cues for syntactic categorization through exposures to novel morphologically varying forms (e.g., lutate vs. lutant) presented in the corresponding sentential positions (noun vs. verb). The third-grade EFL learners revealed emergent sensitivity to the morphological cues in the input but failed in fully processing intraword variations. The learners with poorer L1 PA were likely to encounter difficulties in identifying morphological alternation rules and in discovering the syntactic properties of L2 morphology. In addition to L1 PA, L2 vocabulary knowledge also contributed significantly to L2 morphological learning.