Grouping has a negative effect on both subjective contours and perceived occlusion at T-junctions

Perceived occlusion of aligned T-junctions and subjective contours at implicit T-junctions are often assumed to be related but are rarely examined with respect to common mechanisms. Using the method of paired comparison, we measured the strength of perceived occlusion at explicit T-junctions and the strength of subjective contours at implicit T-junctions (using different subjects) along the aligned edges of eight sets of inducer shapes. Sets varied in the similarity of component shapes with respect to orientation, height, width, and color. With increasing shape similarity, there was a striking decrease in both the strength of subjective contours and the strength of perceived occlusion; the correlation between these two kinds of judgments was .97. We conclude that common mechanisms underlie these two percepts and that edge alignment is a much stronger indicator of occlusion for poorly grouped than for strongly grouped inducers.     

Control of saccades in Parkinson's disease

Parkinson's patients (PD) made pro- and antisaccades: In the no-delay condition, the target appeared concurrent with the GO signal. In the delay condition, the target appeared before the signal for movement. Second, we probed spatial working memory in PD. Subjects looked to the remembered locations of sequential targets. In the no-delay prosaccade condition, PD had faster reaction times, made more express saccades, and exhibited hypometria. In the no-delay antisaccade condition, PD had longer reaction times and made more direction errors. In the delay tasks, PD made more direction errors and had more difficulty withholding a movement. PD made more sequencing errors in the spatial working memory task. These findings are consistent with a basal ganglia pathophysiology influencing eye movement processing in the frontal cortex.     

Effects of the testing situation on item responding: cause for concern

The effects of faking on personality test scores have been studied previously by comparing (a) experimental groups instructed to fake or answer honestly, (b) subgroups created from a single sample of applicants or nonapplicants by using impression management scores, and (c) job applicants and nonapplicants. In this investigation, the latter 2 methods were used to study the effects of faking on the functioning of the items and scales of the Sixteen Personality Factor Questionnaire. A variety of item response theory methods were used to detect differential item/test functioning, interpreted as evidence of faking. The presence of differential item/test functioning across testing situations suggests that faking adversely affects the construct validity of personality scales and that it is problematic to study faking by comparing groups defined by impression management scores.     

Listening back in time: Does attention to memory facilitate word-in-noise identification?

The ephemeral nature of spoken words creates a challenge for oral communications where incoming speech sounds must be processed in relation to representations of just-perceived sounds stored in short-term memory. This can be particularly taxing in noisy environments where perception of speech is often impaired or initially incorrect. Usage of prior contextual information (e.g., a semantically related word) has been shown to improve speech in noise identification. In three experiments, we demonstrate a comparable effect of a semantically related cue word placed after an energetically masked target word in improving accuracy of target-word identification. This effect persisted irrespective of cue modality (visual or auditory cue word) and, in the case of cues after the target, lasted even when the cue word was presented up to 4 seconds after the target. The results are framed in the context of an attention to memory model that seeks to explain the cognitive and neural mechanisms behind processing of items in auditory memory.     

The Impact of Breast Cancer Genetic Risk Assessment on Intentions to Perform Cancer Surveillance Behaviors

One hundred and fifty-four women undergoing breast/ovarian cancer genetic risk assessment completed questionnaires at entry into the Cancer Genetic Service for Wales (CGSW) assessment program and following risk provision, mapping the strength of intentions to engage in a number of preventive/surveillance behaviors, including seeing specialists, breast self-examination, and involvement in screening programs, including mammography. A number of potential predictors of intentions were also assessed, including participants' mood and emotional response to receiving risk information, the perceived benefits (in terms of reassurance and early disease detection) of engaging in each preventive behavior, and the perceived desires of their family and General Practitioner. Intentions to self-examine did not change following risk provision, although strength of intentions to engage in some other preventive behaviors did lessen. Family and General Practitioners appeared to be strong social influences on behavioral intentions, as were the perceived benefits of gaining reassurance and/or early detection of disease.     

The effects of frontal lobe functioning and age on veridical and false recall

Washington University, St. Louis, Missouri Older adults’ heightened susceptibility to false memories has been linked to compromised frontal lobe functioning as estimated by Glisky and colleagues’ (Glisky, Polster, & Routhieaux, 1995) neuropsychological battery (e.g., Butler, McDaniel, Dornburg, Price, & Roediger, 2004). This conclusion, however, rests on the untested assumption that young adults have uniformly high frontal functioning. We tested this assumption, and we correlated younger and older adults’ frontal scores with veridical and false recall probabilities with prose materials. Substantial variability in scores on the Glisky battery occurred for younger (and older) adults. However, frontal scores and age were independent contributors to recall probabilities. Frontal functioning is not the sole cause of older adults’ heightened susceptibility to false memories.     

Alpha3-integrins are required for hippocampal long-term potentiation and working memory

Integrins comprise a large family of heterodimeric, transmembrane cell adhesion receptors that mediate diverse neuronal functions in the developing and adult CNS. Recent pharmacological and genetic studies have suggested that beta1-integrins are critical in synaptic plasticity and memory formation. To further define the role of integrins in these processes, we generated a postnatal forebrain and excitatory neuron-specific knockout of alpha3-integrin, one of several binding partners for beta1 subunit. At hippocampal Schaffer collateral-CA1 synapses, deletion of alpha3-integrin resulted in impaired long-term potentiation (LTP). Basal synaptic transmission and paired-pulse facilitation were normal in the absence of alpha3-integrin. Behavioral studies demonstrated that the mutant mice were selectively defective in a hippocampus-dependent, nonmatch-to-place working memory task, but were normal in other hippocampus-dependent spatial tasks. The impairment in LTP and working memory is similar to that observed in beta1-integrin conditional knockout mice, suggesting that alpha3-integrin is the functional binding partner for beta1 for these processes in the forebrain.     

注意捕获的另一扇窗户——无意视盲

观察者集中注意于某个物体或事件的时候,他们经常不能觉察到显著的、与众不同的物体,这种现象被称为“无意视盲”（Inattentional Blindness）。在无意视盲研究中,存在两类实验范式——静态无意视盲和动态无意视盲研究范式。首先,从刺激的感觉显著性、认知显著性、心理工作负荷、定势和期望以及加工能力等方面分析了影响无意视盲的因素;其次,对无意视盲和无意遗忘的争议以及无意视盲是“全或无”还是连续谱的争议也进行了总结;最后,从无意视盲角度出发探讨了内隐注意捕获和外显注意捕获之间的关系