Sequential Performance in Young and Older Adults: Evidence of Chunking and Inhibition

ABSTRACT

Two experiments were conducted to examine possible sources of age-related decline in sequential performance: age differences in sequence representation, retrieval of sequence elements, and efficiency of inhibitory processes. Healthy young and older participants learned a sequence of eight animal drawings in fixed order, then monitored for these targets within trials of mis-ordered stimuli, responding only when targets were shown in the correct order. Responses were slower for odd numbered targets, suggesting that participants spontaneously organized the sequence in two-element chunks. Perseverations (responses to previously relevant targets) served as an index of inhibitory inefficiency. Efficiency of chunk retrieval and self-inhibition were lower for older than for younger adults. Increasing environmental support in Experiment 2 through overt articulation of current chunk elements showed a pattern of results similar to Experiment 1, with particular benefit for older adults. The findings suggest an underlying susceptibility to interference in old age.     

Electroencephalographic registration of low concentrations of isoamyl acetate

Previous research has demonstrated electroencephalogram (EEG) changes in response to low-odor concentrations, resulting in near-chance detection. Such findings have been taken as evidence for olfaction without awareness. We replicated and extended previous work by examining EEG responses to water-water control, 0.0001, 0. 001, 0.01, and 1 ppm isoamyl acetate (IAA) in water paired with water only. Detection was above chance (>50%) for.001 and above, and alpha decreased only to those concentrations, suggesting that EEG changes corresponded to IAA awareness. However, when correct trial EEGs were compared to incorrect trial EEGs during.001 ppm, right posterior/central alpha decreased during incorrect trials and alpha decreased more globally (including frontal sites) during correct trials. These data may not reflect awareness or unawareness per se. Instead, results are discussed regarding activation of perceptual systems in the posterior region during incorrect trials and the activation of frontal action systems during a subset of correct trials.     

Culture,gender and self–close‐other(s) connectedness in Canadian and Chinese samples

Founded upon the theories of Independent–Interdependent Self‐Construal and I–C, the main goal of this study was to test, via an adapted IOS Scale, whether Anglo‐Canadians were more independent than Mainland Chinese in construing their relationship with family members and friends. Strong cultural differences were found in self–family connectedness, but not in self–friends connectedness. Chinese were closer to their family members than Canadians, but Canadians were as close to their friends as Chinese. In both samples, gender difference was found in self–friends connectedness, but not in self–family connectedness. In the Canadian sample, females were closer to their friends than males, while in the Chinese sample, males were closer to their friends than females. In conclusion, this study contributes to the field in three ways. First, the finding that Canadians are as connected as Chinese to their close friends unprecedentedly contests one fundamental assumption of the theories of independent‐interdependent self‐construal (Markus & Kitayama, 1991 ) and I–C (Hofstede, 1980 ; Triandis, Bontempo, Villareal, Asia & Lucca, 1988 ) that individualists (e.g. Anglo‐Canadians) are more independent than collectivists (e.g. Chinese) on all dimensions of human relations. Second, the proposition (Cross & Madson, 1997 ) that Western males and females differ in the same way individualists and collectivists differ in their self‐construal is not supported. Finally, the adaptation of the IOS Scale proposes a refreshing direction in cross‐cultural research. Graphic representations may be less susceptible to cross‐cultural misconstrual than verbal statements since the former involves little or no translation from one language to another. Copyright © 2002 John Wiley & Sons, Ltd.     

Confirming the Factor Structure of Attention Deficit Hyperactivity Disorder Symptoms in Adult, Nonclinical Samples

Three separate models have been proposed to describe the factor structure of attention deficit hyperactivity disorder (ADHD) in the past 20 years. The Diagnostic and Statistical Manual of Mental Disorders-III (DSM-III, 1980) proposed 3 separate factors of inattention, hyperactivity, and impulsivity. The DSM-III-R (1987) proposed a single factor. The DSM-IV (1994) described the disorder as having 2 factors: hyperactivity/impulsivity and inattention. The following 2 studies employed confirmatory factor analysis to compare each of these models and 3 alternative models. University students completed questionnaires that assessed each of the 18 symptoms listed in the DSM-IV for ADHD. The 3-factor model fit the data significantly better than each of the other models in both studies. These findings suggest that a 3-factor model of inattention, hyperactivity, and impulsivity describes adult ADHD symptoms better than current alternatives.     

Treatment Foster Care in a System of Care: Sequences and Correlates of Residential Placements

We examined Treatment Foster Care (TFC) in residential trajectories for youth with psychiatric disorders and aggressive behavior. We analyzed residential placements of a statewide sample of youth during the 12 months preceding and following admission to TFC. Prior to TFC, the majority of youth were residing in more restrictive settings (group homes or residential treatment). Two-thirds of youth remained in TFC throughout the follow-up year. Of those who left, nearly half returned home, and slightly fewer were discharged to group homes. By the end of the 12-month follow-up period, rates of group home use were similar to those seen in the pre-TFC period. Movement out of TFC during the year was associated with being older at placement and with increased problem behavior (particularly externalizing behaviors). TFC serves as a step-down placement for a substantial number of youth. However, this is not the only way it is used, and models based on short-term transitioning or reunification with families may not be widely implemented or relevant in practice. Additional research is needed to understand current functions of TFC in residential trajectories and to maximize its utility in systems of care.     

Putting order in the impossible

The class of visual illusions called 'impossible figures' (illusory spatial interpretations of pictures) is analyzed in order to introduce an ordering into the great variety of such figures. Such an ordering facilitates reference, unifies terminology, and establishes a conceptual framework for further investigations of the subject, making easier the choice and systematic generation of various types of figures (for example, in systematic psychological experiments). First, the notion of 'impossible figure' is defined and certain other related classes of figures (so-called 'likely' and 'unlikely' figures) are distinguished. Second, the fundamental 'impossibility sources' are identified as elementary 'building blocks' of all impossible figures. Finally, two broad classes of impossible figures, multibars (or 'impossible polygons') and striped figures, are briefly described.     

Support with Strings: Workfare as an 'Impermissible Condition'

abstract Even if a state would have been perfectly within its rights not to provide for people's welfare at all, it might still be wrong for it to exercise that discretion conditional upon something that claimants do (like ‘look for work’). What might make some conditions morally permissible and others impermissible? One answer is in terms of the consonance of the condition with the purposes of the policy. If a policy is supposed to be for one purpose — or, morally, if it can be justified only by reference to one purpose — then that policy must not impose conditions that are appropriate only to some other purpose. It is an improper exercise of power for public officials to tack wholly inappropriate conditions onto programmes justified on some other grounds altogether. Tacking labour‐market conditions onto policies that are ostensibly designed to promote people's welfare can be a case in point.