Context-outcome associations mediate context-switch effects in a human predictive learning task

Four experiments explored the role of contexts in information retrieval after different levels of acquisition training in human predictive learning. Participants were trained where cue (X) was followed by an outcome in context A while a different cue (Y) was followed by the absence of the outcome in context B. When 4 training trials with each cue were conducted, testing the stimuli in the alternative contexts decreased predictive judgments to X and increased predictive judgments to Y. These effects disappeared both when training was increased up to 18 trials (Experiments 1a and 1b), and when the outcome was presented in both contexts A and B (Experiments 2 and 4). When the outcome was presented in both contexts, the nonreinforced cue Y, trained in the presumably excitatory context B, became a conditioned inhibitor (Experiment 3). Additional experience with one of the contexts, but not with both, made the context-switch effect reappear (Experiment 4). These results suggest that irrelevant contexts may enter into direct associations with the outcome before prolonged training leads participants to discard them as predictors.     

Functional ear (a)symmetry in brainstem neural activity relevant to encoding of voice pitch: a precursor for hemispheric specialization?

Pitch processing is lateralized to the right hemisphere; linguistic pitch is further mediated by left cortical areas. This experiment investigates whether ear asymmetries vary in brainstem representation of pitch depending on linguistic status. Brainstem frequency-following responses (FFRs) were elicited by monaural stimulation of the left and right ear of 15 native speakers of Mandarin Chinese using two synthetic speech stimuli that differ in linguistic status of tone. One represented a native lexical tone (Tone 2: T2); the other, T2′, a nonnative variant in which the pitch contour was a mirror image of T2 with the same starting and ending frequencies. Two 40-ms portions of f₀ contours were selected in order to compare two regions (R1, early; R2 late) differing in pitch acceleration rate and perceptual saliency. In R2, linguistic status effects revealed that T2 exhibited a larger degree of FFR rightward ear asymmetry as reflected in f₀ amplitude relative to T2′. Relative to midline (ear asymmetry = 0), the only ear asymmetry reaching significance was that favoring left ear stimulation elicited by T2′. By left- and right-ear stimulation separately, FFRs elicited by T2 were larger than T2′ in the right ear only. Within T2′, FFRs elicited by the earlier region were larger than the later in both ears. Within T2, no significant differences in FFRS were observed between regions in either ear. Collectively, these findings support the idea that origins of cortical processing preferences for perceptually-salient portions of pitch are rooted in early, preattentive stages of processing in the brainstem.     

Updating process of internal model of action as assessed from motor and postural strategies in young adults

Internal models are constantly updated based on the actions and experiences of a person in the world. In the present study, we proposed to assess the updating process of internal models of action by providing new environmental constraints for motor planning, postural control, and execution processes in daily tasks such as STS and BTS. STS and BTS tasks were performed with different inclinations of the support surface on which the participant and the chair were positioned: horizontal support, support tilted 10° to the right, or forward. Twelve healthy adults participated in this experiment. Kinematic characteristics were recorded using an optoelectronic motion analysis system. Movement duration and trunk inclination amplitudes were analyzed for STS and BTS as well as trunk orientation and strategies of head stabilization. Concerning the movement analysis our results showed (1) temporal asymmetry between STS and BTS, attributed mainly to the integration of the mechanical effects of gravity, and (2) a decrease of trunk movements when the support was tilted forward, attesting to an immediate adaptation process. Concerning the postural analysis our study revealed that adults adopted selective head stabilization on space strategy with respect to balance constraints. To conclude, young adults were able to immediately update their internal model of action in order to optimize motor control and vertical body orientation.     

A novel approach to mechanical foot stimulation during human locomotion under body weight support

Input from the foot plays an essential part in perceiving support surfaces and determining kinematic events in human walking. To simulate adequate tactile pressure inputs under body weight support (BWS) conditions that represent an effective form of locomotion training, we here developed a new method of phasic mechanical foot stimulation using light-weight pneumatic insoles placed inside the shoes (under the heel and metatarsus). To test the system, we asked healthy participants to walk on a treadmill with different levels of BWS. The pressure under the stimulated areas of the feet and subjective sensations were higher at high levels of BWS and when applied to the ball and toes rather than heels. Foot stimulation did not disturb significantly the normal motor pattern, and in all participants we evoked a reliable step-synchronized triggering of stimuli for each leg separately. This approach has been performed in a general framework looking for “afferent templates” of human locomotion that could be used for functional sensory stimulation. The proposed technique can be used to imitate or partially restore surrogate contact forces under body weight support conditions.     

The index of autonomous functioning: Development of a scale of human autonomy

A growing interest in the functional importance of dispositional autonomy led to the development and validation of the Index of Autonomous Functioning (IAF) across seven studies. The IAF provides a measure of trait autonomy based on three theoretically derived subscales assessing authorship/self-congruence, interest-taking, and low susceptibility to control. Results showed consistency within and across subscales, and appropriate placement within a nomological network of constructs. Diary studies demonstrated IAF relations with higher well-being, greater daily satisfaction of basic psychological needs, and more autonomous engagement in daily activities. Using an experimental approach, the IAF was shown to predict more positive interactions among dyads. The studies provided a systematic development and validation of a measure of autonomy that is brief and reliable.     

Emotion development system by interacting with human EEG and natural scene understanding

In this paper, we propose a mental development system for understanding the emotional status of humans, and sharing emotions with human subjects. According to the relationship between emotional factors and characteristics of an image, we incorporate the fuzzy concept to extract emotional features using L^*C^*H^* color and orientation information. On the other hand, we also consider the EEG signals which are stimulated by natural stimuli to form the semantic emotional features as well. Emotionally relevant features are firstly clustered into two categories with degrees of belongingness to each cluster to initialize the membership functions of a neuro-fuzzy system. The IF-THEN rules of a neuro-fuzzy system to understand the positive and negative human emotions will be constructed by interacting with human. Then the system attempts to extend the number of understandable emotion. Through the time, the system sub-clusters the emotional features so that the number of membership function of the neuro-fuzzy network will increase to incorporate more complicated human expertise considering more human emotions. Using such a developmental process, the proposed system can develop a mental ability to understand more complex human emotions by mining the characteristics of emotional features and interacting with its environment.     

The general causality orientations scale: Self-determination in personality

This paper describes the development and validation of a general causality orientations scale. Causality orientations are conceptualized as relatively enduring aspects of people that characterize the source of initiation and regulation, and thus the degree of self-determination, of their behavior. Three orientations—autonomy, control, and impersonal—are measured by the three subscales of the instrument. Individuals are given a score on each orientation, thus allowing the use of the theoretically appropriate subscale (or, in some cases, a combination of subscales) to predict affects, cognitions, and behaviors. The scale was shown to have internal consistency and temporal stability. The orientations were shown to fit appropriately into a nomological network of constructs and to relate to various behaviors that were hypothesized to be theoretically relevant.     

The structure of coordination in first language acquisition of Mandarin Chinese: evidence for a universal

This study exemplifies a type of cross-linguistic research which is based on the theory that certain parameters of natural language variation are central to the human competence for language. Sensitivity to these parameters allows the child to develop various specific language structures which follow from setting the parameters. Results of this study provide evidence that children are universally sensitive to one such parameter, namely, Principal Branching Direction.Data are based on results of a standardized elicited imitation test of 68 Chinese children in Taiwan between 2;0 and 4;5 with mean age of 3;3. The test is on a set of coordinate sentences. The results show that children acquiring Mandarin Chinese (a left-branching language) systematically prefer VO sentences with a backward reduction pattern ([V + V]O) over those with a forward reduction pattern (V[O + O]).Children's responses to SV coordinate sentences differ systematically from their VO responses. They very frequently reduce redundant subjects in a forward direction (in SV sentences) and do not prefer backward reduction ([S + S])V) over forward reduction (S[V + V]) in these SV sentences.This paper suggests an explanation of this apparent paradox in terms of an interaction in early language acquisition between children's sensitivity to a predominant Chinese topic-comment structure (in SV) and their sensitivity to the abstract, specifically grammatical concept of “Principal Branching Direction”.     

Free recall by deaf and hearing children: semantic clustering and recall in trained and untrained groups.

Free recall tasks with semantically categorizable stimuli were given to 60 deaf and 60 hearing children, divided equally among Grades 3, 5, and 7 (ages 9, 11, and 13 years, respectively). Half the children were trained to use semantic categorization as a memory aid after the first study-test trial. All subjects were told category labels and sizes on the third recall trial. As hypothesized, older children showed more spontaneous semantic clustering and higher recall scores than younger children. Training increased clustering in all groups, while the provision of category information at retrieval increased clustering regardless of training condition. Contrary to expectations, deaf children used semantic clustering as much as hearing children. Deaf children's recall scores, however, were significantly lower than hearing children's. The specific contrasts observed between deaf and hearing children's performance suggest that deaf children's recall deficiencies probably reflect either inadequate knowledge of category membership or inflexibility in reclassifying individual items, rather than a general inability to recognize and use the categorical nature of a list as a mnemonic aid.     

An evaluation of outcome variables in the systematic desensitization of test anxiety.

This study investigated the effects of group systematic desensitization and group counseling on anxiety and academic performance. Fifty-four undergraduates who requested help for debilitating test anxiety were randomly assigned to Desensitization. Group Counseling, or No-treatment control groups. Measures of test anxiety, trait anxiety, and academic achievement were obtained for all students' pre- and post-treatment. The Desensitization group showed a significant decrease in test anxiety; the Counseling and No-treatment groups showed no changes in these measures. None of the groups showed any change in trait anxiety or academic achievement. The results provided evidence that systematic desensitization was an effective treatment for reducing test anxiety, but not for improving grades.