Out of sight,out of mind? Relations between visual acuity and cognition

Prior research has established significant relations between measures of sensory ability and cognitive function in adults of different ages, and several explanations for this relation have been proposed. One explanation is that sensory abilities restrict cognitive processing, a second is that cognitive abilities influence assessments of sensory ability, and a third is that both sensory function and cognition are affected by a common, potentially age-based, third factor. These explanations were investigated using mediation and moderation analyses, with near visual acuity as the sensory measure and scores on visual speed tests and auditory memory tests as the cognitive measures. Measures of visual acuity, speed, and memory were obtained from three moderately large samples, two cross-sectional (N?=?380, N?=?4,779) and one longitudinal (N?=?2,258), with participants ranging from 18 to 90 years of age. The visual acuity and cognitive measures had different age trajectories, and the visual acuity–cognition relations were similar in each 5-year age band. The results suggest that the age-related differences and changes in near visual acuity are unlikely to contribute to the age-related differences and changes in speed and memory measures.     

Attention switching and working memory spans

Barrouillet and Camos () concluded from their developmental study on working memory that when performing complex span tasks, individuals maintain memory items by switching rapidly their attention from processing to storage while performing the concurrent task. Thus, a processing component that would require a continuous attentional focusing should have a highly detrimental effect on span. The present study verifies two predictions issuing from this hypothesis by comparing the classical self‐paced reading and operation span tasks with new computer‐paced tasks in adults. First, any increase in the pace at which the processing component of a working memory span task has to be performed impedes switching and then leads to lower spans. Second, when presented at a fast pace, even simple activities such as reading letters or adding and subtracting 1 to small numbers have an effect on spans as detrimental as complex activities like reading and understanding sentences or solving complex equations.     

Submovement Organization,Pen Pressure,and Muscle Activity Are Modulated to Precision Demands in 2D Tracking

The authors investigated how tracking performance, submovement organization, pen pressure and muscle activity in forearm and shoulder muscles were affected by target size in a 2D tracking task performed with a pen on a digitizer tablet. Twenty-six subjects took part in an experiment, in which either a small dot or a large dot was tracked, while it moved quasirandomly across a computer screen at a constant velocity of 2 cm/s. The manipulation of precision level was successful, because mean distance to target and the standard deviation of this distance were significantly smaller with the small target than with the large target. With a small target, subjects trailed more behind the center of target and used submovements with larger amplitudes and of shorter duration, resulting in higher tracking accuracy. This change in submovement organization was accompanied by higher pen pressure, while at the same time muscle activity in the forearm extensors and flexors was increased, indicating higher endpoint stability. In conclusion, increased precision demands were accommodated by both a different organization of submovements and higher endpoint stability in a 2D tracking task performed with a pen on a digitizer tablet.     

Guilt by association and honor by association: The role of acquired equivalence

Guilt by association and honor by association are two types of judgments that suggest that a negative or positive quality of a person or object can transfer to another person or object, merely by co-occurrence. Most examples have been demonstrated under conditions of direct associations. Here, we provide experimental evidence of guilt by association and honor by association via indirect associations. We show that participants may treat two individuals alike if they have been separately paired with a common event using an acquired-equivalence paradigm. Our findings suggest that association fallacies can be examined using a paradigm originally developed for research with nonhuman animals and based on a representation mediation account.     

Relative category-specific preservation in semantic dementia? Evidence from 35 cases

Category-specific deficits have rarely been reported in semantic dementia (SD). To our knowledge, only four previous studies have documented category-specific deficits, and these have focused on the living versus non-living things contrast rather than on more fine-grained semantic categories. This study aimed to determine whether a category-specific effect could be highlighted by a semantic sorting task administered to 35 SD patients once at baseline and again after 2 years and to 10 Alzheimer’s disease patients (AD). We found a relative preservation of fruit and vegetables only in SD.This relative preservation of fruit and vegetables could be considered with regard to the importance of color knowledge in their discrimination. Indeed, color knowledge retrieval is known to depend on the left posterior fusiform gyrus which is relatively spared in SD. Finally, according to predictions of semantic memory models, our findings best fitted the Devlin and Gonnerman’s computational account.     

Olive baboons communicate intentionally by pointing

A pointing gesture creates a referential triangle that incorporates distant objects into the relationship between the signaller and the gesture’s recipient. Pointing was long assumed to be specific to our species. However, recent reports have shown that pointing emerges spontaneously in captive chimpanzees and can be learned by monkeys. Studies have demonstrated that both human children and great apes use manual gestures (e.g. pointing), and visual and vocal signals, to communicate intentionally about out-of-reach objects. Our study looked at how monkeys understand and use their learned pointing behaviour, asking whether it is a conditioned, reinforcement-dependent response or whether monkeys understand it to be a mechanism for manipulating the attention of a partner (e.g. a human). We tested nine baboons that had been trained to exhibit pointing, using operant conditioning. More specifically, we investigated their ability to communicate intentionally about the location of an unreachable food reward in three contexts that differed according to the human partner’s attentional state. In each context, we quantified the frequency of communicative behaviour (auditory and visual signals), including gestures and gaze alternations between the distal food and the human partner. We found that the baboons were able to modulate their manual and visual communicative signals as a function of the experimenter’s attentional state. These findings indicate that monkeys can intentionally produce pointing gestures and understand that a human recipient must be looking at the pointing gesture for them to perform their attention-directing actions. The referential and intentional nature of baboons’ communicative signalling is discussed.     

The Carnales

Once, and only once, I had to fight for my life. The experience catapulted me to an edge of my being that I am glad to have found but don't want to visit too often–an edge others may seek by climbing a glacier, trekking in Nepal, or fasting for a week to induce visions. I am not a thrill-seeker, but a lazy quester content to make do with the ample shocks life has brought me unsought.     

Deliberation, cognitive diversity, and democratic inclusiveness: an epistemic argument for the random selection of representatives

This paper argues in favor of the epistemic properties of inclusiveness in the context of democratic deliberative assemblies and derives the implications of this argument in terms of the epistemically superior mode of selection of representatives. The paper makes the general case that, all other things being equal and under some reasonable assumptions, more is smarter. When applied to deliberative assemblies of representatives, where there is an upper limit to the number of people that can be included in the group, the argument translates into a defense of a specific selection mode of participants: random selection.     

Do High- and Low-Active Adolescents Have Different Prototypes of Physically Active Peers?

The Psychological Record - Previous studies have investigated social images in health-risk behaviors, suggesting that these images are important factors in adolescents’ health-related...     

Educational and interpersonal uses of home computers by adolescents with and without specific language impairment

Many uses of new media entail processing language content, yet little is known about the relationship between language ability and media use in young people. This study compares educational versus interpersonal uses of home computers in adolescents with and without a history of specific language impairment (SLI). Participants were 55 17‐year‐olds with SLI and 72 typically developing peers. Measures of frequency and ease of computer use were obtained as well as assessments of participants' psycholinguistic skills. Results showed a strong preference for interpersonal computer use in both groups. Virtually all participants engaged with interpersonal new media, finding them relatively easy to use. In contrast, one third of adolescents with SLI did not use educational applications during a typical week. Regression analyses revealed that lower frequency of educational use was associated with poorer language and literacy skills. However, in adolescents with SLI, this association was mediated by perceived ease of use. The findings show that language ability contributes to new media use and that adolescents with SLI are at a greater risk of low levels of engagement with educational technology.