光栅朝向分辨学习中存在关于45°对角线对称的镜像迁

采用光栅朝向分辨任务来探讨视知觉学习中是否存在关于45°对角线对称的镜像迁移现象。训练被试分辨15°或75°朝向3或5天,每天约1小时,训练前后测量15°、75°、45°朝向的分辨阈值。通过训练,训练朝向（15°或75°）的阈值下降,该学习效应没有迁移至45°朝向,但基本迁移到关于45°对称的朝向（75°或15°）上。这提示,视知觉学习可能发生在中间视皮层,该皮层同时具有一定的朝向特异性和关于45°对角线对称的镜像迁移性     

The role of Broca's area in speech perception: evidence from aphasia revisited

Motor theories of speech perception have been re-vitalized as a consequence of the discovery of mirror neurons. Some authors have even promoted a strong version of the motor theory, arguing that the motor speech system is critical for perception. Part of the evidence that is cited in favor of this claim is the observation from the early 1980s that individuals with Broca’s aphasia, and therefore inferred damage to Broca’s area, can have deficits in speech sound discrimination. Here we re-examine this issue in 24 patients with radiologically confirmed lesions to Broca’s area and various degrees of associated non-fluent speech production. Patients performed two same-different discrimination tasks involving pairs of CV syllables, one in which both CVs were presented auditorily, and the other in which one syllable was auditorily presented and the other visually presented as an orthographic form; word comprehension was also assessed using word-to-picture matching tasks in both auditory and visual forms. Discrimination performance on the all-auditory task was four standard deviations above chance, as measured using d′, and was unrelated to the degree of non-fluency in the patients’ speech production. Performance on the auditory–visual task, however, was worse than, and not correlated with, the all-auditory task. The auditory–visual task was related to the degree of speech non-fluency. Word comprehension was at ceiling for the auditory version (97% accuracy) and near ceiling for the orthographic version (90% accuracy). We conclude that the motor speech system is not necessary for speech perception as measured both by discrimination and comprehension paradigms, but may play a role in orthographic decoding or in auditory–visual matching of phonological forms.     

Time Perception: Modality and Duration Effects in Attention-Deficit/Hyperactivity Disorder (ADHD)

Time perception performance was systematically investigated in adolescents with and without attention-deficit/hyperactivity disorder (ADHD). Specifically, the effects of manipulating modality (auditory and visual) and length of duration (200 and 1000 ms) were examined. Forty-six adolescents with ADHD and 44 controls were administered four duration discrimination tasks and two control tasks, and a set of standardized measures. Participants with ADHD had higher thresholds than controls on all of the duration discrimination tasks, with the largest effect size obtained on the visual 1000 ms duration discrimination task. No group differences were observed on the control tasks. Visual–spatial memory was found to be a significant predictor of visual and auditory duration discrimination at longer intervals (1000 ms) in the ADHD sample, whereas auditory verbal working memory predicted auditory discrimination at longer intervals (1000 ms) in the control sample. These group differences suggest impairments in basic timing mechanisms in ADHD.     

Aging and individual differences in rapid two-choice decisions

The effects of aging on performance were examined in signal detection, letter discrimination, brightness discrimination, and recognition memory, with each subject tested on all four tasks. Ratcliff’s (1978) diffusion model was fit to the data for each subject for each task, and it provided a good account of accuracy and the distributions of correct and error response times. The model’s analysis of the components of processing showed that aging had three main effects: The nondecision components of processing were slower and the decision criteria were more conservative for 60- to 74-year-old and 75- to 85-year-old subjects than for college students, but the quality of the evidence on which decisions were based was as good for the older subjects as for college students on some of the tasks. Individual differences among subjects in components of processing tended to be preserved across the tasks, as was shown by strong correlations across the tasks in the parameters of the model that represent the components of processing. For example, if the evidence on which a subject’s decisions were based was good in one task, it tended to be good in all four tasks.     

Discrimination learning in Rora(sg) and Grid2(ho) mutant mice

Rora(sg) mutants with mild cerebellar granule cell degeneration were compared to Grid2(ho) mutants with more severe granule cell degeneration as well as Purkinle cell atrophy for left-right and dark-light discrimination learning tasks in a water-filled T-maze. The acquisition rate of both cerebellar mutants was slowed down during light-dark but not left-right discrimination learning. However, the mutants were impaired in reversal training in both tasks. In contrast, neither mutant differed from controls in passive avoidance learning. These results indicate that mice with cerebellar damage are affected in some instrumental learning tasks and have perseverative tendencies.     

Do learned irrelevance and perseveration play a role during discrimination learning?

In both healthy participants and various patient populations, performance on attentional set-shifting tasks has been found to be affected by learned irrelevance and/or perseveration. The present study examined whether or not these processes also play a role during the initial discrimination learning phase of those tasks. To this end, participants first solved a multidimensional discrimination learning task. Thereafter, they underwent three types of shift of relevant and/or irrelevant stimulus attributes, which enabled the assessment of the separate contribution of perseveration and learned irrelevance to post-shift task performance. Subsequent correlational analyses revealed that the number of errors during initial discrimination learning was significantly correlated with the number of errors in the learned irrelevance-shift but not the perseveration-shift. This suggests that processes underlying learned irrelevance in post-shift task performance also play a significant role during initial discrimination learning. The implications of these results for interpreting deficits in shifting are discussed.     

Cognitive control factors in speech perception at 11 months

The development of speech perception during the 1st year reflects increasing attunement to native language features, but the mechanisms underlying this development are not completely understood. One previous study linked reductions in nonnative speech discrimination to performance on nonlinguistic tasks, whereas other studies have shown associations between speech perception and vocabulary growth. The present study examined relationships among these abilities in 11-month-old infants using a conditioned head-turn test of native and nonnative speech sound discrimination, nonlinguistic object-retrieval tasks requiring attention and inhibitory control, and the MacArthur-Bates Communicative Development Inventory (L. Fenson et al., 1993). Native speech discrimination was positively linked to receptive vocabulary size but not to the cognitive control tasks, whereas nonnative speech discrimination was negatively linked to cognitive control scores but not to vocabulary size. Speech discrimination, vocabulary size, and cognitive control scores were not associated with more general cognitive measures. These results suggest specific relationships between domain-general inhibitory control processes and the ability to ignore variation in speech that is irrelevant to the native language and between the development of native language speech perception and vocabulary.     

The development of mental models for auditory events: Relational complexity and discrimination of pitch and duration

This experiment investigated relational complexity and relational shift in judgments of auditory patterns. Pitch and duration values were used to construct two‐note perceptually similar sequences (unary relations) and four‐note relationally similar sequences (binary relations). It was hypothesized that 5‐, 8‐ and 11‐year‐old children would perform unary level pitch and duration discrimination tasks accurately. Relational shift predicted a poorer performance of the younger age groups on binary relation tasks; relational primacy predicted no effect of age. Accuracy was operationalized as a discrimination index (DI: hit rate minus false alarm rate). Results supported relational shift: DI for all age groups exceeded chance on unary and binary relation tasks, with significantly poorer performance by all age groups on binary relation tasks. The 5‐years age group showed evidence of perceptual similarity. Relational complexity of auditory dimensions and tasks, and manipulation of domain specific musical knowledge in evaluating theories of relational processing, are discussed.     

Development of gender discrimination: Role of stereotypic and counterstereotypic gender cues

Toddlers (41 girls and 35 boys) between 18 and 37 months old were given four gender discrimination tasks, each consisting of 6 pairs of color drawings. Three tasks depicted pairs of preschool girls and boys holding either sex-typical toys (stereotypic cues), sex-atypical toys (counterstereotypic cues), or no toys. The fourth task paired pictures of female-typed and male-typed toys. For each pair, subjects were asked to point to either the girl (girls' toy) or boy (boys' toy). Gender discrimination increased with age. Young children performed at chance level on all tasks. Older children made fewer correct choices on the Toy Alone task than on the tasks depicting children. Performance generally was unaffected by stereotyping or counterstereotyping of gender cues. Sex differences were minimal.Portions of this paper were presented at the meeting of the Society for Research in Child Development, Baltimore, MD, April 1987.     

NORMAL PEER MODELS AND AUTISTIC CHILDREN'S LEARNING

Present research and legislation regarding mainstreaming autistic children into normal classrooms have raised the importance of studying whether autistic children can benefit from observing normal peer models. The present investigation systematically assessed whether autistic children's learning of discrimination tasks could be improved if they observed normal children perform the tasks correctly. In the context of a multiple baseline design, four autistic children worked on five discrimination tasks that their teachers reported were posing difficulty. Throughout the baseline condition the children evidenced very low levels of correct responding on all five tasks. In the subsequent treatment condition, when normal peers modeled correct responses, the autistic children's correct responding increased dramatically. In each case, the peer modeling procedure produced rapid achievement of the acquisition criterion which was maintained after the peer models were removed. These results are discussed in relation to issues concerning observational learning and in relation to the implications for mainstreaming autistic children into normal classrooms.     

Dominance of configural properties in visual form perception

Perceptual relations between configural and component properties were examined in three experiments. The pattern of performance in discrimination and classification tasks with a set of four lines that varied in curvature (Experiment 1) was compared with the pattern of performance in these tasks with sets of configuration defined on spatial relations among these lines. The configurations in the latter sets varied in their component properties (“curvature”) as well as in their configural properties (“closure” in Experiment 2 and “parallelism” in Experiment 3). The results indicated that discrimination and classification performance with the configurations was dominated by their configural properties, regardless of the discriminability of their component properties. The implications of these results for the role of configural properties in form perception are discussed.     

Redundancy in non-sequential patterns

Recognition, discrimination and delayed discrimination tasks were carried out with selections of composite visual patterns, ordered in terms of a generalized measure of redundancy based upon transmission between determinates under four determinables. Results in the recognition experiment showed a significant relationship with redundancy and there was indication of a similar effect in delayed discrimination. Redundancy levels, however, appeared irrelevant to simultaneous discrimination, where each response could be made discretely without reference to the structure of the selection as a whole.     

辨别作业难度对返回抑制时间进程的影响

在返回抑制范式下,利用线索一靶子模式和辨别作业进行了两个实验,探讨辨别作业难度对返回抑制的影响。以大学生为被试。实验一对辨别作业难度采用组间设计;实验二采用组内设计。结果发现,无论是组间比较(实验一),还是组内比较(实验二)．复杂辨别作业条件下返回抑制出现时间均比简单辨别作业晚,表明作业难度对返回抑制的时间进程有显著影响。该结果对返回抑制的机制研究有一定的意义。     

Emotional processing in psychopathic personality

Emotional‐processing deficits may be one of the characteristic features of impaired affect in individuals with psychopathy. These include shallowness and profound lack of remorse or empathy. Performances on standardized emotion discrimination tasks and mood induction tasks were compared between 17 patients with antisocial personality disorder (DSM‐IV) and 17 nonpsychopaths. Subjects with psychopathic personality demonstrated poorer performance on emotion‐discrimination tasks compared with controls. However, higher scores on factor “emotional detachment” of the Psychopathy Checklist (PCL‐R) were associated with better discrimination ability. Subjective ratings were comparable between groups during mood induction. Although the findings support the hypothesis of a significant association between impaired emotional processing and psychopathy, they also suggest a relationship between emotional discrimination and the core personality features of psychopathy. Aggr. Behav. 28:394–400, 2002. © 2002 Wiley‐Liss, Inc.     

Taste/tactile cue discriminations in taste-aversion learning foIIowing depletion of noradrenaIine

Four experiments were performed to investigate the effect of noradrenaline (NA) depletion, following systemic DSP4 treatment, upon a tastehactile discrimination in taste-aversion learning. In Experiments 1 and 2 , noisy bottle (A) + lithium chloride pairings were alternated with saccharin (B) + saline pairings, and vice versa, during Phase I conditioning. The particular order of reinforcement presentation in each case was then reversed, so that a noisy bottle (A) + saline pairing was now altered with a saccharin (B) + lithium chloride pairing, etc., during Phase II (reversal) conditioning. In Experiments 3 and 4 , saccharin in noisy bottle (AB) + lithium chloride pairings alternated with either noisy bottle (A) + saline or saccharin (B) + saline pairings, and vice versa, during Phase I conditioning; the order of reinforcement presentation was then reversed, as above. None of the four experiments performed offered any evidence of impairments of the discrimination task as a result of NA depletion. These results are discussed in the context of associative preparedness and of discrimination learning in operant tasks and recent findings on compound conditioning, following the loss of NA.     

Does handedness determine which hand leads in a bimanual task?

Right- and left-handers (n = 16 in each group) were tested on a bimanual circle task that required drawing either in the same direction (parallel) or in a mirror symmetrical coordination mode with the two hands. The authors' primary purposes were to examine the effect of circle direction on within-hand and between-hands variables and to determine whether the relation between hand lead and coordination mode (parallel or mirror symmetrical) differs for left- and right-handers. A strong relation was found between lead hand and movement condition, which depended on the direction of the movements and whether the task was parallel or mirror symmetrical. The pattern of results was similar for left- and right-handers on parallel tasks, but group differences were found with respect to mirror symmetrical tasks. At odds with the general claim that the dominant hand leads, the present results indicated that hand dominance does not generally determine which hand leads.     

Response stereotypy without automaticity in pigeons

Previous research has shown that when pigeons are required to peck each of two keys four times in any order for reinforcement, stereotyped response sequences develop though they are not demanded by the task. The present experiment explored whether the functional value of sequence stereotypy was that sequences became automatized, freeing cognitive resources for other activities. Pigeons were exposed to variants of the task requiring four pecks on each key that differed in the degree of task stringency. Concurrent with the sequence task, pigeons were required to process the color of the keys in order to complete successfully either a matching or a conditional discrimination task. The delay between sequence execution and matching or discrimination choice was varied between 0 and 10 sec. Matching and discrimination accuracy were decreasing functions of delay, but the stringency of the concurrent sequence task had no effect on choice accuracy, suggesting that stereotyped sequences were automatized. However, the matching and discrimination tasks produced substantial disruptions of sequence performance, suggesting that stereotyped sequences were not automatized. The data were taken to suggest that response stereotypy need not imply automaticity.     

TASK DIFFICULTY AND ABERRANT BEHAVIOR IN SEVERELY HANDICAPPED STUDENTS

The influence of task difficulty on aberrant behavior was investigated with three severely handicapped students. Noticeably higher rates of problem behavior occurred in demand compared to no-demand conditions. In addition, there were higher rates of problem behaviors on difficult versus easy tasks. Both these findings were validated with visual discrimination and perceptual motor tasks. An errorless learning procedure effectively minimized errors and aberrant behavior in visual discrimination tasks but not in perceptual motor tasks. It was conceptualized that aberrant behavior was maintained by negative reinforcement contingencies. Difficult tasks were aversive to the children, who emitted aberrant responses to escape or avoid such tasks. By contrast, conditions in which no demands were made, easy tasks, and, in visual discrimination learning, errorless tasks, were less aversive and resulted in little or no problem behavior. Implications for reducing maladaptive behaviors through curricular modifications are discussed and contrasted to more traditional consequence manipulation approaches.