Enduring cognitive dysfunction in unipolar major depression: A test–retest study using the Stroop paradigm

Hammar, Å., Sørensen, L., Årdal, G., Oedegaard, K.J., Kroken, R., Roness, A. & Lund, A. (2009). Enduring cognitive dysfunction in unipolar major depression: A test–retest study using the Stroop‐paradigm. Scandinavian Journal of Psychology. The aim of the study was to investigate automatic and effortful information processing with the Stroop paradigm in a long term perspective in patients with major depressive disorder (MDD). Patients were tested at two test occasions: at inclusion with a Hamilton Depression Rating Scale (HDRS) score >18, and after 6 months, when most patients had experienced symptom reduction. The Stroop paradigm is considered to measure aspects of attention and executive functioning and consists of three conditions/cards: naming the color of the patches (Color), reading of the color‐words (Word) and naming the ink color of color‐words (Color‐Word). The Color‐Word condition is proved to be the most cognitive demanding task and requires the proband to actively suppress interference and is therefore considered to require more effortful information processing, whereas naming the color of the patches and reading the color‐words are expected to be more automatic and less cognitive demanding. A homogenous group of 19 patients with unipolar recurrent MDD according to DSM‐IV and a HDRS score of >18 were included in the study. A control group was individually matched for age, gender and level of education. Depressed patients performed equal to the control group on the Color and Word cards at both test occasions. However, the patients were impaired compared with the control group on the Color‐Word card task at both test occasions. Thus, the depressed patients showed no improvement of effortful attention/executive performance as a function of symptom reduction. The results indicate that the depressed patients showed impaired cognitive performance on cognitive demanding tasks when symptomatic and that this impairment prevailed after 6 months, despite significant improvement in their depressive symptoms.     

Aging and visual search: Generalized cognitive slowing or selective deficit in attention?

Abstract

Selective attention in normal aging was investigated using simple and conjoined feature visual search tasks. the effects of varying the location of the target (central vs. peripheral, left vs. right hemifield) and the complement of distractors, together with variability in task performance across subject groups, were also examined. the findings indicated that the feature extraction stage of visual search was preserved in older aged subjects. However, there was a differential age-related impairment in the feature integration stage of visual processing in the two older groups (66-75 years, 76-85 years). This was greater than the magnitude of decline predicted on the basis of generalized cognitive slowing. There was no evidence of a speed-accuracy trade-off in the performance of either search task. the findings of this study contribute towards the delineation of age-dependent and -independent processes subserving visual selective attention. the performance of older individuals may be relatively well preserved on more automatic, less demanding tasks such as simple feature search. By contrast, there may be differential age-related impairments on visual search tasks such as conjoined feature search, which may require more effortful or controlled attentional processing.     

Information processing in patients with first episode major depression

Hammar, Å., Kildal, A. B. & Schmid, M. (2012). Information processing in patients with first episode major depression. Scandinavian Journal of Psychology 53, 445–449. Few studies have investigated cognitive functioning in a group of patients experiencing a first episode of depression. The aim of this study was to investigate how patients diagnosed with a first episode of depression perform in effortful and non‐effortful information processing compared to healthy controls. An experimental paradigm based on a visual search test was applied. Thirty‐one patients and thirty‐one healthy controls were included in the study. All patients experienced a severe level of symptom load at the time of testing. Results showed no significant differences between groups under any of the conditions. Findings in the present study indicate that patients with a first episode of depression perform equally to healthy controls in tasks requiring visual attention in both effortful and non‐effortful information processing.     

Test of a potential link between analytic and nonanalytic category learning and automatic, effortful processing

The link between automatic and effortful processing and nonanalytic and analytic category learning was evaluated in a sample of 29 college undergraduates using declarative memory, semantic category search, and pseudoword categorization tasks. Automatic and effortful processing measures were hypothesized to be associated with nonanalytic and analytic categorization, respectively. Results suggested that contrary to prediction strong criterion-attribute (analytic) responding on the pseudoword categorization task was associated with strong automatic, implicit memory encoding of frequency-of-occurrence information. Data are discussed in terms of the possibility that criterion-attribute category knowledge, once established, may be expressed with few attentional resources. The data indicate that attention resource requirements, even for the same stimuli and task, vary depending on the category rule system utilized. Also, the automaticity emerging from familiarity with analytic category exemplars is very different from the automaticity arising from extensive practice on a semantic category search task. The data do not support any simple mapping of analytic and nonanalytic forms of category learning onto the automatic and effortful processing dichotomy and challenge simple models of brain asymmetries for such procedures.     

Effect of cognitive demand during training on acquisition, retention and transfer of a postural skill

The study examined whether attentional demands of a concurrent cognitive task during balance training affect the acquisition, retention and transfer of a postural control skill. Single-leg balance was evaluated in 64 volunteers (mean age 24.0 years, SD 3.10 years) while performing either a cognitive task requiring little attention (forward counting) or a highly demanding cognitive task (arithmetic manipulation) following three days of training. Skill retention was evaluated two days following the cessation of training, and transfer was determined by changes in the untrained extremity. Three training sessions induced decreases in mean sway velocity and amplitude variability. Skill retention was enhanced in the group trained under conditions with greater attentional demands, suggesting that diverting attention away from the postural task and allowing learning to involve more automatic processes may enhance the learning of such tasks. Practice induced similar changes in the trained and untrained extremities following both training protocols.     

Route learning in Korsakoff's syndrome: Residual acquisition of spatial memory despite profound amnesia

Korsakoff's syndrome (KS) is characterized by explicit amnesia, but relatively spared implicit memory. The aim of this study was to assess to what extent KS patients can acquire spatial information while performing a spatial navigation task. Furthermore, we examined whether residual spatial acquisition in KS was based on automatic or effortful coding processes. Therefore, 20 KS patients and 20 matched healthy controls performed six tasks on spatial navigation after they navigated through a residential area. Ten participants per group were instructed to pay close attention (intentional condition), while 10 received mock instructions (incidental condition). KS patients showed hampered performance on a majority of tasks, yet their performance was superior to chance level on a route time and distance estimation tasks, a map drawing task and a route walking task. Performance was relatively spared on the route distance estimation task, but there were large variations between participants. Acquisition in KS was automatic rather than effortful, since no significant differences were obtained between the intentional and incidental condition on any task, whereas for the healthy controls, the intention to learn was beneficial for the map drawing task and the route walking task. The results of this study suggest that KS patients are still able to acquire spatial information during navigation on multiple domains despite the presence of the explicit amnesia. Residual acquisition is most likely based on automatic coding processes.     

Automatic and effortful processing in Attention Deficit/Hyperactivity Disorder

Twenty-five boys with Attention Deficit/Hyperactivity Disorder and 23 age-matched controls were compared on verbal memory tasks differentiating automatic versus effortful information processing. Automatic processing tasks included the recognition of new or old words in a list and the recognition of frequency of occurrence of words in a list. Effortful tasks included free recall of lists of both related and unrelated words. Hyperactive boys did not differ from controls in automatic processing capabilities but demonstrated significantly poorer effortful processing. Intercorrelations of the variables revealed high correlations between scores on effortful measures and also raise questions about the purity of automaticity in some tasks employed. Stepwise discriminant analysis demonstrated that free recall of related words (an effortful task) best discriminated between groups. Effort-related processing in hyperactive and normal children is discussed in relation to variables of motivation, affect, arousal, and other higher-order cognitive processes.     

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8?s) and long durations (8/16?s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.     

Rumination and attention in major depression

Up until recently, it had been assumed that attentional biases for negative information do not exist in depression. However studies using post-conscious exposure durations have produced contradictory results. The limitations of common attentional tasks, suitability of stimulus materials and differences in stimulus duration times may have contributed to these inconsistencies. We aimed to address many of these issues and examine attentional responses in major depression at two post-conscious exposure times. We also investigated possible roles for rumination and distraction in increasing and lessening attentional biases for negative information. We used a fully controlled experimental design to test the effects of both induced and trait rumination and distraction on attention in patients with major depression and healthy controls. Attention was assessed using the dot-probe task. The findings revealed an attentional bias for negative information in depressed patients only at the longer post-conscious exposure duration. Furthermore although this bias was not influenced by either induced or trait distraction, it was related to trait rumination. Overall, the results showed that depression is associated with a strategic attentional bias towards negative information and that this bias is stronger in individuals who habitually ruminate.     

Attentional control and the relatedness proportion effect in semantic priming

In 2 experiments, participants completed both an attentional control battery (OSPAN, antisaccade, and Stroop tasks) and a modified semantic priming task. The priming task measured relatedness proportion (RP) effects within subjects, with the color of the prime indicating the probability that the to-be-named target would be related. In Experiment 2, participants were cued before each trial with the probability of a related target. Stimulus onset asynchronies traditionally thought to tap automatic processing (267 ms) versus controlled processing (1,240 ms) were used. Across experiments, principal component analysis on the battery revealed a general attentional control component. Moreover, the RP effect increased linearly with attentional control in both experiments. It is concluded that RP effects produced in this paradigm depend purely upon the effortful process of expectancy generation, which renders them sensitive to individual differences in attentional control.     

A parallel distributed processing approach to automaticity.

We consider how a particular set of information processing principles, developed within the parallel distributed processing (PDP) framework, can address issues concerning automaticity. These principles include graded, activation-based processing that is subject to attentional modulation; incremental, connection-based learning; and interactivity and competition in processing. We show how simulation models, based on these principles, can account for the major phenomena associated with automaticity, as well as many of those that have been troublesome for more traditional theories. In particular, we show how the PDP framework provides an alternative to the usual dichotomy between automatic and controlled processing and can explain the relative nature of automaticity as well as the fact that seemingly automatic processes can be influenced by attention. We also discuss how this framework can provide insight into the role that bidirectional influences play in processing: that is, how attention can influence processing at the same time that processing influences attention. Simulation models of the Stroop color-word task and the Eriksen response-competition task are described that help illustrate the application of the principles to performance in specific behavioral tasks.     

Information processing efficiency and regulation at five months

Infants with short look durations are generally thought to have better attentional capabilities due to their efficient information processing. Although effortful attention is considered a key component of developing regulatory abilities, little is known about the relation between speed and efficiency of processing and self-regulation. In this study, 5-month-old infants with shorter look duration had greater EEG power values than infants with longer look duration during baseline, as well as during a distressing task and a post-distress attentional processing task. These short looking infants also demonstrated higher heart rate, relative to long looking infants, during post-distress information processing. Behaviorally the two groups differed in the amount of distraction during distress. These data provide evidence for an association between the efficiency of information processing and beginning regulatory abilities in early infancy.     

Prior self-control exertion and perceptions of pain during a physically demanding task

ObjectivesExertion of self-control has been associated with impaired performance on subsequent physical tasks also requiring self-control, but it remains unknown why this occurs. This study, therefore, explored whether a) prior self-control exertion reduces subsequent persistence on a physically demanding task, and b) whether any observed performance decrements could be explained by changes in perceptions of pain.MethodIn a within-subject design, sixty-three individuals completed an easy (congruent) Stroop task or a difficult (incongruent) Stroop task that required self-control. Participants were then required to remain in a physically demanding posture (i.e., a ‘wall-sit’) until voluntary exhaustion and their perception of pain was recorded during the task.ResultsWhen participants completed the difficult Stroop task, they quit the wall-sit sooner. This decrement in performance was explained by greater perceptions of pain at the beginning of the wall-sit.ConclusionsPerceptions of pain may, therefore, be an important attentional mechanism explaining why self-control use interferes with subsequent persistence during physically effortful tasks.     

Effortful processing deficits in children with reading and/or attention disorders

Three groups of educationally troublesome boys were contrasted with adequate students on several tasks tapping effortful processing. The nonhyperactive reading disabled (RD) group differed both from controls and two attention deficit disorder (ADD) groups, one with and one without hyperactivity (H), on aspects of a memory task involving acoustic and semantic associations. All three clinical groups differed from controls in memory for low-imagery as opposed to high-imagery words and in computational efficiency. A stepwise regression analysis to predict reading grade level showed age and WISC-R IQ to account for 38% of the variance with an additional 28% explained by the effortful task variables (multiple R = .83). It is theorized here that attentional disorder impedes automatization of number facts; and, inasmuch as RD children receive adverse attention ratings, even if not considered hyperactive, they, as well as ADD and H/ADD boys, exhibit this deficiency.     

Effortful versus automatic emotional processing in schizophrenia: Insights from a face-vignette task

Adaptive emotional responding relies on dual automatic and effortful processing streams. Dual-stream models of schizophrenia (SCZ) posit a selective deficit in neural circuits that govern goal-directed, effortful processes versus reactive, automatic processes. This imbalance suggests that when patients are confronted with competing automatic and effortful emotional response cues, they will exhibit diminished effortful responding and intact, possibly elevated, automatic responding compared to controls. This prediction was evaluated using a modified version of the face-vignette task (FVT). Participants viewed emotional faces (automatic response cue) paired with vignettes (effortful response cue) that signalled a different emotion category and were instructed to discriminate the manifest emotion. Patients made less vignette and more face responses than controls. However, the relationship between group and FVT responding was moderated by IQ and reading comprehension ability. These results replicate and extend previous research and provide tentative support for abnormal conflict resolution between automatic and effortful emotional processing predicted by dual-stream models of SCZ.     

Is memory for spatial location automatically encoded?

Naveh-Benjamin (1987, 1988) has shown that memory for spatial location does not meet the criteria for automatic encoding as claimed by Hasher and Zacks (1979). Age, intention, concurrent processing demands, practice, strategies, and individual differences affected memory for location. These variables should have affected effortful but not automatic processing. The experiments reported in the present paper, in which a different task was used, showed that intention, practice, and concurrent processing demands did not affect memory for location. I concluded that (1) the location task used by Naveh-Benjamin included effortful subtasks and also incidental cover or concurrent processing tasks that interfered directly with performance, and (2) the variables that he manipulated may not have affected the encoding of location. The need to differentiate processes from task performance in analyzing the automaticity issue is discussed. The dominant mode for remembering location is automatic, but such information may also be remembered voluntarily.     

颜色字词的识别真的无需注意力资源的参与?——来自Stroop范式的证据

3个实验采用颜色词、颜色词同音词以及颜色语义联想词作为启动词,使启动词的语义和颜色实现时空分离、启动词处于非空间注意焦点位置、降低启动词可视度的情境下,考察具有自动化加工特征的启动词是否受到注意力资源的制约以及启动词在获得不同数量的注意力资源时其自动化程度是否存在显著的差异。结果发现:(1)注意力资源实质性地决定着自动化加工能否顺利进行,具有自动激活特征的刺激在无法获得注意力资源时,自动化加工过程终止。(2)可用的注意力资源数量调控着自动化加工的效率和语义提取的效果,可用的注意力资源数量越多,对启动刺激的语义加工越完善,对目标刺激的促进效果也越有效。本研究结果支持注意力敏感模型关于自动化加工受认知系统的支持和配置才能完成的假设。     

Distinguishing between automaticity and attention in the processing of emotionally significant stimuli

There is contradicting evidence as to whether irrelevant but significant emotional stimuli can be processed outside the focus of attention. In the current study, participants were asked to ignore emotional and neutral pictures while performing a competing task. In Experiment 1, orienting of attention to distracting pictures was manipulated via a peripheral cue. In Experiment 2, attentional load was varied, either leaving spare attention to process the distracting pictures or, alternatively, depleting attentional resources. Although all pictures were task irrelevant, negative pictures were found to interfere more with performance in comparison to neutral pictures. This finding suggests that processing of negative stimuli is automatic in the sense that it does not require execution of conscious monitoring. However, interference occurred only when sufficient attention was available for picture processing. Hence, processing of negative pictures was dependent on sufficient attentional resources. This suggests that processing of emotionally significant stimuli is automatic yet requires attention.     

Evidence for the Involvement of the Rat Prefrontal Cortex in Sustained Attention

Previous studies suggest that, in both humans and rats, the prefrontal cortex (PFC) is involved in both selective and divided attention. We have also shown that the PFC is involved in response selection and that its involvement is modulated by the cognitive effort required by the task. However, the role of the PFC is much less clear when no response selection is required. The purpose of the present experiments was to assess the role of the PFC in attentional functions with a low response-selection demand. We used two tasks in which information processing was effortful but where the demand on a response selection process is low. Moreover, we assessed two different types of visual attentional functions: selective attention (Experiment 1) and sustained attention (Experiment 2). The results showed a differential involvement of the PFC in the two tasks. Selective attention was not impaired by prefrontal lesions when the number of possible positions for the stimulus on which the subjects must focus was restricted to two (Experiment 1). In contrast, prefrontal rats were unable to sustain their attention long enough to detect, and react to, subtle variations in brightness (Experiment 2). This result suggests a dissociation between different types of attentional functions depending upon the integrity of the PFC. More specifically, results in Experiment 2 suggest an involvement of the PFC in sustained attention. Finally, the overall results show that even in tasks involving low demands on response selection the PFC is involved in attentional functions.