Communication Technology and Teacher-Student Relationship in the Tertiary ESL Classroom During the Pandemic: A Case Study.

Introduction: The study aims to present the potential benefits and challenges of incorporating communication technology (CT), namely synchronous computer-mediated communication (SCMC) (e.g., Zoom Video Communications), computer-mediated communication (CMC) (e.

The partial reinforcement extinction effect depends on learning about nonreinforced trials rather than reinforcement rate.

Conditioned responding extinguishes more slowly after partial (inconsistent) reinforcement than after consistent reinforcement. This Partial Reinforcement Extinction Effect (PREE) is usually attributed to learning about nonreinforcement during the partial schedule. An alternative explanation attributes it to any difference in the rate of reinforcement, arguing that animals can detect the change to nonreinforcement more quickly after a denser schedule than a leaner schedule.

The partial-reinforcement extinction effect does not result from reduced sensitivity to nonreinforcement.

Five experiments used a magazine approach paradigm with rats to investigate whether learning about nonreinforcement is impaired in the presence of a conditioned stimulus (CS) that had been partially reinforced (PRf). Experiment 1 trained rats with a PRf CS and a continuously reinforced (CRf) CS, then extinguished responding to both CSs presented together as a compound. Probe trials of each CS presented alone revealed that extinction was slower for the PRf CS than the CRf CS, despite being extinguished in compound.

The probability of reinforcement per trial affects posttrial responding and subsequent extinction but not within-trial responding.

During magazine approach conditioning, rats do not discriminate between a conditional stimulus (CS) that is consistently reinforced with food and a CS that is occasionally (partially) reinforced, as long as the CSs have the same overall reinforcement rate per second. This implies that rats are indifferent to the probability of reinforcement per trial. However, in the same rats, the per-trial reinforcement rate will affect subsequent extinction-responding extinguishes more rapidly for a CS that was consistently reinforced than for a partially reinforced CS.

Situational relevance: Context as a factor in serial overshadowing of taste aversion learning.

In a serial overshadowing procedure, a target stimulus, A, is followed after an interval by a potentially interfering stimulus, B, and this is then followed by an unconditioned stimulus (US). An untested proposal from over four decades ago was that the degree to which B overshadows conditioning of A depends on whether or not the two events take place in the same context. To test this, two experiments used a 1-trial long-delay conditioned taste aversion (CTA) procedure: sucrose served as the target taste (A) and dilute hydrochloric acid (HCl) as the overshadowing taste (B), with lithium chloride injection providing the US.

Asymmetry between excitatory and inhibitory learning.

Five experiments investigated how learning about the added feature in a feature-positive discrimination or feature-negative discrimination is related to the change in reinforcement rate that the feature signals. Rats were trained in a magazine-approach paradigm with 2 concurrent discriminations between A versus AX and B versus BY. In 2 experiments (1 and 3), X and Y signaled an increase of 0.

Timing of interfering events in one-trial serial overshadowing of a taste aversion.

This set of experiments examined the question of when a stimulus would be most effective in overshadowing the acquisition of long-delay taste aversion learning. In Experiment 1 rats drank sucrose, the target solution, followed by a hydrochloric acid (HCl) solution before lithium injection some time later; HCl was presented either early or late in the interval. The late condition produced greater overshadowing than the early condition.

Neuropsychological Profile and Dementia Symptom Recognition in Help-Seekers in a Community Early-Detection Program in Hong Kong.

Objectives: To examine the neuropsychological and clinical profile of help-seekers in an early-detection community dementia program and to explore any relationship between profiles and time to seek help.

Design: Cross-sectional.

Setting: Early-detection community dementia program.

Mediated overshadowing and potentiation of long-delay taste aversion learning: Two versus six cue-taste pairings.

Mediated overshadowing occurs when an evoked representation of one stimulus interferes with the formation of an association between two other stimuli. This study tested whether such an effect can be found in long-delay taste aversion learning. The general methodology was to pair a cue with a sour taste (hydrochloric acid [HCl]) and then introduce the cue during the delay between the target taste, sucrose, and injection with lithium chloride (LiCl).

Proximal, but not distal, pre-exposure reduces serial overshadowing in one-trial taste aversion learning.

This experiment tested whether pre-exposing a taste would reduce its ability to overshadow conditioning to a target taste and whether this effect would depend on the delay between pre-exposure and conditioning. Two groups of rats were pre-exposed to an interfering taste (HCl) either a week before conditioning (Group Distal) or the day preceding conditioning (Group Proximal). In the single conditioning trial, rats were given the target taste (sucrose) and 65min later were injected with lithium.

Conditioned inhibition and reinforcement rate.

We investigated conditioned inhibition in a magazine approach paradigm. Rats were trained on a feature negative discrimination between an auditory conditioned stimulus (CS) reinforced at one rate versus a compound of that CS and a visual stimulus (L) reinforced at a lower rate. This training established L as a conditioned inhibitor.

Elevated plasma free fatty acids are associated with sudden death: a prospective community-based evaluation at the time of cardiac arrest.

Background: In cohort studies, elevated levels of plasma nonesterified free fatty acids (NEFAs) have been associated with increased risk of sudden cardiac death (SCD) in men, but blood samples were drawn several years before SCD.

Objective: To confirm this relationship by evaluating levels of plasma NEFAs at the time of the SCD event in a group of both men and women.

Methods: From the ongoing Oregon Sudden Unexpected Death Study, we compared levels of plasma NEFAs in 149 SCD cases presenting with ventricular fibrillation (mean age 64 ± 12 years; 73% men) and 149 age- and sex-matched controls with coronary artery disease.

Magazine approach during a signal for food depends on Pavlovian, not instrumental, conditioning.

In the conditioned magazine approach paradigm, rats are exposed to a contingent relationship between a conditioned stimulus (CS) and the delivery of food (the unconditioned stimulus, US). As the rats learn the CS-US association, they make frequent anticipatory head entries into the food magazine (the conditioned response, CR) during the CS. Conventionally, this is considered to be a Pavlovian paradigm because food is contingent on the CS and not on the performance of CRs during the CS.

Flavor avoidance learning based on missing calories but not on palatability reduction.

Avoidance of a target flavor can be produced by providing rats with a highly nutritious solution of 20 % maltodextrin (20 %Malto) in some sessions and a 3 % maltodextrin (3 %Malto) solution containing the target flavor in intermixed sessions. Since 20 %Malto is both more nutritious and more palatable than 3 %Malto, flavor avoidance could arise because the flavor signals either a reduction in calories or reduced palatability, or both. Pilot testing established that rats strongly preferred 3 %Malto plus 0.

Serial overshadowing of taste aversion learning by stimuli preceding the target taste.

Three experiments tested whether events taking place before a rat has access to a target taste, sucrose, can proactively interfere with the acquisition of a sucrose aversion when sucrose is followed by a lithium chloride injection. Using a serial overshadowing procedure with various delays before lithium injection, proactive interference by a taste (Experiments 1 and 3) and by a novel context (Experiment 2) was found following two conditioning sessions, but not after a single conditioning session. Conversely, overshadowing by a taste given after the target was detectable after a single conditioning trial (Experiment 3) and, thus, indicated that retroactive interference involves a process different from that producing proactive interference.

Blocking of acquisition of a taste aversion by a context experienced prior to the taste.

This experiment tested the proposal that events taking place before a rat has access to a taste can proactively interfere with acquisition of an aversion to the taste when this has been followed by lithium chloride injection. Rats were initially given context discrimination whereby placement in one distinctive context (target) was followed by lithium injection, while placement in a second context (safe) was followed by saline injection. In the subsequent 1-trial taste conditioning session, rats were first placed in either their target context (Blocking group), their safe context (Control-Safe group) or a neutral context (Control-Neutral group), then given access to sucrose and 30 min later were injected with lithium.