Instrumental learning in hyperdopaminergic mice

In two experiments we investigated the effects of elevated dopaminergic tone on instrumental learning and performance using dopamine transporter knockdown (DAT KD) mice. In Experiment 1, we showed that both DAT KD mice and wild-type controls were similarly sensitive to outcome devaluation induced by sensory specific satiety, indicating normal action-outcome learning in both groups. In Experiment 2, we used a Pavlovian-to-instrumental transfer procedure to assess the potentiation of instrumental responding by Pavlovian conditional stimuli (CS). Although during the Pavlovian training phase the DAT KD mice entered the food magazine more frequently in the absence of the CS, when tested later both groups showed outcome-selective PIT. These results suggest that the elevated dopaminergic tone reduced the selectivity of stimulus control over conditioned behavior, but did not affect instrumental learning.     

Functional analysis of tardive dyskinesia: implications for assessment and treatment

We conducted an analogue functional analysis contrasting motor tasks with varying types of social consequences for movements associated with tardive dyskinesia (TD) in 2 men who had been diagnosed with developmental disabilities and TD. Our findings suggest that TD-related movements were not a function of social reinforcement contingencies. However, motor-activation tasks decreased TD-related movements, suggesting a possible novel intervention.     

The mental nose and the Pinocchio effect: Thermography,planning, anxiety,and lies

We applied thermography to cognitive neuropsychology, particularly as a somatic marker of subjective experience during cognitive and emotional tasks. We found significant correlations between changes in facial temperature and mental set. Specifically, the temperature of the nose tended to decrease during emotional tasks and increase during cognitive tasks. However, for stress tests or high arousal reactions to emotional stimuli, the direction of the thermal change depended on the nature of the setting, real or simulated. Detection of deception is a mixed field where cognitive effort, physiological stress, and empathy have evolved, affecting the direction of the thermal variation—higher or lower temperature of the tip of the nose and forehead. We found that the temperature change of the nose and forehead may enable detecting when people lie about facts (the Pinocchio effect markers). In general, one important contribution is to recover mental thermometry as a potent tool for neurocognitive studies.     

Temporal order judgements as a sensitive measure of the spatial bias in patients with visuospatial neglect

Visuospatial neglect is not a unitary phenomenon, but can be better considered a syndrome, consisting of a multitude of different spatial and non‐spatial components. In this study, we used a temporal order judgement (TOJ) test in a large sample of stroke patients (n = 73) to scrutinize the contribution of a spatial bias to the performance on shape cancellation and line bisection tests. In the TOJ test, patients were presented with two elements, one in each visual field, after which the one needed to indicate which of the two elements was presented earlier. For each visual field, the presentation of the stimuli was determined by a staircase procedure where the interval between the two stimuli was determined by the performance of the patient. Results indicated that the strength of the spatial bias was strongly correlated with an object cancellation test, but not with a line bisection test. We argue that these findings are explained by differences in the extent to which a spatial bias determines performance on both tasks: In contrast to shape cancellation tests, successful performance on line bisection tests depends primarily on an object‐based, allocentric representation of space, unrelated to any spatial bias in the detection of elements in the contralesional visual field.     

Episodic storage and retrieval in visuo-spatial tasks: evidence of indirect retrieval

Episodic storage contends that the relevant target and irrelevant distractor features of a display are processed and then stored together within the boundaries of an episode, and are linked in this way. Accordingly, the selective and “direct” retrieval of either a stored target or distractor should result in the “indirect” and unintended retrieval of the other stimulus. In the present investigation, interest focused upon spatial tasks and the “indirect” retrieval of prime distractor processing. The novel findings obtained supported the existence of the “indirect” retrieval of prime distractor processing in visuo-spatial tasks and, to a lesser extent, of the stored prime target event, consistent with identity tasks (i.e. bi-directional episodically-based retrieval). Clearly, more is retrieved than is presented (Hintzman, D. L. (1984). MINERVA 2: A simulation model of human memory. Behavior Research Methods, Instruments, & Computers, 16, 96–101. doi:10.3758/BF03202365), as an episodic storage structure would predict.     

Using diffusion models to understand clinical disorders

Sequential sampling models provide an alternative to traditional analyses of reaction times and accuracy in two-choice tasks. These models are reviewed with particular focus on the diffusion model (Ratcliff, 1978) and how its application can aid research on clinical disorders. The advantages of a diffusion model analysis over traditional comparisons are shown through simulations and a simple lexical decision experiment. Application of the diffusion model to a clinically relevant topic is demonstrated through an analysis of data from nonclinical participants with high- and low-trait anxiety in a recognition memory task. The model showed that after committing an error, participants with high-trait anxiety responded more cautiously by increasing their boundary separation, whereas participants with low-trait anxiety did not. The article concludes with suggestions for ways to improve and broaden the application of these models to studies of clinical disorders.     

Slow and steady? Strategic adjustments in response caution are moderately reliable and correlate across tasks

Speed-accuracy trade-offs are often considered a confound in speeded choice tasks, but individual differences in strategy have been linked to personality and brain structure. We ask whether strategic adjustments in response caution are reliable, and whether they correlate across tasks and with impulsivity traits. In Study 1, participants performed Eriksen flanker and Stroop tasks in two sessions four weeks apart. We manipulated response caution by emphasising speed or accuracy. We fit the diffusion model for conflict tasks and correlated the change in boundary (accuracy – speed) across session and task. We observed moderate test-retest reliability, and medium to large correlations across tasks. We replicated this between-task correlation in Study 2 using flanker and perceptual decision tasks. We found no consistent correlations with impulsivity. Though moderate reliability poses a challenge for researchers interested in stable traits, consistent correlation between tasks indicates there are meaningful individual differences in the speed-accuracy trade-off.     

抑制控制训练对手机依赖大学生的干预效果

依照手机成瘾倾向量表得分及手机使用时间记录从548名被试中筛选出60名手机依赖大学生,将其随机分配到抑制控制训练组和非训练组进行实验。预期通过抑制控制训练提升手机依赖大学生抑制控制能力,降低其手机依赖水平。结果发现：训练组被试在接受为期8周的抑制控制训练任务后,手机依赖总分、手机使用时间和非训练组相比显著降低,抑制控制能力显著提升。结果表明抑制控制训练对手机依赖大学生的干预效果明显。     

愉快面孔识别优势及其认知神经机制

愉快面孔识别优势表现为被试对高兴面孔比对其他情绪面孔的识别正确率更高、反应时更短。大量研究以简笔画和面孔图片为材料, 在情绪分类任务和视觉搜索任务中均发现这一优势。该优势存在诊断性价值假说、情绪独特性假说和出现频率假说三种不同的理论解释。近年来, 研究者采用ERP技术发现这一优势形成于反应选择阶段, 但其起始阶段尚无一致结论。未来可借助fMRI技术进一步研究其认知神经机制。