Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Latent roots of random data correlation matrices with squared multiple correlations on the diagonal: A monte carlo study

In order to make the parallel analysis criterion for determining the number of factors easy to use, regression equations for predicting the logarithms of the latent roots of random correlation matrices, with squared multiple correlations on the diagonal, are presented. The correlation matrices were derived from distributions of normally distributed random numbers. The independent variables are log (N–1) and log {[n(n–1)/2]–[(i–1)n]}, whereN is the number of observations;n, the number of variables; andi, the ordinal position of the eigenvalue. The results were excellent, with multiple correlation coefficients ranging from .9948 to .9992.This research was supported by the Office of Naval Research under Contract N00014-67-A-0305-0012, Lloyd G. Humphreys, principal investigator, and by the Department of Computer Science of which Richard G. Montanelli, Jr., is a member.     

Influence of individual differences in working memory on the continued influence effect of misinformation

ABSTRACT

Misinformation often continues to influence people’s cognition even after being retracted (the continued influence effect of misinformation, CIE). The current research aimed to investigate whether the individual differences in the central executive function of WM and updating could influence the CIE of misinformation with varying relevance. The results showed that the individual differences in central executive function could significantly affect the CIE, especially for the high-relevant misinformation. While the individual differences in the updating ability had a weaker impact on the CIE in general and only negatively related to the CIE for the low-relevant misinformation. The study extends the understanding of the relationship between individual differences and the CIE from previous studies, which is in line with the mental-model-updating hypothesis, and offers a preliminary clue for identifying the persons vulnerable to the CIE of misinformation in the real world.     

Orientational manoeuvres in the dark: dissociating allocentric and egocentric influences on spatial memory

Subjects in a darkroom saw an array of five phosphorescent objects on a circular table and, after a short delay, indicated which object had been moved. During the delay the subject, the table or a phosphorescent landmark external to the array was moved (a rotation about the centre of the table) either alone or together. The subject then had to indicate which one of the five objects had been moved. A fully factorial design was used to detect the use of three types of representations of object location: (i) visual snapshots; (ii) egocentric representations updated by self-motion; and (iii) representations relative to the external cue. Improved performance was seen whenever the test array was oriented consistently with any of these stored representations. The influence of representations (i) and (ii) replicates previous work. The influence of representation (iii) is a novel finding which implies that allocentric representations play a role in spatial memory, even over short distances and times. The effect of the external cue was greater when initially experienced as stable. Females out-performed males except when the array was consistent with self-motion but not visual snapshots. These results enable a simple egocentric model of spatial memory to be extended to address large-scale navigation, including the effects of allocentric knowledge, landmark stability and gender.     

Brain activation during spatial updating and attentive tracking of moving targets

Keeping aware of the locations of objects while one is moving requires the updating of spatial representations. As long as the objects are visible, attentional tracking is sufficient, but knowing where objects out of view went in relation to one's own body involves an updating of spatial working memory. Here, multiple object tracking was employed to study spatial updating and its neural correlates. In a dynamic 3D-scene, targets moved among visually indistinguishable distractors. The targets and distractors either stayed visible during continuous viewpoint changes or they turned invisible. The parametric variation of tracking load revealed load-dependent activations of the intraparietal sulcus, the superior parietal lobule, and the lateral occipital cortex in response to the attentive tracking task. Viewpoint changes with invisible objects that demanded retention and updating produced load-dependent activation only in the precuneus in line with its presumed involvement in updating spatial working memory.     

Differential recruitment of executive resources during mind wandering

Recent research has shown that mind wandering recruits executive resources away from the external task towards inner thoughts. No studies however have determined whether executive functions are drawn away in a unitary manner during mind wandering episodes, or whether there is variation in specific functions impacted. Accordingly, we examined whether mind wandering differentially modulates three core executive functions—response inhibition, updating of working memory, and mental set shifting. In three experiments, participants performed one of these three executive function tasks and reported their attentional state as either on-task or mind wandering at random intervals. We found that mind wandering led to poorer performance in the response inhibition and working memory tasks, but not the set-shifting task. These findings suggest that mind wandering does not recruit executive functions in a monolithic manner. Rather, it appears to selectively engage certain executive functions, which may reflect the adaptive maintenance of ongoing task performance.     

不稳定控制感剥夺损害工作记忆刷新功能

控制感剥夺会阻碍工作记忆中的转换功能,但对工作记忆中刷新功能的影响机制尚不清楚。据此,本文通过两个实验来探究控制感剥夺对工作记忆刷新功能的影响。结果发现,相较于基线水平,无论是通过行为无助任务（实验1）还是通过信息无助任务（实验2）操纵的稳定控制感剥夺均未阻碍随后的刷新任务;但在不稳定控制感剥夺的条件下（实验2）,刷新任务的成绩显著降低。这表明,控制感剥夺对工作记忆刷新功能的影响依赖于对其操纵的稳定性。     

The longitudinal association between internalizing symptoms and academic achievement among immigrant and non‐immigrant children in Norway

The aim of this study was to explore the longitudinal relation between internalizing symptoms and academic achievement, as two processes of children and youth development, among children in Norway, and whether having an immigrant background moderated this association. Data collected from 4,458 students in Norway in four waves over three years were analyzed with multi‐group latent growth curve modeling (LGM ). Results showed that internalizing symptoms level remained unchanged over time both for immigrant and non‐immigrant children, while levels of academic achievement increased only for children of immigrants with both parents born outside of Norway. Further analyses supported a reciprocal relation between internalizing symptoms and academic achievement and revealed that the initial level of academic achievement predicted the rate of change in internalizing symptoms over time, but not vice versa. Moreover, immigrant background did not moderate the associations in the model, however, children of immigrants with both parents born abroad initially had lower levels of academic achievement, but showed an increase in academic achievement, compared to their non‐immigrant peers as well as to peers with one native‐born parent after controlling for gender and their grade at the first observation. The implications for policy and practice were discussed.