Parents’ Understanding of Genetics and Heritability

Parents have the opportunity to educate their children to facilitate behaviours and lifestyle habits that may prevent or delay genetic disease, or mitigate predispositions within the family. We sought to determine parents’ understanding of genetic knowledge and heritability. Using a quantitative survey methodology 108 volunteer participants were surveyed from a convenience sample of all parents/caregivers within the waiting room of a general children’s outpatient clinic. Results indicated that average genetic knowledge levels were fairly high, with the majority of participants scoring 70–80 % correct on knowledge-based questions. Further, scores were found to be positively correlated with education, but inversely correlated with self-perceived knowledge. This finding suggests that participants with less experience tended to overestimate their knowledge. We suggest that gaps in knowledge of genetics and heritability could be improved by using educational interventions such as media campaigns, provision of informational brochures, or changes to current high school curriculum which would increase exposure to genetics and heritability for both parents and children.     

AMPA receptor endocytosis in rat perirhinal cortex underlies retrieval of object memory

Mechanisms consistent with long-term depression in the perirhinal cortex (PRh) play a fundamental role in object recognition memory; however, whether AMPA receptor endocytosis is involved in distinct phases of recognition memory is not known. To address this question, we used local PRh infusions of the cell membrane-permeable Tat-GluA2(3Y) interference peptide or a scrambled control to block the endocytosis of AMPA receptors during the encoding, consolidation, or retrieval phase of object recognition memory. Tat-GluA2(3Y) infusion before the encoding and consolidation phases did not alter recognition memory. In contrast, Tat-GluA2(3Y) infusion prior to the retrieval phase disrupted object recognition memory. The present results indicate a distinct role for AMPA receptor endocytosis in the retrieval of visual recognition memory.     

The importance of response type to the relationship between temporal order and numerical magnitude

Time, number, and space may be represented in the brain by a common set of cognitive/neural mechanisms. In support of this conjecture, Schwarz and Eiselt (Journal of Experimental Psychology: Human Perception and Performance, 35, 989-1004, 2009) found that numerically smaller digits were perceived to occur earlier than larger digits, and they concluded that this difference reflected faster processing of smaller numbers. This difference, however, could have been related to a response bias, whereby participants map responses of "which first" onto the "first" number along the mental number line. In Experiment 1, participants made temporal order judgements between digits presented to the left or to the right. The point of subjective simultaneity was shifted so that the 9 had to be presented before the 2 in order for simultaneity to be perceived. This difference could reflect either faster processing of the 2 or a response bias. Experiments 2a and 2b eliminated response biases by using simultaneity judgements, which have no logical stimulus mapping. Both of the latter experiments established that the 2 was not processed faster than the 9. Although the present results relate specifically to numerical magnitude and temporal order associations, they also have broader implications. Other studies have reported associations between dimensions such as size, duration, and number and have attributed these to parietal mechanisms. Such associations, however, may also be an artefact of response biases.     

Somatosensory prior entry assessed with temporal order judgments and simultaneity judgments

Attention is central to perception, yet a clear understanding of how attention influences the latency of perception has proven surprisingly elusive. Recent research has indicated that spatially attended stimuli are perceived earlier than unattended stimuli across a range of sensory modalities-an effect termed prior entry. However, the method commonly used to measure this, the temporal order judgment (TOJ) task, has been criticized as susceptible to response bias, despite deliberate attempts to minimize such bias. A preferred alternative is the simultaneity judgment (SJ) task. We tested the prior-entry hypothesis for somatosensory stimuli using both a TOJ task (replicating an earlier experiment) and an SJ task. Prior-entry effects were found for both, though the effect was reduced in the SJ task. Additional experiments (TOJ and SJ) using visual cues established that the earlier perception of cued tactile targets does not result from intramodal sensory interactions between tactile cues and targets.     

Evaluation of the immediate and subsequent effects of response interruption and redirection on vocal stereotypy

We evaluated 2 3-component multiple-schedule sequences-a response interruption and redirection (RIRD) treatment sequence and a no-interaction control sequence-using a multielement design. With this design, we were able to evaluate the immediate and subsequent effects of RIRD on 2 participants' vocal stereotypy. For both participants, RIRD produced an immediate decrease in vocal stereotypy and did not result in a subsequent increase.     

Feasibility and Preliminary Outcomes of a School-Based Mindfulness Intervention for Urban Youth

Youth in underserved, urban communities are at risk for a range of negative outcomes related to stress, including social-emotional difficulties, behavior problems, and poor academic performance. Mindfulness-based approaches may improve adjustment among chronically stressed and disadvantaged youth by enhancing self-regulatory capacities. This paper reports findings from a pilot randomized controlled trial assessing the feasibility, acceptability, and preliminary outcomes of a school-based mindfulness and yoga intervention. Four urban public schools were randomized to an intervention or wait-list control condition (n = 97 fourth and fifth graders, 60.8% female). It was hypothesized that the 12-week intervention would reduce involuntary stress responses and improve mental health outcomes and social adjustment. Stress responses, depressive symptoms, and peer relations were assessed at baseline and post-intervention. Findings suggest the intervention was attractive to students, teachers, and school administrators and that it had a positive impact on problematic responses to stress including rumination, intrusive thoughts, and emotional arousal.     

Activation of the infralimbic cortex in a fear context enhances extinction learning

Activation of the infralimbic region (IL) of the medial prefrontal cortex (mPFC) reduces conditioned fear in a variety of situations, and the IL is thought to play an important role in the extinction of conditioned fear. Here we report a series of experiments using contextual fear conditioning in which the IL is activated with the GABAa antagonist picrotoxin (Ptx) during a single extinction session in the fear context. We investigate the impact of this manipulation on subsequent extinction sessions in which Ptx is no longer present. First, we demonstrate that a single treatment with intra-IL Ptx administered in a conditioned fear context greatly accelerates the rate of extinction on the following days. Importantly, IL-Ptx also enhances extinction to a different fear context than the one in which IL-Ptx was administered. Thus, IL-Ptx primes extinction learning regardless of the fear context in which the IL was initially activated. Second, activation of the IL must occur in conjunction with a fear context in order to enhance extinction; the extinction enhancing effect is not observable if IL-Ptx is administered in a neutral context. Finally, this extinction enhancing effect is specific to the IL for it does not occur if Ptx is injected into the prelimbic region (PL) of the mPFC. The results indicate a novel persisting control of fear induced by activation of the IL and suggest that IL activation induces changes in extinction-related circuitry that prime extinction learning.     

Rightward collisions and their association with pseudoneglect

Whereas right parietal damage can result in left hemineglect, the general population shows a subtle neglect of the right hemispace-known as pseudoneglect. A recent study has demonstrated that people collide to the right more often and attributed this bias to pseudoneglect. [Nicholls, M. E. R., Loftus, A., Meyer, K., & Mattingley, J.B. (2007). Things that go bump in the right: The effect of unimanual activity on rightward collisions. Neuropsychologia, 45, 1122-1126]. Nicholls examined the effect of unimanual activation by requiring participants to fire projectiles at a target whilst walking and found that the rightward bias was exaggerated or reversed when the left and right hands were active, respectively. However, the act of aiming at a target may have inadvertently biased walking trajectory to the right. The current study addressed this issue by requiring participants (n=149) to walk through a narrow doorway three times whilst entering text into a phone using the (a) left, (b) right or (c) both hands. Despite the fact that entering text into a phone should produce no rightward bias, participants bumped to the right more often. Unlike previous research, no effect of unimanual activation was observed. This lack of effect was attributed to the smaller hand movements for entering numbers compared to firing a toy gun. Finally, this study showed an association for the first time between biases in observable bumping and line bisection performance-suggesting that unilateral bumping is related to pseudoneglect.     

Pseudoneglect for the bisection of mental number lines

Patients with unilateral neglect of the left side bisect physical lines to the right whereas individuals with an intact brain bisect lines slightly to the left (pseudoneglect). Similarly, for mental number lines, which are arranged in a left-to-right ascending sequence, neglect patients bisect to the right. This study determined whether individuals with an intact brain show pseudoneglect for mental number lines. In Experiment 1, participants were presented with visual number triplets (e.g., 16, 36, 55) and determined whether the numerical distance was greater on the left or right side of the inner number. Despite changing the spatial configuration of the stimuli, or their temporal order, the numerical length on the left was consistently overestimated. The fact that the bias was unaffected by physical stimulus changes demonstrates that the bias is based on a mental representation. The leftward bias was also observed for sets of negative numbers (Experiment 2)--demonstrating not only that the number line extends into negative space but also that the bias is not the result of an arithmetic distortion caused by logarithmic scaling. The leftward bias could be caused by a rounding-down effect. Using numbers that were prone to large or small rounding-down errors, Experiment 3 showed no effect of rounding down. The task demands were changed in Experiment 4 so that participants determined whether the inner number was the true arithmetic centre or not. Participants mistook inner numbers shifted to the left to be the true numerical centre--reflecting leftward overestimation. The task was applied to 3 patients with right parietal damage with severe, moderate, or no spatial neglect (Experiment 5). A rightward bias was observed, which depended on the severity of neglect symptoms. Together, the data demonstrate a reliable and robust leftward bias for mental number line bisection, which reverses in clinical neglect. The bias mirrors pseudoneglect for physical lines and most likely reflects an expansion of the space occupied by lower numbers on the left side of the line and a contraction of space for higher numbers located on the right.     

Somatosensory prior entry

The perceived timing of sensory events does not necessarily match the actual timing. In the present study, we investigated the effect of location of attention on the perceived timing of somatosensory stimuli. Participants judged the temporal order of two taps, delivered one to each hand, with taps presented at different elevations (upper and lower) on the opposing hands. The task was to discriminate the elevation of the tap presented first (or second). This vertical discrimination task was orthogonal to the horizontal attentional cuing manipulation, removing the response bias confound that has undermined earlier studies investigating the impact of attention on the perceived timing of sensory stimuli. We manipulated spatial attention either (1) exogenously (Experiment 1) in 13 participants, using brief taps to either the left or right hand, or (2) endogenously (Experiment 2) in 22 participants, using centrally presented symbolic cues. The results supported the hypothesis that attended stimuli are perceived more rapidly than unattended stimuli. This effect was larger when attention was exogenously manipulated. Previous research has demonstrated a similar effect for visual stimuli. The present study, which extends this result to somatosensory perception, indicates that the phenomenon may represent a more global feature of the perceptual system, which is possibly mediated by a common modality-independent mechanism.