Promoting Generalization of Oral Reading Fluency: Providing Drill versus Practice Opportunities

Extensive evidence exists demonstrating the benefits of repeated readings (RR) interventions at increasing students’ fluency on intervention passages. Few studies however have examined the extent to which repeatedly reading one passage improves students’ reading fluency on similar passages. Using an alternating treatment design, we examined the extent to which two interventions resulted in improvements in students’ fluency on generalization passages. While both interventions incorporated RR, one intervention involved students reading one passage four times and the other involved students reading two similar passages each twice. Intervention effects were evaluated by having students read a generalization passage prior to and following intervention implementation. Results indicate that both interventions were effective in increasing students reading fluency on generalization passages. For 3 participants the RR intervention produced greater gains in fluency on the generalization passages, while data for the remaining 3 participants are inconclusive. Implications of these findings for practice and for better understanding application of the instructional hierarchy to the development of reading interventions are discussed.

Dissimilarity cumulation theory and subjective metrics

We present a new mathematical notion, dissimilarity function, and based on it, a radical extension of Fechnerian Scaling, a theory dealing with the computation of subjective distances from pairwise discrimination probabilities. The new theory is applicable to all possible stimulus spaces subject to the following two assumptions: (A) that discrimination probabilities satisfy the Regular Minimality law and (B) that the canonical psychometric increments of the first and second kind are dissimilarity functions. A dissimilarity function Dab for pairs of stimuli in a canonical representation is defined by the following properties: (1) a≠b?Dab>0; (2) Daa=0; (3) If and , then ; and (4) for any sequence {a_nX_nb_n}_n∈N, where X_n is a chain of stimuli, Da_nX_nb_n→0?Da_nb_n→0. The expression DaXb refers to the dissimilarity value cumulated along successive links of the chain aXb. The subjective (Fechnerian) distance between a and b is defined as the infimum of DaXb+DbYa across all possible chains X and Y inserted between a and b.     

Differential recognition of pitch patterns in discrete and gliding stimuli in congenital amusia: evidence from Mandarin speakers

This study examined whether "melodic contour deafness" (insensitivity to the direction of pitch movement) in congenital amusia is associated with specific types of pitch patterns (discrete versus gliding pitches) or stimulus types (speech syllables versus complex tones). Thresholds for identification of pitch direction were obtained using discrete or gliding pitches in the syllable /ma/ or its complex tone analog, from nineteen amusics and nineteen controls, all healthy university students with Mandarin Chinese as their native language. Amusics, unlike controls, had more difficulty recognizing pitch direction in discrete than in gliding pitches, for both speech and non-speech stimuli. Also, amusic thresholds were not significantly affected by stimulus types (speech versus non-speech), whereas controls showed lower thresholds for tones than for speech. These findings help explain why amusics have greater difficulty with discrete musical pitch perception than with speech perception, in which continuously changing pitch movements are prevalent.     

Pharmacological Shock Therapy as a Psycho-Biological Problem

Five mothers of 50 newborn rat pups were maintained on either standard lab chow or a diet composed of the same chow with onion powder added. Taste preference tests administered during weaning indicated that the pups whose mother was fed the onion chow showed a preference for onion diet, but that such preference dissipated across the five day testing period. A control group of pups who were exposed to any onion diet cues available through channels other than the mother's milk did not show a preference for onion diet. It was concluded that exposure to onion taste in mother's milk was responsible for an initial preference for onion diet.     

Technological Resources to Support Adaptive Responding with Persons with Multiple Disabilities

This study assessed technological resources for supporting adaptive responses in 2 men with profound multiple disabilities. The technological resources (an electronic control device connected to optic sensors and pleasant stimuli) ensured the activation of those stimuli contingent on adaptive responses. The responses consisted of putting various objects in a container fitted to a desk. Data showed that both participants reached satisfactory levels of adaptive responses in the intervention and generalization settings. Procedural issues, practical implications of the findings and measures for promoting response maintenance were discussed.     

Blocking by fixed and variable stimuli: Effects of stimulus distribution on blocking

An experiment with rats compared the ability of fixed and variable duration cues to produce blocking. Rats in group B (Blocking) were trained that both fixed- (F) and variable- (V) duration cues would be followed by food delivery. In a subsequent training stage F and V continued to be reinforced, but F was accompanied by X, and V by Y. In the test phase responding to X and Y was examined. Control group O (Overshadowing) received identical treatment, except that F and V were nonreinforced in the first training stage. In group B there was evidence for blocking, but only of X, which had been conditioned in compound with the fixed-duration F; there was no evidence for blocking of Y, which had been conditioned in compound with the variable-duration V. It is suggested that this result may occur because fixed cues reach a higher, more stable asymptote of associative strength than do their variable equivalents.     

An investigation of spatial representation of pitch in individuals with congenital amusia

Spatial representation of pitch plays a central role in auditory processing. However, it is unknown whether impaired auditory processing is associated with impaired pitch–space mapping. Experiment 1 examined spatial representation of pitch in individuals with congenital amusia using a stimulus–response compatibility (SRC) task. For amusic and non-amusic participants, pitch classification was faster and more accurate when correct responses involved a physical action that was spatially congruent with the pitch height of the stimulus than when it was incongruent. However, this spatial representation of pitch was not as stable in amusic individuals, revealed by slower response times when compared with control individuals. One explanation is that the SRC effect in amusics reflects a linguistic association, requiring additional time to link pitch height and spatial location. To test this possibility, Experiment 2 employed a colour-classification task. Participants judged colour while ignoring a concurrent pitch by pressing one of two response keys positioned vertically to be congruent or incongruent with the pitch. The association between pitch and space was found in both groups, with comparable response times in the two groups, suggesting that amusic individuals are only slower to respond to tasks involving explicit judgments of pitch.     

Task-switch costs subsequent to cue-only trials

There is abundant evidence that there is a performance cost associated with switching between tasks. This “switch cost” has been postulated to be driven by task performance on the preceding trial, but recent research challenges any necessary role of previous task performance in driving the cost. Across three experiments, we investigated whether it is difficult to switch from a task that was prepared but never performed. We replicated the finding of a switch cost following cue-only trials (involving no task performance) whilst controlling for a potential cue-switching confound. This cost was larger than that following completed trials when preparation interval was short (300?ms), and it reduced significantly with a longer preparation interval (1000?ms) on the current trial. We also found that preparing only to attend to a particular visual dimension (colour or shape) was sufficient to drive a significant subsequent switch cost, which appeared to be residual in nature; we speculate that this cost may reflect the persistence of unfulfilled task intentions and/or a strategic slowing when consecutive intentions conflict.     

Inferred threat and safety: Symbolic generalization of human avoidance learning

Symbolic generalization of avoidance may underlie the aetiology and maintenance of anxiety disorders. The aim of the present study was to demonstrate inferred threat-avoidance and safety (non-avoidance) behaviours that occur in the presence of stimuli indirectly related to learned threat and safety cues. A laboratory experiment was conducted involving two symbolic stimulus equivalence relations consisting of three physically dissimilar stimuli (avoidance cues: AV1–AV2–AV3 and neutral cues: N1–N2–N3). During avoidance learning involving aversive images and sounds, a key-press avoidance response was trained for one member of one of the relations (AV2) and non-avoidance for another (N2). Inferred threat and safety behaviour and ratings of the likelihood of aversive events were tested with presentations of all remaining stimuli. Findings showed a significantly high percentage of avoidance to both the learned and inferred threat cues and less avoidance to both the learned and inferred safety cues. Ratings in the absence of avoidance were high during training and testing to threat cues and low to safety cues and were generally lower in the presence of avoidance. Implications for associative and behavioural accounts of avoidance, and modern therapies for anxiety disorders are discussed.