Effects of atropine on the repeated acquisition and performance of response sequences in humans.

The present study assessed a 24-hr time course for the acute effects of intramuscular injections of atropine sulfate (0, 1.5, 3.0, and 6.0 mg/70 kg) in healthy adult humans responding under a two-component multiple schedule of repeated acquisition and performance of response sequences. Subjects resided in an inpatient research ward for the duration of the study. In each component of the multiple schedule, subjects completed a different sequence of 10 responses in a predetermined order using three keys of a numeric keypad. In the acquisition component, the subjects' task was to acquire a new sequence each session. Eight sessions were conducted daily: one immediately before administration of the drug and then 0.5, 1.5, 3.0, 5.0, 7.0, 9.0, and 24.0 hr after administration. In the performance component, the response sequence always remained the same. Overall percentage of errors increased and overall response rates decreased in the acquisition and performance components as an orderly function of drug dose. However, these effects were selective in that behavior in the acquisition component generally was affected at lower doses than in the performance component. When behavior was affected in both the acquisition and performance components, the time courses of effects were similar. Drug effects began at 0.5 or 1.5 hr, reached peak effects between 3.0 and 5.0 hr, and returned to placebo levels between 7.0 and 9.0 hr postdrug in both schedule components. None of the drug doses produced reliable effects the day after drug administration (24-hr postdrug) in either schedule component. The present study provides the first within-subject assessment of the magnitude and duration of the effects of an anticholinergic on repeated acquisition and performance baselines and extends to atropine the selective effects on these two baselines demonstrated previously with other compounds in humans and nonhumans.     

Equivalence classes generated by sequence training

In Experiment 1, 3, adult females were taught with verbal instructions and contingencies to select, in sequence, three arbitrary visual stimuli from an array of five stimuli. After four different sequences were taught, match-to-sample tests assessed emergent conditional relations among all stimuli that had been selected in the same order in the sequences. Subjects' performances indicated development of four stimulus classes, three based on ordinal position and one based on nonselection. Next, match-to-sample training established conditional relations between each of four novel figures and one member of each of the ordinal stimulus classes. Tests confirmed that the classes were equivalence classes, each expanded by one new member. In subsequent sequence tests, the new stimuli were selected in a sequence that was consistent with ordinal class membership. Experiment 2 replicated Experiment 1 with 2 different adult females, but the verbal instructions were omitted. Results were similar to Experiment 1, except that extensive review and retesting were required before expansion of the ordinal classes with the novel figures was observed.     

The role of instructions in the transfer of ordinal functions through equivalence classes

In two experiments, adult subjects completed match-to-sample training and testing to establish four equivalence classes of four figures each. Then the subjects were taught one three-position sequence consisting of one stimulus from Class 1, one from Class 2, and one from Class 3. Inclusion of Class 4 stimuli in sequences was never reinforced, but two different stimuli from Class 4 appeared as distractors on each sequence trial. Tests assessed whether subjects would produce novel three-position sequences composed of members of Classes 1 through 3 that had not been used in sequence training. Three subjects in Experiment 1 received instructions about the match-to-sample and sequencing tasks, in addition to training contingencies. All 3 demonstrated equivalence class formation after match-to-sample training. After they were taught one sequence with one member of Classes 1 through 3, none of these subjects produced untrained sequences with other equivalence class members reliably. One additional sequence was trained directly; thereafter 1 subject showed some evidence of transfer of the trained ordinal functions across the remaining members of the equivalence classes, but the other 2 did not. Following a review of equivalence class training and testing and a review of the original sequence training, all 3 subjects produced most of the predicted, untrained sequences on tests. Experiment 2 replicated Experiment 1 with 2 adults but omitted all instructions except the minimal ones necessary to initiate responding. Unlike the subjects in Experiment 1, both of these subjects demonstrated virtually complete transfer of ordinal functions through the equivalence classes after direct training on just one sequence composed of one member of Classes 1 through 3.     

Response patterns and cardiovascular effects during response sequence acquisition by humans.

The effects of temporal delays imposed between successive responses and of vitamin C administration were examined on the acquisition of response sequences and on cardiovascular reactivity during sequence acquisition. Thirteen adult subjects (6 female, 7 male), in good health, gave written consent prior to participating in 12 weekly 45-min sessions. Points, exchanged for money after each session, were presented when subjects completed 15-response sequences on a touch-sensitive three-response keypad. A position counter increased from 0 to 14 as subjects emitted correct responses in the sequence. Four novel 15-response sequences were presented each session. No delays were imposed between successive responses during the acquisition of one sequence; delays were imposed immediately following each response during the acquisition of a second sequence, thereby delaying response feedback; delays were imposed following feedback during acquisition of a third sequence, resulting in the removal of the stimulus correlated with sequence position; and, as a control condition, delays were imposed following feedback, but stimuli correlated with sequence position were reinstated prior to the next response during acquisition of a fourth sequence. Subjects were exposed to one of two delay durations (0.2 and 0.5 or 0.5 and 1.0 s) each session, and delay durations alternated every session. During Weeks 5 to 8, subjects received 3 grams of vitamin C per day, whereas during Weeks 1 to 4 and 9 to 12, subjects received placebo under single-blind conditions. All subjects acquired the sequences, as evidenced by decreasing percentages of incorrect responses across trials. When temporal delays were imposed between successive responses during sequence acquisition, acquisition efficiency was enhanced. Examination of response latencies suggested that the status of preceding responses (i.e., correct or incorrect) rather than the status of the position counter influenced subsequent responding. Cardiovascular effects were inversely related to the length of the temporal delay. Neither cardiovascular reactivity or sequence acquisition were related to vitamin C administration.     

类推理的发展序列与年龄特点

类推理主要涉及类别层级包含关系的理解和判断。使用修订的类包含、替代包含和二元律任务,以162名二至五年级儿童为被试,利用Raseh模型分析方法,旨在揭示儿童逻辑包含能力的发展序列。此外,探讨了儿童类推理发展的年龄特点。结果表明：1）类推理发展中儿童最先掌握类包含推理,其次是替代包含,最后是二元律推理;2）三、四、五年级儿童已能解决多数类包含任务,其成绩显著优于二年级儿童。四、五年级儿童能解决多数替代包含任务,其成绩均显著优于二年级儿童;3）二元律任务对二至五年级儿童来讲均比较困难。     

Temporal order judgment reveals how number magnitude affects visuospatial attention

The existence of spatial components in the mental representation of number magnitude has raised the question regarding the relation between numbers and spatial attention. We present six experiments in which this relation was examined using a temporal order judgment task to index attentional allocation. Results demonstrate that one important consequence of numerical processing is the automatic allocation of spatial attention, which in turn affects the perception of the temporal order of visual events. Given equal onset time, left-side stimuli are perceived to occur before right-side stimuli when a small number (1, 2) is processed, whereas right-side stimuli are perceived to occur before left-side stimuli when a larger number (8, 9) is processed. In addition, we show that this attentional effect is specific to quantity processing and does not generalize to non-numerical ordinal sequences.     

Detecting performance invalidity in children: Not quite as easy as A,B, C, 1, 2, 3 but automatized sequences appears promising

In adult populations, embedded performance validity indicators are well established, as they are time efficient, resistant to coaching, and allow for more continuous monitoring of effort than standalone measures. Although several recent studies have demonstrated the appropriateness of using standalone validity tests with school-age children, a paucity of pediatric work has examined embedded indicators. The present study investigated the value of a simple automatized sequences task to detect performance invalidity in 439 clinically referred patients with mild head injury aged 8 through 17 years. Sixteen percent of the participants failed the Medical Symptom Validity Test (MSVT). Thirteen percent failed the MSVT and also performed below established cutoffs on either the Test of Memory Malingering or Wechsler Digit Span subtest. The group classified as providing invalid data performed significantly worse than the group passing the MSVT across all sequencing conditions. Sensitivity and specificity for the total time on the sequencing task compared favorably to data produced for many respected adult-based embedded indicators (i.e., sensitivity around 50% when specificity ≥ 90%). Classification statistics for any embedded performance validity test can be expected to be worse in more severely affected populations; however, the current sequencing task appears to have value in detecting invalid performance in relatively high-functioning older children and adolescents. The fact that the task takes less than a couple of minutes to administer makes it especially appealing.     

Abstracting Sequences: Reasoning That Is a Key to Academic Achievement

The ability to understand sequences of items may be an important cognitive ability. To test this proposition, 8 first-grade children from each of 36 classes were randomly assigned to four conditions. Some were taught sequences that represented increasing or decreasing values, or were symmetrical, or were rotations of an object through 6 or 8 positions. Control children received equal numbers of sessions on mathematics, reading, or social studies. Instruction was conducted three times weekly in 15-min sessions for seven months. In May, the children taught sequences applied their understanding to novel sequences, and scored as well or better on three standardized reading tests as the control children. They outscored all children on tests of mathematics concepts, and scored better than control children on some mathematics scales. These findings indicate that developing an understanding of sequences is a form of abstraction, probably involving fluid reasoning, that provides a foundation for academic achievement in early education.     

Implicit task sequence learning with auditory stimuli

We investigated implicit task sequence learning with auditory stimuli. In previous studies only visual stimuli have been used and thus learning may have been due to visuoperceptual learning. Further, we explored the generality of the correlated streams account which holds that correlated streams of information are necessary for implicit sequence learning to occur. We used three classification tasks with auditory stimuli. The presence or absence of a task sequence was orthogonally manipulated with that of a response sequence. Sequence-specific learning was found, but only in the condition with both a task and a response sequence. No learning was found in the conditions with a single task sequence and with a single response sequence. These results show that task–response sequence learning occurs with auditory stimuli and that visuoperceptual learning is not necessary. Moreover, they underscore the importance of correlated streams of information for implicit sequence learning.     

3～5岁幼儿在视野阻隔任务中的长度传递性推理

设计视野阻隔任务,控制了短时记忆和直接比较的两难问题,考察3～5岁幼儿长度传递性推理能力的发展趋势和传递性推理这一认知过程的发展序列。以2(间隔长度)×2(摆放方式)×4(年龄)的三因素混合设计,研究了240名幼儿,结果表明:(1)3～4岁是长度传递性推理能力的快速发展期,4岁以后的幼儿大部分具备了这一能力,发展速度趋于平缓;(2)任务类型影响推理成绩;(3)基于传递关系的推理依据与推理总成绩显著正相关。研究认为:年仅4岁幼儿具备传递性推理能力蕴含教育价值;传递性推理的认知过程经历了四个可辨别的发展序列,依次主要发生在36～42个月、43～48个月、49～54个月和55～60个月的幼儿当中。