Individual differences: Either relational learning or item-specific learning in a same/different task

Three pigeons were trained in a three-item simultaneous same/different task. Three of six stimulus combinations were not trained (untrained set) and were tested later. Following acquisition, the subjects were tested with novel stimuli, the untrained set, training-stimulus inversions, and object shape and color manipulations. There was no novel-stimulus transfer—that is, no abstract-concept learning. Two pigeons showed partial transfer to untrained pairs and good transfer to stimulus inversions, suggesting that they had learned the relationship between the stimuli. Lack of transfer by the third pigeon suggests item-specific learning. The somewhat surprising finding of relational learning by 2 pigeons with only six training pairs suggests restricted-domain relational learning that was controlled more by color than by shape features. Individual differences of item-specific learning by 1 pigeon and relational learning by 2 others demonstrate that this task can be learned in different ways and that relational learning can occur in the absence of novel-stimulus transfer.     

Re-examination of the possible role of Golgi tendon organ and muscle spindle reflexes in proprioceptive neuromuscular facilitation muscle stretching

Literature concerning the theoretical role of spinal reflex circuits and their sensorimotor signals in proprioceptive neuromuscular facilitation (PNF) muscle stretching techniques was examined. Reviewed data do not support the assertion commonly made in PNF literature that contraction of a stretched muscle prior to further stretch, or contraction of opposing muscles during muscle stretch, produces relaxation of the stretched muscle. Further, following contraction of a stretched muscle, inhibition of the stretch reflex response lasts only 1 s. Studies examined suggested that decreases in the response amplitude of the Hoffmann and muscle stretch reflexes following a contraction of a stretched muscle are not due to the activation of Golgi tendon organs, as commonly purported, but instead may be due to presynaptic inhibition of the muscle spindle sensory signal. The current view on the complex manner by which the spinal cord processes proprioceptive signals was discussed. The ability of acute PNF stretching procedures to often produce a joint range of motion greater than that observed with static stretching must be explained by mechanisms other than the spinal processing of proprioceptive information. Studies reviewed indicate that changes in the ability to tolerate stretch and/or the viscoelastic properties of the stretched muscle, induced by PNF procedures, are possible mechanisms.     

Do Golgi tendon organs really inhibit muscle activity at high force levels to save muscles from injury, and adapt with strength training?

Introductory textbooks commonly state that Golgi tendon organs (GTOs) are responsible for a reflex response that inhibits a muscle producing dangerously high tension (autogenic inhibition). Review of the relevant data from animal studies demonstrates that there is wide variability in the magnitude of, and even the presence of, GTO autogenic effects among locomotor hindlimb muscles, and that data on GTO effects under conditions of voluntary maximal muscle activation are lacking. A single available study on GTO function in humans, during a moderate contraction, surprisingly shows a reduction in autogenic inhibition during muscle-force production. Further, it is not possible to find experimental evidence supporting the idea that strength training may produce a decrease in GTO mediated autogenic inhibition, allowing greater muscle activation levels and hence greater force production.     

Genetic and Environmental Links Between Natural Language Use and Cognitive Ability in Toddlers

Although the phenotypic correlation between language and nonverbal cognitive ability is well‐documented, studies examining the etiology of the covariance between these abilities are scant, particularly in very young children. The goal of this study was to address this gap in the literature by examining the genetic and environmental links between language use, assessed through conversational language samples, and nonverbal cognition in a sample of 3‐year‐old twins (N = 281 pairs). Significant genetic and nonshared environmental influences were found for nonverbal cognitive ability and language measures, including mean length of utterance and number of different words, as well as significant genetic covariance between cognitive ability and both language measures.     

The U.S. Military Veteran in News Photographs: Representation and Stereotypes

Commenters have expressed concern over media content related to military veterans, saying journalists fail to provide the public with an accurate understanding of what it means to be a veteran. Nevertheless, few studies have examined the representation of veterans in news media content. The present study analyzed 740 photographs shared by regional news outlets on the popular social media platform Twitter. Coders documented the representation of veteran groups (gender, race, and service period) and stereotypes concerning veterans (homelessness, charity, and trauma) in the images. Results showed that the photographs rarely communicated stereotypes about veterans. Photographs overrepresented female veterans, although male veterans remained the significant majority. Minority veterans were underrepresented. Photographs most often contained images associated with World War II.     

How teachers manage their work in inclusive classrooms

The aim of the study reported in this paper was to develop substantive theory regarding how teachers manage their classroom work when they are placed in the position of having a student with a severe or profound intellectual disability included in their class. The result was the theory of selective adaptation. The theory proposes that teachers can be classified as ‘technicians', ‘strategists', or ‘improvisers’ according to the extent to which they selectively adapt their classroom practices. Furthermore, there is a correspondence between the extent to which teachers selectively adapt their classroom work and the impact of inclusion on their lives.     

A Statewide Analysis of North Carolina Public Libraries and Their Response to the Opioid Epidemic

ABSTRACT

This study sought to investigate the opioid epidemic impact on North Carolina public libraries. Libraries in half of all 100 counties were chosen through a random, geographically systematic process, and structured interviews were completed with library directors. Twenty directors were interviewed, representing 28 counties. All reported their communities were affected; nine reported direct impacts on library function. Fifteen directors felt libraries should be involved in response; some felt Narcan administration was beyond library purview. Two libraries reported having Narcan available; five reported providing staff training. Given librarians’ willingness to respond, it is time to provide necessary support for those efforts.