Many thanks to the developers of this paradigm, especially Wesley Clapp, Anne Berry, Jyoti Mishra, Michael Rubens, and Theodore Zanto. This work was supported by NIH grant 5R01AG0403333 (AG).

The steps below enumerate how to execute this novel cognitive paradigm designed to elucidate the neuro-behavioral aspects of external interference on delayed recognition working memory, with variations optimized for pairing with EEG or fMRI. Prior to beginning data collection, complete all necessary human-participants research approvals through the appropriate Institutional Review Board and/or human participants review committee.
1. Preparation
<ol>
	<li>Download and install experiment presentation software such as E-Prime, Presentation, or PsychoPy, as per manufacturer&#8217;s instructions, onto a dedicated stimulus presentation computer.</li>
	<li>Prepare an appropriate keypad for experimental responses. Add &#8220;YES&#8221; and &#8220;NO&#8221; labels to two adjacent keys (Figure 1). 
	NOTE: For versions of this experiment utilizing MRI, use an MR-compatible keypad.</li>
	<li>For auditory versions of this paradigm, prepare headphones appropriate for testing modality (ie: EEG or MR-compatible, if necessary), as per manufacturer&#8217;s instructions, and adjust sound level for presentation at 65 decibels (dB) sound pressure level (SPL), which is a comfortable level for normal hearing individuals.</li>
	<li>For experiments with older adults, conduct preliminary neuropsychological and sensory screenings such as vision and hearing to select an appropriately screened study population.
	<ol>
		<li>Neuropscyhological screening
		<ol>
			<li>Create a neuropsychological assessment battery to screen for cognitive impairment in older adults. Administer tests by paper-and-pencil, or adapt a battery for testing on a computer. 
			NOTE: Tests may include the Mini Mental Status Exam (MMSE) 35 , Global Deterioration Score (GDS) 36, California Verbal Learning Test (CLVT) 37, Digit Span 38,39, Symbol Span 40, Letter-Number Sequencing 41, Delis-Kaplan Executive Function System (D-KEFS) &#8211; Trail Making Test 42, Controlled Word Association Test (COWAT) 43, 44.</li>
			<li>Administer this battery to all prospective adult participants. Score all tests per their respective scoring guidelines.</li>
			<li>If recruiting for healthy older adults, exclude prospective participants with scores greater than two standard deviations below the population mean, or per custom exclusion criterion.</li>
		</ol>
		</li>
		<li>Vision screening
		<ol>
			<li>For visual experiments, screen for normal or corrected-to-normal vision using a preliminary questionnaire asking whether participants have normal or corrected-to-normal vision.</li>
			<li>To follow up, conduct a Snellen chart vision test, and exclude participants without normal or corrected-to-normal (20/20 or greater) vision.</li>
		</ol>
		</li>
		<li>For auditory experiments, screen for normal hearing:
		<ol>
			<li>In a preliminary questionnaire, ask whether participants have normal or corrected-to-normal hearing, and exclude those who do not.</li>
			<li>To follow up, obtain an objective measurement of hearing sensitivity. Conduct an in-lab audiometric assessment with one of several methods:
			<ol>
				<li>Utilize a hearing loss screening test application such as &#8216;uHear&#8217;. Using this application&#8217;s auto-calculated results, exclude subjects with hearing sensitivity outside of the &#8216;normal hearing&#8217; range.</li>
				<li>Assess audiometric thresholds in the 250 - 6,000 Hz frequency range in both ears by the method of ascending and descending limits. Individuals with mean audiometric thresholds greater than 50 dB at any test frequency in either ear, signifying moderate hearing loss, should be excluded</li>
			</ol>
			</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
2. Experimental Design
<ol>
	<li>Administer a delayed recognition working memory task under three distinct interference conditions (and a fourth baseline condition for neural experiments) in a block design (see also Figure 2 and Table 1). Repeat each condition twice, in counterbalanced order (a balanced Latin square design is recommended). Note that experimental timing and number of trials vary between paradigm variants; utilize the parameters detailed in Table 1.</li>
	<li>Ignore Distracting Stimulus Condition (DS):
	<ol>
		<li>Display a prompt instructing participant to remember the cue stimulus and ignore the distracting stimulus while continuing to maintain a representation of the cue stimulus. Instruct the participant to respond &#8220;YES&#8221; if the probe stimulus matches the cue stimulus or &#8220;NO&#8221; if the probe does not match the stimulus.</li>
		<li>Present the cue stimulus, immediately followed by a short delay (Delay 1).</li>
		<li>Display an interfering &#8216;distractor&#8217; stimulus, immediately followed by a second short delay (Delay 2). 
		NOTE: The participant does not need to (and should not) interact with the distractor stimulus.</li>
		<li>Present a probe stimulus and collect responses.</li>
	</ol>
	</li>
	<li>Attend to Interrupting Stimulus (Secondary Task) Condition (IS):
	<ol>
		<li>Display a prompt instructing participant to remember the cue stimulus and complete a secondary task using the interfering stimulus that appears thereafter. Display instructions to complete the secondary task as follows, &#8220;press a button only if the interrupting stimulus matches a set of discrimination criteria&#8221;. Instruct the participant to respond &#8220;YES&#8221; if the probe stimulus matches the cue stimulus or &#8220;NO&#8221; if the probe does not match the stimulus. 
		NOTE: The discrimination criteria are distinct for each paradigm variant and described in the next section.</li>
		<li>Present the cue stimulus, immediately followed by a short delay (Delay 1).) Present an interfering &#8216;interruptor&#8217; stimulus and collect responses for the secondary (discrimination) task. Following, present a second short delay (Delay 2). 
		NOTE: Completing the secondary task requires attention to the &#8216;interruptor&#8217;.</li>
		<li>Present a probe stimulus and collect responses. 
		NOTE: Ten percent of trials are catch trials in which the interruptor matches the discrimination criteria; add additional trials (10%) to this block to compensate for the discarded trials. Exclude all catch trials from neural analysis due to the confounding motor response.</li>
	</ol>
	</li>
	<li>No Interfering Stimulus Condition (NI):
	<ol>
		<li>Display a prompt instructing the participant to remember the cue stimulus and keep it in mind. Instruct the participant to respond &#8220;YES&#8221; if the probe stimulus matches the cue stimulus or &#8220;NO&#8221; if the probe does not match the stimulus.</li>
		<li>Present the cue stimulus, immediately followed by a delay. Display a central fixation cross on a blank screen during the delay.</li>
		<li>Present a probe stimulus and collect responses.</li>
	</ol>
	</li>
	<li>Baseline/Passive View (or Listen) Condition (only for neural experiments) (PV/PL)
	<ol>
		<li>Include a passive-view/listen condition during neuroimaging tasks to enable calculation of &#8216;enhancement&#8217; and &#8216;suppression&#8217; of neural activity during IS/DS conditions relative to baseline activity when participants passively view (/listen to) the working memory and interfering stimuli, free from task goals. (See Table 2.)</li>
		<li>Display a prompt instructing participant to passively view (/listen to) all visual (/auditory) task stimuli. Display instructions to complete the simple discrimination task.
		<ol>
			<li>For visual tasks, instruct the participant to press a button corresponding to the direction of a displayed arrow (left or right).</li>
			<li>For auditory tasks, instruct the participant to press a button corresponding to the frequency range of an easily discriminable high (2 kHz) or low (0.5 kHz) frequency sound sweep (high or low).</li>
		</ol>
		</li>
		<li>Sequentially present or display the cue stimulus, Delay 1, interfering stimulus, and Delay 2.</li>
		<li>Present an arrow (visual) or sound sweep (auditory) in place of the probe stimulus and collect responses as the participant completes the simple discrimination task (described above).</li>
	</ol>
	</li>
</ol>
3. Stimuli
1. General Preparation of Stimuli
	<ol>
		<li>Select a set of stimuli from the categories described below (see also Figure 2 and Table 1).</li>
		<li>Carefully decide whether to pair primary working memory task stimuli with thematically congruent or incongruent interfering stimuli (see NOTE below).</li>
		<li>Ensure that all images are sized or re-sized to 225 pixels wide and 300 pixels tall (14 x 18 cm).</li>
		<li>Present images foveally, subtending 3 degrees of visual angle from fixation. 
		NOTE: For fMRI experiments, use interference stimuli incongruent with the primary working memory task stimuli, for example, face interference during scene working memory or vice versa. To precisely localize face and scene specific sensory cortical regions, apply a fMRI localizer task prior to the working memory experiment. Then, during the interference paradigm, use these scene and face selective cortical regions to simultaneously parse neural activity dynamics to the working memory cue stimuli (e.g., scenes) and to the incongruent interference stimuli.&#160;(e.g., faces)</li>
	</ol>
2. High-level Visual Stimuli
<ol>
	<li>For face stimuli, prepare several hundred Cue/Probe Face stimuli from gray-scale photos of male and female faces, with neutral expression, across a large adult age range. Remove hair and ears digitally, and apply a blur across the contours of the face.</li>
	<li>For scene stimuli, prepare several hundred Cue/Probe Scene stimuli from gray-scale photos of natural scenes.</li>
	<li>After Delay 1, present a interfering stimulus consisting of a scene or face. On 90% of trials, present a face that is not &#8216;male AND aged over 40 years old&#8217;; on the other 10% of trials, present a face that is male and aged over 40 years old.</li>
	<li>For &#8220;Attend to Interruption&#8221; condition, instruct participants to complete the following secondary task using the interfering stimulus (presented between the cue and the probe). Ask the participant to respond &#8220;YES&#8221; if interrupting face is male and aged over 40 years old.</li>
</ol>
3. &#160;Low-level Visual Motion Stimuli
<ol>
	<li>Create Cue/Probe stimuli of a circular aperture containing 290 spatially-random grey scale dots (0.08 degrees x 0.08 degrees each) that subtend 8 degrees of visual angle at a 75 cm viewing distance, centered at the fovea.</li>
	<li>Display moving dots with 100% motion coherence at an oblique angle of 10 degrees per sec, at one of 12 different directions of motion (3 in each sector).</li>
	<li>Use an adaptive staircase thresholding procedure (2 degree increments) to establish a visual discrimination value yielding just under 100% accuracy, such that the discrimination threshold is reached upon the first error trial.</li>
	<li>After Delay 1, present an interfering stimulus consisting of dots in counter-clockwise circular motion. Render this motion at a &#8216;normal&#8217; speed (10 degrees per sec) on 90% of trials, and fast on the other 10% of trials.</li>
	<li>In the Attend to Interruption condition, instruct participants to complete the following secondary task: respond &#8220;YES&#8221; if interrupting swirl is fast.</li>
</ol>
4. &#160;Low-level Auditory Motion Stimuli
<ol>
	<li>Create Cue/Probe Stimuli of sound motion sweeps across a frequency range with mid-frequencies randomly chosen between 900 and 1,100 Hz. Construct the sound motion sweep frequencies to start at &#177;&#160;0.5 octaves from the mid-frequency and end at &#177;&#160;0.5 octaves from the mid-frequency.</li>
	<li>Present an equal portion of &#8216;up&#8217; (starting at -0.5 and ending at +0.5 octaves) and &#8216;down&#8217; (starting at +0.5 and ending at -0.5 octaves) motion sweep stimuli.</li>
	<li>Adjust the volume to comfortable hearing level of 65 dB SPL.</li>
	<li>Thresholding: use an adaptive Zest procedure to establish auditory discrimination accuracy at 85% correct performance.</li>
	<li>After Delay 1, present an interfering stimulus consisting of a single tone. Play a tone of frequency 2 kHz on 90% of trials, and a tone of 2.3 kHz on the other 10% of trials.</li>
	<li>In the Attend to Interruption condition, instruct participants to complete the following secondary task: respond if interrupting tone is a higher frequency cue (2.3 kHz).</li>
</ol>
5. Probe Stimuli
<ol>
	<li>For all WM tasks, ensure that 50% of probe stimuli match the cue.</li>
	<li>In the low-level motion tasks with thresholded discrimination levels 5,10,11, set 50% of the probe stimuli, which do not match the cue, to differ from the cue by the absolute value of the participant&#8217;s thresholded stimulus discrimination level. 
	NOTE: For instance, if thresholding establishes a participant&#8217;s visual discrimination level to be 10 degrees, pair a visual motion cue moving at 45 degrees with a probe moving at either 45 degrees (match on 50% trials) or 45 &#177; 10 degrees (35 or 55 degrees; each non-matches on 50% trials).</li>
</ol>
4. Comparing Interference Conditions
<ol>
	<li>Use statistical software, such as SPSS, to compare behavioral performance and neural activity at important time-points before, during, and after different types of interference. 
	NOTE: Several manuals online provide step-by-step instructions and screenshots describing how to use and run simple statistical analyses in SPSS.
	<ol>
		<li>Calculate the impact of distractions versus interruptions on behavioral performance by contrasting working memory accuracies and response times during the interference conditions relative to the performance during the no interference condition (Figure 4). For instance, paired t-tests can be used to compare accuracy or RT between any two interference (or baseline) conditions. 
		NOTE: Prior to t-test comparisons between two specific task conditions, a repeated measures ANOVA is recommended to compare across all working memory conditions in the paradigm .</li>
		<li>For neuro-imaging studies, pre-process and process the data according to the appropriate pipline for the modality and measures of interest.
		<ol>
			<li>For EEG studies, process EEG data with EEGLAB or the software package of choice, using software&#8217;s instructions and recommended processing stream.</li>
			<li>For fMRI studies, process fMRI data with the software package of choice (such as AFNI, SPM, FSL, etc.), using software&#8217;s instructions and recommended processing stream.</li>
		</ol>
		</li>
		<li>To assess neural activity modulations as a consequence of interference during working memory, statistically contrast neural data in these conditions to neural activity during passive view(/listen) conditions, thus controlling for basic perceptual processing (Figure 4).
		<ol>
			<li>Calculate the Measurements such that a positive value always indicates greater enhancement above baseline or greater suppression below baseline. For P100, calculate neural suppression by subtracting quantified neural activity to the distracting stimulus (DS) from that evoked by the passively viewed stimulus (PV) (i.e: PV - DS). Calculate enhancement in fMRI by subtracting quantified BOLD activity to the baseline passively viewed stimulus from that evoked by the interrupting stimulus (IS) (i.e: IS &#8211; PV).</li>
		</ol>
		</li>
		<li>Statistically compare neural modulations elicited by ignored distractions versus activity during attended interruptions to begin to ascertain the specific impact of top-down attention on the resolution of different types of interference in working memory.</li>
	</ol>
	</li>
</ol>

The authors have nothing to disclose.

A novel cognitive paradigm has shown efficacy in investigating working memory interference by distractions and interruptions. This paradigm and its several variants, extending its use across sensory modalities, stimulus complexity levels, and imaging methods, are detailed.
Before beginning the experiment, pre-screen all participants to ensure appropriate cognitive and perceptual abilities. For experiments using low-level perceptual stimuli, administer an adaptive thresholding procedure to cali...

An extensive literature has demonstrated a detriment to the maintenance of information in working memory (WM) by interference from the external environment 1-9. External interference can be classified into two general types; interference by irrelevant information one intends to ignore: distraction, and interfering information which demands attention as part of another (secondary) task goal: interruption. Studies comparing these types of external interference using a within-participant design enable assessment of the neuro-behavioral impact of goal-focused top-down attention in the processing and resolution of external interference.
Recently, the Gazzaley lab designed a paradigm that facilitates comparison of &#8216;to-be-attended&#8217; interruptions and &#8216;to-be-ignored&#8217; distractions that occur in the setting of a working memory task. Emerging evidence from this paradigm suggests that these different types of external interference exert distinct effects on behavior and have distinct underlying neural mechanisms 2-5,10,11. This paradigm has revealed differences in external interference processing in normal aging 2,3,4,10,11; though aging deficits in the context of interference are not always found 5; it has also distinguished mechanisms of interference by distractors versus interruptors using high-level visual stimulation of faces and scenes 2,3,4,12, low-level visual motion of dot kinematograms 5,10,11, and low-level auditory motion of frequency sweeps 5.
External Interference and Aging
External interference induces a detrimental impact on working memory throughout the lifespan, although older adults exhibit a more negative impact than younger adults 2,3,13-18. Older adults also exhibit different patterns of neural activity compared to younger adults when attempting to resolve this interference 3,4,17,21. However, some studies do not find evidence for such age-related behavioral 5,19,20 or neural 5 differences with interference.
Interestingly, the impact of aging on resolving interference seems to differ by sensory modality, although this issue remains unresolved at present. Visual intrasensory interference has been widely shown to exhibit age-related decline (summarized in an extensive review 22). In contrast, many experiments suggest no age-related deficits during intra-sensory auditory interference 19,22-25, while other studies demonstrate significant age-related increases in auditory distractibility 19,22,26-32. In addition, the salience of interfering stimuli (congruent or incongruent between the cue and probe stimuli) 2, and stimulus complexity (high or low processing load) 5 may interact with interference processing and its differences across task goals and age.
The paradigm described here supplements the aging interference literature by probing the mechanisms of top-down attention (in the form of task goals) and resolution of external interfering stimuli. Evidence from the visual face &#38; scene version of this paradigm indicates an interaction between aging and interference type, with older adults demonstrating even greater vulnerability to attended interruptors relative to ignored distractors 3,4. Characterizing the behavioral and neural differences between these types of interference are important to understand how cognitive control abilities change with aging.
Why do older adults show exacerbated deficits in resolving to-be-attended interruptors? Are older adults impaired by excessive processing of interruptors when they are presented, or by an inability to re-activate representations of the primary goal-relevant stimuli after interruptions, or by prolonged processing of interruptors after they are no longer present or relevant 33? To address these questions, the current paradigm&#8217;s design allows for comparison of neural activity at time-points before, during, and after different types of interference. For instance, by comparing neural activity elicited by ignored distraction versus activity during attended interruptions, one can ascertain the specific impact of top-down attention on resolution of interference in working memory.
Several studies have implemented multiple variants of this interference paradigm to understand the neural correlates of the different types of external interference both at high spatial and temporal resolution using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), respectively. This paradigm has also been used to clarify important distinctions between interference in the visual and auditory domains, as well as the impact of stimulus complexity and congruence on interference. Here, the paradigm variants are described in detail.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Computer for stimulus presentation</td>
			<td>Dell</td>
			<td>Optiplex GX620</td>
			<td>hardware/software requirements will vary based on stimulus presentation software</td>
		</tr>
		<tr>
			<td>Cathody Ray Tube (CRT) monitor</td>
			<td>ViewSonic</td>
			<td>G220fb</td>
			<td>21&#34;; recommended due to its superior latency relative to that of LCD monitors in displaying visual stimuli; chair should be positioned 75 cm away</td>
		</tr>
		<tr>
			<td>E-Prime software</td>
			<td>Psychology Software Tools, Inc.</td>
			<td>E-Prime 2.0 Standard</td>
			<td>a different experimental presentation software can be used in place of E-Prime (e.g. Presentation (Neurobehavioral Systems), or PsychoPy (open-source); E-Prime and Presentation are compatible with Microsoft Windows, PsychoPy is compatible with Microsoft Windows, Mac OS X, and Linux)</td>
		</tr>
		<tr>
			<td>Keyboard/response pad for Behavioral or EEG experiments</td>
			<td>Keyboard: Razer; Response Pad: Cedrus</td>
			<td>Keyboard: BlackWidow Ultimate; Response Pad: RB-830</td>
			<td>any standard computer keyboard is acceptable, though response pads may offer more precise timing (ie: Cedrus RB-830 guarantees 1 ms resolution)</td>
		</tr>
		<tr>
			<td>Keyboard/response pad for MRI experiments</td>
			<td>Curdes</td>
			<td>Package 904</td>
			<td>ensure that keypad is MR-compatible</td>
		</tr>
		<tr>
			<td>Headphones (for auditory behavioral experiments)</td>
			<td>Koss</td>
			<td>UR29</td>
			<td></td>
		</tr>
		<tr>
			<td>EEG-compatible Headphones (for auditory EEG experiments)</td>
			<td>Etymotic</td>
			<td>ER3-50; ER3-21; ER3-14A</td>
			<td></td>
		</tr>
		<tr>
			<td>MRI-compatible Headphones (for auditory MR experiments)</td>
			<td>Etymotic</td>
			<td>SD-AU-EAER30</td>
			<td></td>
		</tr>
	</tbody>
</table>

a cognitive paradigm to investigate interference in working memory by distractions and interruptions

Goal-directed behavior is often impaired by interference from the external environment, either in the form of distraction by irrelevant information that one attempts to ignore, or by interrupting information that demands attention as part of another (secondary) task goal. Both forms of external interference have been shown to detrimentally impact the ability to maintain information in working memory (WM). Emerging evidence suggests that these different types of external interference exert different effects on behavior and may be mediated by distinct neural mechanisms. Better characterizing the distinct neuro-behavioral impact of irrelevant distractions versus attended interruptions is essential for advancing an understanding of top-down attention, resolution of external interference, and how these abilities become degraded in healthy aging and in neuropsychiatric conditions. This manuscript describes a novel cognitive paradigm developed the Gazzaley lab that has now been modified into several distinct versions used to elucidate behavioral and neural correlates of interference, by to-be-ignored distractors versus to-be-attended interruptors. Details are provided on variants of this paradigm for investigating interference in visual and auditory modalities, at multiple levels of stimulus complexity, and with experimental timing optimized for electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) studies. In addition, data from younger and older adult participants obtained using this paradigm is reviewed and discussed in the context of its relationship with the broader literatures on external interference and age-related neuro-behavioral changes in resolving interference in working memory.

This interference paradigm has enabled generation of important findings regarding the distinct behavioral impact and neural mechanisms of distraction and interruption on working memory in younger and older adults (see Table 2 for summary).
Behavior. Behaviorally, in line with the existing literature, interruption consistently imparts a greater detrimental impact versus distraction on working memory performance 2-5, 10,11,12. Older adults exhibit eve...

Watch this Scientific Journal Video about A Cognitive Paradigm to Investigate Interference in Working Memory by Distractions and Interruptions at JoVE.com

A Cognitive Paradigm to Investigate Interference in Working Memory by Distractions and Interruptions

A novel cognitive paradigm is developed to elucidate behavioral and neural correlates of interference by to-be-ignored distractors versus interference by to-be-attended interruptors during a working memory task. In this manuscript, several variants of this paradigm are detailed, and data obtained with this paradigm in younger/older adult participants is reviewed.

Goal-directed behavior is often impaired by interference from the external environment, either in the form of distraction by irrelevant information that ...

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13.5K Views.  University of New Mexico. A novel cognitive paradigm is developed to elucidate behavioral and neural correlates of interference by to-be-ignored distractors versus interference by to-be-attended interruptors during a working memory task. In this manuscript, several variants of this paradigm are detailed, and data obtained with this paradigm in younger/older adult participants is reviewed.

Video: A Cognitive Paradigm to Investigate Interference in Working Memory by Distractions and Interruptions

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

Use of an Eight-arm Radial Water Maze to Assess Working and Reference Memory Following Neonatal Brain Injury

Working and reference memory are commonly assessed using the land based radial arm maze.&#160;However, this paradigm requires pretraining, food deprivation, and may introduce scent cue confounds. The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs. Specifically, subjects are required to avoid the arms previously used for escape during each testing day (working memory) as well as avoid the fixed arms, which never contain escape platforms (reference memory). Re-entries into arms that have already been used for escape during a testing session (and thus the escape platform has been removed) and re-entries into reference memory arms are indicative of working memory deficits. Alternatively, first entries into reference memory arms are indicative of reference memory deficits. We used this maze to compare performance of rats with neonatal brain injury and sham controls following induction of hypoxia-ischemia and show significant deficits in both working and reference memory after eleven days of testing. This protocol could be easily modified to examine many other models of learning impairment.

The eight-arm radial water maze is designed to evaluate reference and working memory performance simultaneously by requiring subjects to use extra-maze cues to locate escape platforms and remedies the limitations observed in land based radial arm maze designs.

Working and reference memory are commonly assessed using the land based radial arm maze.&#160;However, this paradigm requires pretraining, food ...

Irrelevant Stimuli and Action Control: Analyzing the Influence of Ignored Stimuli via the Distractor-Response Binding Paradigm

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are frequently used in the research on human action control. One important question in these settings is how distractor stimuli, competing with the target stimulus for a response, influence actions. The distractor-response binding paradigm can be used to investigate this influence. It is particular useful to separately analyze response retrieval and distractor inhibition effects. Computer-based experiments are used to collect the data (reaction times and error rates). In a number of sequentially presented pairs of stimulus arrays (prime-probe design), participants respond to targets while ignoring distractor stimuli. Importantly, the factors response relation in the arrays of each pair (repetition vs. change) and distractor relation (repetition vs. change) are varied orthogonally. The repetition of the same distractor then has a different effect depending on response relation (repetition vs. change) between arrays. This result pattern can be explained by response retrieval due to distractor repetition. In addition, distractor inhibition effects are indicated by a general advantage due to distractor repetition. The described paradigm has proven useful to determine relevant parameters for response retrieval effects on human action.

The distractor-response binding paradigm is described. It can be used to shed light on the influence irrelevant stimuli, competing with targets for a response, can have on human action. Both response retrieval effects and distractor inhibition effects can be analyzed within the paradigm.

Selection tasks in which simple stimuli (e.g. letters) are presented and a target stimulus has to be selected against one or more distractor stimuli are ...

Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here with the goal of uncovering rhythm disorders, such as beat deafness. Beat deafness is characterized by poor performance in perceiving durations in auditory rhythmic patterns or poor synchronization of movement with auditory rhythms (e.g., with musical beats). These tasks include the synchronization of finger tapping to the beat of simple and complex auditory stimuli and the detection of rhythmic irregularities (anisochrony detection task) embedded in the same stimuli. These tests, which are easy to administer, include an assessment of both perceptual and sensorimotor timing abilities under different conditions (e.g., beat rates and types of auditory material) and are based on the same auditory stimuli, ranging from a simple metronome to a complex musical excerpt. The analysis of synchronized tapping data is performed with circular statistics, which provide reliable measures of synchronization accuracy (e.g., the difference between the timing of the taps and the timing of the pacing stimuli) and consistency. Circular statistics on tapping data are particularly well-suited for detecting individual differences in the general population. Synchronized tapping and anisochrony detection are sensitive measures for identifying profiles of rhythm disorders and have been used with success to uncover cases of poor synchronization with spared perceptual timing. This systematic assessment of perceptual and sensorimotor timing can be extended to populations of patients with brain damage, neurodegenerative diseases (e.g., Parkinson&#8217;s disease), and developmental disorders (e.g., Attention Deficit Hyperactivity Disorder).

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here ...

Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic &#946;-Blocker

The basic design used in our human fear-conditioning studies on disrupting reconsolidation includes testing over different phases across three consecutive days. On day 1 - the fear acquisition phase, healthy participants are exposed to a series of picture presentations. One picture stimulus (CS1+) is repeatedly paired with an aversive electric stimulus (US), resulting in the acquisition of a fear association, whereas another picture stimulus (CS2-) is never followed by an US. On day 2 - the memory reactivation phase, the participants are re-exposed to the conditioned stimulus without the US (CS1-), which typically triggers a conditioned fear response. After the memory reactivation we administer an oral dose of 40 mg of propranolol HCl, a &#946;-adrenergic receptor antagonist that indirectly targets the protein synthesis required for reconsolidation by inhibiting the noradrenaline-stimulated CREB phosphorylation. On day 3 - the test phase, the participants are again exposed to the unreinforced conditioned stimuli (CS1- and CS2-) in order to measure the fear-reducing effect of the manipulation. This retention test is followed by an extinction procedure and the presentation of situational triggers to test for the return of fear. Potentiation of the eye blink startle reflex is measured as an index for conditioned fear responding. Declarative knowledge of the fear association is measured through online US expectancy ratings during each CS presentation. In contrast to extinction learning, disrupting reconsolidation targets the original fear memory thereby preventing the return of fear. Although the clinical applications are still in their infancy, disrupting reconsolidation of fear memory seems to be a promising new technique with the prospect to persistently dampen the expression of fear memory in patients suffering from anxiety disorders and other psychiatric disorders.

Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic &amp;#946;-Blocker

Disrupting reconsolidation is a promising approach to dampen the behavioral expression of fear memory in patients with anxiety disorders or posttraumatic stress disorder. In a series of human fear conditioning studies we showed that disrupting reconsolidation by the noradrenergic &#946;-blocker propranolol is very effective in erasing conditioned fear responding.

The basic design used in our human fear-conditioning studies on disrupting reconsolidation includes testing over different phases across three consecutive ...

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is commonly assessed using verbal report paradigms in adults, studying the development of this ability in preverbal infants and children proved challenging. Over the past 30 years, researchers have developed a non-verbal means of assessing recall memory known as the elicited or deferred imitation paradigm. In one variant of the procedure, participants are presented with novel three-dimensional stimuli for a brief baseline period before a researcher demonstrates a series of actions that culminate in an end- or goal-state. The participant is allowed to imitate the demonstrated actions immediately, after a delay, or both. Recall performance is then compared to baseline or to performance on novel control sequences presented at the same session; memory can be assessed for the individual target actions and the order in which they were completed. This procedure is an accepted analogue to the verbal report techniques used with adults, and it has served to establish a solid foundation of the nature of recall memory in infancy and early childhood. In addition, the elicited or deferred imitation procedure has been modified and adapted to answer questions relevant to other aspects of cognitive functioning. The broad utility and application of imitation paradigms is discussed, along with limitations of the approach and directions for future research.

The elicited imitation procedure was established to examine the development of recall memory in infancy and early childhood. This procedure has been widely used to establish a solid foundation of the nature of recall memory in infancy and early childhood.

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is ...

Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional rubber-hand illusion or the more recently discovered enfacement illusion. However, these examples require rather artificial experimental setups, in which the artificial effector needs to be stroked in synchrony with the participants&#39; real hand or face&#8212;a situation in which participants have no control over the stroking or the movements of their real or artificial effector. Here, we describe a technique to establish ownership illusions in a setup that is more realistic, more intuitive, and of presumably higher ecological validity. It allows creating the virtual-hand illusion by having participants control the movements of a virtual hand presented on a screen or in virtual space in front of them. If the virtual hand moves in synchrony with the participants&#39; own real hand, they tend to perceive the virtual hand as part of their own body. The technique also creates the virtual-face illusion by having participants control the movements of a virtual face in front of them, again with the effect that they tend to perceive the face as their own if it moves in synchrony with their real face. Studying the circumstances that illusions of this sort can be created, increased, or reduced provides important information about how people create and maintain representations of themselves.

Here, we describe virtual-hand and virtual-face illusion paradigms that can be used to study body-related self-perception/-representation. They have already been used in various studies to demonstrate that, under specific conditions, a virtual hand or face can be incorporated into one&#39;s body representation, suggesting that body representations are rather flexible.

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional ...

The Deese-Roediger-McDermott (DRM) Task: A Simple Cognitive Paradigm to Investigate False Memories in the Laboratory

The Deese,&#160;Roediger and McDermott&#160;(DRM) task is a false memory paradigm in which subjects are presented with lists of semantically related words (e.g., nurse, hospital, etc.) at encoding. After a delay, subjects are asked to recall or recognize these words. In the recognition memory version of the task, subjects are asked whether they remember previously presented words, as well as related (but never presented) critical lure words (&#39;doctor&#39;). Typically, the critical word is recognized with high probability and confidence. This false memory effect has been robustly demonstrated across short (e.g., immediate, 20 min) and long (e.g., 1, 7, 60 d) delays between encoding and memory testing. A strength of using this task to study false memory is its simplicity and short duration. If encoding and retrieval components of the task occur in the same session, the entire task can take as little as 2 - 30 min. However, although the DRM task is widely considered a &#39;false memory&#39; paradigm, some researchers consider DRM illusions to be based on the activation of semantic memory networks in the brain, and argue that such semantic gist-based false memory errors may actually be useful in some scenarios (e.g., remembering the forest for the trees; remembering that a word list was about &#34;doctors&#34;, even though the actual word &#34;doctor&#34; was never presented for study). Remembering the gist of experience (instead of or along with individual details) is arguably an adaptive process and this task has provided a great deal of knowledge about the constructive, adaptive nature of memory. Therefore, researchers should use caution when discussing the overall reach and implications of their experiments when using this task to study &#39;false memory&#39;, as DRM memory errors may not adequately reflect false memories in the real world, such as false memory in eyewitness testimony, or false memories of sexual abuse.

The Deese-Roediger-McDermott DRM Task: A Simple Cognitive Paradigm to Investigate False Memories in the Laboratory

Here we present the Deese,&#160;Roediger and McDermott&#160;(DRM) task, a tool to study false memories in the laboratory. Subjects study lists of semantically related words (e.g.,&#160;nurse, sick, etc.), and later falsely remember an unstudied word (doctor) that represents the gist, or theme, of the word list.

The Deese,&#160;Roediger and McDermott&#160;(DRM) task is a false memory paradigm in which subjects are presented with lists of semantically related words ...

Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children &#8211; Working Memory (CABC-WM)

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of working memory in young school-age children. Working memory deficits have been identified in children with language-based learning disabilities, including dyslexia1,2 and language impairment3,4, but it is not clear whether these children exhibit deficits in subcomponents of working memory, such as visuospatial or phonological working memory. The CABC-WM is administered on a desktop computer with a touchscreen interface and was specifically developed to be engaging and motivating for children. Although the long-term goal of the CABC-WM is to provide individualized working memory profiles in children, the present study focuses on the initial success and utility of the CABC-WM for measuring central executive, visuospatial, phonological loop, and binding constructs in children with typical development. Immediate next steps are to administer the CABC-WM to children with specific language impairment, dyslexia, and comorbid specific language impairment and dyslexia.

Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children &amp;#8211; Working Memory (CABC-WM)

Working memory predicts a significant amount of variance for a variety of cognitive tasks, including speaking, reading, and writing. However, few tools are available to assess working memory in children. We present an innovative, computer-based battery that comprehensively assesses different components of working memory in school-age children.

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of ...

Reducing State Anxiety Using Working Memory Maintenance

The purpose of this protocol is to explain how to examine the relationship between working memory processes and anxiety by combining the Sternberg Working Memory (WM) and the threat of shock paradigms. In the Sternberg WM paradigm, subjects are required to maintain a series of letters in the WM for a brief interval and respond by identifying whether the position of a given letter in the series matches a numerical prompt. In the threat of shock paradigm, subjects are exposed to alternating blocks where they are either at risk of receiving unpredictable presentations of a mild electric shock or are safe from the shock. Anxiety is probed throughout the safe and threat blocks using the acoustic startle reflex, which is potentiated under threat (Anxiety-Potentiated Startle (APS)). By conducting the Sternberg WM paradigm during the threat of shock and probing the startle response during either the WM maintenance interval or the intertrial interval, it is possible to determine the effect of WM maintenance on APS.

This protocol demonstrates how to measure anxiety-potentiated startle during the Sternberg Working Memory paradigm.

The purpose of this protocol is to explain how to examine the relationship between working memory processes and anxiety by combining the Sternberg Working ...