Continuous Performance Test

The CPT assesses visual vigilance in scanning and concentrating on a stimulus array—a type of performance that must have accurate, split-second timing of both stimuli and responses—a perfect application of computers in test administration.

From: Comprehensive Clinical Psychology , 1998

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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Transcranial Magnetic Stimulation in Autism Spectrum Disorder

Peter G. Enticott , ... Lindsay M. Oberman , in Neurotechnology and Brain Stimulation in Pediatric Psychiatric and Neurodevelopmental Disorders, 2019

Abbreviations

μV

microvolts

ASD

autism spectrum disorder

CPT

continuous performance test

cTBS

continuous theta burst stimulation

DLPFC

dorsolateral prefrontal cortex

EEG

electroencephalography

EMG

electromyography

GABA

gamma-amino-butyric-acid

ICF

intracortical facilitation

ISP

interhemispheric signal propagation

iTBS

intermittent theta burst stimulation

NMDA

N-methyl-d-aspartate

LICI

long-interval cortical inhibition

M1

primary motor cortex

MEP

motor-evoked potential

MSO

maximum stimulator output

mV

millivolts

NIBS

noninvasive brain stimulation

RMT

resting motor threshold

rTMS

repetitive transcranial magnetic stimulation

SICI

short-interval cortical inhibition

SMA

supplementary motor area

TBS

theta burst stimulation

TMS

transcranial magnetic stimulation

TPJ

temporoparietal junction

WCST

Wisconsin card sorting test

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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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Mammalian Hormone-Behavior Systems

Nicole J. Gervais , ... Agnès Lacreuse , in Hormones, Brain and Behavior (Third Edition), 2017

1.16.3.2.2.1 Humans

A test of selective visual attention is the continuous performance test ( Rosvold et al., 1956). Although there are several versions of this test, they all involve presentation of stimuli on a screen, and the participant must respond by pressing a key when the target stimulus is presented. Other tests include the Digit Symbol subtest of the WAIS. This test involves presenting a set of digit–symbol pairs, and participants are shown a list of digits and are asked to identify the symbols that are paired with each symbol as quickly as possible. Studies report inconsistent results, with some studies reporting no effect of HRT on attention (Keenan et al., 2001; Wolf et al., 2005), while other studies report improved attention following HRT (Smith et al., 2001; Schmidt et al., 1996).

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Inside the Triple-Decker

Kjell Tore Hovik , ... Elkhonon Goldberg , in Executive Functions in Health and Disease, 2017

Tests of Focused and Sustained Attention

Accuracy and sustainability of attention: Conners' Continuous Performance Test-II (CCPT-II). In this task, the child is presented with a repetitive array of visual stimuli on a computer screen for 14  min (Conners, 2004). The child is instructed to press the space bar every time a letter other than "X" appears and to not press the space bar when "X" appears. The rate of stimulus presentation varies according to 1, 2, and 4   s intervals throughout the task. From the 12 measures available on the test, 4 composites were calculated based on findings in an earlier study applying principal component analysis to derive four salient measures of attention (Egeland & Kovalik-Gran, 2010). Focused attention is the mean t-score of Omissions, Perseverations, Variability, and Hit Reaction time Standard Error. Hyperactivity–Impulsivity is the mean t-scores of Hit Reaction Time, Commission Errors, and Response Style. Sustained attention is computed from Block Change and Block Change Standard Error, measuring the change in reaction time or increase in variability of reaction time as a function of time on task. Vigilance is computed from the Interstimulus interval (ISI) change score and the standard error of ISI change.

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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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Gray Matter, Lateral Ventricle Volumes, and Executive Functioning in Cannabis Users with First-Episode Psychosis

P.J. Cunha , ... M.S. Schaufelberger , in Handbook of Cannabis and Related Pathologies, 2017

List of abbreviations

ACC

Anterior cingulate cortex

ARMS

At-risk mental state

BD

Backward Digits

CBD

Cannabidiol

CB1

Type-1 cannabinoid receptors

CPT

Continuous Performance Test

DARTEL

Diffeomorphic registration algorithm

FD

Forward Digits

FEP

First-episode psychosis

FES

First-episode schizophrenia

GM

Gray matter

LVs

Lateral ventricles

MRI

Magnetic resonance imaging

PCC

Posterior cingulate cortex

PFC

Prefrontal cortex

ROIs

Regions of interest

ROP

Recent-onset psychosis

ROS

Recent-onset schizophrenia

THC

Δ9-Tetrahydrocannabinol

THs

Temporal horns

VBM

Voxel-based morphometry

VBRs

Ventricle-to-brain ratios

WCST

Wisconsin Card Sorting Test

WMS-III

Wechsler Memory Scale

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COGNITIVE DYSFUNCTION AND OTHER COMORBIDITIES | Attention Deficit Disorder and Epilepsy in Children

R. Schubert , in Encyclopedia of Basic Epilepsy Research, 2009

Methods

The diagnosis of ADHD is still made clinically, predominantly by using observer behavior rating scales. Supportive information can be provided by formal neuropsychological testing and continuous performance tests. PET and functional MRI (fMRI) are utilized as research tools. A wide variety of behavior rating scales are available. Commonly used scales include Conner's rating scales, Vanderbilt scales, SNAP-IV, Aschenbach scales, and Child Behavior Checklist. These scales screen for core symptoms of inattention, hyperactivity, and impulsivity. Most also provide information on oppositional defiant behaviors and symptoms of conduct disorder, as well as an overview of classroom academic performance. Assessments via rating scales are typically made by parents and teachers, although adolescent and adult self-rating scales are also utilized. Shorter follow-up rating scales are used to monitor treatment response. Additional observer and self-rating scales are sometimes used to screen for co-morbid disorders, such as anxiety, depression, and mood dysregulation.

Continuous performance tests are computerized tests of attention. Typically, a series of varying shapes, pictures or letters flash on the screen, and the test subject has to click a mouse button whenever the correct figure appears. The tests typically measure errors of omission (not clicking at the appropriate stimulus) – which correlate with inattention, and errors of commission (clicking when you shouldn't click) – which correlate with impulsivity. Time needed to click and variability of response time are also measured. These measures are typically increased in individuals with ADHD. Formal neuropsychological testing provides additional evidence of frontal lobe dysfunction by demonstrating deficits of working memory, planning, sorting, and shifting attention between sensory modalities.

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Neuropharmacology of Attention

Jean A. Milstein , ... Trevor W. Robbins , in Neurobiology of Attention, 2005

2. Studies of the Effects of Systemic Cholinergic Agents

The effects of nicotine as a cognitive enhancer were shown by improved performance of patients with Alzheimer's disease, as well as normal elderly and young volunteers, on a rapid visual information processing continuous performance test, a demanding version of the CPT task in which the subject responds to odd or even numerical sequences; in this case, ascending triads of odd or even numbers (i.e., 2, 4, 6 or 1, 3, 5) More specifically, it increased hits and decreased RT ( Sahakian et al., 1989).

Similarly, nicotine enhanced performance of the 5CSRT task, but only under specific task conditions, specifically, a low event rate, with punishment only for incorrect responses, thus removing the response-inhibition component of the task and reducing the requirement for executive control. In this version, nicotine decreased the detrimental effects of bursts of white noise on performance (Hahn et al., 2002). Also, for rats at low baseline accuracy, nicotine increased accuracy and speeded latencies, indicating a possible role in signal detection or response selection.

In the cued target detection task, nicotine facilitated response disengagement. In casual cigarette smokers, nicotine induced larger validity effects, specifically by reducing the response latency to invalidly cued targets (Murphy and Klein, 1998). There is some cross-species convergence from studies in the rat, in which although nicotine abolished the validity effect, it did so by significantly decreasing RT to invalid cues as well as speeding RTs in general (Phillips et al., 2000); Witte et al., (1997) obtained similar results in two rhesus monkeys treated with nicotine, as well as in cigarette smokers.

Whereas nicotinic receptor agonists generally appear to enhance attention and response selection, muscarinic receptor antagonists broadly have the opposite effects. For example, scopolamine impaired selective attention in the five-choice task when white noise was presented prior to stimulus onset. Similarly, whereas nicotine improved attentional shiftining/response disengagement in the rat covert orienting task, scopolamine induced a slowing of RT generally, as well as a specific inability to shift from the invalid cue to make a correct response measured by RT (Phillips et al., 2000).

In general, there is converging evidence from each of the tasks described that the frontal cholinergic projections are involved in a variety of aspects of attentional processing. Aside from having disinhibitory effects similar to those observed with the stimulant drugs (which presumably act via the catecholamines), acetylcholine also facilitates switching between response sets and modulates attentional disengagement, as well as attentional performance, with increasing task demand. Note that all three of the main tasks described require rapid response selection and signal detection, as well as rapid shifts in attention. This often leads to improvements in many settings, but it may cause potential impairment in others with different demands, for example, by increasing response lability.

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