Insufficient augmentation of ambient GABA responsible for age-related cognitive deficit

Age-related degeneration of intracortical inhibition could underlie declines in cognitive function during senescence. Based on a hypothesis that a decrease in basal concentration of ambient (extrasynaptic) GABA with aging leads to depressing intracortical inhibition, we investigated how the basal concentration affects stimulus-evoked activity (as signal), ongoing-spontaneous activity (as noise) of neurons and their (signal-to-noise) ratio S/N. We simulated a neural network model equipped with a GABA transport system that regulates ambient GABA concentration in a neuronal activity-dependent manner. An increase in basal concentration augmented ambient GABA, increased GABA-mediated inhibitory current, and depressed ongoing-spontaneous activity while still keeping stimulus-evoked activity. This led to S/N improvement, for which it was necessary for the reversal potential of GABA transporter to be close to the resting potential of neurons. Above the resting potential, ongoing-spontaneous activity was predominantly enhanced due to excessive GABA-uptake from the extracellular space by transporters. Below the resting potential, stimulus-evoked activity was predominantly depressed, caused by excessive GABA-release. We suggest that the insufficient augmentation of ambient GABA due to a decrease in its basal concentration may be one of the possible causes of cognitive deficit with aging, increasing ongoing-spontaneous neuronal activity as noise. GABA transporter may contribute to improving S/N, provided that its reversal potential is close to the resting potential.     

Affective and cognitive modulation of performance monitoring: Behavioral and ERP evidence

This study investigates the effects of negative affect on performance monitoring. EEG was acquired during a lateralized, numeric Stroop working memory task that featured task-irrelevant aversive and neutral pictures between stimuli. Performance accuracy showed a right-hemisphere advantage for stimuli that followed aversive pictures. Response-locked event-related potentials (ERPs) from accurate trials showed an early negative component (CRN; correct response/conflict-related negativity) followed by a positive wave comparable to the Pe (error positivity). The CRN was bi-peaked with an earlier peak that was sensitive to aversive pictures during early portions of the experiment and a later peak that increased with error likelihood later in the experiment. Pe amplitude was increased with aversive pictures early in the experiment and was sensitive to picture type, Stroop interference, and hemisphere of stimulus delivery during later trials. This suggests that ERP indices of performance monitoring, the CRN and Pe, are dynamically modulated by both affective and cognitive demands.     

Hypnotizability, preference for an imagic cognitive style, and memory creation in hypnosis

We sought to extend the finding (Laurence & Perry, 1983) that it is possible through hypnosis to create a pseudomemory of a specific event. Subjects were compared on their responses to a hypnotic suggestion. We also examined the relation between nonhypnotic measures (Preference for an Imagic Cognitive Style [PICS] test and the Tellegen Absorption Scale [TAS]) and response to the suggestion. Highly (45.45%) and moderately-highly (46.15%) susceptible subjects believed that the pseudomemory was veridical, but none of the low susceptible subjects did so. Together, hypnotic susceptibility, the PICS, and their interaction more strongly predicted pseudomemory creation than any of these main effects alone. Performance on the TAS was also related to the occurrence of pseudomemory, but this relation was redundant with performance on the other measures. These results point to the complexity of the variables involved in pseudomemory creation during hypnosis.     

Sex role orientation, level of cognitive development and mathematics performance in late adolescence

Sex differences in mathematics performance are found in late adolescence. This study investigates the effects of psychological sex role orientation (BSRI: masculine, feminine, undifferentiated, androgynous) and level of cognitive development (concrete, formal) on performance in mathematics. ANOVA analysis (N = 69; 18 males, 51 females) revealed significant effects for level of cognitive development and for masculine by feminine sex role orientation interaction. Subjects whose BSRI masculine and feminine scores were either both low or both high scored significantly lower on the mathematics test than subjects whose scores on either masculine or feminine scales were high. This indicates lower mathematics performance for androgynous and undifferentiated subjects. This result is hypothesized to be a function of the particular age level of these subjects and their concomitant overconcern with appropriate sex role development.     

A limited role for the hippocampus in the modulation of novel-object preference by contextual cues

Recent evidence suggests that rats require an intact hippocampus in order to recognize familiar objects when they encounter them again in a different context. The two experiments reported here further examined how changes in context affect rats' performance on the novel-object preference (NOP) test of object-recognition memory, and how those effects interact with the effects of HPC damage. Rats with HPC lesions and control rats received NOP testing in either the same context in which they had previously encountered sample objects, or in a different but equally familiar context. In Experiment 1, the two contexts had very few overlapping cues within or outside the apparatus; thus, the differences between them were global. Consistent with previous results, control rats showed a novel-object preference in both the unchanged and (globally) changed contexts, whereas rats with HPC lesions displayed a preference only in the unchanged context. In Experiment 2, the context shift included only local features proximal to the test objects. The main results were the reverse of Experiment 1--rats with HPC lesions displayed a novel-object preference in both the unchanged and (locally) changed contexts, whereas control rats displayed a preference only in the unchanged context. The findings are consistent with the view that HPC damage does not cause a general inability to recognize objects, nor an inability to encode or store a representation of the context in which the objects are encountered. They suggest instead that HPC damage impairs the ability to remember specific locations of familiar objects within a particular context.     

Dynamic awareness of age-related losses predict concurrent and subsequent changes in daily inductive reasoning performance

To address gaps in previous research, we examined daily within-person associations between awareness of age-related change (AARC) and cognitive performance in older adults. One hundred twelve adults aged 60–90 participated in an online daily diary study for nine consecutive days. On Day 1, they reported demographic information. On Days 2–9, they reported daily AARC, subjective age, and stressors and completed three tasks that gauged memory (word recall), perceptual speed (number comparison), and reasoning (letter series), respectively, once per day. Unconditional multilevel models revealed significant within-person fluctuations in daily cognitive performance and daily AARC. Controlling for age, education, health, and daily stressors, daily awareness of age-related losses was negatively associated with letter series scores of the same day and changes from one day to the next. The effects held over and above AARC gains and subjective age. Dynamic, naturally occurring perceptions of ageing may influence within-person concurrent and subsequent changes in reasoning performance on a daily basis and point to a promising avenue of intervention.     

Emotional modulation of cognitive control: approach-withdrawal states double-dissociate spatial from verbal two-back task performance

Emotional states might selectively modulate components of cognitive control. To test this hypothesis, the author randomly assigned 152 undergraduates (equal numbers of men and women) to watch short videos intended to induce emotional states (approach, neutral, or withdrawal). Each video was followed by a computerized 2-back working memory task (spatial or verbal, equated for difficulty and appearance). Spatial 2-back performance was enhanced by a withdrawal state and impaired by an approach state; the opposite pattern held for verbal performance. The double dissociation held more strongly for participants who made more errors than average across conditions. The results suggest that approach-withdrawal states can have selective influences on components of cognitive control, possibly on a hemispheric basis. They support and extend several frameworks for conceptualizing emotion-cognition interactions.     

Alcohol effects on performance monitoring and adjustment: affect modulation and impairment of evaluative cognitive control

Alcohol is known to impair self-regulatory control of behavior, though mechanisms for this effect remain unclear. Here, we tested the hypothesis that alcohol's reduction of negative affect (NA) is a key mechanism for such impairment. This hypothesis was tested by measuring the amplitude of the error-related negativity (ERN), a component of the event-related brain potential (ERP) posited to reflect the extent to which behavioral control failures are experienced as distressing, while participants completed a laboratory task requiring self-regulatory control. Alcohol reduced both the ERN and error positivity (Pe) components of the ERP following errors and impaired typical posterror behavioral adjustment. Structural equation modeling indicated that effects of alcohol on both the ERN and posterror adjustment were significantly mediated by reductions in NA. Effects of alcohol on Pe amplitude were unrelated to posterror adjustment, however. These findings indicate a role for affect modulation in understanding alcohol's effects on self-regulatory impairment and more generally support theories linking the ERN with a distress-related response to control failures.     

Strength of hand preference and dual task performance by common marmosets

Study of avian and piscine species has shown that animals with stronger lateralization of the brain are able to perform two tasks presented simultaneously better than can animals with weaker lateralization. We investigated whether this might apply also to primates by testing common marmosets to see whether there is a relationship between the strength of hand preference, as an indicator of strength of brain lateralization, and the ability to carry out two tasks simultaneously. A model predator was introduced into the testing room while the marmoset was foraging. Marmosets with stronger hand preferences detected the ‘predator’ after shorter latency than those with weaker hand preferences. Furthermore, the marmosets with stronger hand preferences produced more mobbing (tsik) vocalizations when they reacted to the predators than did those with weaker hand preferences. There was no such association between hand preference and either latency to respond to the predator or mobbing reaction when the marmosets were not foraging at the time the predator was introduced. Hence, strength of lateralization is associated with the ability to perform foraging and predator detection simultaneously. These results are discussed with reference to the evolution of brain lateralization.     

The role of facial orientation in newborn infants’ preference for attractive faces

Several previous experiments have found that newborn and young infants will spend more time looking at attractive faces when these are shown paired with faces judged by adults to be unattractive. Two experimental conditions are described whose aim was to find whether the ‘attractiveness effect’ is affected by the orientation of the facial stimuli. Pairs of attractive and less attractive faces (as judged by adults) were shown to newborn infants (mean age 2 days 20.5 hours), where each pair was presented both upright and inverted through 180°. In the former (upright) condition, but not the latter (inverted) condition, the infants looked longer at the attractive faces, and the difference in attractiveness preference between the conditions was statistically significant. These findings are clear evidence that infants’ early representation of faces contains information about faces that is orientation‐specific. The results are discussed in terms of innate facial representations and rapid learning about faces in the hours from birth.     

Interrelationships among three measures of preference for cognitive style based on hemisphere specialization theory

Right and left cerebral hemisphere and limbic scores derived from the Herrmann Brain Dominance Profile were correlated with left, right, and integrated scores from the Torrance-Reynolds Your Style of Learning and Thinking and four cognitive style scores from the Kolb Learning Style Inventory. Coefficients from 40 students in occupational therapy indicated low moderate positive relationships between like-named hemisphere scores, lack of significant relationships between cognitive style and two independent measures of hemispheric preference, and relative independence of preferred hemisphere mode as well as relative independence between cerebral and limbic systems. The data are interpreted as requiring cautious concern about the validity of these measures by potential users.     

People's awareness of their age-related sensory and cognitive deficits and the implications for road safety

Inevitable declines in sensory abilities may put older drivers and pedestrians at risk unless they become aware of these changes and can safeguard themselves by modifying their behaviour. A questionnaire designed to evaluate older people's awareness of their sensory abilities with regard to road use was administered to 80 individuals aged from 50 to 79 years, who were also given eyesight and hearing tests. Despite marked declines in their objective sensory efficiency, people in their 70s did not rate their sensory abilities as poor any more than did people in their 50s. Individuals of any age who did subjectively perceive declines in their sensory abilities also reported that they had made very sensible adjustments in their road-use behaviour, for example, avoiding complex junctions. Those individuals who reported taking such precautions also reported fewer recent accidents. One month after completing the questionnaire, and being given the results of their eyesight and hearing tests, two-thirds of individuals reported that they had made important changes in their behaviour on the roads. Many now avoided or took particular care in dangerous situations, and some had started to wear prescribed spectacles more appropriately. The implications of older people's lack of awareness of changes in their sensory abilities to their safety on the roads, and in general, are discussed. Factors causing the age-related mismatch between actual and subjectively perceived sensory abilities are discussed.     

Dopamine modulation affects the performance of parkinsonian patients in a precision motor task measured by an antropomorphic device

Several parameters related to the timing, grip force and load force involved in a precision grasping task were studied in patients with Parkinson's disease (PD) at different moments of medication and healthy controls, using a sensorized anthropomorphic device which was totally adapted to the human hand. The aim of this work was to carry out an accurate study of the reach-load-grip-hold-place-release subtasks to identify any physical motor impairment, its relation to medication and Parkinsonian strategies. Twenty seven patients in ON and OFF-like medication moments, and twenty seven age-matched controls took part in the experiment, which consisted of using the index finger and the thumb to perform a precision motor task involving different experimental objects. Visual cues were used as distracting elements. Results showed several motor parameters impaired in OFF-like medication moment but attenuated in ON state, suggesting a medication effect on the performance of the task.     

Sustained and transient modulation of performance induced by emotional picture viewing

We investigated how viewing task-irrelevant emotional pictures affects the performance of a subsequent nonemotional visual detection task. Subjects performed target-detection trials following the offset of individual unpleasant, pleasant, and neutral pictures. Sustained interference occurred when subjects viewed unpleasant pictures (mutilated bodies) in a sequential, "blocked" fashion. Such slowing down of reaction time appeared to build up with time, consistent with the instatement of a defensive emotional state. With a randomized picture presentation, only a transient interference effect was observed, consistent with increased attentional demands during the processing of unpleasant pictures. During blocked presentation of affiliative pleasant pictures, reaction times were faster, suggesting the activation of appetitive motivational systems. Ultimately, both attentional and motivational systems are intricately tied in the brain and, together, determine behavior.     

Influence of win-loss ratio on performance,satisfaction and preference for opponents

Hypotheses about the preference for opponents in competitive situations, about performance under various win-loss ratios, and about task and opponent satisfaction under various win-loss ratios were tested. A 5 × 5 latin square with four replications and a repeated measure factor of trials was the design used with 20 female college students as subjects. The five different win percents were W₁₀, W₃₀, W₅₀, W₇₀, and W₉₀. A manipulative maze task was used with subjects receiving 20 trials against each of five confederate opponents. Results indicated that (a) when a person knows little or nothing about her ability level she initially prefers to compete with opponents of low ability but with each subsequent contest opponents of higher ability levels are preferred; (b) subjects performed better in the W₅₀ condition; (c) task satisfaction is higher when the percent of wins is equal to or greater than the percent of losses; and (d) opponent satisfaction is greater for opponents who perform equal to or better than the subject.     

The effects of an appraisal manipulation: Affect,intrusive cognitions,and performance for two cognitive tasks

We examined the relationship between trait measures of general appraisal and test anxiety, state measures of stress appraisals, affect, and intrusive cognition, and performance measures on two cognitive tests (mental math and Raven matrices). Participants were randomly assigned to threat, challenge, or control conditions that were created by manipulating both primary and secondary appraisals. We predicted that the threat condition would lead to more negative affect, stress appraisals, intrusive cognitions, and more errors. While our manipulated conditions led to inconsistent effects, path analyses tended to confirm predictions that negative task appraisals and trait test anxiety lead to negative affect and to intrusive cognitions, and that for mental math test performance a path from intrusive cognitions to test errors was established. The importance of understanding dispositionaland situational variables and their interactions during stress encounters are discussed, as is future research involving the general appraisal dimension. The authors wish to thank the many students who acted as experimenters and helped with data entry. Thanks go to James Johnson, Ann Schuller, and Brandon Vancura for all their hard work. Special thanks go to Roger Lott for his expert performance as the main investigator in the threat and challenge conditions. An enormous debt of gratitude also goes to my wife Kathy for all her patience and support, and for her help with the audio tapes used in this study. This study was completed as partial fulfillment of the requirements for a Master’s Degree for the first author. Portions of this work will be presented at the annual meeting of the Midwestern Psychological Association, 1997.     

认知负荷对疼痛共情的影响:来自ERP研究的证据

先前研究表明,对他人的疼痛共情受到多种因素的调节。认知负荷对疼痛共情的调节作用尚无研究。本研究使用事件相关电位技术探究高低认知负荷对疼痛共情神经加工过程的影响。实验通过不同长度的数字串记忆任务,形成高/低两种认知负荷,要求被试在不同认知负荷条件下观看他人处于疼痛/不疼痛情境下的图片,同时记录被试的在观看图片时的EEG数据。通过比较不同条件下观看图片诱发的ERP成分发现:早期成分P2和N2上认知负荷水平与图片类型出现了显著的交互作用,即在高认知负荷下疼痛图片诱发的波幅与非疼痛图片诱发的波幅差异显著,而低认知负荷下两种图片诱发的波幅差异不显著。这表明认知负荷主要影响疼痛共情加工的早期、自动化加工阶段。相比较于低认知负荷条件下,在高认知负荷下他人的疼痛获得了更好的加工。     

Effects of sleep deprivation on cognitive performance by United States Air Force pilots

This study examined the effects of 35 h of continuous sleep deprivation on performance in a variety of cognitive tasks as well as simulated flight. Ten United States Air Force pilots completed the Multi-Attribute Task Battery (MATB), Psychomotor Vigilance Task (PVT), and Operation Span Task (OSPAN), as well as simulated flight at 3 h intervals over a 35 h sleep deprivation period. Performance declined on all tests after about 18–20 h of continuous sleep deprivation, although the degree to which performance degraded varied. During the second half of the sleep deprivation period, performance on the simulated flight was predicted by PVT and OSPAN reasonably well but much less so by the MATB. Variance from optimal flight performance was predicted by both PVT and OSPAN but each measure added incremental validity to the prediction. The two measures together accounted for 58% of the variance in flight performance in the second half of the sleep deprivation period.     

Studying individual aging in an interindividual context: typical paths of age-related, dementia-related, and mortality-related cognitive development in old age

This study has 2 objectives: (a) to explore typical paths of cognitive development associated with aging, terminal decline, and dementia and (b) to promote and illustrate an individual-oriented approach to the study of cognitive aging based on longitudinal panel data from a population-based sample (N = 500; age range-sub(T1)= 60-80, where T refers to time) tested at 3 occasions 5 years apart. Results document interindividual differences in multivariate patterns of change. Although cognitive changes generally covary, the present study indicates that subgroups of individuals develop along different paths characterized by selective changes in subsets of cognitive functions. Typical progression of dementia followed a developmental cascade from low declarative memory, via low functioning across all observed cognitive measures, to dementia diagnosis, and finally, death.