Effects of CS preexposure on inhibition of delay

Two experiments examined the effects of preexposure to a stimulus on the subsequent acquisition of conditioned suppression by rats. Variations in the level of suppression within conditioning trials were noted so thatinhibition of delay (taken here to mean less suppression at the beginning of a trial than at the end) could be detected. Inhibition of delay was observed both during the acquisition of suppression and (in Experiment 1) when suppression began to wane with continued postasymptotic training. Preexposure to the to-be-conditioned stimulus retarded acquisition of suppression and slowed the appearance of inhibition of delay both in acquisition and (in Experiment 1) in postasymptotic performance. Experiment 2 demonstrated that inhibition of delay was attenuated during conditioning that followed preexposure in which the stimulus was paired with a weak reinforcer. These results provide no support for the suggestion that preexposure to a stimulus retards later conditioning because it allows the subject to acquire information about stimulus duration that in turn fosters the development of inhibition of delay. Rather, they are compatible with the suggestion that preexposure causes the stimulus to lose associability.     

The influence of brief stimuli uncorrelated with reinforcement on choice between variable-ratio schedules

Experiment 1 investigated the behavior of rats trained to leverpress on a concurrent variable ratio (VR) 30 VR-30 schedule with a brief, 500-msec, light occurring at the midpoint of the ratio on one of the levers. Higher response rates were recorded on the lever associated with this stimulus, a finding that paralleled the effect produced by inserting primary reinforcement at the midpoint (i.e., by training on a concurrent VR-30 VR-15 schedule). Similar results were found in Experiment 2 using a concurrent VR-20 VR-20 schedule with a 2-sec visual stimulus presented midway through one of the components. In addition, a brief stimulus inserted midway through the VR-20 component of a concurrent VR-20 VR-10 schedule retarded the development of a difference in response rates between the components relative to a VR-20 VR-10 group lacking the signal. In Experiment 3, multiple VR VR schedules were used. Again, the response rate was higher in the component that had the added stimulus or, for a second group of subjects, on the component with the smaller response requirement. Probe-choice trials revealed a preference for the component that generated the higher rate in both groups. Presenting a stimulus partway through a ratio appears to reduce the effect on response rate and choice of a large ratio value.     

Reading,spelling and two types of irregularity in word recognition

How do good and poor readers, and good and poor spellers, vary in their decisions about words which have varying spelling-to-sound correspondences? This experiment isolates the effects of visual and phonological characteristics of words with schoolchildren of varying reading and spelling ability, aged between 9 and 11.5 years. Three groups of children were tested: good readers and good spellers, good readers who were poor spellers, and children who were both poor readers and poor spellers. The difference between‘good’and‘poor’was about two years according to the standardised tests which were used. The children performed a lexical decision task, deciding whether each letter-string was a word or not. Response times to three types of words were compared: standard regular words (e.g. SLOT, SPADE), words with common orthography but irregular spelling-to-sound relationships (e.g. HAVE, FEVER), and words with unusual orthography as well as irregular spelling-to-sound relationships (e.g. BISCUIT, ANSWER). The performance of good readers but not of poor readers was impaired on the words which were phonologically irregular (compared with regular words). Poor spellers were worse again on the dually irregular words, although not significantly, while the good spellers performed almost as well on these words as on the regular words. These results have a number of implications: that the regularity effect is phonologically and not orthographically mediated, that good readers use a predominantly phonological strategy in lexical decision while poor readers do not, and that for the best readers/spellers as tested here the orthographically and phonologically irregular words have some sort of special status which allows them to gain fast and accurate responses.     

Potentiation of delayed matching with variable delays

In a delayed matching-to-sample procedure, pigeons chose a comparison stimulus that matched a sample stimulus presented earlier in the trial. The duration of the delay between sample-stimulus presentation and comparison-stimulus presentation was either varied over five values within each session or held constant within each session but varied over five blocks of sessions. Accuracy of matching to sample was higher overall with variable delays than with delays fixed within sessions. The result indicates that remembering depends on the temporal context provided by delay intervals.     

Digital storytelling as a disciplinary literacy enhancement tool for EFL students

Educational technology research and development - This research compared the process of disciplinary literacy acquisition of students who experienced two different pedagogical approaches to...     

Cognitive Style and Pupil Learning Preferences

A total of 78 12‐year‐old pupils from four secondary comprehensive schools were given the computer‐presented Cognitive Styles Analysis, which determined the position of each pupil on two learning style dimensions: Wholist‐Analytic and Verbal‐Imagery. They were also given individually a structured interview questionnaire to assess their learning preferences in English and science in terms of: (a) mode of working, (b) task outcomes and (c) social context. The English and science teachers were asked to rate the achievement level of the pupils in their subject and this was used as an index of ability. The main findings were as follows, (a) Preferred Mode of Working: As expected, there was a tendency for Imagers to use pictures and Verbalisers to prefer writing, and this increased with ability and what the subject would naturally allow. There was evidence that lower ability pupils were more constrained by the usual format for the subject than were those of higher ability, (b) Social Context: Overall, Group or Pair was preferred to Individual work. Group work was particularly liked by Wholists and especially by lower ability Wholist‐Imagers. Individual work was least disliked by Analytics, particularly in the case of higher ability Verbalisers (c) Task Outcomes. For open versus closed tasks, open tasks were preferred by lower ability pupils, while high‐ability Wholist‐Imagers preferred closed tasks. The findings were discussed in terms of their implications for current practice.