The utility of intraindividual variability in selective attention tasks as an early marker for Alzheimer’s disease.

This study explored differences in intraindividual variability in 3 attention tasks across a large sample of healthy older adults and individuals with very mild dementia of the Alzheimer’s type (DAT). Three groups of participants (healthy young adults, healthy older adults, very mild DAT) were administered 3 experimental measures of attentional selection and switching (Stroop, Simon, task switching). The results indicated that a measure of intraindividual variability, coefficient of variation (CoV; SD/M), increased across age and early stage DAT. The CoV in Stroop discriminated the performance of ε4 carriers from noncarriers in healthy older controls and the CoV in task switching was correlated with cerebrospinal fluid (CSF) biomarkers predictive of DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The neuropsychology of the prefrontal cortex

Single photon emission computed tomography with the xenon inhalation technique is used to compare activation of regional cerebral blood flow in frontal brain regions during the performance of four widely used neuropsychological tests: the Continuous Performance Test, the Wisconsin Card Sorting Test, the Tower of London, and Porteus Mazes. Healthy normal volunteers performing these tasks show significant increases in frontal regions during the Continuous Performance Test, the Wisconsin Card Sorting Test, and the Tower of London, but not the Porteus Mazes. Activation produced by the Continuous Performance Test and the Tower of London are mesial and bilateral and may reflect stimulation of midline attentional circuits. The Wisconsin Card Sorting Test produces a left dorsolateral area of prefrontal activation. These findings indicate that regional activation of the frontal lobes occurs in response to cognitive challenges produced through performance of standard neuropsychological tests.     

Working memory and control of attention in persons with Alzheimer's disease and mild cognitive impairment.

The goal of the present study was to assess 3 attentional control processes--divided attention, manipulation capacities, and inhibition--in persons with mild cognitive impairment (MCI) and with mild Alzheimer's disease (AD). Manipulation capacities were tested by comparing immediate serial recall with alphabetical-order recall of words. Divided attention was tested with the Brown-Peterson procedure, in which participants divide their attention between simple addition tasks and consonant trigrams over delays. Inhibition was tested with the Hayling procedure, in which participants complete sentences with words irrelevant to their context. Persons with AD showed severe impairment on the 3 attentional control components. Persons with MCI exhibited impaired performance on the Brown-Peterson procedure but normal performance on the other 2 tasks. With AD and MCI participants, there was a negative correlation between general cognitive deficits and impairment on attentional control tasks, indicating that attentional control deficits increase in the MCI/AD continuum. When separating MCI with and without significant subsequent decline, those with subsequent decline showed impaired performance on both the Brown-Peterson procedure and manipulation task. These data suggest that control of attention tasks can track AD at a preclinical stage and that impairment increases gradually during the preclinical phase of AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The utility of Stroop task switching as a marker for early-stage Alzheimer's disease.

[Correction Notice: An erratum for this article was reported in Vol 25(4) of Psychology and Aging (see record 2010-22172-001). Author Janet M. Duchek’s name was misspelled as Janet M. Ducheck. The online version has been corrected.] Past studies have suggested attentional control tasks such as the Stroop task and the task-switching paradigm may be sensitive for the early detection of dementia of the Alzheimer's type (DAT). The authors of the current study combined these tasks to create a Stroop switching task. Performance was compared across young adults, older adults, and individuals diagnosed with very mild dementia. Results indicated that this task strongly discriminated individuals with healthy aging from those with early-stage DAT. In a logistic regression analysis, incongruent error rates from the Stroop switching task discriminated healthy aging from DAT better than any of the other 18 cognitive tasks given in a psychometric battery. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Correction to Hutchison, Balota, and Duchek (2010).

Reports an error in "The utility of Stroop task switching as a marker for early-stage Alzheimer's disease" by Keith A. Hutchison, David A. Balota and Janet M. Ducheck (Psychology and Aging, 2010[Sep], Vol 25[3], 545-559). Author Janet M. Duchek’s name was misspelled as Janet M. Ducheck. The online version has been corrected. (The following abstract of the original article appeared in record 2010-18944-003.) Past studies have suggested attentional control tasks such as the Stroop task and the task-switching paradigm may be sensitive for the early detection of dementia of the Alzheimer's type (DAT). The authors of the current study combined these tasks to create a Stroop switching task. Performance was compared across young adults, older adults, and individuals diagnosed with very mild dementia. Results indicated that this task strongly discriminated individuals with healthy aging from those with early-stage DAT. In a logistic regression analysis, incongruent error rates from the Stroop switching task discriminated healthy aging from DAT better than any of the other 18 cognitive tasks given in a psychometric battery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional bias is associated with incentive-related physiological and subjective measures.

Drug cue reactivity is theoretically and clinically important. The modified Stroop task has been widely used to assess attention capture by drug cues (attentional bias). Attentional bias to drug cues is assumed to reflect the incentive value of those cues, but this has not been directly tested. The authors examined whether the smoking Stroop effect was associated with facial electromyography (EMG) assessed in real time. Heart-rate (HR) and skin conductance (SC) responses were also assessed. Smokers (n = 79) attended up to four experimental sessions. Presession Abstinence state and within-session Smoking were manipulated across sessions. Over all assessments, participants exhibited a robust smoking Stroop effect. Using Generalized Estimating Equations (GEE) analyses, the smoking Stroop effect was positively associated with zygomaticus major activity but not with corrugator supercilii activity, HR, or SC. The smoking Stroop effect was also positively associated with self-reported positive outcome expectancies from smoking and with craving. In sum, attentional bias was more strongly associated with appetitive responses (zygomaticus major activity, positive outcome expectancies) than with withdrawal responses (e.g., corrugator supercilii activity) or measures of physiological arousal (e.g., HR, SC). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for executive dysfunction in autism

A group of young people with autism (ranging in ability from high functioning to moderately learning disabled), and ability-matched control groups of (i) non-autistic individuals with moderate learning disabilities, and (ii) normally developing children, were presented with two tests of executive function: the Intra-dimensional/Extra-dimensional set-shifting task and the Tower of London planning task. These tests were graded in difficulty and included internal control measures. On each task, the autistic group was differentially impaired with respect to both control groups. Moreover, this impairment was specific to the stages of each task which placed greatest demands upon executive control. This evidence for executive dysfunction in autism is discussed in the context of Norman and Shallice's (Centre for Human Information Processing Technical Report 99, 1980) "Supervisory Attentional System" model of frontal function.     

Organizational and spatial dynamics of attentional focusing in hierarchically structured objects.

Is the focusing of visual attention object-based, space-based, both, or neither? Attentional focusing latencies in hierarchically structured compound-letter objects were examined, orthogonally manipulating global size (larger vs. smaller) and organizational complexity (two-level structure vs. three-level structure). In a dynamic focusing task, participants successively identified the global and local letters in the same trial. Overall response latencies were generally longer for larger versus smaller global objects and for three-level versus two-level object structure, indicating that attentional focusing time increases both with the magnitude of change in attentional aperture size and with the number of traversed levels of object structure. Additional experiments showed that this pattern is unique to tasks that require dynamic attentional focusing. Taken together, the results support a hierarchical object-based-spatial model of attentional focusing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Stroop Tasks Reveal Abnormal Selective Attention Among Psychopathic Offenders.

Selective attention among offenders with psychopathy was investigated using 3 Stroop paradigms: a standard color-word (CW) Stroop, a picture-word (PW) Stroop, and a color-word Stroop in which the word and color were spatially separated (separated CW). Consistent with "overselective" attention, offenders with psychopathy displayed reduced Stroop interference on the separated CW and PW tasks relative to offenders who were not psychopathic. However, offenders with psychopathy displayed normal Stroop interference on the standard CW Stroop. Further, the reduced interference of offenders with psychopathy on the separated CW Stroop was accompanied by normal facilitation. These findings suggest a circumscribed attentional deficit in psychopathy that hinders the use of unattended information that is (a) not integrated with deliberately attended information and (b) not compatible with current goal-directed behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in the inhibition of return of visual attention.

Responses to targets are slower when they appear at a location to which attention has previously been directed than when they appear at other locations. This inhibition of return (IOR) effect is subserved by posterior brain attentional systems. In 4 experiments the IOR effect in elderly adults was found to be at least as large as in young adults for both discrimination tasks and for detection tasks. The time course and the spread of inhibition within the visual field were also equivalent in the 2 age groups. Additive factors logic was then used to test the hypothesis that the Stroop and IOR effects are due to a common mechanism, a failure to suppress attention. This hypothesis was not confirmed. The results of the 6 experiments are consistent with the hypothesis that there are changes in posterior brain systems responsible for selective attention to a location, contrary to prior claims. They cannot be explained by a general slowing of processing in old age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of healthy aging and early stage dementia of the Alzheimer's type on components of response time distributions in three attention tasks.

Objective: The characteristics of response time (RT) distributions beyond measures of central tendency were explored in 3 attention tasks across groups of young adults, healthy older adults, and individuals with very mild dementia of the Alzheimer's type (DAT). Method: Participants were administered computerized Stroop, Simon, and switching tasks, along with psychometric tasks that tap various cognitive abilities and a standard personality inventory (NEO-FFI). Ex-Gaussian (and Vincentile) analyses were used to capture the characteristics of the RT distributions for each participant across the 3 tasks, which afforded 3 components: μ and σ (mean and standard deviation of the modal portion of the distribution) and τ (the positive tail of the distribution). Results: The results indicated that across all 3 attention tasks, healthy aging produced large changes in the central tendency μ parameter of the distribution along with some change in σ and τ (mean ηp2 = .17, .08, and .04, respectively). In contrast, early stage DAT primarily produced an increase in the τ component (mean ηp2 = .06). τ was also correlated with the psychometric measures of episodic/semantic memory, working memory, and processing speed, and with the personality traits of neuroticism and conscientiousness. Structural equation modeling indicated a unique relation between a latent τ construct (–.90), as opposed to σ (–.09) and μ constructs (.24), with working memory measures. Conclusions: The results suggest a critical role of attentional control systems in discriminating healthy aging from early stage DAT and the utility of RT distribution analyses to better specify the nature of such change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sustained attentional and disattentional abilities: Differences between low and highly hypnotizable persons.

Relations between sustained attentional and disattentional abilities and hypnotic susceptibility (Harvard Group Scale of Hypnotic Susceptibility: Form A; Stanford Hypnotic Susceptibility Scale: Form C) were examined in 38 low (0–3) and 39 highly (10–22) hypnotizable college students. Highs showed greater sustained attention on Necker cube and autokinetic movement tasks and self-reported greater absorption (Tellegen Absorption Scale) and extremely focused attentional (Differential Attentional Processes Inventory) styles. Hypnotizability was unrelated to dichotic selective attention (R. A. Karlin, 1979) and random number generation (C. Graham and F. J. Evans, 1977) tasks. Discriminant analysis correctly classified 74% of the lows and 69% of the highs. Results support H. J. Crawford and J. H. Gruzelier's (1992) neuropsychophysiological model of hypnosis that proposes that highly hypnotizable persons have a more efficient far frontolimbic sustained attentional and disattentional system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional attention set-shifting and its relationship to anxiety and emotion regulation.

Attentional deployment is a primary strategy individuals use to regulate emotion. In 2 experiments, a measure of an individual’s ability to deploy attention toward and away from emotional mental representations was developed. This measure of attentional control capacity for emotion adapted an explicit-cuing task switching paradigm in which participants had to shift between emotional and neutral mental sets. Experiment 1 (N = 118) showed that those higher in trait anxiety and worrisome thoughts took longer to switch from a neutral to an emotional mental set. In Experiment 2 (N = 42), participants were given a stressful anagram task, and those who switched more efficiently from a neutral set to an emotional set were more frustrated by the stressful task. In addition, those who switched more efficiently from an emotional set to a neutral set persisted longer on the stressful task. These findings provide an initial step toward identifying possible mechanisms through which individuals apply attentional control to emotional mental representations to regulate emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mood-Congruent Attentional Bias in Dysphoria: Maintained Attention to and Impaired Disengagement From Negative Information.

Attentional bias to negative information has been proposed to be a cognitive vulnerability factor for the development of depression. In 2 experiments, the authors examined mood-congruent attentional bias in dysphoria. In both experiments, dysphoric and nondysphoric participants performed an attentional task with negative, positive, and neutral word cues preceding a target. Targets appeared either at the same or at the opposite location of the cue. Overall, results indicate that dysphoric participants show maintained attention for negative words at longer stimulus presentations, which is probably caused by impaired attentional disengagement from negative words. Furthermore, nondysphoric participants maintain their attention more strongly to positive words. These results are discussed in relation to recent developments in the pathogenesis and treatment of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional bias predicts outcome in smoking cessation.

Most attempts to quit smoking end in failure, with many quitters relapsing in the first few days. Responses to smoking-related cues may precipitate relapse. A modified emotional Stroop task-which measures the extent to which smoking-related words disrupt performance on a reaction time (RT) task-was used to index the distracting effects of smoking-related cues. Smokers (N=158) randomized to a high-dose nicotine patch (35 mg) or placebo patch completed the Stroop task on the 1st day of a quit attempt. Smokers using an active patch exhibited less attentional bias, making fewer errors on smoking related words. Smokers who showed greater attentional bias (slowed RT on the first block of smoking words) were significantly more likely to lapse in the short-term, even when controlling for self-reported urges at the test session. Attentional bias measures may tap an important component of dependence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study of performance on tests from the CANTAB battery sensitive to frontal lobe dysfunction in a large sample of normal volunteers: implications for theories of executive functioning and cognitive aging. Cambridge Neuropsychological Test Automated Battery

Several tests from the CANTAB neuropsychological test battery previously shown to be sensitive to frontal lobe dysfunction were administered to a large group of normal volunteers (N = 341) ranging in age from 21 to 79 years. The main tests included a computerized form of the Tower of London test of planning, a self-ordered spatial working memory task, and a test of attentional set formation and shifting. A computerized form of the Corsi spatial span task was also given. Age-related graded declines in performance were seen, sometimes in a discontinuous manner, especially for the attentional set shifting task (at the extradimensional shift stage). Patterns of deficits reminiscent of frontal lobe or basal ganglia damage were observed in the oldest age group (74-79). However, overall the data were only partially consistent with the hypothesis that frontal lobe functions are the most sensitive to effects of aging. Factor analyses showed that performance in the executive tests was not simply related to a measure of fluid intelligence, and their performance had a factor loading structure distinct from that for the CANTAB tests of visual memory and learning previously administered to the same sample. Finally, only limited support was found for the hypothesis that cognitive aging depends on slowed information processing.     

A Combi-Stroop test for measuring food-related attentional bias.

There are methodological complexities with the supraliminal–lexical versions of the modified versions of the Stroop tests that could be responsible for inconsistencies across the literature (Field & Cox, 2008). We tested whether a combination of subliminal–pictorial and classic Stroop tests can differentiate between dieters' and nondieters' food attentional bias (FAB). Participants were dieters (n = 30) and nondieters (n = 32) who were tested 3 hr after having a meal. Each picture from among 24 high-calorie and 24 low-calorie food pictures was presented for 32 ms before the appearance of a congruent or an incongruent color word, in response to which participants were required to manually report, via a tagged keyboard, the correct color of the word as quickly and accurately as possible. Color-naming latencies and interference scores were calculated. Dieters showed the highest reaction times to incongruent color words following high-calorie food pictures; overall, dieters showed significantly higher FABs than nondieters. The Combi-Stroop test has differential validity. Moreover, findings suggest that FAB can result from early allocation of dieters' attention to food-related stimuli. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The effect of divided attention on memory for items and their context.

Examined differences between item and context memory using divided attention at encoding and retrieval. Ss, in 3 experiments, were presented with word lists and were instructed to learn the items (i.e., words), the intrinsic context (i.e., the color of the cards on which each word was presented), and the extrinsic context (i.e., the temporal order of the words). In Exp 1 24 undergraduates (aged 20–32 yrs) participated in a digit-monitoring and memory tasks. In Exp 2 the authors examined the effect of divided attention at retrieval using 24 undergraduates (aged 18–29 yrs). In Exp 3 the authors examined memory performance when divided attention was employed at encoding on all lists, and attentional load was manipulated at retrieval using 24 undergraduates (aged 19–32 yrs). Among young adults, in comparison to conditions of full attention, divided attention applied at encoding only or retrieval only resulted in equally lower performance on all memory tasks; in contrast, divided attention applied at both encoding and retrieval resulted in lower performance only on memory for temporal order. The findings support the idea that memory for temporal order requires greater attentional resources and strategic processing than memory for items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new clinical measure of attention: The Attentional Capacity Test.

Developed the Attentional Capacity Test (ACAT), which uses tasks that involve the processing of aurally presented numbers. A 60-item and a 24-item version of the ACAT were validated in 2 studies with a total of 144 normal Ss (aged 16–58 yrs) and 31 brain-damaged patients (aged 17–55 yrs). Other measures included the Digits Forward and Digits Backward tests from the Wechsler Adult Intelligence Scale—Revised (WAIS—R) and a paced auditory serial addition test. Overall, the ACAT appears to be a valid measure of attentional capacity. Normative data are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)