Effects of Response Blocking and Programmed Stimulus Control on Motor Stereotypy: A Pilot Study

We evaluated response blocking with programmed stimulus control, wearing tennis wrist bands, to reduce motor stereotypy in a student with autism. Response blocking was effective and subsequent analysis revealed that wearing the tennis wrist bands alone maintained low frequency stereotypy. Results suggest that controlling effects from a procedure such as response blocking can be transferred to a programmed stimulus in the absence of physical intervention.     

Task Interruption and its Effects on Memory

We investigated the recovery from memory of a primary task after an interruption. If the primary task lacked associative support among its task components, recovery was more difficult following an interruption that overlapped either completely or partially in the amount of information shared with the primary task (an interruption-similarity effect). In addition, memory for completed actions was superior to memory for impending unfinished actions. However, if the primary task had associative support among its task components, there was no adverse effect of interruption similarity, and completed and unfinished actions were recalled equally well. We explore possible explanations and implications of these results.     

Use of an Antecedent Intervention to Decrease Vocal Stereotypy of a Student With Autism in the General Education Classroom

This study examined the use of an antecedent-based intervention to reduce the vocal stereotypy of a student diagnosed with Autism within the general education classroom. The student displayed frequent nonfunctional speech and disruptive vocal sounds. An antecedent-based intervention, involving the use of qualitatively different cards—to cue the student when it was appropriate or inappropriate to engage in vocal stereotypy—was designed and implemented. An adaptive alternating treatment design was utilized and conditions were randomized and counterbalanced across treatment sessions. Data on vocal stereotypy were collected using partial interval recording. The results indicated the participant was successful in discriminating between cues and decreased stereotypy during intervention compared to baseline conditions. Similar findings were found when the intervention was implemented across a second school setting.     

Effects of Task Interruption and Background Speech on Word Processed Writing

Task interruptions and background speech, both part of the everyday situation in office environments, impair cognitive performance. The current experiments explored the combined effects of background speech and task interruptions on word processed writing—arguably, a task representative of office work. Participants wrote stories, in silence or in the presence of background speech (monologues, halfalogues and dialogues), and were occasionally interrupted by a secondary task. Writing speed was comparably low during the immediate period after the interruption (Experiments 1 and 2); it took 10–15 s to regain full writing speed. Background speech had only a small effect on performance (Experiment 1), but a dialogue was more disruptive than a halfalogue (Experiment 2). Background speech did not add to the cost caused by task interruptions. However, subjective measures suggested that speech, just as interruptions, contributed to perceived workload. The findings are discussed in view of attentional capture and interference‐by‐process mechanisms.© 2016 The Authors. Applied Cognitive Psychology published by John Wiley & Sons, Ltd.     

The Effects of Brain Lateralization on Motor Control and Adaptation

ABSTRACT

Lateralization of mechanisms mediating functions such as language and perception is widely accepted as a fundamental feature of neural organization. Recent research has revealed that a similar organization exists for the control of motor actions, in that each brain hemisphere contributes unique control mechanisms to the movements of each arm. The authors review present research that addresses the nature of the control mechanisms that are lateralized to each hemisphere and how they impact motor adaptation and learning. In general, the studies suggest an enhanced role for the left hemisphere during adaptation, and the learning of new sequences and skills. The authors suggest that this specialization emerges from a left hemisphere specialization for predictive control—the ability to effectively plan and coordinate motor actions, possibly by optimizing certain cost functions. In contrast, right hemisphere circuits appear to be important for updating ongoing actions and stopping at a goal position, through modulation of sensorimotor stabilization mechanisms such as reflexes. The authors also propose that each brain hemisphere contributes its mechanism to the control of both arms. They also discuss the potential advantages of such a lateralized control system.     

Response Interruption and Differential Reinforcement of Alternative Behavior for the Treatment of Pica

Pica displayed by two individuals with autism was decreased by a treatment involving differential reinforcement and response interruption that altered the chain of behavior involved in pica (i.e., picking up items and placing them in the mouth). The treatment involved establishing prompts to ‘clean‐up’ as a new discriminative stimulus (SD) for picking up items from the floor; and holding potential pica items was established as an SD for discarding those items in a trash receptacle, putting them away, or using them appropriately. After demonstrating the effectiveness of the treatment in an analog setting, the treatment package was systematically generalized to community settings. Copyright © 2011 John Wiley & Sons, Ltd.     

The Effects of Practice Trials and Prior Learning on Motor Memory

The effects of prior positions (PL), practice reinforcements of the criterion distance (CT), and retention intervals on proactive interference (PI) in a 20-cm. linear positioning task were examined. Independent treatment groups had either 0, 3, or 5 PL, with 1, 3, or 10 CT, and a 5-, 15-, or 50-sec. retention interval. Only absolute error scores at recall indicated PI. This forgetting occurred only under the highly restricted conditions of 5 PL and 1 CT after 15-and 50-sec. retention intervals. Since 0 PL groups showed no differences in recall over levels of retention intervals, PI alone apparently caused the forgetting.     

Intra-Limb Specificity of Motor Response Consistency

Two separate experiment using motor responses evaluated the specificity vs. generality of response consistency when the various tasks used the same limb for response. In Exp. I four similar tasks requiring rapid right arm movement were defined and, in Exp. II, Ss had to “hit” a moving target with either a maximal or moderately fast right hand movement. Although the mean intercorrelations among tasks were generally moderate to low (mean r = .85 and .30, respectively for Exp. I and II) the intercorrelations using response consistency scores (the SD of S’s responses about his own mean) were lower for Exp. I (mean r = .54) and similar for Exp. II (mean r = .30). These findings provided little support for a notion of a general within-limb factor of motor response consistency.     

The Development and Sex-Related Use of Interruption Behavior

In this article the authors argue that claims of sex differences in interruption behavior should not be uncritically accepted as there are limitations in previous research that make such acceptance questionable. The frequency of interruption was examined over a portion of the early life span (Grades 4 and 9 and college). Twenty-minute structured conversations of 90 dyads (30 male, 30 female, and 30 mixed sex) were scored for four types of interruption, and both developmental and sex differences in interruption behavior were examined. Interruption frequency did not change over age or across dyads of different sex composition. Males did not interrupt any more than females did and females were interrupted by their partners as frequently as males were interrupted by theirs, with one exception: Grade 9females were interrupted more by their female partners. Interruptions were asymmetrically distributed in same-sex and opposite-sex dyads; however, the asymmetry in opposite-sex dyads was not predictablefrom sex of subject or sex of partner. That is, males did not interrupt females any more than females interrupted males. The authors conclude that wholesale acceptance of sex differences in interruption behavior is not warranted.     

Effects of a Synthetic Predator Odor (TMT) on Freezing,Analgesia, Stereotypy,and Spatial Memory

The Psychological Record - Exposing rats to the predator odor of trimethylthiazoline (TMT), obtained from the red fox, was compared to exposure to the novel control odor of citronella. In...     

A Developmental Investigation of Prospective Memory: Effects of Interruption

The effects of interrupting an event-based prospective memory (PM) task and its associated ongoing task were compared for two groups of children: 8- to 9-year-olds (n?=?35) and 12- to 13-year-olds (n?=?28). Additionally, PM performance was examined as a function of attainment on a battery of tests of executive functioning (viz., Controlled Oral Word Association Test, Letter Number Sequencing Test, Stroop Color and Word Test, and Trail Making Test). A significant main effect of age indicated that the older children correctly carried out intended actions more often than the younger children. Consistent with the prefrontal model of PM, interruption had no impact on PM accuracy in the older group but produced reliable decrements to the accuracy of the younger group. Whereas IQ showed no association with PM performance, reliable relations between PM skills and aspects of their executive functioning were found.     

Influence of Response Similarity on Interference in Perceptual Motor Learning

Motor interference was measured in terms of average response time in sorting 15 pairs of cards, each pair containing words which were either unrelated or identical but printed in different colors. The two words of each pair were used in labeling two cubicles in such a way that they were apart by 0, 1, 2, or 3 intervening cubicles in quasirandomly chosen directions. Interference was inversely related to response similarity, but this relationship may not appear in the absence of sufficient stimulus similarity. The findings are interpreted in the light of a hypothesis which views motor interference as a tendency for responses to deflect from their own courses and be pulled towards those of other responses with which they are at conflict.     

The Effects of Acute Aerobic Exercise on the Primary Motor Cortex

ABSTRACT. The effect of aerobic exercise on primary motor cortical excitability is a relevant area of interest for both motor learning and motor rehabilitation. Transient excitability changes that may follow an exercise session are a necessary precursor to more lasting neuroplastic changes. While the number of studies is limited, research suggests that a session of aerobic exercise can create an ideal environment for the early induction of plasticity. Potential mechanisms include the upregulation of neurotransmitter activity, altered cerebral metabolism and cortisol levels, and increases in brain-derived neurotrophic factor. While there is considerable evidence that chronic physical activity positively impacts brain health and function, studies examining cortical excitability changes and motor performance after a single session of exercise are lacking. Further research is required to determine the clinical utility and feasibility of aerobic exercise.     

The Influence of Number Magnitude on Vocal Responses

The study investigated whether number magnitude can influence vocal responses. Participants produced either short or long version of the vowel [ɑ] (Experiment 1), or high or low-pitched version of that vowel (Experiment 2), according to the parity of a visually presented number. In addition to measuring reaction times (RT) of vocal responses, we measured the intensity, the fundamental frequency (f₀) and the first and second formants of the vocalization. The RTs showed that the long and high-pitched vocal responses were associated with large numbers, while short and low-pitched vocal responses were associated with small numbers. It was also found that high-pitched vocalizations were mapped with the odd numbers, while the low-pitched vocalizations were mapped with the even numbers. Finally, large numbers increased the f₀ values. The study shows systematic interactions between the processes that represent number magnitude and produce vocal responses.     

The Effects of Objectives and Constraints on Motor Control Strategy in Reciprocal Aiming Movements

The goal of this study was to examine how the kinematics of reciprocal aiming movements were affected by both the objective of the movement and the constraints operating on that movement. In Experiment 1, the objective of the movement was indirectly manipulated by capitalizing on the fact that subjects determine their own accuracy and speed limits, despite uniform task instructions to move as quickly and accurately as possible. A Fitts' type reciprocal aiming paradigm was employed, in which 69 subjects were asked to move a stylus repetitively between two spatially separated targets. Four target widths were orthogonally combined with four movement amplitudes, resulting in 16 conditions. Movements were made on an X-Y digitizing tablet. Based on the mean variable error produced on both targets, subjects were differentiated post hoc into three movement objective groups: speed, accuracy, and speed-plus-accuracy. Kinematic analyses revealed that the programming and execution of movements were systematically influenced by both the movement objective and the movement constraints. That is, movement time, peak velocity, dwell time, acceleration and deceleration time, normalized acceleration and normalized deceleration varied systematically as a function of both the speed-accuracy movement objective and the movement constraints of target size and movement distance. Moreover, the consequences of changing the constraints of the movement were affected by an interaction with the objective of the movement. In Experiment 2, the objective of the movement was directly manipulated by varying speed and/or accuracy instructions to subjects. The basic results of Experiment 1 were substantiated. Overall, the results were consistent with the view that motor control is dependent upon sensory consequences.     

Motor Performance and Response Consistency as a Function of Age

The specificity versus generality of motor performance and motor response consistency was investigated as a function of age. 120 Ss, 30 each at age 7, 11, 15, and 19 yr., were given 120 practice trials (60 trials per session with 24 hr interpolated between sessions) on both simple and choice RT tasks. For motor performance the reliability of individual differences was high in both tasks at all ages, while the amount of generality was moderately high in the two younger groups but diminished with age. The reliability coefficients for motor response consistency were low for both tasks but, with two exceptions, statistically significant. There was no evidence for generality in motor response consistency at any age.     

Motor Response Variations: Peripheral and Central Sources of Error

The purpose of this research was to test the hypothesis that the relative involvement of peripheral versus central nervous system activity during response variations determines the locus of error production in a subsequent criterion response. The hypothesis was tested by comparing ipsilateral and contralateral transfer of a criterion response following response variations that emphasized proportionately different involvement of the peripheral and central systems. When subjects were provided with knowledge of results (KR) to maintain a 30% maximum voluntary contraction (MVC), ipsilateral but not contralateral bias errors occurred on a subsequent dynamic response. When subjects maintained a 30% MVC without KR, however, subsequent ipsilateral bias errors were greater than contralateral bias errors. Finally, when subjects imaged a 30% MVC, subsequent bias errors were equivalent across limbs. These results are interpreted as support for the hypothesis.