Reorganization of functional and effective connectivity during real-time fMRI-BCI modulation of prosody processing

Mechanisms of cortical reorganization underlying the enhancement of speech processing have been poorly investigated. In the present study, we addressed changes in functional and effective connectivity induced in subjects who learned to deliberately increase activation in the right inferior frontal gyrus (rIFG), and improved their ability to identify emotional intonations by using a real-time fMRI Brain-Computer Interface. At the beginning of their training process, we observed a massive connectivity of the rIFG to a widespread network of frontal and temporal areas, which decreased and lateralized to the right hemisphere with practice. Volitional control of activation strengthened connectivity of this brain region to the right prefrontal cortex, whereas training increased its connectivity to bilateral precentral gyri. These findings suggest that changes of connectivity in a functionally specific manner play an important role in the enhancement of speech processing. Also, these findings support previous accounts suggesting that motor circuits play a role in the comprehension of speech.     

False-positive tangible outcomes of functional analyses

Functional analysis (FA) methodology is the most precise method for identifying variables that maintain problem behavior. Occasionally, however, results of an FA may be influenced by idiosyncratic sensitivity to aspects of the assessment conditions. For example, data from several studies suggest that inclusion of a tangible condition during an FA may be prone to a false-positive outcome, although the extent to which tangible reinforcement routinely produces such outcomes is unknown. We examined susceptibility to tangible reinforcement by determining whether a new response was acquired more readily when exposed to a tangible contingency relative to others commonly used in an FA (Study 1), and whether problem behavior known not to have a social function nevertheless emerged when exposed to tangible reinforcement (Study 2). Results indicated that inclusion of items in the tangible condition should be done with care and that selection should be based on those items typically found in the individual's environment.     

An evaluation of antecedent exercise on behavior maintained by automatic reinforcement using a three-component multiple schedule

We evaluated antecedent exercise for treating the automatically reinforced problem behavior of 4 individuals with autism. We conducted preference assessments to identify leisure and exercise items that were associated with high levels of engagement and low levels of problem behavior. Next, we conducted three 3-component multiple-schedule sequences: an antecedent-exercise test sequence, a noncontingent leisure-item control sequence, and a social-interaction control sequence. Within each sequence, we used a 3-component multiple schedule to evaluate preintervention, intervention, and postintervention effects. Problem behavior decreased during the postintervention component relative to the preintervention component for 3 of the 4 participants during the exercise-item assessment; however, the effects could not be attributed solely to exercise for 1 of these participants.     

Functional analysis and treatment of coprophagia

In the current investigation, functional analysis results suggested that coprophagia, the ingestion of fecal matter, was maintained by automatic reinforcement. Providing noncontingent access to alternative stimuli decreased coprophagia, and the intervention was generalized to two settings.     

The role of common motor responses in stimulus categorization by preschool children

The purpose of this study was to assess the role of common motor responses as the "speaker" behavior on stimulus class formation, and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct category-sort responses for 5 typically developing preschool children. Three of the children passed the categorization tests. Experiment 2 examined whether the classes formed in Experiment 1 were functional classes, and whether participants who did not pass categorization tests in Experiment 1 would do so following common vocal tact training. The 2 participants who failed categorization tests in Experiment 1 passed these tests in Experiment 2, although none of the participants passed the tests for functional classes. The results of the current study did not unequivocally support the naming hypothesis. Future research should therefore evaluate other possible sources of control that aid in stimulus categorization.     

SYSTEMATIC EVALUATION OF VARIABLES THAT CONTRIBUTE TO NONCOMPLIANCE: A REPLICATION AND EXTENSION

The effects of time‐out and escape extinction were examined with 2 preschoolers after we identified variables that may have resulted in noncompliance. Results of a functional analysis showed that noncompliance was highest in the escape condition for both participants. During the treatment evaluation, escape extinction resulted in greater reductions in noncompliance relative to time‐out.     

FUNCTIONAL ANALYSIS OF INAPPROPRIATE SOCIAL INTERACTIONS IN STUDENTS WITH ASPERGER'S SYNDROME

We analyzed the inappropriate social interactions of 3 students with Asperger's syndrome whose behavior was maintained by social positive reinforcement. We tested whether inappropriate social behavior was sensitive to social positive reinforcement contingencies and whether such contingencies could be reversed to increase the probability of socially appropriate responding. Our results show that social positive reinforcers can be identified for inappropriate social interactions and that appropriate social behaviors can be sensitive to reinforcement contingency reversals.     

Functional analysis and treatment of arranging and ordering by individuals with an autism spectrum disorder

Of the diagnostic features of autism, relatively little research has been devoted to restricted and repetitive behavior, particularly topographically complex forms of restricted and repetitive behavior such as rigidity in routines or compulsive-like behavior (e.g., arranging objects in patterns or rows). Like vocal or motor stereotypy, topographically complex forms of restricted and repetitive behavior may be associated with negative outcomes such as interference with skill acquisition, negative social consequences, and severe problem behavior associated with interruption of restricted and repetitive behavior. In the present study, we extended functional analysis methodology to the assessment and treatment of arranging and ordering for 3 individuals with an autism spectrum disorder. For all 3 participants, arranging and ordering was found to be maintained by automatic reinforcement, and treatments based on function reduced arranging and ordering.     

Output order reflects the cognitive accessibility of goals

Goal accessibility--the ease or speed with which a goal is activated--increases the likelihood that it will be acted on. The present studies validate output order as a measure of goal accessibility that can be applied to goal lists in both laboratory and naturalistic settings. In three studies, output order (the order in which goals are listed in a free-response format) was related to self-reported goal value but was not redundant with it. Furthermore, output order was affected by motivational priming whereas value was not, and order associated with typical student goals (e.g., achievement) compared with atypical goals (e.g., power). Output order is well suited to bring the study of accessibility to naturalistic studies of goals and goal pursuit.     

婴儿语音感知发展及其机制

语音感知的发展状况对个体的语言发展有着深远影响。生命的第一年中, 在语言经验的作用下, 婴儿的语音感知从最初的普遍性感知逐渐发展为对母语的特异性感知。研究者们提出统计学习机制对这一过程加以解释, 即婴儿对语言环境中语音的频次分布十分敏感, 可以通过对频次分布的计算, 从语音的连续体中区分出在母语中起区别意义作用的各个语音范畴。同时, 功能性重组机制和一些社会性线索也会对婴儿语音感知的发展产生重要影响。