Additive summation following intradimensional discrimination training

Rats were exposed to intradimensional composite stimuli presented on the response lever that varied in both light intensity and flicker rate. For all subjects, pressing the lever was reinforced when it was illuminated at a high intensity and flickered at a low rate (I + f) or when it was illuminated at a low intensity and flickered at a high rate (i + F). For half the subjects, lever responding was not reinforced when it was illuminated at a low intensity and flickering at a low rate (i + f). For the remaining subjects, lever presses were not reinforced when the lever was illuminated at a high intensity and flickered at a high rate (I + F). When the composite stimulus composed of the light intensity and flicker rates that had been associated only with reinforced responding was displayed (I + F for half the subjects and i + f for the remaining subjects), it controlled the highest response rate of all stimuli (additive summation). The results demonstrated that similar attentional processes control intra- and interdimensional composite-stimulus discriminations in a manner consistent with Weiss' (1972) analysis of summation.     

The fear potentiated startle effect. Blink reflex modulation as a result of classical aversive conditioning

A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.     

Does attention follow the motion in the "shooting line" illusion?

When a line is presented in the vicinity of a recent luminance change (peripheral cue), it is perceived to be drawn over time away from its "cued" end even though the line is actually presented all at once. This study was designed to determine whether attention, exogenously attracted to the cue, would come under the exogenous control of this illusory motion and follow the drawing motion from the cued end to its terminus. Each trial began with the display of four small squares at the corners of an imaginary square centered about fixation. On the critical trials, one of the four squares brightened briefly, after which a horizontal line was presented joining either the two upper or the two lower squares. Shortly thereafter, the distribution of attention was determined by asking the observer to indicate the nature of a change that was equally likely to occur to one of the squares. Responses to targets presented at a noncued location that was at the end of an illusorily drawn line were as fast as those to targets at the cued location and were much faster than those to targets at the remaining noncued locations. This pattern was not shown when the line preceded the cue, strongly suggesting that attention follows the motion in this illusion.     

Selection for encoding: No evidence of better endogenous orienting following forget than following remember instructions

In an item-method directed forgetting task, attentional resources are withdrawn from forget item processing (e.g., Taylor & Fawcett in Attention, Perception, & Psychophysics, 73, 1790–1814, 2011). Taylor and Hamm (Attention, Perception, & Psychophysics, 78, 168–186, 2016) demonstrated that there is no corresponding increase in the proclivity for exogenous attention to be captured following a forget instruction. This means either that the attentional resources withdrawn from the forget item are reallocated immediately (and therefore not especially vulnerable to capture) or that it is not exogenous attention that is withdrawn. Given that endogenous attention is distinct from exogenous attention, we therefore extended the Taylor and Hamm study by using endogenous orienting rather than exogenous orienting. Words appeared individually in a peripheral location (Exp. 1) or in a central location (Exp. 2), followed by an instruction to either remember or forget. After a short (50-ms) or long (250-ms) interstimulus interval (ISI), a central cue (80% accurate) directed participants to allocate their attention to the left or right. This was followed by a discrimination target that appeared at a 1,000-ms cue–target stimulus onset asynchrony. A subsequent yes–no recognition test assessed memory for all study items. In both experiments, we observed better recognition of remember words than forget words—a directed forgetting effect. We also found a cueing effect, revealed as faster reaction times to discriminate cued targets than to discriminate uncued targets. There was not, however, an effect of memory instruction (and/or instruction–cue ISI) on the magnitude of this cueing effect. Thus, neither exogenous attention nor endogenous attention remains in an unengaged state following an instruction to forget.     

Volition and the idle cortex: beta oscillatory activity preceding planned and spontaneous movement

Prior to the initiation of spontaneous movement, evoked potentials can be seen to precede awareness of the impending movement by several hundreds of milliseconds, meaning that this recorded neural activity is the result of unconscious processing. This study investigates the neural representations of impending movement with and without awareness. Specifically, the relationship between awareness and 'idling' cortical oscillations in the beta range (18-24Hz) was assessed. It was found that, in situations where there was awareness of the impending movement, pre-movement evoked potentials were associated with a decrease in beta range oscillations. In contrast, when awareness of the impending movement was not present, the onset of the pre-movement potential was associated with tonic levels of beta range oscillations. A model is considered where by distributed neural activity remains outside of conscious awareness through the persistence of tonic slow wave cortical oscillations.     

Family Empowerment as a Mediator between Family-Centered Systems of Care and Changes in Child Functioning: Identifying an Important Mechanism of Change

We investigated the associations among perceived fidelity to family-centered systems of care, family empowerment, and improvements in children's problem behaviors. Participants included 79 families, interviewed at two time points across a one-year period. Paired samples t-tests indicated that problem behaviors decreased significantly across a one-year period. Hierarchical multiple regressions indicated that both fidelity to family-centered systems of care and family empowerment independently predicted positive change in children's problem behavior over a one-year period. However, when family empowerment is entered first in the regression, the relationship between fidelity to family-centered systems of care and change in children's problem behavior drops out, indicating that family empowerment mediates the relationship between family-centered care and positive changes in problem behaviors. Consistent with other literature on help-giving practices, family empowerment appears to be an important mechanism of change within the system of care philosophy of service delivery. Implications for practice and staff training are discussed.     

Depression, constructive thinking and patient satisfaction in cardiac treatment adherence

Many patients fail to adhere to prescribed treatment regimens, particularly patients who are depressed. This study examined the link between depression and adherence among 92 patients undergoing post-operative cardiac rehabilitation. Self-reported adherence was measured in terms of both general recommendations and specific health behaviours. Greater depression was associated with general - but not specific - adherence, and this relationship was mediated by lower satisfaction with their doctor - patient interactions. The link between depression and patient satisfaction was itself mediated by less constructive thinking among patients. These results suggest that adherence among cardiac rehabilitation patients may be enhanced by addressing patients' cognitive coping, and by improving the quality of their doctor - patient interactions.     

Effects of memory instruction on attention and information processing: Further investigation of inhibition of return in item-method directed forgetting

In the item-method directed-forgetting paradigm, the magnitude of inhibition of return (IOR) is larger after an instruction to forget (F) than after an instruction to remember (R). In the present experiments, we further investigated this increased magnitude of IOR after F as compared to R memory instructions (dubbed the F > R IOR difference), in order to understand both the consequences for information processing and the purpose of the differential withdrawal of attention that results in this difference. Words were presented in one of four peripheral locations, followed by either an F or an R memory instruction. Then, a target appeared in either the same location as the previous word or one of the other locations. The results showed that the F > R IOR difference cannot be explained by attentional momentum (Exp. 1), that the spatial compatibility of the response options with target locations is not necessary for the F > R IOR difference to emerge (Exp. 2), and that the F > R IOR difference is location-specific rather than response-specific (Exp. 3). These results are consistent with the view that F > R IOR represents a bias against responding to information emanating from an unreliable source (Taylor & Fawcett, 2011).     

U.S. ethnic minorities' attitudes towards Whites: The role of shared reality theory in intergroup relations

In the current research, we suggest that shared reality, the belief that one perceives the world the same way as another group, can predict attitudes towards that group. We tested shared reality theory in the context of American ethnic minority groups' (i.e., African Americans, Asian Americans, and Latinas/os) attitudes towards White Americans. In surveys of two samples recruited from different geographical locations in the USA, we tested predictions derived from different theories of intergroup relations. Using mediational analysis, we defined models to assess the extent to which shared reality theory predicted—directly and indirectly—prejudicial attitudes towards Whites. We tested the model derived from shared reality theory against other theoretical alternatives. Taken together, the results of the research indicated that shared reality predicts attitudes towards White Americans among these three ethnic groups. Thus, shared reality is a relevant, though largely overlooked, factor in intergroup dynamics.