Intelligence and the Frontal Lobe: The Organization of Goal-Directed Behavior

Basic to the study of individual differences is the concept of “general intelligence” or Spearman'sg.In this article we suggest thatgis largely a reflection of the control functions of the frontal lobe. A series of experiments investigates a phenomenon we callgoal neglect:disregard of a task requirement even though it has been understood and remembered. Subjectively it is as though the neglected requirement “slips the subject's mind.” Previously described in frontal patients, we show that goal neglect can also be seen in some members of the normal population. In line with conventional distinctions between controlled and automatic processing, eliciting conditions for goal neglect include novelty, weak error feedback, and multiple concurrent task requirements. Under these conditions neglect is linked closely togand extremely common after frontal lesions. Following many other models, we suggest that behavior in any task is structured by a set of action constraints or requirements, derived in part from verbal instructions and specified at multiple levels of abstraction. A frontal process of constraint or requirement activation is fundamental to Spearman'sg.     

Temporal pattern of agonist-antagonist EMG activity during rapid limb movements in man

Analysis of elbow-extension movements, executed at maximal velocity, show positive correlations of timing of agonist-antagonist EMG activity with both movement velocity and displacement. Results indirectly support the notion that the antagonist musculature provides a braking force to arrest rapid limb movements.     

Effects of delayed conditioned reinforcement in chain schedules.

The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement.     

Distributional learning has immediate and long-lasting effects

Evidence of distributional learning, a statistical learning mechanism centered on relative frequency of exposure to different tokens, has mainly come from short-term learning and therefore does not ostensibly address the development of important learning processes. The present longitudinal study examines both short- and long-term effects of distributional learning of phonetic categories on non-native sound discrimination over a 12-month period. Two groups of listeners were exposed to a two-minute distribution of auditory stimuli in which the most frequently presented tokens either approximated or exaggerated the natural production of the speech sounds, whereas a control group listened to a piece of classical music for the same length of time. Discrimination by listeners in the two distribution groups improved immediately after the short exposure, replicating previous results. Crucially, this improvement was maintained after six and 12 months, demonstrating that distributional learning has long-lasting effects.     

A correction for recruitment bias in norms derived from meta-analysis

Normative comparisons are an integral component of neuropsychological test interpretation and provide the basis for an inference of abnormal function and impairment. In order to remedy a deficit of normative standards for a large number of neuropsychology tests, Mitrushina, Boone, Razani, and D'Elia (2005) used the meta-analysis of studies that incorporated normal volunteers to create a type of normative standard for many tests in neuropsychology that were not adequately normed in the past. The present study examined this method by contrasting meta-analysis norms of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981) with its published quota norms. The study examined 12 experimental studies of the WAIS-R that included normal, control volunteers (N = 2,147). These were combined by meta-analysis, and the summary scores were compared. The meta-analysis revealed a significant sampling bias with studies recruiting more White and higher educated respondents than indicated by the U.S. Census. This bias was successfully corrected using Monte Carlo simulation and adjustments for quota sampling. The corrections could be applied to all meta-analysis norms currently in use and bring them in line with the U.S. Census demographics.     

Relationship of Adult Representations of Childhood Parenting and Personality Tendencies to Adult Stressors and Political Ideology

Undergraduate students in a Southeastern US University (n = 232) responded to an inventory that included retrospective measures of their parents’ style of parenting (authoritarian vs. authoritative) and their own childhood psychological tendencies (insecurity vs. confidence), as well as their adult stressors and political orientation. Authoritative parenting positively correlated with childhood confidence and negatively correlated with both childhood insecurity and adult stressors. Conversely, authoritarian parenting was positively associated with childhood insecurity and adult stressors but was not significantly correlated with childhood confidence. For the most part, parenting styles, early childhood tendencies, and adult stressors were unrelated to adult political ideology, contrary to previous longitudinal research reporting these connections.     

Surviving the Kosovo Conflict: A Study of Social Identity, Appraisal of Extreme Events, and Mental Well-Being

Our study examined the role of social identity processes in determining how individuals evaluate, deal with, and are affected by severe events of war. We reasoned that for those who experience such events collectively and who identify strongly with their group, primary appraisal will be filtered through the prism of social identity. In a sample of Kosovo Albanians who had survived the armed conflict in 1999, we found that those who were able to evaluate the war as affirming their group identity presented lower levels of depressive mood and anxiety and higher levels of self-efficacy. Furthermore, this process of war appraisal affected the process of secondary appraisal. Specifically, positive war appraisal increased availability of support from close others and reduced the importance of positive individual coping strategies in dealing with extreme events. Conversely, negative war appraisal reduced availability of support from close others and reduced the importance of negative coping strategies in dealing with extreme events.     

Animal Disenhancement and the Non-Identity Problem: A Response to Thompson

In his paper “The Opposite of Human Enhancement: Nanotechnology and the Blind Chicken problem” (Nanoethics 2:305–316, 2008) Paul Thompson argues that the possibility of “disenhancing” animals in order to improve animal welfare poses a philosophical conundrum. Although many people intuitively think such disenhancement would be morally impermissible, it’s difficult to find good arguments to support such intuitions. In this brief response to Thompson, I accept that there’s a conundrum here. But I argue that if we seriously consider whether creating beings can harm or benefit them, and introduce the non-identity problem to discussions of animal disehancement, the conundrum is even deeper than Thompson suggests.