Knowledge of object manipulation and object function: dissociations in apraxic and nonapraxic subjects

An influential account of selective semantic deficits posits that visual features are heavily weighted in the representations of animals, whereas information about function is central in the representations of tools (e.g., Warrington & Shallice, 1984 ). An alternative account proposes that information about all types of objects-animate and inanimate alike-is represented in a distributed semantic architecture by verbal-propositional, tactile, visual, and proprioceptive-motor nodes, reflecting the degree to which these systems were activated when the knowledge was acquired (e.g., Allport, 1985 ). We studied a group of left hemisphere chronic stroke patients, some of whom were apraxic, with measures of declarative tool and animal knowledge, body part knowledge, and function and manipulation knowledge of artifacts. Apraxic (n=7) and nonapraxic (n=6) subjects demonstrated a double dissociation of performance on tests of tool and animal knowledge, suggesting that the apraxic group was not simply more severely impaired overall. Apraxics were relatively impaired in manipulation knowledge, whereas nonapraxics tended to be relatively impaired in function knowledge. Apraxics were also more impaired with body parts than nonapraxics. The association of gestural praxis, tool knowledge, body part knowledge, and manipulation knowledge suggests a coherent basis for the organization of semantic artifact knowledge in frontoparietal cortical regions specialized for sensorimotor functions, and thus provides support for the distributed architecture account of the semantic system.     

The demands of an ongoing activity influence the success of event-based prospective memory

Four experiments were conducted to evaluate whether event-based prospective memory would be sensitive to the concurrent demands of the ongoing activity in which intention-related cues were embedded. In Experiments 1 and 2, random alternation between two judgments in the ongoing task reduced prospective memory as compared with having a single task throughout. In Experiment 3, participants' making two binary judgments on every trial resulted in worse prospective memory than did their making single four-alternative judgments. In Experiment 4, participants' making two related judgments resulted in better prospective memory than did their making two unrelated judgments. The results are consistent in spirit with a production rule account of the processing resources that are available when intention-related cues are encountered. Therefore, event-based prospective memory can inversely covary with the cognitive demands of the ongoing activity.     

Remembering Alexandra Symonds

The American Journal of Psychoanalysis -     

An examination of Euro-American and African-American differences in social physique anxiety among college women

Many studies have examined sex differences in social physique anxiety; however, few researchers have examined possible perceptual differences in such anxiety based on ethnicity. The present purpose was to examine social physique anxiety among college-age women of Euro-American and African-American descent. Participants (N = 91) from physical activity classes at a university located in the southeastern United States completed the Social Physique Anxiety Scale. The participants were 67 Euro-Americans and 24 African Americans. An independent t test yielded a significant difference (p =.01) between groups on Eklund's scale, which supports the hypothesis.     

Responding for sucrose and wheel-running reinforcement: effects of sucrose concentration and wheel-running reinforcer duration

Six male albino rats were placed in running wheels and exposed to a fixed-interval 30-s schedule of lever pressing that produced either a drop of sucrose solution or the opportunity to run for a fixed duration as reinforcers. Each reinforcer type was signaled by a different stimulus. In Experiment 1, the duration of running was held constant at 15 s while the concentration of sucrose solution was varied across values of 0, 2.5. 5, 10, and 15%. As concentration decreased, postreinforcement pause duration increased and local rates decreased in the presence of the stimulus signaling sucrose. Consequently, the difference between responding in the presence of stimuli signaling wheel-running and sucrose reinforcers diminished, and at 2.5%, response functions for the two reinforcers were similar. In Experiment 2, the concentration of sucrose solution was held constant at 15% while the duration of the opportunity to run was first varied across values of 15, 45, and 90 s then subsequently across values of 5, 10, and 15 s. As run duration increased, postreinforcement pause duration in the presence of the wheel-running stimulus increased and local rates increased then decreased. In summary, inhibitory aftereffects of previous reinforcers occurred when both sucrose concentration and run duration varied; changes in responding were attributable to changes in the excitatory value of the stimuli signaling the two reinforcers.     

Is car following the real question – are equations the answer?

Within the constraints that they set themselves, Brackstone, M. and McDonald, M. (Transportation Research: Part F (2000)), do a good job in elucidating the current state-of-the-art concerning car following models. Further, their protestation concerning the importance of such models in the light of growing intelligent transportation systems (ITS) technology and potential application in collision-warning and collision-avoidance systems is also undoubtedly correct. Also, as a member of the human factors expert panel cited (Intelligent Transportation Society of America. (1997). In Proceedings of the Intelligent Vehicle Initiative Human Factors Workshop. Washington DC: ITS America) it can be confirmed that normative models of driving remain a crucial unsolved issue. Thus, for these reasons their present review is both helpful and timely and deserves wide circulation. The points of contention do not concern their specific observations but rather the intrinsic assumptions upon which they are based. In particular, the question asked is, is car following the real question and equations the answer?     

“Girls Are as Good as Boys at Math” Implies That Boys Are Probably Better: A Study of Expressions of Gender Equality

Although “Girls are as good as boys at math” explicitly expresses equality, we predict it could nevertheless suggest that boys have more raw talent. In statements with this subject‐complement structure, the item in the complement position serves as the reference point and is thus considered more typical and prominent. This explains why “Tents are like houses,” for instance, sounds better than “Houses are like tents”—people generally think of houses as more typical. For domains about ability, the reference point should be the item that is typically more skilled. We further propose that the reference point should be naturally more skilled. In two experiments, we presented adults with summaries of actual scientific evidence for gender equality in math (Experiment 1) or verbal ability (Experiment 2), but we manipulated whether the reference point in the statements of equality in the summaries (e.g., “Boys’ verbal ability is as good as girls’”) was girls or boys. As predicted, adults attributed more natural ability to each gender when it was in the complement rather than subject position. Yet, in Experiment 3, we found that when explicitly asked, participants judged that such sentences were not biased in favor of either gender, indicating that subject‐complement statements must be transmitting this bias in a subtle way. Thus, statements such as “Girls are as good as boys at math” can actually backfire and perpetuate gender stereotypes about natural ability.     

Noise effects on human performance: a meta-analytic synthesis

Noise is a pervasive and influential source of stress. Whether through the acute effects of impulse noise or the chronic influence of prolonged exposure, the challenge of noise confronts many who must accomplish vital performance duties in its presence. Although noise has diffuse effects, which are shared in common with many other chronic forms of stress, it also exerts its own specific influences on various forms of cognitive and motor response. We present a quantitative evaluation of these influences so that their harmful effects can be mitigated, their beneficial effects exploited, and any residual effects incorporated and synthesized into selection, training, and design strategies to facilitate human performance capacities. Predictions of single and joint moderator effects were made on the basis of major theories of noise and performance, specifically those explanations based on arousal, masking, or cognitive-resource mechanisms. These predictions were tested through moderator analyses of effects as a function of task type, performance measure, noise type and schedule, and the intensity and duration of exposure. Observed outcome effects (797 effect sizes derived from 242 studies) varied as a function of each of these moderators. Collective findings identified continuous versus intermittent noise, noise type, and type of task as the major distinguishing characteristics that moderated response. Mixed evidence was obtained for the traditional arousal and masking explanations for noise effects. The overall pattern of findings was most consistent with the maximal adaptability theory, a mental-resource-based explanation of stress and performance variation.     

What factors underlie children’s susceptibility to semantic and phonological false memories? Investigating the roles of language skills and auditory short-term memory

Two experiments investigated the cognitive skills that underlie children’s susceptibility to semantic and phonological false memories in the Deese/Roediger–McDermott procedure ( and ). In Experiment 1, performance on the Verbal Similarities subtest of the British Ability Scales (BAS) II (Elliott, Smith, & McCulloch, 1997) predicted correct and false recall of semantic lures. In Experiment 2, performance on the Yopp–Singer Test of Phonemic Segmentation (Yopp, 1988) did not predict correct recall, but inversely predicted the false recall of phonological lures. Auditory short-term memory was a negative predictor of false recall in Experiment 1, but not in Experiment 2. The findings are discussed in terms of the formation of gist and verbatim traces as proposed by fuzzy trace theory (Reyna & Brainerd, 1998) and the increasing automaticity of associations as proposed by associative activation theory (Howe, Wimmer, Gagnon, & Plumpton, 2009).