Discrimination of amount of spinal flexion for movements made with and without vision after lumbar disc replacement

Discrimination of differences between small lumbar flexion movements made when standing may differ depending on whether vision is available. Dependence on general vision during trunk movements may be increased following surgery, in which an intervertebral disc is replaced with a prosthetic disc. This study investigated whether the availability of vision changed discrimination of small differences in lumbar forward flexion movement when standing for patients with lumbar disc replacement and healthy peers. 20 volunteers without a history of back pain and 20 with disc replacement undertook a 100-trial sequence of forward flexion movements to a set of physical stops, making an absolute judgement as to the position after each movement. General (nontarget) vision during the movement was available or removed randomly trial by trial. Availability of vision did not affect discrimination of flexion movements of the lumbar spine either in normal healthy individuals or those with disc replacement.     

Drug use as consumer behavior

Seeking integration of drug consumption research by a theory of memory function and emphasizing drug consumption rather than addiction, Müller & Schumann (M&S) treat drug self-administration as part of a general pattern of consumption. This insight is located within a more comprehensive framework for understanding drug use as consumer behavior that explicates the reinforcement contingencies associated with modes of drug consumption.     

You must have been a beautiful baby: ratings of infant facial attractiveness fail to predict ratings of adult attractiveness

Facial attractiveness has been studied extensively, but little research has examined the stability of facial attractiveness of individuals across different stages of development. We conducted a study examining the relationship between facial attractiveness in infants (age 24 months and under) and the same individuals as young adults (age 16–18 years) using infant and adult photographs from high school yearbooks. Contrary to expectations, independent raters’ assessments of infant facial attractiveness did not correlate with adult facial attractiveness. These results are discussed in terms of the adaptive function of heightened attractiveness in infancy, which likely evolved to elicit and maintain parental care.     

Balancing cognitive demands: control adjustments in the stop-signal paradigm

Cognitive control enables flexible interaction with a dynamic environment. In 2 experiments, the authors investigated control adjustments in the stop-signal paradigm, a procedure that requires balancing speed (going) and caution (stopping) in a dual-task environment. Focusing on the slowing of go reaction times after stop signals, the authors tested 5 competing hypotheses for post-stop-signal adjustments: goal priority, error detection, conflict monitoring, surprise, and memory. Reaction times increased after both successful and failed inhibition, consistent with the goal priority hypothesis and inconsistent with the error detection and conflict hypotheses. Post-stop-signal slowing was greater if the go task stimulus repeated on consecutive trials, suggesting a contribution of memory. We also found evidence for slowing based on more than the immediately preceding stop signal. Post-stop-signal slowing was greater when stop signals occurred more frequently (Experiment 1), inconsistent with the surprise hypothesis, and when inhibition failed more frequently (Experiment 2). This suggests that more global manipulations encompassing many trials affect post-stop-signal adjustments.     

Turtles (Pseudemys nelsoni) learn about visual cues indicating food from experienced turtles

We investigated whether turtles (Pseudemys nelsoni) could learn about a visual object cue to obtain food reinforcement by observing conspecifics that had learned the task. This study was designed with a three part task which, if completed by the observer turtles, would provide evidence of their abilities to learn from other turtles using stimulus enhancement, goal emulation, or copying. All four P. nelsoni turtles tested after observation of a trained demonstrator, whom they had direct access to during the demonstrator training trials, learned not only to follow another turtle to the stimulus indicating food, but also, in the absence of the demonstrator, to approach the correct stimulus regardless of spatial position. Therefore, all four P. nelsoni turtles tested showed evidence of stimulus enhancement learning. This is the first experimental study of social learning in any aquatic reptile demonstrating that they have the ability to learn from conspecifics.     

Maternal and paternal plasma, salivary, and urinary oxytocin and parent-infant synchrony: considering stress and affiliation components of human bonding

Studies in mammals have implicated the neuropeptide oxytocin (OT) in processes of bond formation and stress modulation, yet the involvement of OT in human bonding throughout life remains poorly understood. We assessed OT in the plasma, saliva, and urine of 112 mothers and fathers interacting with their 4-6-month-old infants. Parent-infant interactions were micro-coded for parent and child's social behaviors and for the temporal coordination of their socio-affective cues. Parents were interviewed regarding their attachment to the infant and reported on bonding to own parents, romantic attachment, and parenting stress. Results indicated that OT in plasma (pOT) and saliva (sOT) were inter-related and were unrelated to OT in urine (uOT). pOT and sOT in mothers and fathers were associated with parent and child's social engagement, affect synchrony, and positive communicative sequences between parent and child. uOT was related to moments of interactive stress among mothers only, indexed by the co-occurrence of infant negative engagement and mother re-engagement attempts. pOT and sOT were associated with mothers' and fathers' attachment relationships throughout life: to own parents, partner, and infant, whereas uOT correlated with relationship anxiety and parenting stress among mothers only. Similar to other mammals, OT is involved in human attachment and contingent parenting. The dual role of OT in stress and affiliation underscores its complex involvement in processes of social bonding throughout life.     

Does the brain calculate value?

How do people choose between options? At one extreme, the 'value-first' view is that the brain computes the value of different options and simply favours options with higher values. An intermediate position, taken by many psychological models of judgment and decision making, is that values are computed but that the resulting choices depend heavily on the context of available options. At the other extreme, the 'comparison-only' view argues that choice depends directly on comparisons, with or even without any intermediate computation of value. In this paper, we place past and current psychological and neuroscientific theories on this spectrum, and review empirical data that have led to an increasing focus on comparison rather than value as the driver of choice.     

Understanding driver anger and aggression: attributional theory in the driving environment

Two studies tested the applicability of Weiner's (1995, 1996, 2001, 2006) attributional model of social conduct to roadway environments. This model highlights the role of inferences of responsibility after making causal judgments for social transgressions. Study 1 employed written scenarios where participants were asked to imagine themselves driving on a major highway. The degree of controllability and intentionality of the driving act was manipulated experimentally by altering the specific event-related details provided to the participants. Study 2 extended this research to life events by having participants complete online driving diaries every 2 days, identifying their most negative/upsetting encounter with another motorist. The most anger-provoking event was selected from among 4 diary entries and participants were asked to respond to a questionnaire similar to that used in Study 1. Path analyses in both studies generally supported predictions derived from Weiner's model; the association between perceived controllability, intentionality, and dispositional locus of causality of the negative driving event and subsequent anger was mediated by perceptions of responsibility. Additional results in Study 2 suggested that low perceived controllability, intentionality, and dispositional locus of causality were associated with reduced perceived responsibility, which, in turn, facilitated feelings of sympathy. Anger was associated with aggressive responses to the offending driver, whereas sympathy was associated with prosocial responses. Recommendations were offered for improved driver safety, including the development of attributional retraining programs to combat self-serving attributional biases, teaching novice drivers about both formal and informal roadway communication, and the promotion of forgiveness among drivers     

Songs as a medium for embedded reproductive messages

Research shows that sensational news stories as well as popular romance novels often feature themes related to important topics in evolutionary psychology. In the first of four studies described in this paper we examined the song lyrics from three Billboard charts: Country, Pop, and R&B. A content analysis of the lyrics revealed 18 reproductive themes that read like an outline for a course in evolutionary psychology. Approximately 92% of the 174 songs that made it into the Top Ten in 2009 contained one or more reproductive messages, with an average of 10.49 reproductive phrases per song. Although differences in the frequency of different themes between charts were found, further analyses showed that the most popular/bestselling songs contained significantly more reproductive messages. An analysis of the lyrics of opera arias and art songs also revealed evidence for many of the same embedded reproductive messages extending back more than 400 years.