Regional brain activity change predicts responsiveness to treatment for stuttering in adults

Developmental stuttering is known to be associated with aberrant brain activity, but there is no evidence that this knowledge has benefited stuttering treatment. This study investigated whether brain activity could predict progress during stuttering treatment for 21 dextral adults who stutter (AWS). They received one of two treatment programs that included periodic H₂¹⁵O PET scanning (during oral reading, monologue, and eyes-closed rest conditions). All participants successfully completed an initial treatment phase and then entered a phase designed to transfer treatment gains; 9/21 failed to complete this latter phase. The 12 pass and 9 fail participants were similar on speech and neural system variables before treatment, and similar in speech performance after the initial phase of their treatment. At the end of the initial treatment phase, however, decreased activation within a single region, L. putamen, in all 3 scanning conditions was highly predictive of successful treatment progress.     

音乐知觉的神经基础：脑成像研究的元分析

本研究根据音乐加工的层级结构, 对现有的脑成像研究进行了元分析, 探讨了音乐知觉的神经基础。具体而言, 对特异于音乐知觉加工的两个层级, 音程分析和结构分析的神经基础进行了分析, 并在此基础上对比了参与两个层级加工的脑区。结果发现, 音程分析主要的激活分布在双侧颞上回和右侧额下回, 在中央前回、角回和脑岛等脑区也有分布。音程分析在颞上回激活最多, 可能表明颞上回为音程分析的核心区域。结构分析激活分布较广, 主要激活颞上回、颞横回和前额叶区域, 此外, 还激活了下顶叶、缘上回和舌回等顶枕区域。结构分析在前额叶激活最多, 可能表明前额叶为结构分析的核心区域。最后, 对比两层级激活的脑区发现, 二者仅在后侧颞上回存在着重合, 而在绝大部分脑区则表现出分离, 这暗示了音程分析和结构分析通过颞上回进行交流, 并负责音乐不同层面的加工。     

不同线索下特质焦虑个体的返回抑制

焦虑与注意偏向的研究是近年来情绪与认知领域的热点。为探讨特质焦虑个体的注意偏向特点及其返回抑制能力是否受不同线索的调节, 采用特质焦虑量表筛选高特质焦虑大学生29名, 低特质焦虑大学生28名完成线索-靶子任务。要求被试在提示线索消失后, 对位置进行快而准地辨别反应, 分别探索中性和情绪性提示线索下被试的返回抑制。结果发现：(1)在中性线索条件下, 高焦虑个体平均反应时慢于低焦虑个体。(2) 在情绪线索条件下, 高焦虑个体在负性线索下的反应时小于在正性线索下的反应时; 高、低焦虑个体在各种SOA条件下均出现了返回抑制, 但各组返回抑制量受到情绪线索的调节：在正性情绪线索条件下, 两组返回抑制量没有显著差异; 在负性情绪线索下, 高焦虑个体返回抑制量显著小于低焦虑个体。这表明, (1)焦虑个体的注意偏向受到刺激信息的影响：只对负性情绪线索出现注意警觉; (2)只有在涉及负性情绪信息时高、低焦虑个体返回抑制能力才有差异, 高焦虑个体存在对负性情绪线索的抑制困难。     

Perception of relative depth interval: Systematic biases in perceived depth

Given an estimate of the binocular disparity between a pair of points and an estimate of the viewing distance, or knowledge of eye position, it should be possible to obtain an estimate of their depth separation. Here we show that, when points are arranged in different vertical geometric configurations across two intervals, many observers find this task difficult. Those who can do the task tend to perceive the depth interval in one configuration as very different from depth in the other configuration. We explore two plausible explanations for this effect. The first is the tilt of the empirical vertical horopter: Points perceived along an apparently vertical line correspond to a physical line of points tilted backwards in space. Second, the eyes can rotate in response to a particular stimulus. Without compensation for this rotation, biases in depth perception would result. We measured cyclovergence indirectly, using a standard psychophysical task, while observers viewed our depth configuration. Biases predicted from error due either to cyclovergence or to the tilted vertical horopter were not consistent with the depth configuration results. Our data suggest that, even for the simplest scenes, we do not have ready access to metric depth from binocular disparity.     

The effects of preexposure-test and conditioning-test intervals on the magnitude of latent inhibition

Using the conditioned taste aversion paradigm, two experiments were conducted to examine the effects of the interval between preexposure and test and that between conditioning and test on the magnitude of latent inhibition. Experiment 1 revealed that the degree of latent inhibition was attenuated when rats were given a 21‐day interval between preexposure and test. It was also found that this attenuation was more marked in subjects which were given conditioning immediately after preexposure than those which were conditioned shortly before the test. Retention interval between preexposure and test was reduced to 12 days in Experiment 2, and exactly the same pattern of results as those found in Experiment 1 was obtained. These findings suggest that the memory of conditioning as well as that of preexposure decreases its retrievability after a long retention interval, although the former is more retainable than the latter.     

Taste avoidance caused by spontaneous wheel running: effects of duration and delay of wheel confinement

Confinement of a rat in a running wheel results in the rat's subsequent avoidance of the taste consumed before the confinement. This phenomenon has been ascribed to taste aversion conditioned by spontaneous wheel running. As a first step toward clarification of the underlying mechanism of this phenomenon, we manipulated two parameters of the taste-confinement procedure: duration of wheel confinement (Experiments 1A and 1B) and temporal intervals between the taste consumption and the wheel confinement (Experiments 2A and 2B). In general, longer confinement and shorter inter-event interval caused stronger taste avoidance. However, the results also suggested that it is possible to establish taste avoidance when wheel confinement was delayed 1-h after the taste consumption. These results correspond to those of conventional taste aversion caused by illness-inducing agents, suggesting similar mechanisms in the both preparations. Experiment 3 revealed that running in a wheel rather than wheel confinement itself is the effective factor for establishing taste avoidance.     

Timing inter-reward intervals

Rats judged inter-reward intervals (IRIs) in a two-alternative, forced-choice task. The IRI was either short (S) or long (L). At the end of each IRI, two response levers were inserted into the box. A press to the lever designated as correct or incorrect produced a large (3-5 food pellets) or small (1 pellet) reward, respectively. Psychophysical functions were obtained by testing intermediate IRIs, which were followed by the small reward, independent of the response location. S and L intervals were manipulated across groups, as specified (in seconds) by the group name, S-L: 3-12 (n=12), 25-100 (n=12), and 50-200 (n=7). The psychophysical functions (p[L] vs. IRI) were ogival in shape and had bisection points (p[S]=p[L]=0.5) near the geometric mean of S and L intervals. The psychophysical functions did not superimpose in relative time (IRI/L). Instead, 3-12 was timed with greater relative sensitivity than were 25-100 and 50-200.     

Response persistence under ratio and interval reinforcement schedules

In Experiment 1, rats were exposed to progressive-ratio schedules of food reinforcement while other rats were exposed simultaneously to yoked-interval schedules that arranged equivalent interreinforcer intervals but required only a single response at the end of the interval for food delivery. In Experiment 2, a within-subject yoked-control procedure was employed in which pigeons were exposed to alternating sessions (one per day) of progressive-ratio schedules and yoked-interval schedules as described above. In both experiments, responding under the yoked-interval schedule persisted beyond the point at which responding under the progressive-ratio schedule had ceased. The progressive-ratio schedules controlled break-and-run distributions, and the yoked-interval schedules controlled more even distributions of responses in time. Response rates decreased and postreinforcement pauses increased over time within individual sessions under both schedules. The results suggest that responding maintained by interval schedules is more persistent than that maintained by ratio schedules. The limitations and implications of this conclusion are discussed in the context of other investigations of response strength and behavioral momentum.     

Temporal control in rats: analysis of nonlocalized effects from short interfood intervals.

The present experiment analyzed temporal control of postreinforcement pause duration during within-session changes in the criterion for reinforcement (interfood interval, IFI). Analysis of interval-by-interval changes in the pause revealed localized and nonlocalized effects from short intervals that caused specific changes in performance. In Phase 1, rats were presented with five consecutive 15-s IFIs intercalated into a series of 60-s IFIs. The 15-s set decreased the pause in adjacent and more remote 60-s intervals. In Phase 2, two sets of 15-s intervals were intercalated. The spacing between the two sets varied so that 0, 5, 10, or 15 60-s IFIs separated the sets. The postreinforcement pause tracked all changes in the IFI duration, and the localized effect from a short set extended beyond the next interval to the next few 60-s IFIs. Effects from one set, however, did not combine with a second set: Changes in the pause after two sets were the same regardless of the spacing between sets.