Continuous Performance Task

Continuous Performance Tests (CPT) are classic examples of tests which require sustained attention (see Riccio, Reynolds, & Lowe, 2001 for a comprehensive review).

From: WISC-IV Clinical Use and Interpretation , 2008

Psychometrics and Neuropsychological Assessment

Juri D. Kropotov , in Functional Neuromarkers for Psychiatry, 2016

Continuous performance tasks

To obtain reliable parameters of behavior, continuous performance tasks (CPTs) are usually used where the subject performs a constant-difficulty task for minutes or tens of minutes without interruptions. The first version of the CPT was developed in 1956 by Haldor Rosvold and coworkers and demonstrated that patients with brain damage had difficulties in task performance compared with healthy controls. The most commonly used CPTs are the Test of Variables of Attention (TOVA), the Integrated Visual and Auditory CPT (IVA), and Conners' CPT (Rosvold, Mirsky, Sarason, Bransome, & Beck, 1956). These tests are often used for helping to support or rule out a diagnosis of ADHD. In addition there are some CPTs, such as the QbTest and Quotient, that combine attention and impulsivity measures with motion tracking analysis.

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Executive System

Juri D. Kropotov , in Quantitative EEG, Event-Related Potentials and Neurotherapy, 2009

E Error-Related Negativities

Monitoring operation is also studied in continuous performance tasks that are accompanied by errors in some trials 31 . Errors generate a component named error-related negativity (ERN) followed by a positive component. The negative wave is observed immediately following errors and has peak latency around 100   ms. It has a fronto–central distribution and dubbed as the error negativity (NE) or ERN. The ERN has repeatedly been modeled by a single dipole source, located in the vicinity of the ACC. In support of these dipole models, studies using fMRI have shown increased activation of the ventral part of the ACC during error trials relative to correct trials.

Error-related components in ERPs can be also observed in the mathematical paradigm. In this task subjects viewed brief presentations of a math operation on two numbers (such as 2   +   2) followed by a second number (say 4 or 5) with the subject's task to press a button if the second stimulus matches the result of mathematical operation (in this example, number 4) or to withhold from pressing in the mismatch condition (in this example, number 5). To separate these components we need to compare two conditions: incorrect pressing to mismatch stimuli (commission errors) and correct pressing to match cues. Figure 12.14 represents the results of decomposing ERN into three independent components. The data are taken from the Human Brain Institute Normative Database. Subjects performed the mathematical task. The task is quite difficult to perform so that the subjects did a substantial number of errors. In each subject ERPs were computed for correct match trials 32 and incorrect mismatch trials 33 . Button pressing served as trigger events. The difference (incorrect–correct) waves were also computed. As one can see the ERN actually consists of two independent components, one is located in the dorsal anterior (cognitive) and the other one is located in the more posterior (motor) regions of the cingulate cortex. In addition to these two components elicited just after the incorrect motor response ERN also includes the component that starts before the motor response and is generated in the left sensory motor area of the cortex 34 .

Figure 12.14. Error-related negativities. ICA was performed on a set of more than 200 individual ERPs taken from the Human Brain Institute Normative Database. ERP were triggered by correct and incorrect responses in the Mathematical task. The largest three independent components are presented from top to bottom. From left to right – topographies, individual color-coded vertically stalked components, and s-LORETA images. Below are components computed for superimposed correct trials (thin line), incorrect trials (think line) and separately for ERPs differences.

It should be noted here that the clinical use of ERN is limited for at least two reasons. First, the error is a very subjective event depending on a subject motivation, attention, and abilities of the sensory system. Because of that the number of errors in the same task but for different subjects differs substantially. Consequently, the number of "error" trials for averaging ERPs is not a constant value which has an effect on the individual parameter of ERN. Second, to get enough trials for a reliable ERN measurement the task must be quite difficult. But, some people (such as young children, Alzheimer patients) can not perform difficult tasks.

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Animal Models (Nonprimate) for Human Stress*

J.E. Ottenweller , in Encyclopedia of Stress (Second Edition), 2007

Chronic stressors

Commonly used chronic stressors include repeated exposures to the acute stressors previously listed, continuous performance tasks, overcrowding, and complex social situations when appropriate for the species. Repeated exposures to the same stressor can lead to habituation, that is, smaller responses over time and eventually no response to the stressor. Two approaches have been used to prevent this habituation. In the first, different acute stressors are alternated on consecutive days. The second approach uses relatively few exposures to a very intense stressor that prevents habituation and may actually produce sensitization, that is, larger responses to the stressor over time. Whether habituation or sensitization occurs can be related to the intensity of the stressor inasmuch as animals will habituate to low-intensity shock stress and sensitize to the same shock stress at higher intensities.

Continuous performance tasks are generally operant tasks that require frequent responses to avoid aversive stimuli or, in a few cases, to obtain positive reinforcement. Frequent motor responses are one aspect of this stressor, but another is the requirement for frequent or continuous attentiveness over days. Increasing the number of animals (three or more) in a cage is stressful, but so is single housing of social species. Finally, several chronic stress models involve the daily changing of cagemates in species with dominance hierarchies, which leads to the continual disruption of and need to reestablish the hierarchies. Most recently, a few laboratories have added naturalistic environments to the disruption of dominance hierarchies and social interactions. In these chronic social stressors, rank in the hierarchy usually determines stressfulness with more dominant individuals generally showing less stress.

Finally, there is an extensive literature on two other specific animal stress models: learned helplessness and fear conditioning. The learned helplessness paradigm was used in the past as a model to understand the physiological underpinnings of depression and to screen compounds for antidepressant activity. In this model, an animal was first exposed to inescapable shock, and then it failed to escape subsequent shock when given the opportunity. Antidepressants will reverse this failure to escape, and so the paradigm was used to screen novel compounds for antidepressant activity. More recently, inescapable stress without the helpless behavior has been used for animal models of depression.

Another model of psychological stress is fear-conditioned behavior. In these models, an animal is stressed in a particular context and later returned to the context without the stressor. On reexposure to the context, the animal becomes hyperresponsive, which may be manifested in fear-potentiated startle, freezing behavior, or elevated stress hormones (e.g., glucocorticoids).

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Schizophrenia

Juri D. Kropotov , in Functional Neuromarkers for Psychiatry, 2016

Motor abnormalities

In general, patients with SZ are slower in motor response and perform more omission and commission errors in continuous performance tasks indicating impairment of the motor system. The effect sizes of discriminating a group of SZ patients from HCs is 0.6–1.1 for reaction time and 0.5–3.0 for omission/commission errors.

There are also signs of impairment of the ocular motor system. A group of SZ patients differs significantly from a group of HCs in viewing pictures or pursuing target movements. For example, Philip Benson and coworkers from King's College, University of Aberdeen (United Kingdom) in their 2012 study showed that a group of SZ patients could be discriminated from HCs with near-perfect accuracy at 98% on almost all eye movement tests (Fig. 5.2.3).

Figure 5.2.3. Simple viewing tests distinguish patients with SZ from HCs with exceptional accuracy.

Scanpaths superposed on the stimulus trajectory for a HC and a patient with SZ.

 Adapted with permission from Benson et al. (2012).

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What does Medial Frontal Cortex Signal During Behavior? Insights from Behavioral Neurophysiology

Stefanie Hardung , ... Ilka Diester , in International Review of Neurobiology, 2021

The 5-Choice Serial Reaction Time Task (5CSRTT ). Another powerful paradigm for studying ongoing cognitive and motor processes is the 5CSRTT procedure which was originally developed as a rodent homologue to the continuous performance task for humans ( Robbins, 2002). The basic form of the 5CSRTT requires the subject to scan a horizontal array of five apertures for the presentation of brief flashes of light presented in a pseudorandom order in one of the five locations. Once the subject detects the cue it must poke its nose inside the illuminated port to receive a reward. Although the task was originally designed to assess attention, it is nowadays widely used to analyze a variety of cognitive and motor processes, such as decision-making, impulsive as well as compulsive behavior (Asinof & Paine, 2014).

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Neural Basis of Attention-Deficit/Hyperactivity Disorder

P. Berquin , O. Godefroy , in Encyclopedia of Behavioral Neuroscience, 2010

Attention and Cognitive Deficits Underlying AD/HD

Recent advances in cognitive neuroscience lead to a better understanding of mechanisms underlying AD/HD symptoms and related cerebral networks. Sustained AD is usually thought to be the key deficit in AD/HD. However, studies using computerized Continuous Performance Task showed inconsistent or negative findings supporting that symptoms in AD/HD are not attributable to a true sustained AD per se.

Recent studies indicate that AD/HD children suffer from disorders of executive functions and suggest the core deficit concerns inhibition. Studies have documented deficits of various executive processes, including planning, set shifting, and inhibition of prepotent responses. The inhibitory hypothesis of AD/HD provides a good account of clinical symptoms observed in daily life and clinical examination, especially excessive distractibility, as well as deficits on Go/No-go or Continuous Performance Tasks. Although less studied, children suffering from AD/HD show robust slowness and variability of RT in various experimental tasks. This finding could reflect a more diffuse AD than a specific inhibitory deficit. However, convergent data suggest that slowness in AD/HD especially concerns tasks involving controlled processes (i.e., involving executive functions) than those involving automatic processes.

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Occupational Neurology

Margit L. Bleecker , Sheryl K. Barnes , in Handbook of Clinical Neurology, 2015

Cognitive impairment in traumatic brain injury

Very mild TBI is associated with prefrontal axonal injury involving the dorsolateral prefrontal cortex found on diffusion tensor imaging. This results in impaired executive function that continues to develop over time following the injury (Lipton et al., 2009 ). Executive function impairment demonstrated increased errors of omission on continuous performance task and slower times to complete a maze. Use of methylphenidate helped the attentional component and memory in these patients ( Cernich et al., 2010). Individuals with persistent neuropsychologic deficits following minor head injury did not differ according to the neurologic deficit immediately following the injury – namely, loss of consciousness, disorientation, or confusion (Leininger et al., 1990). Functional recovery to being disability-free at 1 year from moderate/severe TBI was significantly influenced by educational attainment, a measure of cognitive reserve (Schneider et al., 2014). Response to cognitive training for attention and executive functions after brain injury is dependent upon functional brain network modularity (Arnemann et al., 2015).

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Assessment, Methodology, Training, and Policies of Sleep

M.R. Schoenberg , W.D.S. Killgore , in Encyclopedia of Sleep, 2013

Abstract

Sleep disorders have a significant adverse impact on alertness, vigilance/sustained attention, and higher cognitive functions (e.g., executive functioning and visual memory) as well as mood/affect. Neuropsychological evaluation can be helpful to evaluate the extent and severity of adverse effects of sleep disruption on cognitive functioning. Neuropsychological assessment of deficits should target the assessment of vigilance/sustained attention (frequently using a continuous performance task), executive functions (sequencing, problem solving, disinhibition, and problem solving), mood/affective functioning, and, sometimes, visual memory. Neuropsychological evaluations can have implications for identifying the extent and severity of cognitive impairments. Treatment for insomnia can improve neuropsychological function. Patients with acute sleep deprivation show improved neuropsychological functioning with a variety of stimulant medications (e.g., dextroamphetamine, modafinil, ritalin, etc.). Patients with obstructive sleep apnea show improved neuropsychological functioning following initiation of continuous positive airway pressure or bilevel positive airway pressure. Neuropsychological evaluation is also a method to document the effectiveness of treatment for sleep disorders.

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Attention Deficit–Hyperactivity Disorder

David E. Mandelbaum , in Swaiman's Pediatric Neurology (Sixth Edition), 2017

Biofeedback Programs

Various forms of computerized training programs have been studied in treating children with ADHD. Computerized working memory training improved working memory capacity in children with ADHD and adults without ADHD. Improvement generalized to nonpracticed tasks involving prefrontal cortex, and associated with improvement in working memory was a decrease in head movements in children with ADHD. Children with ADHD trained to modify their slow cortical potentials also showed an increase in contingent negative variation (CNV) during a continuous performance task compared with those who did not receive training. Associated with this electrophysiologic phenomenon were fewer impulsivity errors on the continuous performance task, suggesting that the CNV increase represented a neurophysiologic correlate of improved self-regulatory capabilities. A meta-analysis of studies of nonpharmacologic treatments of ADHD ( Hodgson et al., 2014), which was limited to studies of treatment and control groups and excluded studies using within-subjects designs to minimize placebo effects, found that behavior modification was effective in treating ADHD in children, achieving improved function across a number of domains including behavior and test performance. Neurofeedback was found to result in significant improvement in DSM-IV symptoms, test performance and behavior. There was no significant benefit established for school based treatments, parent training, working memory training, self monitoring or multimodal psychosocial treatment interventions in measurements of ADHD functional domains. Psychological treatments for ADHD were more effective among girls than boys and were least effective for children with combined-type ADHD (Martijn et al., 2009).

Use of an EEG biofeedback program was compared with the effectiveness of methylphenidate. After 3 months of the program, both groups had significant improvements in all four subscales on the TOVA and improvement on a behavior rating scale. Changes in the EEG as a result of biofeedback were not monitored in this study. A previous study using biofeedback reported greater improvement on the test of variables of attention (TOVA) in participants with significant EEG changes than in those without changes (although there were improvements in both groups). There was no correlation between behavioral changes reported by the parents and changes in the EEG. This study did not include a control group. A study of EEG biofeedback that used a control group (i.e., association between EEG patterns and feedback to the participants was random) found no benefit from EEG biofeedback.

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Emotion and Cognition

Juyoen Hur , ... Alexander J. Shackman , in Progress in Brain Research, 2019

4.1 The nature of executive function and cognitive control

Lapses in concentration and problems with cognitive function are clinically significant features of anxiety disorders and other psychiatric illnesses (American Psychiatric Association, 2013). Yet the contributions of executive function and cognitive control—the basic building blocks of intelligence and complex everyday cognition—to pathological anxiety have received considerably less empirical attention than attentional biases to threat. Executive function refers to the processes involved in shifting between mental sets or tasks, updating and monitoring working memory (e.g., n -back continuous performance task), and inhibiting prepotent responses (Banich, 2009; Miyake and Friedman, 2012; Miyake et al., 2000). Cognitive control encompasses a range of processes—including attention, inhibition, and learning—that are engaged when automatic or habitual responses are insufficient to sustain goal-directed behavior, as with the inhibitory facet of executive function (Shackman et al., 2011b). Like fear and anxiety, cognitive control is a component of the NIMH Research Domain Criteria (RDoC) (Clark et al., 2017b; Kozak and Cuthbert, 2016). Common assays of cognitive control include variants of the Anti-Saccade, Eriksen Flanker, Go/No-Go, Simon, Stop-Signal, and Stroop tasks. Here, we use "executive control" as a rubric for executive function and cognitive control.

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