The subjective quality of episodic future thought and the experience of meaning in life

Two studies assessed whether mentally simulating specific future events to occur in familiar (vs. unfamiliar) settings indirectly increases meaning life via the subjective quality of the simulations. Participants in both studies (N = 344) were randomly assigned to visualize themselves doing something in familiar (e.g. home) or unfamiliar (e.g. fantasy world) settings in the future. They then rated the subjective quality of these visualizations and completed a measure of meaning in life. We replicated previous findings by showing that mental simulations involving familiar settings were of greater subjective quality than simulations involving unfamiliar settings. However, we also found that simulating future events in familiar (vs. unfamiliar) settings indirectly increased the perceived meaningfulness of life. These findings integrate research in cognitive psychology with research on the psychology of well-being and reveal how mental time travel contributes to the perception that one’s life has meaning.     

Numerical Subtraction in the Pigeon: Evidence for a Linear Subjective Number Scale

When humans and animals compare two numbers, responding is faster and more accurate with increasing numerical disparity and decreasing numerical size. Researchers explaining these distance and size effects often assume that the subjective number continuum is logarithmically compressed. An alternative hypothesis is that the subjective number continuum is linear, but positions farther along it are proportionately fuzzier, that is, less precisely located. These two hypotheses have been treated as functionally equivalent because of their similar empirical predictions. The current experiment sought to resolve this issue with a paradigm originally developed to address the subjective representation of time (time left). In our adaptation, pigeons were required to compare a constant number with the number remaining after a numerical subtraction. Our results indicate that subjective number is linearly, not logarithmically, related to objective number.     

Binding serial order to representations in working memory: a spatial/verbal dissociation

Verbal information is coded naturally as ordered representations in working memory (WM). However, this may not be true for spatial information. Accordingly, we used memory span tasks to test the hypothesis that serial order is more readily bound to verbal than to spatial representations. Removing serial-order requirements improved performance more for spatial locations than for digits. Furthermore, serial order was freely reproduced twice as frequently for digits as for locations. When participants reordered spatial sequences, they minimized the mean distance between items. Participants also failed to detect changes in serial order more frequently for spatial than for verbal sequences. These results provide converging evidence for a dissociation in the binding of serial order to spatial versus verbal representations. There may be separable domain-specific control processes responsible for this binding. Alternatively, there may be fundamental differences in how effectively temporal information can be bound to different types of stimulus features in WM.     

Further evaluation of response interruption and redirection as treatment for stereotypy

The effects of 2 forms of response interruption and redirection (RIRD)-motor RIRD and vocal RIRD-were examined with 4 boys with autism to evaluate further the effects of this intervention and its potential underlying mechanisms. In Experiment 1, the effects of motor RIRD and vocal RIRD on vocal stereotypy and appropriate vocalizations were compared for 2 participants. In Experiment 2, the effects of both RIRD procedures on both vocal and motor stereotypy and appropriate vocalizations were compared with 2 additional participants. Results suggested that RIRD was effective regardless of the procedural variation or topography of stereotypy and that vocal RIRD functioned as a punisher. This mechanism was further explored with 1 participant by manipulating the schedule of RIRD in Experiment 3. Results were consistent with the punishment interpretation.     

Strategies adopted by late middle-age and older adults with HIV/AIDS to explain their physical symptoms

Although the attributions individuals make about what causes their physical symptoms are known to influence their care seeking and self-care behaviours, much less is known about the strategies they use to arrive at these attributions. The strategies employed to understand the causes of their symptoms were investigated using in-depth interviews with 100 late middle-age and older adults with HIV/AIDS in New York City. The data revealed that most participants actively sought to explain their symptoms. The explanatory strategies identified included: relying upon illness or medication representations, lay beliefs about the body and ageing, invoking pre-existing vulnerabilities, engaging in lay experimentation, social comparison processes, considering temporal ordering and consulting authoritative sources. While most of them offered a single cause for their symptoms, some offered more complex multi-causal explanations. These findings provide understanding into the reasons why some older adults with HIV/AIDS misattribute symptoms resulting in delay in care or care over-utilisation, suggesting the need for patient education.     

Confirmatory Analyses of the School Refusal Assessment Scale-Revised: Replication and Extension to a Truancy Sample

School absenteeism and school refusal behavior are prevalent and serious issues for youth, but few measures have been developed specifically for this population. The School Refusal Assessment Scale-Revised (child and parent versions) provides clinicians with a profile of the relative strength of four functions or maintaining variables regarding school refusal behavior. The scales have been previously tested largely on clinical samples in outpatient treatment settings, however. This study examined 216 youth with primary school refusal behavior and their parent/guardian referred to a community-based truancy court or truancy diversion setting for problematic absenteeism. The four-factor structure of the scales (Kearney Journal of Psychopathology and Behavioral Assessment 24:235–245, 2002a; Journal of Psychopathology and Behavioral Assessment 28:139–144, 2006) was supported via confirmatory factor analysis and specific functions were associated with specific symptom sets as predicted. The results help extend the generalizability of the scales to youths and their families who are more ethnically diverse and referred to a legal process.     

Object recognition in Williams syndrome: uneven ventral stream activation

Williams syndrome (WS) is a genetic disorder associated with severe visuospatial deficits, relatively strong language skills, heightened social interest, and increased attention to faces. On the basis of the visuospatial deficits, this disorder has been characterized primarily as a deficit of the dorsal stream, the occipitoparietal brain regions that subserve visuospatial processing. However, some evidence indicates that this disorder may also affect the development of the ventral stream, the occipitotemporal cortical regions that subserve face and object recognition. The present studies examined ventral stream function in WS, with the hypothesis that faces would produce a relatively more mature pattern of ventral occipitotemporal activation, relative to other objects that are also represented across these visual areas. Using functional magnetic imaging, we compared activation patterns during viewing of human faces, cat faces, houses and shoes in individuals with WS (age 14-27), typically developing 6-9-year-olds (matched approximately on mental age), and typically developing 14-26-year-olds (matched on chronological age). Typically developing individuals exhibited changes in the pattern of activation over age, consistent with previous reports. The ventral stream topography of individuals with WS differed from both control groups, however, reflecting the same level of activation to face stimuli as chronological age matches, but less activation to house stimuli than either mental age or chronological age matches. We discuss the possible causes of this unusual topography and implications for understanding the behavioral profile of people with WS.     

Telling the right hand from the left hand: multisensory integration, not motor imagery, solves the problem

Judging the laterality of a hand seen at unanticipated orientations evokes a robust feeling of bodily movement, even though no movement is produced. In two experiments, we tested a novel hypothesis to explain this phenomenon: A hand's laterality is determined via a multisensory binding of the visual representation of the seen hand and a proprioceptive representation of the observer's felt hand, and the felt "movement" is an obligatory aftereffect of intersensory recalibration. Consistent with the predictions implied by such a cross-modal mechanism, our results in Experiment 1 showed that manipulating observers' selective attention can evoke illusory feelings of movement in the "wrong" hand (i.e., the hand whose laterality does not match that of the stimulus). In Experiment 2, these illusions were readily extinguished in conditions in which binding was predicted to fail, a result indicating that cross-modal binding was necessary to produce them. These results are not explained by imagery, a mechanism widely assumed to account for how hand laterality is identified.     

Myosin II motor activity in the lateral amygdala is required for fear memory consolidation

Learning induces dynamic changes to the actin cytoskeleton that are required to support memory formation. However, the molecular mechanisms that mediate filamentous actin (F-actin) dynamics during learning and memory are poorly understood. Myosin II motors are highly expressed in actin-rich growth structures including dendritic spines, and we have recently shown that these molecular machines mobilize F-actin in response to synaptic stimulation and learning in the hippocampus. In this study, we report that Myosin II motors in the rat lateral amygdala (LA) are essential for fear memory formation. Pretraining infusions of the Myosin II inhibitor, blebbistatin (blebb), disrupted long term memory, while short term memory was unaffected. Interestingly, both post-training and pretesting infusions had no effect on memory formation, indicating that Myosin II motors operate during or shortly after learning to promote memory consolidation. These data support the idea that Myosin II motor-force generation is a general mechanism that supports memory consolidation in the mammalian CNS.