The effects of the stimulus-reinforcer correlation in a discrete-trials IRT>t procedure

The correlation between a keylight and food in a discrete-trials, interresponse-time-greater-than 6-sec (IRT>6-sec) procedure was varied by manipulating the rate of response-independent food presentation in the intertrial interval. When the correlation was positive, the rates of pecking in the IRT>6-sec condition were high and food was obtained on only about 5% of the trials. Likewise, responding was maintained at a high rate in yoked birds that received the same presentations of the light and food as the birds in the IRT>6-sec condition. When the rate of reinforcement between trials was equated to or made greater than the rate of reinforcement within trials, the response rate decreased for all birds, and those decreases were considerably larger for the yoked birds. However, the percentage of trials in which reinforced responses occurred under the IRT>6-sec procedure did not increase substantially when the light and food were either uncorrelated or negatively correlated. The percentage of trials in which a reinforcer was obtained increased when the keylight was left on continuously and the discriminative stimulus was not presented on the key. The results show that the stimulus-reinforcer correlation affects responding in the discrete-trials IRT>6-sec procedure, but that the effects of the stimulus-reinforcer correlation vary as a function of whether reinforcement is response-dependent or response-independent. The differences between the effects of response-independent and response-dependent pairings and nonpairings of the light and food are best accounted for in terms of differences in the control of responding by background stimuli.     

Maintaining Accurate Math Responses In Elementary School Students: The Effects Of Delayed Intermittent Reinforcement And Programming Common Stimuli.

This study examined the effect of delayed reinforcement on digits completed by elementary school children and the effect of programming stimuli common to reinforcement conditions on the maintenance of their performance. Participants exhibited similar levels of responding during intermittent and continuous reinforcement. Responding continued for a number of sessions at similar levels during a maintenance phase that included stimuli present during delayed reinforcement.     

Conditional discrimination and equivalence relations: Control by negative stimuli

Three adult subjects were taught the following two-sample, two-comparison conditional discriminations (each sample is shown with its positive and negative comparison, in that order): A1-B1B2, A2-B2B1; B1-C1C2, B2-C2C1; and C1-D1D2, C2-D2D1. A teaching procedure was designed to encourage control by negative comparisons. Subjects were then tested for emergent performances that would indicate whether the baseline conditional discriminations were reflexive, symmetric, and transitive. The tests documented the emergence of two classes of equivalent stimuli: A1, B2, C1, D2 and A2, B1, C2, D1. These were the classes to be expected if the negative comparisons were the controlling comparisons in the baseline conditional discriminations. The negative comparisons, however, were not the comparisons that subjects were recorded as having chosen in the baseline conditional discriminations. Differential test results confirmed predictions arising from a stimulus-control analysis: In reflexivity tests (AA, BB, CC, DD), subjects chose comparisons that differed from the sample; one-node transitivity (AC, BD) and "equivalence" (CA, DB) tests also yielded results that were the opposite of those to be expected from control by positive comparisons; symmetry tests (BA, CB, DC), two-node transitivity (AD) tests, and two-node "equivalence" (DA) tests yielded results that were to be expected from control by either positive or negative comparisons.     

Compound stimuli in emergent stimulus relations: Extending the scope of stimulus equivalence

Three experiments were conducted to investigate stimulus relations that might emerge when college students are taught relations between compound sample stimuli and unitary comparison stimuli using match-to-sample procedures. In Experiment 1, subjects were taught nine AB-C stimulus relations, then tested for the emergence of 18 AC-B and BC-A relations. All subjects showed the emergence of all tested relations. Twelve subjects participated in Experiment 2. Six subjects were taught nine AB-C relations and were then tested for symmetrical (C-AB) relations. Six subjects were taught nine AB-C and three C-D relations and were then tested for nine AB-D (transitive) relations. Five of 6 subjects demonstrated the emergence of symmetrical relations, and 6 subjects showed the emergence of transitivity. In Experiment 3, 5 college students were taught nine AB-C and three C-D relations and were then tested for nine equivalence (D-AB) relations and 18 AD-B and BD-A relations. Three subjects demonstrated all tested relations. One subject demonstrated the AD-B and BD-A relations but not the D-AB relations. One subject did not respond systematically during testing. The results of these experiments extend stimulus equivalence research to more complex cases.     

Development of the Basel Version of the Awareness of Social Inference Test – Theory of Mind (BASIT-ToM) in healthy adults

Impairments of Theory of Mind (ToM) abilities occur in a wide range of brain disorders. Therefore, reliable and ecologically valid examination of these abilities is a crucial part of any comprehensive neuropsychological assessment. An established and ecologically valid, English-language test identifying deficits in ToM abilities is “The Awareness of Social Inference Test – Social Inference Minimal (TASIT-SIM)”. However, no comparable German-language ToM test currently exists. In this study, we aimed to develop the first German-language adaption of TASIT-SIM in healthy adults. We selected 13 scenes [four scenes per message type (i.e., honesty, simple sarcasm, paradoxical sarcasm) and one practice scene] out of the 30 TASIT-SIM scenes. In collaboration with a film institute, we filmed each scene at three different intensities. These intensity version scenes were then administered to 240 healthy adults, equally distributed in sex and age, ranging from 35 to 92 years. By applying Rasch analysis, we selected intensity versions that showed neither floor nor ceiling effects in the majority of ToM questions in participants whose ToM abilities were in the medium range. In conclusion, we have developed the first German-language adaption of TASIT-SIM, i.e., the “Basel Version of the Awareness of Social Inference Test – Theory of Mind (BASIT-ToM)”. The BASIT-ToM incorporates the strengths of TASIT-SIM, while overcoming its limitations such as inconsistencies in cinematic realization and ceiling effects in healthy participants. Next, the BASIT-ToM needs to be validated in healthy people and clinical populations.     

客体工作记忆的保持对时距知觉的影响

初步探讨毫秒范围内,客体信息保持对时间知觉的影响。实验一发现,知觉到的时间不受记忆负荷的影响,但当保持时间短时,低负荷的反应时低于高负荷的反应时;实验二仅要求被试完成时间知觉任务,发现知觉负荷异于记忆负荷对时间知觉的影响。结果说明,客体工作记忆保持对时间知觉的影响受到工作记忆资源的调节。     

The two-alternative observing response procedure in rats: Preference for nondiscriminative stimuli and the effect of delay

A two-alternative choice procedure was used with rats to examine preference for discriminative stimuli (correlated with the occurrence of reinforcement) versus uncorrelated cues. Choice of discriminative stimuli was below chance, despite the use of very low levels of reinforcement (12.5% for some rats) known to produce a preference for discriminative cues. Levers that had been retracted during the stimulus presentation in Experiment 1 were extended in Experiment 2 to assess the role of response elicitation during the observed stimuli. In Experiment 3, the impact of cue-duration behaviors was further evaluated by lengthening the duration of the cues and providing an opportunity for an escape response. The preference for nondiscriminative stimuli was reversed only with increased exposure to the cues. The present results point to fundamental differences in the prevailing context of the choice procedure as compared to the usual free-operant observing design.     

Gaze Patterns When Looking at Emotional Pictures: Motivationally Biased Attention

Pictures of either emotionally neutral, pleasant (affectionate), or unpleasant (threat and injury) scenes were paired with nonemotional control pictures and presented for 3 s, while eye fixations were monitored. Preferential attention to the emotional picture of eah pair occurred at an early processing stage: The probability of placement of the first fixation and the proportion of viewing time during the first 500 ms were higher for both pleasant and unpleasant pictures than for neutral pictures, whereas later fixation location and time were not differentially affected. This suggests that, when emotional and nonemotional stimuli are presented simultaneously, emotional meaning captures initial overt orienting and engages attention early, as measured by gaze direction and duration. The possibility that this effect could be accounted for by perceptual differences—such as luminance and complexity—between emotional and neutral pictures was ruled out.     

Go/no‐go procedure with compound stimuli with children with autism

The go/no‐go with compound stimuli is an alternative to matching‐to‐sample to produce conditional and emergent relations in adults. The aim of this study was to evaluate the effectiveness of this procedure with two children diagnosed with autism. We trained and tested participants to respond to conditional relations among arbitrary stimuli using the go/no‐go procedure. Both learned all the trained conditional relations without developing response bias or responding to no‐go trials. Participants demonstrated performance consistent with symmetry, but not equivalence.     

Integrating Dimensional and Discrete Theories of Emotions: A New Set of Anger- and Fear-Eliciting Stimuli for Children

The selection of appropriate stimuli for inducing specific emotional states has become one of the most challenging topics in psychological research. In the literature there is a lack of affective picture database specifically suited to investigate emotional response in children. Here the authors present the methodology that led us to create a new database (called Anger- and Fear-Eliciting Stimuli for Children) of affective stimuli inducing experiences of 3 target emotions (neutral, anger, and fear) to use in experimental session involving children. A total of 84 children were asked to (a) indicate the perceived emotion and its intensity and (b) rate the three affective dimensions of the Self-Assessment Manikin (SAM). Based on concordance between labeled and expected target emotion, the authors decided to select 15 stimuli to be included in Multivariate modeling techniques were applied to evaluate the association between expected target emotion and SAM ratings. The authors found that the hit rate for the neutral pictures was good (greater than 81%), for fear-eliciting pictures it was greater than 64%, and for anger-eliciting pictures it was moderate (between 45% and 56%). The study results reveal also an age effect only in the arousal scale. However, the authors did not find significant gender-related differences in SAM ratings.