Interference of Sentence and Picture Contexts on Learning Prepositions

The effects of extra stimulus cues, such as pictures and sentences, on learning of preposition words were examined in two experiments. A one-way repeated-measures design was applied in the study. The results show that both sentences and pictures interfered with and blocked the learning of these context-dependent words in the simultaneous presentations. The superiority of feedback presentations over simultaneous presentations indicate that feedback techniques neutralize the blocking effect. More interestingly, however, the prepositions were learned more quickly in the absence of any context cues and this suggested that it is better to teach basic preposition words either by the presentation of them alone or if extra stimulus cues are to be used they should be presented as feedback.     

Comparison of Different Feedback Procedures in Second Language Vocabulary Learning

Research into the learning of Second Language (SL) vocabulary by beginning learners has indicated that the simultaneous presentation of the First and Second Language words results in blocking of the learning process by the familiar First Language (FL) word. Previous research also suggests that blocking by the First Language can be eliminated by bringing it in as informative feedback (either as a written or spoken word). Our experiments were designed to further extend this research. The use of a picture, either as feedback or simultaneously presented with its equivalent, along with the aural feedback and the conventional procedures were investigated in Experiment 1. Results revealed that pictures blocked the learning process less than the written FL word when both were presented with their SL referent. When used as feedback, however, pictures were not as good as the spoken FL word. Experiment 2 demonstrated that aural feedback was the best type of feedback when compared with the picture and written FL presentations, and that the picture feedback was better than the written feedback. Taken together, the results of these two studies showed that all forms of feedback overcame the problem of blocking created by simultaneous presentation of the FL and SL words, and that aural feedback was the most effective feedback procedure. It was suggested that the superiority of aural feedback was likely to be a consequence of the use of a different input channel to that of the visually presented written SL word.     

Blocking, unblocking, and overexpectation in autoshaping with pigeons

Three experiments used pigeons in an autoshaping procedure and a single-subject design to examine compound stimulus control in classical conditioning. Experiment 1 examined the blocking effect, and Experiment 2 examined the unblocking effect. In both experiments, response-independent food was first delivered intermittently in the presence of one distinctively colored houselight but not another. Then, conventional autoshaping trials were carried out in the presence of each houselight. In Experiment 1, the keylight readily elicited responding in the presence of the houselight that had been negatively correlated with food, but not in the presence of the houselight that had been positively correlated with food. In Experiment 2, the keylight readily elicited responding in the presence of the houselight positively correlated with food, but only when the amount of food used on the autoshaping trials was either greater or less than that previously delivered in the presence of the houselight. Experiment 3 examined the overexpectation effect. Conventional autoshaping trials were first carried out by presenting each of two keylights individually. Then, additional autoshaping trials were carried out by presenting the two keylights as a compound, with either the same amount of food or a greater amount of food per trial. Finally, the keylights were retested by again presenting them individually. The number of responses per trial elicited by the keylights decreased when the amount of food used in compound trials was the same as that used in individual trials. However, the number of responses per trial remained approximately the same when the amount of food used in compound trials was greater than that used in individual trials. Taken together, the results of the three experiments demonstrate (a) the generality of the blocking, unblocking, and overexpectation effects by virtue of their extension to appetitive unconditioned stimuli; (b) the suitability of pigeons as subjects and autoshaping as a procedure for studying classical conditioning; and (c) the appropriateness of single-subject designs.     

Acquisition of stimulus control while introducing new stimuli in fading.

After establishing discrimination between a red positive stimulus and a green negative stimulus, the lowest intensity colors that restricted all responding to the positive stimulus were determined. Then, two new white lines differing in terms of line orientation were each superimposed on one of the colors and were increased in intensity. Thereafter, the intensity of the colors was decreased and eventually eliminated. Probe stimuli consisting of the lines presented against dark backgrounds were presented before each change of stimulus intensity, and probe responding was used to assess the control acquired by various dimension of the new stimuli during the course of fading. The lines acquired control of responding while they were being introduced, and control was strengthened as the colors were attenuated. Such a locus of acquisition was attributed to the starting intensity of the original controlling stimuli and was explained in terms of stimulus blocking. Finally, using probes while introducing the new stimuli enhanced the acquisition of control by the new stimuli.     

REDUCTION OF SELF-INJURIOUS HAND MOUTHING USING RESPONSE BLOCKING

We evaluated a response-blocking procedure for reducing the self-injurious hand mouthing of 2 adults with profound disabilities. The procedure reduced mouthing in both cases. The results suggest research is warranted to delineate the behavioral process responsible for the effect of response blocking and to determine the procedure's long-term utility.     

A STIMULUS CONTROL ANALYSIS OF THE PICTURE-WORD PROBLEM IN CHILDREN WHO ARE MENTALLY RETARDED: THE BLOCKING EFFECT

Conditioning to one member of a compound stimulus can be blocked by the presence of a second member to which the response was previously conditioned. This account of selective stimulus control can be used to explain the finding that pictures inhibit learning of written words if the relevant pictures and their verbal equivalents have been paired previously. We tested the blocking explanation of the picture-word problem with 8 mentally retarded students. Following baseline, each student was presented daily with four conditions in an alternating treatments design. In Condition A (blocking), a picture was presented alone and then was followed by the presentation of a picture and written word compound stimulus; in Condition B (blocking/control), a word was presented alone; in Condition C (blocking minimized), a word was enhanced in size and presented alone followed by the word and a picture; and, in Condition D (blocking minimized/control), the enhanced word was presented alone. Each stimulus was presented for 15 s. All students had the lowest percentage of words read correctly in the blocking condition, and all improved when blocking was minimized. Six of 8 students reached their highest percentage of words read correctly in the two control conditions when the words were presented as a single stimulus without pictures. These results indicate that pictures inhibit some students' learning of new words; this may be due to the blocking of conditioning to written words by prior conditioning to pictures.     

Context learning for threat detection

It is hypothesised that threatening stimuli are detected better due to their salience or physical properties. However, these stimuli are typically embedded in a rich context, motivating the question whether threat detection is facilitated via learning of contexts in which threat stimuli appear. To address this question, we presented threatening face targets in new or old spatial configurations consisting of schematic faces and found that detection of threatening targets was faster in old configurations. This indicates that individuals are able to learn regularities within visual contexts and use this contextual information to guide detection of threatening targets. Next, we presented threatening and non-threatening face targets embedded in new or old spatial configurations. Detection of threatening targets was facilitated in old configurations, and this effect was reversed for non-threatening targets. Present findings show that detection of threatening targets is driven not only by stimulus properties as theorised traditionally but also by learning of contexts in which threatening stimuli appear. Further, results show that context learning for threatening targets obstructs context learning for non-threatening targets. Overall, in addition to typically emphasised bottom-up factors, our findings highlight the importance of top-down factors such as context and learning in detection of salient, threatening stimuli.     

The Episodic Nature of Experience: A Dynamical Systems Analysis

Context is an important construct in many domains of cognition, including learning, memory, and emotion. We used dynamical systems methods to demonstrate the episodic nature of experience by showing a natural separation between the scales over which within‐context and between‐context relationships operate. To do this, we represented an individual's emails extending over about 5 years in a high‐dimensional semantic space and computed the dimensionalities of the subspaces occupied by these emails. Personal discourse has a two‐scaled geometry with smaller within‐context dimensionalities than between‐context dimensionalities. Prior studies have shown that reading experience (Doxas, Dennis, & Oliver, 2010) and visual experience (Sreekumar, Dennis, Doxas, Zhuang, & Belkin, 2014) have a similar two‐scaled structure. Furthermore, the recurrence plot of the emails revealed that experience is predictable and hierarchical, supporting the constructs of some influential theories of memory. The results demonstrate that experience is not scale‐free and provide an important target for accounts of how experience shapes cognition.     

Behavioral and genetic characterization of habituation using Caenorhabditis elegans

This review surveys the literature that investigates the behavioral characterization and cellular and molecular mechanisms of habituation using the model organism Caenorhabditis elegans. In 1990, C. elegans was first observed to show habituation to a non-localized mechanical tap. The parameters that govern this behavioral plasticity in C. elegans were subsequently characterized, which lead to the important hypothesis that habituation is mediated by multiple mechanisms. Many tools are available to C. elegans researchers that allow for relatively easy genetic manipulation. This has lead to a number of recent genetic studies that have begun to identify key genes and molecules that play a role in the mechanisms of habituation. Some of these genes include a vesicular glutamate transporter, a glutamate receptor subunit, a dopamine receptor and downstream intracellular signaling molecules, such as G proteins and kinases. Some of these genes only affect certain parameters of habituation, but not others supporting the hypothesis that multiple mechanisms mediate habituation. The field of research has also led to the dissection of different phases of memory (short-term vs. long-term memory for habituation), which are triggered by different training paradigms. The differences in mechanism between these various forms of memory are also beginning to be revealed.     

Super-latent inhibition of conditioned taste preference with a long retention interval

A long delay inserted between conditioning and test phases of a 3-stage Latent Inhibition (LI) procedure produces differential effects on LI depending on the delay context. Thus, enhanced LI has been obtained when the delay is spent in a context that is different from the remaining experimental contexts, but not when it is the same. The present paper examined the effect of delayed testing using a conditioned taste preference procedure. In Experiment 1, three groups received preexposure to either water, or almond, or citrus solutions. Subsequently, the animals were conditioned by pairing the almond and the citrus solutions with sucrose. In a two-bottle preference test conducted 1 day after conditioning, the preexposed flavored solutions were consumed less than the non-preexposed flavors (LI). Experiments 2 and 3 used the same basic procedure, but varied the retention interval duration (1 and 21 days) and the delay context, similar (Experiment 2) and different (Experiment 3) from that of the other stages of the experiments. LI was greater after the long than the short-retention interval when the context was different, thereby demonstrating super-LI. The results were explained by a time-induced context differentiation process.