The role of eye movements in motor sequence learning

An experiment that utilized a 16-element movement sequence was designed to determine the impact of eye movements on sequence learning. The participants were randomly assigned to two experimental groups: a group that was permitted to use eye movements (FREE) and a second group (FIX) that was instructed to fixate on a marker during acquisition (ACQ). A retention test (RET) was designed to provide a measure of learning, and two transfer tests were designed to determine the extent to which eye movements influenced sequence learning. The results demonstrated that both groups decreased the response time to produce the sequence, but the participants in the FREE group performed the sequence more quickly than participants of the FIX group during the ACQ, RET and the two transfer tests. Furthermore, continuous visual control of response execution was reduced over the course of learning. The results of the transfer tests indicated that oculomotor information regarding the sequence can be stored in memory and enhances response production.     

Cognitive disruption and altered hippocampus synaptic function in Reelin haploinsufficient mice

The heterozygote reeler mouse (HRM) shows many neuroanatomical and biochemical features that are also present in some human cognitive disorders, such as schizophrenia. In the present study, hippocampal dependent plasticity and cognitive function of the HRM were characterized in detail in an attempt to reveal phenotypic functional differences that result from Reelin haploinsufficiency. The HRM and wild type mice show similar levels of overall activity, coordination, thermal nociception, startle responses, and anxiety-like behavior. In addition, both genotypes show similar shock threshold, identical cued freezing behavior and comparable spatial learning in Morris water maze tasks. However, a significant reduction in contextual fear conditioned learning was observed in the HRM. Electrophysiological studies in hippocampal CA1 synapses revealed a plethora of differences between genotypes. The HRM exhibits reduced field excitatory postsynaptic potentials in responses to similar synaptic inputs, lowered paired pulse facilitation ratio and impaired long-term depression and tetanus-induced long-term potentiation (LTP). Also, deficits were detected in LTP elicited by theta burst stimulation or by a whole cell pairing protocol. These physiologic differences could not be accounted for by changes in the overall amount of glutamate receptor subunits. In addition, it was determined that network-driven excitatory and inhibitory activities recorded in CA1 pyramidal neurons showed that the HRM had comparable amplitude and frequency of spontaneous excitatory postsynaptic currents, but a marked reduction in spontaneous inhibitory postsynaptic currents. Thus, the HRM exhibits a specific hippocampal-dependent learning deficit accompanied with a pronounced impairment of hippocampal plasticity and functional inhibitory innervation.     

Imitation: definitions, evidence, and mechanisms

Imitation can be defined as the copying of behavior. To a biologist, interest in imitation is focused on its adaptive value for the survival of the organism, but to a psychologist, the mechanisms responsible for imitation are the most interesting. For psychologists, the most important cases of imitation are those that involve demonstrated behavior that the imitator cannot see when it performs the behavior (e.g., scratching one's head). Such examples of imitation are sometimes referred to as opaque imitation because they are difficult to account for without positing cognitive mechanisms, such as perspective taking, that most animals have not been acknowledged to have. The present review first identifies various forms of social influence and social learning that do not qualify as opaque imitation, including species-typical mechanisms (e.g., mimicry and contagion), motivational mechanisms (e.g., social facilitation, incentive motivation, transfer of fear), attentional mechanisms (e.g., local enhancement, stimulus enhancement), imprinting, following, observational conditioning, and learning how the environment works (affordance learning). It then presents evidence for different forms of opaque imitation in animals, and identifies characteristics of human imitation that have been proposed to distinguish it from animal imitation. Finally, it examines the role played in opaque imitation by demonstrator reinforcement and observer motivation. Although accounts of imitation have been proposed that vary in their level of analysis from neural to cognitive, at present no theory of imitation appears to be adequate to account for the varied results that have been found.     

DSM-defined anxiety disorders symptoms in South African youths: Their assessment and relationship with perceived parental rearing behaviors

This study investigated DSM-defined anxiety symptoms in South African youths. Children and adolescents (N = 701) from various cultural groups completed the SCARED and a questionnaire measuring perceived parental rearing behaviors. Results indicated that the psychometric properties of the SCARED were satisfactory in the total sample of South African youths, and acceptable in colored and black children and adolescents. Further, colored and black youths displayed higher SCARED scores than white youths, and there were also differences in the perceived parental rearing behaviors of the cultural groups. White youths generally rated their parents' rearing behaviors as less anxious, overprotective, and rejective, but more emotionally warm than colored and black youths. Finally, positive correlations were found between anxious rearing, overprotection, and rejection and anxiety symptoms. The clinical and research implications of these findings are briefly discussed.     

A cognitive behavioral workshop for subclinical obsessions and compulsions

The present study investigates the effectiveness of a 3-h cognitive behavioral workshop for individuals, ages 18-22, with subclinical obsessions and compulsions. It was hypothesized that, compared to individuals in an assessment-only waitlist group (n = 42), individuals assigned to the workshop group (n = 43) would experience a significant decrease in obsessive-compulsive (OC) symptomatology, comorbidity, and thought action fusion endorsement at 1-month and 5-month follow-up assessments. An additional outcome of interest was the number of incident cases of obsessive-compulsive disorder (OCD) over the course of the study. The results indicated that the workshop group reported a significantly fewer number of OC symptoms at 5-month follow-up and endorsed significantly less thought action fusion at both follow-up points. However, there were no differences between groups in severity of OC symptoms and number of comorbid diagnoses endorsed. Only one incident case of OCD was observed during the study, from a participant in the waitlist group. These results are discussed in reference to treatment of subclinical anxiety symptoms.     

Instrumental and vocal music effects on EEG and EKG in neonates of depressed and non-depressed mothers

Neonates (M age = 16 days) born to depressed and non-depressed mothers were randomly assigned to hear an audiotaped lullaby of instrumental music with vocals or without vocals. Neonatal EEG and EKG were recorded for 2 min (baseline) of silence and for 2 min of one or the other music presentation. Neonates of non-depressed mothers showed greater relative right frontal EEG asymmetry to both types of music, suggesting a withdrawal response. Neonates of depressed mothers on the other hand showed greater relative left frontal EEG asymmetry to the instrumental without vocal segment, suggesting an approach response, and greater relative right frontal EEG asymmetry to the instrumental with vocal segment, suggesting a withdrawal response. Heart rate decelerations occurred following the music onset for both groups of infants, however, compared to infants of non-depressed mothers, infants of depressed mothers showed a delayed heart rate deceleration, suggesting slower processing and/or delayed attention. These findings suggest that neonates of depressed and non-depressed mothers show different EKG and EEG responses to instrumental music with versus without vocals.     

Motivational Predictors of Change in Oral Health: An Experimental Test of Self-Determination Theory

We tested the hypothesis that a psychosocial dental intervention formulated in terms of self-determination theory would increase patients’ perceived competence and autonomous motivation for dental care and would decrease their plaque and gingivitis over a seven month period, compared to standard dental treatment. We also tested a process model in which the intervention was expected to increase perceived dental competence and autonomous motivation, that they would be positively associated with oral health behaviors (i.e., brushing and flossing), which was expected to decrease plaque and, in turn, decrease gingivitis. We also examined whether: changes in perceived competence and autonomous motivation would mediate the effect of the intervention on dental-health behaviors; dental-health behaviors would mediate the links from changes in perceived competence and autonomous motivation to change in plaque; and change in plaque would mediate the relation of dental health behaviors to change in gingivitis. Finally, we examined the fit of the overall model with structural equation modelling. Results supported all predictions.

Early child grammars: qualitative and quantitative analysis of morphosyntactic production

This article reports on a series of 5 analyses of spontaneous production of verbal inflection (tense and person–number agreement) by 2-year-olds acquiring French as a native language. A formal analysis of the qualitative and quantitative results is developed using the unique resources of Optimality Theory (OT; Prince & Smolensky, 2004). It is argued that acquisition of morphosyntax proceeds via overlapping grammars (rather than through abrupt changes), which OT formalizes in terms of partial rather than total constraint rankings. Initially, economy of structure constraints take priority over faithfulness constraints that demand faithful expression of a speaker's intent, resulting in child production of tense that is comparable in level to that of child-directed speech. Using the independent Predominant Length of Utterance measure of syntactic development proposed in Vainikka, Legendre, and Todorova (1999), production of agreement is shown first to lag behind tense then to compete with tense at an intermediate stage of development. As the child's development progresses, faithfulness constraints become more dominant, and the overall production of tense and agreement becomes adult-like.     

Fix and sample with rats in the dynamics of choice

The generality of the molar view of behavior was extended to the study of choice with rats, showing the usefulness of studying order at various levels of extendedness. Rats' presses on two levers produced food according to concurrent variable-interval variable-interval schedules. Seven different reinforcer ratios were arranged within each session, without cues identifying them, and separated by blackouts. To alternate between levers, rats pressed on a third changeover lever. Choice changed rapidly with changes in component reinforcer ratio, and more presses occurred on the lever with the higher reinforcer rate. With continuing reinforcers, choice shifted progressively in the direction of the reinforced lever, but shifted more slowly with each new reinforcer. Sensitivity to reinforcer ratio, as estimated by the generalized matching law, reached an average of 0.9 and exceeded that documented in previous studies with pigeons. Visits to the more-reinforced lever preceded by a reinforcer from that lever increased in duration, while all visits to the less-reinforced lever decreased in duration. Thus, the rats' performances moved faster toward fix and sample than did pigeons' performances in previous studies. Analysis of the effects of sequences of reinforcer sources indicated that sequences of five to seven reinforcers might have sufficed for studying local effects of reinforcers with rats. This study supports the idea that reinforcer sequences control choice between reinforcers, pulses in preference, and visits following reinforcers.     

Social support, locus of control, and depressive symptoms in hemodialysis patients

This study aimed to reveal how social support and psychological well-being association might differ with locus of control orientation for chronically ill patients receiving a restrictive and unpleasant medical treatment (i.e., hemodialysis). Data were collected from 104 hemodialysis patients. After controlling for the variance accounted for by gender and duration of dialysis, for patients with internal locus of control, lack of "perceived social support" was found to be associated with depressive symptoms. On the other hand, for patients with external locus of control, the same analysis revealed that lack of "satisfaction from the received social support" was associated with depressive symptoms. Thus, for hemodialysis patients the variables associated with depressive symptoms varied with their locus of control orientations. Furthermore, the present study underlined the importance of considering different aspects of social support while studying with chronically ill patients.