Selective improvement of strain-dependent performances of cognitive tasks by food restriction

Temporary food restriction affects strain differences for behavioral phenotypes in the inbred strains of mice C57BL/6 (C57) and DBA/2 (DBA). Since food restriction is a routine procedure to motivate learning, we evaluated its influence on differences for spatial and non-spatial discrimination between these strains of mice by using two non-associative tasks: the Spatial Novelty Test (SNT) and the Spontaneous Object Recognition Test (SORT). The results confirmed the poor performance of the DBA mice in SNT. Nonetheless, DBA mice were perfectly able to recognize the novel object in SORT. By contrast, C57 mice were good performers in SNT but failed to recognize a novel object in SORT. Finally, food restriction selectively improved C57 performance in SNT and DBA performance in SORT. These results support the view that a food restricting procedure enhances strain differences for discrimination of configurational information.     

Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluation of two cases

Technological aids such as microswitches may be critical to foster learning and development in children with multiple disabilities. In study I, a child with minimal motor behavior was provided with a microswitch for chin movements to assess whether he could learn to use these movements to activate environmental stimuli. In study II, a child with dystonic (difficult-to-control) behavior was provided with microswitches for two motor responses and two vocal utterances. We wanted to assess whether he could use both types of responses effectively (varying within each pair, consistent with choice performance). The results were highly encouraging with both children. In study I, there was a significant increase in the childs responding, suggesting learning and contingency awareness. In study II, there was a significant increase in responding as well as response variation that suggested choice behavior. The importance of microswitch devices in promoting new learning/developmental objectives and improving quality of life is discussed.     

The breakdown of semantic knowledge: insights from a statistical model of meaning representation

Investigations of patients with semantic category-specific deficits have revealed a wide range of performance and variability in categories that are impaired or spared; this variability presents a challenge to accounts of category specificity. Accounts based only on impairment to semantic features of a particular type (e.g., visual), as well as accounts based only on featural properties (e.g., feature intercorrelations), are insufficient to explain the variability of patients' performance. A first goal of the paper is to discuss how a hybrid account incorporating both a level of organization according to feature types (a level of nonlinguistic conceptual representations) and a level of organization dictated by featural properties may provide a more comprehensive account of the cases reported in the literature. The second and most novel goal of the study reported here is to derive from our hybrid account a series of novel predictions concerning the representation and impairment of a different domain of knowledge: knowledge of actions and events, a domain of knowledge that has received remarkably little attention to date.     

Canceling out both the real and the spectral lines

Neglect patients typically show motor perseveration while canceling targets on the ipsilesional side. This behavior can be influenced by the presence vs. absence of targets on the (neglected) contralesional side (). As alternative explanations, the authors proposed (i) directional hypokinesia--the patient cannot perform reaching movements towards detected left-sided targets, and thus carries on canceling on the right side, and (ii) allochiria--the patient misperceives left-sided targets as located on the right side, and cancels them there. We report here data from a patient (EZ) that might confirm the second hypothesis. EZ was presented with 19 displays in which the number and position of cancellation targets on both sides were varied systematically. EZ showed motor perseveration while canceling, but this tendency did not vary across conditions. Interestingly though, EZ also drew cancellation marks in the empty space between the ipsilesional targets, and this phenomenon was significantly more intense when there were more targets on the neglected side. As EZ's comments suggested, such a behavior might reflect the attempt to cancel out delusional targets. Our speculation is that those objects were generated by allochiria.     

The role of executive function in autobiographical memory retrieval: does the type of cue word matter?

ABSTRACT

Autobiographical memories are memories for personally experienced life events. Previous research has revealed individual differences in the ability to recall specific memories that happened at a particular time and place. Some studies suggest such differences can be attributed to the varying capacity of executive function. However, little is known regarding which specific executive function skills predict autobiographical memory specificity. Participants were asked to complete multiple measures of executive function as well as an autobiographical memory task in which they were asked to recall a specific personal memory connected to concrete and abstract cue words. We hypothesised that executive function will be positively related to autobiographical memory specificity and that this relation will be moderated by the cue word type. The results revealed that individuals with higher executive function skills, specifically, higher inhibitory control and cognitive flexibility, recalled significantly more specific memories than those with lower executive function skills; however, no significant interaction between executive function ability and cue word type was found.     

Introspection on uncertainty and judicious help‐seeking during the preschool years

Little is known about the mechanisms underlying a ubiquitous behavior in preschoolers, help‐seeking. We tested the hypothesis that preschoolers' awareness of their own uncertainty is associated with help‐seeking. Three‐, 4‐, and 5‐year‐olds (N = 125) completed a perceptual identification task twice: once independently and once when they could request help from a confederate whose competence level was manipulated. Consistent with our hypothesis, participants sought help more frequently on trials for which, when required to answer independently, they expressed lower confidence. Children in the bad‐helper condition were slower to respond after receiving help than those in the good‐helper condition. Finally, females and children with more advanced theory of mind were more likely to seek help, identifying additional factors that relate to help‐seeking.